Sample records for tomography ct scanners

  1. Development of a proton Computed Tomography (pCT) scanner at NIU

    E-Print Network [OSTI]

    Uzunyan, S A; Boi, S; Coutrakon, G; Dyshkant, A; Erdelyi, B; Gearhart, A; Hedin, D; Johnson, E; Krider, J; Zutshi, V; Ford, R; Fitzpatrick, T; Sellberg, G; Rauch, J E; Roman, M; Rubinov, P; Wilson, P; Lalwani, K; Naimuddin, M

    2013-01-01T23:59:59.000Z

    We describe the development of a proton Computed Tomography (pCT) scanner at Northern Illinois University (NIU) in collaboration with Fermilab and Delhi University. This paper provides an overview of major components of the scanner and a detailed description of the data acquisition system (DAQ).

  2. Development of a proton Computed Tomography (pCT) scanner at NIU

    E-Print Network [OSTI]

    S. A. Uzunyan; G. Blazey; S. Boi; G. Coutrakon; A. Dyshkant; B. Erdelyi; A. Gearhart; D. Hedin; E. Johnson; J. Krider; V. Zutshi; R. Ford; T. Fitzpatrick; G. Sellberg; J. E. Rauch; M. Roman; P. Rubinov; P. Wilson; K. Lalwani; M. Naimuddin

    2013-12-13T23:59:59.000Z

    We describe the development of a proton Computed Tomography (pCT) scanner at Northern Illinois University (NIU) in collaboration with Fermilab and Delhi University. This paper provides an overview of major components of the scanner and a detailed description of the data acquisition system (DAQ).

  3. Verrucous carcinoma of the foot affecting the bone: Utility of the computed tomography scanner

    E-Print Network [OSTI]

    García-Gavín, J; González-Vilas, D; Rodríguez-Pazos, L; Sánchez-Aguilar, D; Toribio, J

    2010-01-01T23:59:59.000Z

    Frassica FJ, Fishman EK. Computed tomography of the bones ofbone: Utility of the computed tomography scanner J García-of bone invasion. Computed tomography (CT) showed a lytic

  4. Medical Imaging Computed Tomography (CT)

    E-Print Network [OSTI]

    Massey, Thomas N.

    Module 10 Medical Imaging · X-rays · Computed Tomography (CT) · Positron Emission Tomography (PET Sources PET-TOF #12;Four Sources PET #12;Four Sources PET-TOF #12;PET Scan MRI CT scan #12;Endocrine Gland,000 pixels! #12;Modern Example of CT Scan with the addition of Surface Shading Standard CT With Surface

  5. Compact conscious animal positron emission tomography scanner

    DOE Patents [OSTI]

    Schyler, David J. (Bellport, NY); O'Connor, Paul (Bellport, NY); Woody, Craig (Setauket, NY); Junnarkar, Sachin Shrirang (Sound Beach, NY); Radeka, Veljko (Bellport, NY); Vaska, Paul (Sound Beach, NY); Pratte, Jean-Francois (Stony Brook, NY); Volkow, Nora (Chevy Chase, MD)

    2006-10-24T23:59:59.000Z

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

  6. Potentially Low Cost Solution to Extend Use of Early Generation Computed Tomography

    E-Print Network [OSTI]

    Tonna, Joseph E; Balanoff, Amy M; Lewin, Matthew R; Saandari, Namjilmaa; Wintermark, Max

    2010-01-01T23:59:59.000Z

    of Early Generation Computed Tomography Joseph E. Tonna, MD*two- dimensional (2D) computed tomography (CT) images. ThisWhile many modern computed tomography (CT) scanners contain

  7. SU-E-I-18: CT Scanner QA Using Normalized CTDI Ratio

    SciTech Connect (OSTI)

    Randazzo, M; Tambasco, M; Russell, B [San Diego State University, San Diego, CA (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To create a ratio of weighted computed tomography dose index (CTDIw) data normalized to in-air measurements (CTDIair) as a function of beam quality to create a look-up table for frequent, rapid quality assurance (QA) checks of CTDI. Methods: The CTDIw values were measured according to TG-63 protocol using a pencil ionization chamber (Unfors Xi CT detector) and head and body Polymethyl methacrylate (PMMA) phantoms (16 and 32 cm diameter, respectively). Single scan dose profiles were measured at each clinically available energy (80,100,120,140 kVp) on three different CT scanners (two Siemens SOMATOM Definition Flash and one GE Optima), using a tube current of 400 mA, a one second rotation time, and the widest available beam width (32 × 0.6 mm and 16 × 1.25 mm, respectively). These values were normalized to CTDIair measurements using the same conditions as CTDIw. The ratios (expressed in cGy/R) were assessed for each scanner as a function of each energy's half value layer (HVL) paired with the phantom's appropriate bow tie filter measured in mmAl. Results: Normalized CTDI values vary linearly with HVL for both the head and body phantoms. The ratios for the two Siemens machines are very similar at each energy. Compared to the GE scanner, these values vary between 10–20% for each kVp setting. Differences in CTDIair contribute most to the deviation of the ratios across machines. Ratios are independent of both mAs and collimation. Conclusion: Look-up tables constructed of normalized CTDI values as a function of HVL can be used to derive CTDIw data from only three in-air measurements (one for CTDIair and two with added filtration for HVL) to allow for simple, frequent QA checks without CT phantom setup. Future investigations will involve comparing results with Monte Carlo simulations for validation.

  8. Quantitative comparison of noise texture across CT scanners from different manufacturers

    SciTech Connect (OSTI)

    Solomon, Justin B.; Christianson, Olav; Samei, Ehsan [Carl E. Ravin Advanced Imaging Laboratories and Clinical Imaging Physics Group, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories and Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories and Clinical Imaging Physics Group, Medical Physics Graduate Program, Departments of Radiology, Physics, Biomedical Engineering, and Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States)

    2012-10-15T23:59:59.000Z

    Purpose: To quantitatively compare noise texture across computed tomography (CT) scanners from different manufacturers using the noise power spectrum (NPS). Methods: The American College of Radiology CT accreditation phantom (Gammex 464, Gammex, Inc., Middleton, WI) was imaged on two scanners: Discovery CT 750HD (GE Healthcare, Waukesha, WI), and SOMATOM Definition Flash (Siemens Healthcare, Germany), using a consistent acquisition protocol (120 kVp, 0.625/0.6 mm slice thickness, 250 mAs, and 22 cm field of view). Images were reconstructed using filtered backprojection and a wide selection of reconstruction kernels. For each image set, the 2D NPS were estimated from the uniform section of the phantom. The 2D spectra were normalized by their integral value, radially averaged, and filtered by the human visual response function. A systematic kernel-by-kernel comparison across manufacturers was performed by computing the root mean square difference (RMSD) and the peak frequency difference (PFD) between the NPS from different kernels. GE and Siemens kernels were compared and kernel pairs that minimized the RMSD and |PFD| were identified. Results: The RMSD (|PFD|) values between the NPS of GE and Siemens kernels varied from 0.01 mm{sup 2} (0.002 mm{sup -1}) to 0.29 mm{sup 2} (0.74 mm{sup -1}). The GE kernels 'Soft,''Standard,''Chest,' and 'Lung' closely matched the Siemens kernels 'B35f,''B43f,''B41f,' and 'B80f' (RMSD < 0.05 mm{sup 2}, |PFD| < 0.02 mm{sup -1}, respectively). The GE 'Bone,''Bone+,' and 'Edge' kernels all matched most closely with Siemens 'B75f' kernel but with sizeable RMSD and |PFD| values up to 0.18 mm{sup 2} and 0.41 mm{sup -1}, respectively. These sizeable RMSD and |PFD| values corresponded to visually perceivable differences in the noise texture of the images. Conclusions: It is possible to use the NPS to quantitatively compare noise texture across CT systems. The degree to which similar texture across scanners could be achieved varies and is limited by the kernels available on each scanner.

  9. ModPET: A Novel Small-Animal PET System Positron Emission Tomography (PET) and PET/CT systems have become the gold standard for imaging

    E-Print Network [OSTI]

    Arizona, University of

    ModPET: A Novel Small-Animal PET System Positron Emission Tomography (PET) and PET/CT systems have these results to their human counterparts. Current small-animal PET scanners are very costly and complicated for Gamma-Ray Imaging, we are developing a novel small-animal PET scanner that utilizes common modular

  10. A rapid method for converting medical Computed Tomography scanner topogram attenuation scale to Hounsfield Unit scale and to obtain relative density values

    E-Print Network [OSTI]

    Long, Bernard

    A rapid method for converting medical Computed Tomography scanner topogram attenuation scale online 17 July 2008 Keywords: Computed Tomography Attenuation Density calibration Minerals Medical Computed Tomography scanners permit to rapidly obtain qualitative and quantitative information on objects

  11. Effects of the difference in tube voltage of the CT scanner on dose calculation

    E-Print Network [OSTI]

    Rhee, Dong Joo; Moon, Young Min; Kim, Jung Ki; Jeong, Dong Hyeok

    2015-01-01T23:59:59.000Z

    Computed Tomography (CT) measures the attenuation coefficient of an object and converts the value assigned to each voxel into a CT number. In radiation therapy, CT number, which is directly proportional to the linear attenuation coefficient, is required to be converted to electron density for radiation dose calculation for cancer treatment. However, if various tube voltages were applied to take the patient CT image without applying the specific CT number to electron density conversion curve, the accuracy of dose calculation would be unassured. In this study, changes in CT numbers for different materials due to change in tube voltage were demonstrated and the dose calculation errors in percentage depth dose (PDD) and a clinical case were analyzed. The maximum dose difference in PDD from TPS dose calculation and Monte Carlo simulation were 1.3 % and 1.1 % respectively when applying the same CT number to electron density conversion curve to the 80 kVp and 140 kVp images. In the clinical case, the different CT nu...

  12. A modular VME or IBM PC based data acquisition system for multi-modality PET/CT scanners of different sizes and detector types

    E-Print Network [OSTI]

    Crosetto, D B

    2000-01-01T23:59:59.000Z

    A modular VME or IBM PC based data acquisition system for multi-modality PET/CT scanners of different sizes and detector types

  13. Real-time, programmable, digital signal-processing electronics for extracting the information from a detector module for multi-modality PET/SPECT/CT scanners

    E-Print Network [OSTI]

    Crosetto, D B

    2000-01-01T23:59:59.000Z

    Real-time, programmable, digital signal-processing electronics for extracting the information from a detector module for multi-modality PET/SPECT/CT scanners

  14. Stationary table CT dosimetry and anomalous scanner-reported values of CTDI{sub vol}

    SciTech Connect (OSTI)

    Dixon, Robert L., E-mail: rdixon@wfubmc.edu [Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157 (United States); Boone, John M. [Departments of Radiology and Biomedical Engineering, University of California Davis, Sacramento, California 95817 (United States)] [Departments of Radiology and Biomedical Engineering, University of California Davis, Sacramento, California 95817 (United States)

    2014-01-15T23:59:59.000Z

    Purpose: Anomalous, scanner-reported values of CTDI{sub vol} for stationary phantom/table protocols (having elevated values of CTDI{sub vol} over 300% higher than the actual dose to the phantom) have been observed; which are well-beyond the typical accuracy expected of CTDI{sub vol} as a phantom dose. Recognition of these outliers as “bad data” is important to users of CT dose index tracking systems (e.g., ACR DIR), and a method for recognition and correction is provided. Methods: Rigorous methods and equations are presented which describe the dose distributions for stationary-table CT. A comparison with formulae for scanner-reported values of CTDI{sub vol} clearly identifies the source of these anomalies. Results: For the stationary table, use of the CTDI{sub 100} formula (applicable to a moving phantom only) overestimates the dose due to extra scatter and also includes an overbeaming correction, both of which are nonexistent when the phantom (or patient) is held stationary. The reported DLP remains robust for the stationary phantom. Conclusions: The CTDI-paradigm does not apply in the case of a stationary phantom and simpler nonintegral equations suffice. A method of correction of the currently reported CTDI{sub vol} using the approach-to-equilibrium formula H(a) and an overbeaming correction factor serves to scale the reported CTDI{sub vol} values to more accurate levels for stationary-table CT, as well as serving as an indicator in the detection of “bad data.”.

  15. Omni-tomography / Multi-tomography Integrating Multiple Modalities for Simultaneous Imaging

    E-Print Network [OSTI]

    Wang, Ge

    registration and combined acquisition on PET-CT, PET-MRI and other hybrid scanners. There are intrinsic relevant imaging mechanisms such as CT, MRI, PET, SPECT, US, optical, and possibly more. In this paper applications of omni-tomography. Key Words: Tomography, CT, MRI, PET, SPECT, US imaging, optical imaging

  16. 200 MeV Proton Radiography Studies with a Hand Phantom Using a Prototype Proton CT Scanner

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    200 MeV Proton Radiography Studies with a Hand Phantom Using a Prototype Proton CT Scanner Tia.F.W. Sadrozinski, K. Schubert, R. Schulte, B. Schultze, D. Steinberg, M. Witt, A. Zatserklyaniy Abstract--Proton alignment and verification procedures for proton beam radiation therapy. The quality of the image, both

  17. Dose uncertainty due to computed tomography ,,CT... slice thickness in CT-based high dose rate brachytherapy of the prostate cancer

    E-Print Network [OSTI]

    Pouliot, Jean

    Dose uncertainty due to computed tomography ,,CT... slice thickness in CT-based high dose rate in Medicine. DOI: 10.1118/1.1785454 Key words: high dose rate brachytherapy, computed tomography, prostate at risk OARs by providing three-dimensional 3D anatomical information from computed tomography CT

  18. Combining a Breathing Model and Tumor-Specific Rigidity Constraints for Registration of CT-PET Thoracic

    E-Print Network [OSTI]

    Chambon, Sylvie

    Combining a Breathing Model and Tumor-Specific Rigidity Constraints for Registration of CT-PET modalities, namely Computerized Tomography (CT) and Positron Emission Tomography (PET). While recent technical advancements in combined CT/PET scanners provide 3D CT and PET data of the thoracic region

  19. Simultaneous CT and SPECT tomography using CZT detectors

    DOE Patents [OSTI]

    Paulus, Michael J. (Knoxville, TN); Sari-Sarraf, Hamed (Lubbock, TX); Simpson, Michael L. (Knoxville, TN); Britton, Jr., Charles L. (Alcoa, TN)

    2002-01-01T23:59:59.000Z

    A method for simultaneous transmission x-ray computed tomography (CT) and single photon emission tomography (SPECT) comprises the steps of: injecting a subject with a tracer compound tagged with a .gamma.-ray emitting nuclide; directing an x-ray source toward the subject; rotating the x-ray source around the subject; emitting x-rays during the rotating step; rotating a cadmium zinc telluride (CZT) two-sided detector on an opposite side of the subject from the source; simultaneously detecting the position and energy of each pulsed x-ray and each emitted .gamma.-ray captured by the CZT detector; recording data for each position and each energy of each the captured x-ray and .gamma.-ray; and, creating CT and SPECT images from the recorded data. The transmitted energy levels of the x-rays lower are biased lower than energy levels of the .gamma.-rays. The x-ray source is operated in a continuous mode. The method can be implemented at ambient temperatures.

  20. An Exact Modeling of Signal Statistics in Energy-integrating X-ray Computed Tomography

    E-Print Network [OSTI]

    An Exact Modeling of Signal Statistics in Energy-integrating X-ray Computed Tomography Yi Fan1 used by modern computed tomography (CT) scanners and has been an interesting research topic 1. INTRODUCTION In x-ray computed tomography (CT), Poisson noise model has been widely used in noise

  1. Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner

    SciTech Connect (OSTI)

    Kim, Haksoo; Welford, Scott [Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)] [Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States); Fabien, Jeffrey; Zheng, Yiran; Yuan, Jake; Brindle, James; Yao, Min; Lo, Simon; Wessels, Barry; Machtay, Mitchell; Sohn, Jason W., E-mail: jason.sohn@case.edu [Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 and University Hospitals of Cleveland, 11100 Euclid Avenue, Cleveland, Ohio 44106 (United States); Sloan, Andrew [Department of Neurosurgery, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)] [Department of Neurosurgery, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)

    2014-02-15T23:59:59.000Z

    Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images. Methods: These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system—MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was “printed” using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis. Results: For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm). A passing rate of 99% was measured in areas of above 40% of the prescription dose. The final inverse treatment plan was comprised of 43 beams ranging from 5 to 12.5 mm in diameter (2.5 mm size increments are available up to 15 mm in diameter collimation). Using the Xsight Spine Tracking module, the CyberKnife system could not reliably identify and track the tiny mouse spine; however, the CyberKnife system could identify and track the fiducial markers on the 3D mold.In vivo positional accuracy analysis using the 3D mold generated a mean error of 1.41 mm ± 0.73 mm when fiducial markers were used for position tracking. Analysis of the dissected brain confirmed the ability to target the correct brain volume. Conclusions: With the use of a stereotactic body mold with fiducial markers, microCT imaging, and resolution down-sampling, the CyberKnife system can successfully perform small-animal radiotherapy studies.

  2. Design and evaluation of a variable aperture collimator for conformal radiotherapy of small animals using a microCT scanner

    SciTech Connect (OSTI)

    Graves, Edward E.; Zhou Hu; Chatterjee, Raja; Keall, Paul J.; Gambhir, Sanjiv Sam; Contag, Christopher H.; Boyer, Arthur L. [Department of Radiology Oncology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California 94305 (United States); Department of Mechanical Engineering, Molecular Imaging Program at Stanford, Stanford University, Stanford, California 94305 (United States); Department of Radiology Oncology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California 94305 (United States); Department of Radiology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California 94305 (United States); Department of Radiology, Scott and White Hospital, Temple, Texas 76508 (United States)

    2007-11-15T23:59:59.000Z

    Treatment of small animals with radiation has in general been limited to planar fields shaped with lead blocks, complicating spatial localization of dose and treatment of deep-seated targets. In order to advance laboratory radiotherapy toward what is accomplished in the clinic, we have constructed a variable aperture collimator for use in shaping the beam of microCT scanner. This unit can image small animal subjects at high resolution, and is capable of delivering therapeutic doses in reasonable exposure times. The proposed collimator consists of two stages, each containing six trapezoidal brass blocks that move along a frame in a manner similar to a camera iris producing a hexagonal aperture of variable size. The two stages are offset by 30 deg. and adjusted for the divergence of the x-ray beam so as to produce a dodecagonal profile at isocenter. Slotted rotating driving plates are used to apply force to pins in the collimator blocks and effect collimator motion. This device has been investigated through both simulation and measurement. The collimator aperture size varied from 0 to 8.5 cm as the driving plate angle increased from 0 to 41 deg. . The torque required to adjust the collimator varied from 0.5 to 5 N{center_dot}m, increasing with increasing driving plate angle. The transmission profiles produced by the scanner at isocenter exhibited a penumbra of approximately 10% of the collimator aperture width. Misalignment between the collimator assembly and the x-ray source could be identified on the transmission images and corrected by adjustment of the collimator location. This variable aperture collimator technology is therefore a feasible and flexible solution for adjustable shaping of radiation beams for use in small animal radiotherapy as well as other applications in which beam shaping is desired.

  3. Abstract-Proton Computed Tomography (CT) has important implications for both image-guided diagnosis and radiation

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Abstract- Proton Computed Tomography (CT) has important implications for both image-guided diagnosis and radiation therapy. For diagnosis, the fact that the patient dose committed by proton CT and contrast, may be exploited in dose-critical clinical settings. Proton CT is also the most appropriate

  4. Adaptive Noise Reduction toward Low-dose Computed Tomography Hongbing Lu*ad

    E-Print Network [OSTI]

    Adaptive Noise Reduction toward Low-dose Computed Tomography Hongbing Lu*ad , Xiang Lia , Lihong phantom projections acquired by a GE spiral computed tomography (CT) scanner under 10 mAs tube current, computed tomography, adaptive filtering, edge- preserving smoothing, streak artifacts. 1. INTRODUCTION

  5. for Proton CT R. P. Johnson, Member, IEEE, V. Bashkirov, V. Giacometti, R. F. Hurley, P. Piersimoni,

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    for Proton CT R. P. Johnson, Member, IEEE, V. Bashkirov, V. Giacometti, R. F. Hurley, P. Piersimoni beam test results with our pre-clinical (Phase-II) head scanner developed for proton computed tomography (pCT). After extensive preclinical testing, pCT will be employed in support of proton therapy

  6. Radiation dose reduction in medical CT through equally sloped tomography Benjamin P. Fahimian1,2,6

    E-Print Network [OSTI]

    Soatto, Stefano

    Council on Radiation Protection & Measurements10 , CT accounts for about 15% of the total radiological50Radiation dose reduction in medical CT through equally sloped tomography Benjamin P. Fahimian1 Department of Radiation Oncology, Stanford University, Stanford, CA 94305 3 Biomedical Physics

  7. 2002 IEEE NSS/MIC pCT: Hartmut F.-W. Sadrozinski , SCIPP Towards Proton Computed Tomography

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    2002 IEEE NSS/MIC pCT: Hartmut F.-W. Sadrozinski , SCIPP SCIPPSCIPP Towards Proton Computed Tomography L. R. Johnson, B. Keeney, G. Ross, H. F.-W. Sadrozinski, A. Seiden, D.C. Williams, L. Zhang Santa Radiography MC Study #12;2002 IEEE NSS/MIC pCT: Hartmut F.-W. Sadrozinski , SCIPP SCIPPSCIPP Computed

  8. NETL CT Imaging Facility

    ScienceCinema (OSTI)

    None

    2014-05-21T23:59:59.000Z

    NETL's CT Scanner laboratory is equipped with three CT scanners and a mobile core logging unit that work together to provide characteristic geologic and geophysical information at different scales, non-destructively.

  9. NETL CT Imaging Facility

    SciTech Connect (OSTI)

    None

    2013-09-04T23:59:59.000Z

    NETL's CT Scanner laboratory is equipped with three CT scanners and a mobile core logging unit that work together to provide characteristic geologic and geophysical information at different scales, non-destructively.

  10. International Conference on Fully 3D Reconstruction in Radiology and Nuclear Medicine, Linau, Germany, July 9-13, 2007 Abstract--Four-dimensional computed tomography (4D-CT)

    E-Print Network [OSTI]

    , Germany, July 9-13, 2007 Abstract--Four-dimensional computed tomography (4D-CT) plays an important role computed tomography (4D-CT) with respiratory gating provides dynamic volume imaging datasets of the moving

  11. Computed tomography of cryogenic cells

    E-Print Network [OSTI]

    2001-01-01T23:59:59.000Z

    COMPUTED TOMOGRAPHY OF CRYOGENIC CELLS G. SCHNEIDER, and E.absorption, computed tomography (CT) can be performed. Sincethis work is to apply computed tomography, which has already

  12. Application of neutron computed tomography in the geosciences

    E-Print Network [OSTI]

    Wilding, M.; Shields, K.; Lesher, C. E.

    2005-01-01T23:59:59.000Z

    of neutron computed tomography in the geosciences Martinthat applies neutron computed tomography (CT) to geologicalthe use of neutron computed tomography (CT) in the analy-

  13. Hyperdense Cerebral Sinus Vein Thrombosis on Computed Tomography

    E-Print Network [OSTI]

    Zeina, Abdel-Rauf; Kassem, Eiass; Klein, Adi; Nachtigal, Alicia

    2010-01-01T23:59:59.000Z

    Vein Thrombosis on Computed Tomography Abdel-Rauf Zeina*1. Unenhanced axial computed tomography (CT) (a-c) shows theBrain unenhanced computed tomography (CT) on admission

  14. Prevalence of Incidental Findings on Abdominal Computed Tomography Angiograms on Prospective Renal Donors

    E-Print Network [OSTI]

    2015-01-01T23:59:59.000Z

    multidetector computed tomography angiography. Transplantof Radiology CT: computed tomography IF: incidental findings

  15. Design of an advanced positron emission tomography detector system and algorithms for imaging small animal models of human disease

    E-Print Network [OSTI]

    Foudray, Angela Marie Klohs

    2009-01-01T23:59:59.000Z

    for an lsobased combined pet/ct scan- ner using the nationalsimulation of the siemens pet/ct biograph 6 scanner. Nucl.pet scanner and its use with a coaxial small animal volume ct

  16. Abnormal Arterial Blood Gas and Lactate Levels Do Not Alter Disposition in Adult Blunt Trauma Patients after Early Computed Tomography

    E-Print Network [OSTI]

    Vohra, Taher; Paxton, James

    2013-01-01T23:59:59.000Z

    Patients after Early Computed Tomography Taher Vohra, MDwho also receive computed tomographies (CT) of the chest,cross-sectional computed tomography (CT) of the chest,

  17. Artifact Simulating Fracture on Cervical Spine Computed Tomography

    E-Print Network [OSTI]

    Shockley, Lee W.; Kendall, John L.

    2011-01-01T23:59:59.000Z

    on Cervical Spine Computed Tomography Lee W. Shockley, MD,patient with computed tomography concerning significant C3-scalp laceration. Computed tomography (CT) of her head was

  18. CT Scans of Cores Metadata, Barrow, Alaska 2015

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Katie McKnight; Tim Kneafsey; Craig Ulrich

    Individual ice cores were collected from Barrow Environmental Observatory in Barrow, Alaska, throughout 2013 and 2014. Cores were drilled along different transects to sample polygonal features (i.e. the trough, center and rim of high, transitional and low center polygons). Most cores were drilled around 1 meter in depth and a few deep cores were drilled around 3 meters in depth. Three-dimensional images of the frozen cores were constructed using a medical X-ray computed tomography (CT) scanner. TIFF files can be uploaded to ImageJ (an open-source imaging software) to examine soil structure and densities within each core.

  19. Basic Idea on Interior Tomography Development and Applications of Interior Tomography

    E-Print Network [OSTI]

    Wang, Ge

    transforms. International Journal of Biomedical Imaging, Article ID 63634, 8 pages, 2007 Yu H, Wang G. 14-15, March 2010 Siemens dual-source scanner was introduced in 2005 but it is still not suffi Demonstration with Animal CT/Micro-CT Data Siemens Clinical CT Scanner http://www.siemens.com A sheep

  20. Sample size requirements for estimating effective dose from computed tomography using solid-state metal-oxide-semiconductor field-effect transistor dosimetry

    SciTech Connect (OSTI)

    Trattner, Sigal [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States)] [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States); Cheng, Bin [Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032 (United States)] [Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032 (United States); Pieniazek, Radoslaw L. [Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States)] [Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)] [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Douglas, Pamela S. [Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715 (United States)] [Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715 (United States); Einstein, Andrew J., E-mail: andrew.einstein@columbia.edu [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York and Department of Radiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York (United States)

    2014-04-15T23:59:59.000Z

    Purpose: Effective dose (ED) is a widely used metric for comparing ionizing radiation burden between different imaging modalities, scanners, and scan protocols. In computed tomography (CT), ED can be estimated by performing scans on an anthropomorphic phantom in which metal-oxide-semiconductor field-effect transistor (MOSFET) solid-state dosimeters have been placed to enable organ dose measurements. Here a statistical framework is established to determine the sample size (number of scans) needed for estimating ED to a desired precision and confidence, for a particular scanner and scan protocol, subject to practical limitations. Methods: The statistical scheme involves solving equations which minimize the sample size required for estimating ED to desired precision and confidence. It is subject to a constrained variation of the estimated ED and solved using the Lagrange multiplier method. The scheme incorporates measurement variation introduced both by MOSFET calibration, and by variation in MOSFET readings between repeated CT scans. Sample size requirements are illustrated on cardiac, chest, and abdomen–pelvis CT scans performed on a 320-row scanner and chest CT performed on a 16-row scanner. Results: Sample sizes for estimating ED vary considerably between scanners and protocols. Sample size increases as the required precision or confidence is higher and also as the anticipated ED is lower. For example, for a helical chest protocol, for 95% confidence and 5% precision for the ED, 30 measurements are required on the 320-row scanner and 11 on the 16-row scanner when the anticipated ED is 4 mSv; these sample sizes are 5 and 2, respectively, when the anticipated ED is 10 mSv. Conclusions: Applying the suggested scheme, it was found that even at modest sample sizes, it is feasible to estimate ED with high precision and a high degree of confidence. As CT technology develops enabling ED to be lowered, more MOSFET measurements are needed to estimate ED with the same precision and confidence.

  1. Prospects for in vivo estimation of photon linear attenuation coefficients using postprocessing dual-energy CT imaging on a commercial scanner: Comparison of analytic and polyenergetic statistical reconstruction algorithms

    SciTech Connect (OSTI)

    Evans, Joshua D., E-mail: jevans2@mcvh-vcu.edu; Yu, Yaduo; Williamson, Jeffrey F. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)] [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Whiting, Bruce R. [Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States)] [Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States); O’Sullivan, Joseph A. [Department of Electrical and Systems Engineering, Washington University, St. Louis, Missouri 63130 (United States)] [Department of Electrical and Systems Engineering, Washington University, St. Louis, Missouri 63130 (United States); Politte, David G. [Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri 63110 (United States)] [Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri 63110 (United States); Klahr, Paul H. [Philips Healthcare, 595 Miner Rd., Highland Hts., Ohio 44143 (United States)] [Philips Healthcare, 595 Miner Rd., Highland Hts., Ohio 44143 (United States)

    2013-12-15T23:59:59.000Z

    Purpose: Accurate patient-specific photon cross-section information is needed to support more accurate model-based dose calculation for low energy photon-emitting modalities in medicine such as brachytherapy and kilovoltage x-ray imaging procedures. A postprocessing dual-energy CT (pDECT) technique for noninvasivein vivo estimation of photon linear attenuation coefficients has been experimentally implemented on a commercial CT scanner and its accuracy assessed in idealized phantom geometries. Methods: Eight test materials of known composition and density were used to compare pDECT-estimated linear attenuation coefficients to NIST reference values over an energy range from 10 keV to 1 MeV. As statistical image reconstruction (SIR) has been shown to reconstruct images with less random and systematic error than conventional filtered backprojection (FBP), the pDECT technique was implemented with both an in-house polyenergetic SIR algorithm, alternating minimization (AM), as well as a conventional FBP reconstruction algorithm. Improvement from increased spectral separation was also investigated by filtering the high-energy beam with an additional 0.5 mm of tin. The law of propagated uncertainty was employed to assess the sensitivity of the pDECT process to errors in reconstructed images. Results: Mean pDECT-estimated linear attenuation coefficients for the eight test materials agreed within 1% of NIST reference values for energies from 1 MeV down to 30 keV, with mean errors rising to between 3% and 6% at 10 keV, indicating that the method is unbiased when measurement and calibration phantom geometries are matched. Reconstruction with FBP and AM algorithms conferred similar mean pDECT accuracy. However, single-voxel pDECT estimates reconstructed on a 1 × 1 × 3 mm{sup 3} grid are shown to be highly sensitive to reconstructed image uncertainty; in some cases pDECT attenuation coefficient estimates exhibited standard deviations on the order of 20% around the mean. Reconstruction with the statistical AM algorithm led to standard deviations roughly 40% to 60% less than FBP reconstruction. Additional tin filtration of the high energy beam exhibits similar pDECT estimation accuracy as the unfiltered beam, even when scanning with only 25% of the dose. Using the law of propagated uncertainty, low Z materials are found to be more sensitive to image reconstruction errors than high Z materials. Furthermore, it is estimated that reconstructed CT image uncertainty must be limited to less than 0.25% to achieve a target linear-attenuation coefficient estimation uncertainty of 3% at 28 keV. Conclusions: That pDECT supports mean linear attenuation coefficient measurement accuracies of 1% of reference values for energies greater than 30 keV is encouraging. However, the sensitivity of the pDECT measurements to noise and systematic errors in reconstructed CT images warrants further investigation in more complex phantom geometries. The investigated statistical reconstruction algorithm, AM, reduced random measurement uncertainty relative to FBP owing to improved noise performance. These early results also support efforts to increase DE spectral separation, which can further reduce the pDECT sensitivity to measurement uncertainty.

  2. Sensitivity of Emergency Bedside Ultrasound to Detect Hydronephrosis in Patients with Computed Tomography-proven Stones

    E-Print Network [OSTI]

    2014-01-01T23:59:59.000Z

    DJ, Hall EJ. Computed tomography-an increasing source ofin Patients with Computed Tomography-proven Stones JeffNon-contrast computed tomography (CT) is widely regarded as

  3. Adherence to Head Computed Tomography Guidelines in the Setting of Mild Traumatic Brain Injury

    E-Print Network [OSTI]

    Jones, Landon A; Morley, Eric J; Grant, William D; Wojcik, Susan M; Paolo, William F

    2014-01-01T23:59:59.000Z

    Adherence to Head Computed Tomography Guidelines for Mildal Adherence to Head Computed Tomography Guidelines system,non-contrast head computed tomography (CT) in patients with

  4. Emergency Department Frequent User: Pilot Study of Intensive Case Management to Reduce Visits and Computed Tomography

    E-Print Network [OSTI]

    Grover, Casey A; Close, Reb JH; Villarreal, Kathy; Goldman, Lee M

    2010-01-01T23:59:59.000Z

    33. Brenner DJ, Hall EJ. Computed tomography – an increasingReduce Visits and Computed Tomography Casey A. Grover* Rebof total images in all computed tomography (CT) scans during

  5. Yield and Clinical Predictors of Thoracic Spine Injury from Chest Computed Tomography for Blunt Trauma

    E-Print Network [OSTI]

    2014-01-01T23:59:59.000Z

    Injury from Chest Computed Tomography for Blunt Trauma Markthe use of chest computed tomography (CT), (CCT) in bluntinjury. 6,7 Chest computed tomography (CCT) evaluation for

  6. Nondestructive and quantitative characterization of TRU and LLW mixed-waste using active and passive gamma-ray spectrometry and computed tomography

    SciTech Connect (OSTI)

    Camp, D.C.; Martz, H.E.

    1991-11-12T23:59:59.000Z

    The technology being proposed by LLNL is an Active and Passive Computed Tomography (A P CT) Drum Scanner for contact-handled (CH) wastes. It combines the advantages offered by two well-developed nondestructive assay technologies: gamma-ray spectrometry and computed tomography (CT). Coupled together, these two technologies offer to nondestructively and quantitatively characterize mixed- wastes forms. Gamma-ray spectroscopy uses one or more external radiation detectors to passively and nondestructively measure the energy spectrum emitted from a closed container. From the resulting spectrum one can identify most radioactivities detected, be they transuranic isotopes, mixed-fission products, activation products or environmental radioactivities. Spectral libraries exist at LLNL for all four. Active (A) or transmission CT is a well-developed, nondestructive medical and industrial technique that uses an external-radiation beam to map regions of varying attenuation within a container. Passive (P) or emission CT is a technique mainly developed for medical application, e.g., single-photon emission CT. Nondestructive industrial uses of PCT are under development and just coming into use. This report discuses work on the A P CT Drum Scanner at LLNL.

  7. aided ct image: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Imaging X-rays Computed Tomography (CT) Positron Emission Tomography (PET 12;LSO-APD Array Schematic 12;Time-of-Flight PET 12;Energy Spectrum with lutetium...

  8. SU-E-I-52: Validation of Multi-Frequency Electrical Impedance Tomography Using Computed Tomography

    SciTech Connect (OSTI)

    Kohli, K; Liu, F; Krishnan, K [BC Cancer Agency, Surrey, BC (United Kingdom)

    2014-06-01T23:59:59.000Z

    Purpose: Multi-frequency EIT has been reported to be a potential tool in distinguishing a tissue anomaly from background. In this study, we investigate the feasibility of acquiring functional information by comparing multi-frequency EIT images in reference to the structural information from the CT image through fusion. Methods: EIT data was acquired from a slice of winter melon using sixteen electrodes around the phantom, injecting a current of 0.4mA at 100, 66, 24.8 and 9.9 kHz. Differential EIT images were generated by considering different combinations of pair frequencies, one serving as reference data and the other as test data. The experiment was repeated after creating an anomaly in the form of an off-centered cavity of diameter 4.5 cm inside the melon. All EIT images were reconstructed using Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software (EIDORS) package in 2-D differential imaging mode using one-step Gaussian Newton minimization solver. CT image of the melon was obtained using a Phillips CT Scanner. A segmented binary mask image was generated based on the reference electrode position and the CT image to define the regions of interest. The region selected by the user was fused with the CT image through logical indexing. Results: Differential images based on the reference and test signal frequencies were reconstructed from EIT data. Result illustrated distinct structural inhomogeneity in seeded region compared to fruit flesh. The seeded region was seen as a higherimpedance region if the test frequency was lower than the base frequency in the differential EIT reconstruction. When the test frequency was higher than the base frequency, the signal experienced less electrical impedance in the seeded region during the EIT data acquisition. Conclusion: Frequency-based differential EIT imaging can be explored to provide additional functional information along with structural information from CT for identifying different tissues.

  9. Artifact reduction in industrial computed tomography via data fusion

    SciTech Connect (OSTI)

    Schrapp, Michael; Goldammer, Matthias; Stephan, Jürgen [Siemens AG, Corporate Technology, Otto-Hahn-Ring 6, 81739 Munich (Germany)

    2014-02-18T23:59:59.000Z

    As the most stressed part of a gas turbine the first row of turbine blades is not only a challenge for the materials used. Also the testing of these parts have to meet the highest standards. Computed tomography (CT) as the technique which could reveal the most details also provides the biggest challenges [1]: A full penetration of large sized turbine blades is often only possible at high X-ray voltages causing disproportional high costs. A reduction of the X-ray voltage is able to reduce these arising costs but yields non penetration artifacts in the reconstructed CT image. In most instances, these artifacts manifests itself as blurred and smeared regions at concave edges due to a reduced signal to noise ratio. In order to complement the missing information and to increase the overall image quality of our reconstruction, we use further imaging modalities such as a 3-D Scanner and ultrasonic imaging. A 3-D scanner is easy and cost effective to implement and is able to acquire all relevant data simultaneously with the CT projections. If, however, the interior structure is of supplemental interest, an ultrasonic imaging method is additionally used. We consider this data as a priori knowledge to employ them in an iterative reconstruction. To do so, standard iterative reconstruction methods are modified to incorporate the a priori data in a regularization approach in combination with minimizing the total variation of our image. Applying this procedure on turbine blades, we are able to reduce the apparent artifacts almost completely.

  10. The Relationship between Organ Dose and Patients Size in Multidetector Computed Tomography (MDCT) Scans Utilizing Tube Current Modulation (TCM)

    E-Print Network [OSTI]

    Khatonabadi, Maryam

    2013-01-01T23:59:59.000Z

    D. and E. Hall, Computed tomography - An increasing source7430): p. 19. FDA, Computed Tomography (CT). Food and Drugtransmission x-ray computed tomography. Med Phys, 1981. 8(

  11. Organ doses for reference adult male and female undergoing computed tomography estimated by Monte Carlo simulations

    SciTech Connect (OSTI)

    Lee, Choonsik; Kim, Kwang Pyo; Long, Daniel; Fisher, Ryan; Tien, Chris; Simon, Steven L.; Bouville, Andre; Bolch, Wesley E. [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, Maryland 20852 (United States); Department of Nuclear Engineering, Kyung Hee University, Yongin 446-701 (Korea, Republic of); Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, Florida 32611 (United States); Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institute of Health, Bethesda, Maryland 20852 (United States); Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, Florida 32611 (United States)

    2011-03-15T23:59:59.000Z

    Purpose: To develop a computed tomography (CT) organ dose estimation method designed to readily provide organ doses in a reference adult male and female for different scan ranges to investigate the degree to which existing commercial programs can reasonably match organ doses defined in these more anatomically realistic adult hybrid phantomsMethods: The x-ray fan beam in the SOMATOM Sensation 16 multidetector CT scanner was simulated within the Monte Carlo radiation transport code MCNPX2.6. The simulated CT scanner model was validated through comparison with experimentally measured lateral free-in-air dose profiles and computed tomography dose index (CTDI) values. The reference adult male and female hybrid phantoms were coupled with the established CT scanner model following arm removal to simulate clinical head and other body region scans. A set of organ dose matrices were calculated for a series of consecutive axial scans ranging from the top of the head to the bottom of the phantoms with a beam thickness of 10 mm and the tube potentials of 80, 100, and 120 kVp. The organ doses for head, chest, and abdomen/pelvis examinations were calculated based on the organ dose matrices and compared to those obtained from two commercial programs, CT-EXPO and CTDOSIMETRY. Organ dose calculations were repeated for an adult stylized phantom by using the same simulation method used for the adult hybrid phantom. Results: Comparisons of both lateral free-in-air dose profiles and CTDI values through experimental measurement with the Monte Carlo simulations showed good agreement to within 9%. Organ doses for head, chest, and abdomen/pelvis scans reported in the commercial programs exceeded those from the Monte Carlo calculations in both the hybrid and stylized phantoms in this study, sometimes by orders of magnitude. Conclusions: The organ dose estimation method and dose matrices established in this study readily provides organ doses for a reference adult male and female for different CT scan ranges and technical parameters. Organ doses from existing commercial programs do not reasonably match organ doses calculated for the hybrid phantoms due to differences in phantom anatomy, as well as differences in organ dose scaling parameters. The organ dose matrices developed in this study will be extended to cover different technical parameters, CT scanner models, and various age groups.

  12. Molecular imaging in oncology: the acceptance of PET/CT and the emergence of MR/PET imaging

    E-Print Network [OSTI]

    Schiepers, Christiaan; Dahlbom, Magnus

    2011-01-01T23:59:59.000Z

    CT—Computed tomography . PET—Positron Emission Tomography .body imaging with MRI or PET/CT: the future for single-Sollitto RA et al (2009) 18F-FDG PET/CT of transitional cell

  13. Limited View Angle Iterative CT Reconstruction

    E-Print Network [OSTI]

    . Connelly, "CT Technologies," in Aspects of Explosives Detection, Elsevier 2009. Dual energy CT Z. Ying, R. Nam and C. R. Crawford, "Dual energy computed tomography for explosive detection," Journal of X

  14. Proton Computed Tomography and Constructing Tracker Boards Gatlin Bredeson

    E-Print Network [OSTI]

    Belanger, David P.

    1 ABSTRACT Proton Computed Tomography and Constructing Tracker Boards By Gatlin Bredeson Scientists tomography (xCT) with proton computed tomography (pCT). During a CT scan, protons pass through a phantom University to build tracker boards to assist in creating a system that seeks to replace X-ray computed

  15. -CT CT)Computed Tomography(. ,. , -100 ,

    E-Print Network [OSTI]

    Pinsky, Ross

    ) QSR. / ( · -ISO 13485. ·. ·ISO 13485 / /-FDA-. ·.( ,) Manual Assembler : . /BB-. ·. Compliance ExpertProduction · -FDA . , ISO , . · , , , . : · 2-4 . · GMP

  16. Biochip scanner device

    DOE Patents [OSTI]

    Perov, Alexander (Troitsk, RU); Belgovskiy, Alexander I. (Mayfield Heights, OH); Mirzabekov, Andrei D. (Darien, IL)

    2001-01-01T23:59:59.000Z

    A biochip scanner device used to detect and acquire fluorescence signal data from biological microchips or biochips and method of use are provided. The biochip scanner device includes a laser for emitting a laser beam. A modulator, such as an optical chopper modulates the laser beam. A scanning head receives the modulated laser beam and a scanning mechanics coupled to the scanning head moves the scanning head relative to the biochip. An optical fiber delivers the modulated laser beam to the scanning head. The scanning head collects the fluorescence light from the biochip, launches it into the same optical fiber, which delivers the fluorescence into a photodetector, such as a photodiode. The biochip scanner device is used in a row scanning method to scan selected rows of the biochip with the laser beam size matching the size of the immobilization site.

  17. Does High Body Mass Index Obviate the Need for Oral Contrast for Abdominal-Pelvic Computed Tomography in Emergency Department Patients?

    E-Print Network [OSTI]

    Harrison, Matthew Lee; Lizotte, Paul E; Holmes, Talmage M; Kenney, Phillip J; Buckner, Charles Barry; Shah, Hemendra R

    2013-01-01T23:59:59.000Z

    1. Brenner DJ, Hall EJ. Computed Tomography. An Increasingis necessary for the computed tomography diagnosis ofto read a computed tomography (CT) of the abdomen and

  18. Modeling pure methane hydrate dissociation using a numerical simulator from a novel combination of X-ray computed tomography and macroscopic data

    E-Print Network [OSTI]

    Gupta, A.

    2010-01-01T23:59:59.000Z

    Combination of X-ray Computed Tomography and Macroscopicdissociation data. X-ray computed tomography (CT) was usedobtained from x-ray computed tomography analysis combined

  19. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with AAS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with AAS Radiologic Technology 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography (CT) 2 C RIS 44025 Computed Tomography (CT) Clinical Education I 3 C

  20. Examination of viscous fingering using the Cat-Scanner

    E-Print Network [OSTI]

    D'Souza, Michael Anthony

    1993-01-01T23:59:59.000Z

    & APPLICATION OF CT-SCANNING. . . 2. 1 Introduction . 2. 2 Fundamentals of Computed Tomography. . . . . . . . . . . 2. 3 Fundamentals of CT-Scanning. . 2. 4 Problems Associated With CT-Scanning, . . . . . . . . . , . . 2. 5 Petroleum Engineering... . . . . . . . 85 LIST OF FIGURES Figure Page 1. BLOCK DIAGRAM OF CAT-SCAN&DR SETUP. . . . . . . 2A. X-RAY PASSING THROUGH A VOXEL. . . . . . . . . . . . . . . . . . . . 2B. PIXELS IN A CROSS-SECTIONAL OBJECT. . 3. 4. 5. 6. 7. 8. 9. PRODUCIION OF X...

  1. Metal Artifact Reduction in Computed Tomography /

    E-Print Network [OSTI]

    Karimi, Seemeen

    2014-01-01T23:59:59.000Z

    Monoenergetic imaging of dual-energy CT reduces artifactsartifact reduction by dual energy computed tomography usingimage re- construction for dual energy X-ray transmission

  2. Reduction of radiation dose to radiosensitive organs and its tradeoff with image quality in Computed Tomography

    E-Print Network [OSTI]

    Zhang, Di

    2012-01-01T23:59:59.000Z

    of CT scanners such as spectra, bowtie filtration, and beamaccount, including spectra, bowtie filtration, and so on.In addition, the „moving? bowtie shaped filter cannot be

  3. Improved proton computed tomography by dual modality image reconstruction

    SciTech Connect (OSTI)

    Hansen, David C., E-mail: dch@ki.au.dk; Bassler, Niels [Experimental Clinical Oncology, Aarhus University, 8000 Aarhus C (Denmark)] [Experimental Clinical Oncology, Aarhus University, 8000 Aarhus C (Denmark); Petersen, Jørgen Breede Baltzer [Medical Physics, Aarhus University Hospital, 8000 Aarhus C (Denmark)] [Medical Physics, Aarhus University Hospital, 8000 Aarhus C (Denmark); Sørensen, Thomas Sangild [Computer Science, Aarhus University, 8000 Aarhus C, Denmark and Clinical Medicine, Aarhus University, 8200 Aarhus N (Denmark)] [Computer Science, Aarhus University, 8000 Aarhus C, Denmark and Clinical Medicine, Aarhus University, 8200 Aarhus N (Denmark)

    2014-03-15T23:59:59.000Z

    Purpose: Proton computed tomography (CT) is a promising image modality for improving the stopping power estimates and dose calculations for particle therapy. However, the finite range of about 33 cm of water of most commercial proton therapy systems limits the sites that can be scanned from a full 360° rotation. In this paper the authors propose a method to overcome the problem using a dual modality reconstruction (DMR) combining the proton data with a cone-beam x-ray prior. Methods: A Catphan 600 phantom was scanned using a cone beam x-ray CT scanner. A digital replica of the phantom was created in the Monte Carlo code Geant4 and a 360° proton CT scan was simulated, storing the entrance and exit position and momentum vector of every proton. Proton CT images were reconstructed using a varying number of angles from the scan. The proton CT images were reconstructed using a constrained nonlinear conjugate gradient algorithm, minimizing total variation and the x-ray CT prior while remaining consistent with the proton projection data. The proton histories were reconstructed along curved cubic-spline paths. Results: The spatial resolution of the cone beam CT prior was retained for the fully sampled case and the 90° interval case, with the MTF = 0.5 (modulation transfer function) ranging from 5.22 to 5.65?linepairs/cm. In the 45° interval case, the MTF = 0.5 dropped to 3.91?linepairs/cm For the fully sampled DMR, the maximal root mean square (RMS) error was 0.006 in units of relative stopping power. For the limited angle cases the maximal RMS error was 0.18, an almost five-fold improvement over the cone beam CT estimate. Conclusions: Dual modality reconstruction yields the high spatial resolution of cone beam x-ray CT while maintaining the improved stopping power estimation of proton CT. In the case of limited angles, the use of prior image proton CT greatly improves the resolution and stopping power estimate, but does not fully achieve the quality of a 360° proton CT scan.

  4. High throughput optical scanner

    DOE Patents [OSTI]

    Basiji, David A. (Seattle, WA); van den Engh, Gerrit J. (Seattle, WA)

    2001-01-01T23:59:59.000Z

    A scanning apparatus is provided to obtain automated, rapid and sensitive scanning of substrate fluorescence, optical density or phosphorescence. The scanner uses a constant path length optical train, which enables the combination of a moving beam for high speed scanning with phase-sensitive detection for noise reduction, comprising a light source, a scanning mirror to receive light from the light source and sweep it across a steering mirror, a steering mirror to receive light from the scanning mirror and reflect it to the substrate, whereby it is swept across the substrate along a scan arc, and a photodetector to receive emitted or scattered light from the substrate, wherein the optical path length from the light source to the photodetector is substantially constant throughout the sweep across the substrate. The optical train can further include a waveguide or mirror to collect emitted or scattered light from the substrate and direct it to the photodetector. For phase-sensitive detection the light source is intensity modulated and the detector is connected to phase-sensitive detection electronics. A scanner using a substrate translator is also provided. For two dimensional imaging the substrate is translated in one dimension while the scanning mirror scans the beam in a second dimension. For a high throughput scanner, stacks of substrates are loaded onto a conveyor belt from a tray feeder.

  5. In-patient to isocenter KERMA ratios in CT

    SciTech Connect (OSTI)

    Huda, Walter; Ogden, Kent M.; Lavallee, Robert L.; Roskopf, Marsha L.; Scalzetti, Ernest M. [Department of Radiology and Radiological Science, Medical University of South Carolina (MUSC), 96 Jonathan Lucas Street (MSC 323), Charleston, South Carolina 29425-3230 (United States); Department of Radiology, SUNY Upstate Medical University, 750 E Adams Street, Syracuse, New York 13210 (United States)

    2011-10-15T23:59:59.000Z

    Purpose: To estimate in-patient KERMA for specific organs in computed tomography (CT) scanning using ratios to isocenter free-in-air KERMA obtained using a Rando phantom.Method: A CT scan of an anthropomorphic phantom results in an air KERMA K at a selected phantom location and air kerma K{sub CT} at the CT scanner isocenter when the scan is repeated in the absence of the phantom. The authors define the KERMA ratio (R{sub K}) as K/ K{sub CT}, which were experimentally determined in a Male Rando Phantom using lithium fluoride chips (TLD-100). R{sub K} values were obtained for a total of 400 individual point locations, as well as for 25 individual organs of interest in CT dosimetry. CT examinations of Rando were performed on a GE LightSpeed Ultra scanner operated at 80 kV, 120 kV, and 140 kV, as well as a Siemens Sensation 16 operated at 120 kV. Results: At 120 kV, median R{sub K} values for the GE and Siemens scanners were 0.60 and 0.64, respectively. The 10th percentile R{sub K} values ranged from 0.34 at 80 kV to 0.54 at 140 kV, and the 90th percentile R{sub K} values ranged from 0.64 at 80 kV to 0.78 at 140 kV. The average R{sub K} for the 25 Rando organs at 120 kV was 0.61 {+-} 0.08. Average R{sub K} values in the head, chest, and abdomen showed little variation. Relative to R{sub K} values in the head, chest, and abdomen obtained at 120 kV, R{sub K} values were about 12% lower in the pelvis and about 58% higher in the cervical spine region. Average R{sub K} values were about 6% higher on the Siemens Sensation 16 scanner than the GE LightSpeed Ultra. Reducing the x-ray tube voltage from 120 kV to 80 kV resulted in an average reduction in R{sub K} value of 34%, whereas increasing the x-ray tube voltage to 140 kV increased the average R{sub K} value by 9%. Conclusions: In-patient to isocenter relative KERMA values in Rando phantom can be used to estimate organ doses in similar sized adults undergoing CT examinations from easily measured air KERMA values at the isocenter (free in air). Conversion from in-patient air KERMA values to tissue dose would require the use of energy-appropriate conversion factors.

  6. Atlas-based attenuation correction for small animal PET/MRI scanners Abhijit J. Chaudhari, ajchaudhari@ucdavis.edu,

    E-Print Network [OSTI]

    Leahy, Richard M.

    of MRI values to absolute CT intensities [3]. Rotating a PET transmission source around the animalAtlas-based attenuation correction for small animal PET/MRI scanners 1 Abhijit J. Chaudhari PET/MRI scanners producing anatomically co-registered simultaneously-acquired images of morphology

  7. Integrated display scanner

    DOE Patents [OSTI]

    Veligdan, James T.

    2004-12-21T23:59:59.000Z

    A display scanner includes an optical panel having a plurality of stacked optical waveguides. The waveguides define an inlet face at one end and a screen at an opposite end, with each waveguide having a core laminated between cladding. A projector projects a scan beam of light into the panel inlet face for transmission from the screen as a scan line to scan a barcode. A light sensor at the inlet face detects a return beam reflected from the barcode into the screen. A decoder decodes the return beam detected by the sensor for reading the barcode. In an exemplary embodiment, the optical panel also displays a visual image thereon.

  8. Analysis framework for the J-PET scanner

    E-Print Network [OSTI]

    Krzemie?, W; Gruntowski, A; Stola, K; Trybek, D; Bednarski, T; Bia?as, P; Czerwi?ski, E; Kami?ska, D; Kap?on, L; Kochanowski, A; Korcyl, G; Kowal, J; Kowalski, P; Kozik, T; Kubicz, E; Moskal, P; Nied?wiecki, Sz; Pa?ka, M; Raczy?ski, L; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; S?omski, A; Smyrski, J; Strzelecki, A; Wieczorek, A; Wi?licki, W; Zieli?ski, M; Zo?, N

    2015-01-01T23:59:59.000Z

    J-PET analysis framework is a flexible, lightweight, ROOT-based software package which provides the tools to develop reconstruction and calibration procedures for PET tomography. In this article we present the implementation of the full data-processing chain in the J-PET framework which is used for the data analysis of the J-PET tomography scanner. The Framework incorporates automated handling of PET setup parameters' database as well as high level tools for building data reconstruction procedures. Each of these components is briefly discussed.

  9. REVIEW Open Access Micro computed tomography for

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    REVIEW Open Access Micro computed tomography for vascular exploration Lyubomir Zagorchev1 studies. Micro Computed Tomography (micro-CT) has emerged in recent years as the preferred modality and suggestions aimed at making micro-CT more accurate, replicable, and robust. Introduction Micro Computed

  10. Review of Parallel Computing Techniques for Computed Tomography Image Reconstruction

    E-Print Network [OSTI]

    Wang, Ge

    Review of Parallel Computing Techniques for Computed Tomography Image Reconstruction Jun Ni1, 3 representative analytic and iterative reconstruction algorithms for X-ray computed tomography (CT), we address X-ray computed tomography (CT) is one of the most important non-invasive medical imaging techniques

  11. Individual patient data meta-analysis for the clinical assessment of coronary computed tomography angiography: protocol of the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT)

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    Feyter PJ: 64-slice computed tomography coronary angiographyof 64-slice computed tomography coronary angiography inmultislice spiral computed tomography: impact of heart rate.

  12. Respiratory correlated cone beam CT

    SciTech Connect (OSTI)

    Sonke, Jan-Jakob; Zijp, Lambert; Remeijer, Peter; Herk, Marcel van [Department of Radiation Oncology, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands)

    2005-04-01T23:59:59.000Z

    A cone beam computed tomography (CBCT) scanner integrated with a linear accelerator is a powerful tool for image guided radiotherapy. Respiratory motion, however, induces artifacts in CBCT, while the respiratory correlated procedures, developed to reduce motion artifacts in axial and helical CT are not suitable for such CBCT scanners. We have developed an alternative respiratory correlated procedure for CBCT and evaluated its performance. This respiratory correlated CBCT procedure consists of retrospective sorting in projection space, yielding subsets of projections that each corresponds to a certain breathing phase. Subsequently, these subsets are reconstructed into a four-dimensional (4D) CBCT dataset. The breathing signal, required for respiratory correlation, was directly extracted from the 2D projection data, removing the need for an additional respiratory monitor system. Due to the reduced number of projections per phase, the contrast-to-noise ratio in a 4D scan reduced by a factor 2.6-3.7 compared to a 3D scan based on all projections. Projection data of a spherical phantom moving with a 3 and 5 s period with and without simulated breathing irregularities were acquired and reconstructed into 3D and 4D CBCT datasets. The positional deviations of the phantoms center of gravity between 4D CBCT and fluoroscopy were small: 0.13{+-}0.09 mm for the regular motion and 0.39{+-}0.24 mm for the irregular motion. Motion artifacts, clearly present in the 3D CBCT datasets, were substantially reduced in the 4D datasets, even in the presence of breathing irregularities, such that the shape of the moving structures could be identified more accurately. Moreover, the 4D CBCT dataset provided information on the 3D trajectory of the moving structures, absent in the 3D data. Considerable breathing irregularities, however, substantially reduces the image quality. Data presented for three different lung cancer patients were in line with the results obtained from the phantom study. In conclusion, we have successfully implemented a respiratory correlated CBCT procedure yielding a 4D dataset. With respiratory correlated CBCT on a linear accelerator, the mean position, trajectory, and shape of a moving tumor can be verified just prior to treatment. Such verification reduces respiration induced geometrical uncertainties, enabling safe delivery of 4D radiotherapy such as gated radiotherapy with small margins.

  13. abdominal multislice ct: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    planning. It includes an abdominal computer tomography (CT) image Leow, Wee Kheng 17 CT-PET Landmark-based Lung Registration Using a Dynamic Breathing Model S. Chambon1 Physics...

  14. abdominal ct findings: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    planning. It includes an abdominal computer tomography (CT) image Leow, Wee Kheng 11 CT-PET Landmark-based Lung Registration Using a Dynamic Breathing Model S. Chambon1 Physics...

  15. Specific recommendations for accurate and direct use of PET-CT in PET guided radiotherapy for head and neck sites

    SciTech Connect (OSTI)

    Thomas, C. M., E-mail: christopher.thomas@gstt.nhs.uk; Convery, D. J.; Greener, A. G. [Guy's and St. Thomas’ NHS Foundation Trust, Medical Physics Department, St. Thomas’ Hospital, London SE1 7EH (United Kingdom)] [Guy's and St. Thomas’ NHS Foundation Trust, Medical Physics Department, St. Thomas’ Hospital, London SE1 7EH (United Kingdom); Pike, L. C.; Baker, S.; Woods, E. [Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas’ Hospital, London SE1 7EH (United Kingdom)] [Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas’ Hospital, London SE1 7EH (United Kingdom); Hartill, C. E. [Guy's and St. Thomas’ NHS Foundation Trust, Radiotherapy, Clinical Outpatients Clinic, St. Thomas’ Hospital, London SE1 7EH (United Kingdom)] [Guy's and St. Thomas’ NHS Foundation Trust, Radiotherapy, Clinical Outpatients Clinic, St. Thomas’ Hospital, London SE1 7EH (United Kingdom)

    2014-04-15T23:59:59.000Z

    Purpose: To provide specific experience-based guidance and recommendations for centers wishing to develop, validate, and implement an accurate and efficient process for directly using positron emission tomography-computed tomography (PET-CT) for the radiotherapy planning of head and neck cancer patients. Methods: A PET-CT system was modified with hard-top couch, external lasers and radiotherapy immobilization and indexing devices and was subject to a commissioning and quality assurance program. PET-CT imaging protocols were developed specifically for radiotherapy planning and the image quality and pathway tested using phantoms and five patients recruited into an in-house study. Security and accuracy of data transfer was tested throughout the whole data pathway. The patient pathway was fully established and tested ready for implementation in a PET-guided dose-escalation trial for head and neck cancer patients. Results: Couch deflection was greater than for departmental CT simulator machines. An area of high attenuation in the couch generated image artifacts and adjustments were made accordingly. Using newly developed protocols CT image quality was suitable to maintain delineation and treatment accuracy. Upon transfer of data to the treatment planning system a half pixel offset between PET and CT was observed and corrected. By taking this into account, PET to CT alignment accuracy was maintained below 1 mm in all systems in the data pathway. Transfer of structures delineated in the PET fusion software to the radiotherapy treatment planning system was validated. Conclusions: A method to perform direct PET-guided radiotherapy planning was successfully validated and specific recommendations were developed to assist other centers. Of major concern is ensuring that the quality of PET and CT data is appropriate for radiotherapy treatment planning and on-treatment verification. Couch movements can be compromised, bore-size can be a limitation for certain immobilization techniques, laser positioning may affect setup accuracy and couch deflection may be greater than scanners dedicated to radiotherapy. The full set of departmental commissioning and routine quality assurance tests applied to radiotherapy CT simulators must be carried out on the PET-CT scanner. CT image quality must be optimized for radiotherapy planning whilst understanding that the appearance will differ between scanners and may affect delineation. PET-CT quality assurance schedules will need to be added to and modified to incorporate radiotherapy quality assurance. Methods of working for radiotherapy and PET staff will change to take into account considerations of both parties. PET to CT alignment must be subject to quality control on a loaded and unloaded couch preferably using a suitable emission phantom, and tested throughout the whole data pathway. Data integrity must be tested throughout the whole pathway and a system included to verify that delineated structures are transferred correctly. Excellent multidisciplinary team communication and working is vital, and key staff members on both sides should be specifically dedicated to the project. Patient pathway should be clearly devised to optimize patient care and the resources of all departments. Recruitment of a cohort of patients into a methodology study is valuable to test the quality assurance methods and pathway.

  16. The feasibility of head motion tracking in helical CT: A step toward motion correction

    SciTech Connect (OSTI)

    Kim, Jung-Ha [Medical Radiation Sciences, University of Sydney, NSW 2141 (Australia); Nuyts, Johan [Department of Nuclear Medicine, Katholieke Universiteit, Leuven, Belgium and Medical Imaging Research Center, Katholieke Universiteit, Leuven (Belgium); Kuncic, Zdenka [School of Physics, University of Sydney, NSW 2006 (Australia); Fulton, Roger [Medical Radiation Sciences, University of Sydney, NSW 2141 (Australia); School of Physics, University of Sydney, NSW 2006 (Australia); Department of Medical Physics, Westmead Hospital, Westmead, NSW 2145 (Australia)

    2013-04-15T23:59:59.000Z

    Purpose: To establish a practical and accurate motion tracking method for the development of rigid motion correction methods in helical x-ray computed tomography (CT). Methods: A commercially available optical motion tracking system provided 6 degrees of freedom pose measurements at 60 Hz. A 4 Multiplication-Sign 4 calibration matrix was determined to convert raw pose data acquired in tracker coordinates to a fixed CT coordinate system with origin at the isocenter of the scanner. Two calibration methods, absolute orientation (AO), and a new method based on image registration (IR), were compared by means of landmark analysis and correlation coefficient in phantom images coregistered using the derived motion transformations. Results: Transformations calculated using the IR-derived calibration matrix were found to be more accurate, with positional errors less than 0.5 mm (mean RMS), and highly correlated image voxel intensities. The AO-derived calibration matrix yielded larger mean RMS positional errors ( Asymptotically-Equal-To 1.0 mm), and poorer correlation coefficients. Conclusions: The authors have demonstrated the feasibility of accurate motion tracking for retrospective motion correction in helical CT. Their new IR-based calibration method based on image registration and function minimization was simpler to perform and delivered more accurate calibration matrices. This technique is a useful tool for future work on rigid motion correction in helical CT and potentially also other imaging modalities.

  17. Root-canal preparation with FlexMaster: canal shapes analysed by micro-computed tomography

    E-Print Network [OSTI]

    Hubscher, W; Barbakow, F; Peters, O A

    2003-01-01T23:59:59.000Z

    analysed by micro-computed tomography W. Hu bscher 1 , F.shapes analysed by micro-computed tomography. Internationalemploying micro-computed tomography (mCT) at a resolution of

  18. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with certification and ATS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with certification and ATS Radiologic 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography (CT) 2 C RIS 44025 Computed Tomography (CT) Clinical Education I 3 C

  19. F]-Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography in Response

    E-Print Network [OSTI]

    Hemminki, Akseli

    , and [18 F]-FDG-uptake was quantitated with small animal PET/CT. Second, we describe a retrospective molecules. Here we investigated the prognostic utility of CT and [18 F]-fluor- odeoxyglucose (FDG) positron[18 F]-Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography in Response

  20. CT head-scan dosimetry in an anthropomorphic phantom and associated measurement of ACR accreditation-phantom imaging metrics under clinically representative scan conditions

    SciTech Connect (OSTI)

    Brunner, Claudia C.; Stern, Stanley H.; Chakrabarti, Kish [U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993 (United States)] [U.S. Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, Maryland 20993 (United States); Minniti, Ronaldo [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899 (United States)] [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899 (United States); Parry, Marie I. [Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, Maryland 20889 (United States)] [Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, Maryland 20889 (United States); Skopec, Marlene [National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892 (United States)] [National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892 (United States)

    2013-08-15T23:59:59.000Z

    Purpose: To measure radiation absorbed dose and its distribution in an anthropomorphic head phantom under clinically representative scan conditions in three widely used computed tomography (CT) scanners, and to relate those dose values to metrics such as high-contrast resolution, noise, and contrast-to-noise ratio (CNR) in the American College of Radiology CT accreditation phantom.Methods: By inserting optically stimulated luminescence dosimeters (OSLDs) in the head of an anthropomorphic phantom specially developed for CT dosimetry (University of Florida, Gainesville), we measured dose with three commonly used scanners (GE Discovery CT750 HD, Siemens Definition, Philips Brilliance 64) at two different clinical sites (Walter Reed National Military Medical Center, National Institutes of Health). The scanners were set to operate with the same data-acquisition and image-reconstruction protocols as used clinically for typical head scans, respective of the practices of each facility for each scanner. We also analyzed images of the ACR CT accreditation phantom with the corresponding protocols. While the Siemens Definition and the Philips Brilliance protocols utilized only conventional, filtered back-projection (FBP) image-reconstruction methods, the GE Discovery also employed its particular version of an adaptive statistical iterative reconstruction (ASIR) algorithm that can be blended in desired proportions with the FBP algorithm. We did an objective image-metrics analysis evaluating the modulation transfer function (MTF), noise power spectrum (NPS), and CNR for images reconstructed with FBP. For images reconstructed with ASIR, we only analyzed the CNR, since MTF and NPS results are expected to depend on the object for iterative reconstruction algorithms.Results: The OSLD measurements showed that the Siemens Definition and the Philips Brilliance scanners (located at two different clinical facilities) yield average absorbed doses in tissue of 42.6 and 43.1 mGy, respectively. The GE Discovery delivers about the same amount of dose (43.7 mGy) when run under similar operating and image-reconstruction conditions, i.e., without tube current modulation and ASIR. The image-metrics analysis likewise showed that the MTF, NPS, and CNR associated with the reconstructed images are mutually comparable when the three scanners are run with similar settings, and differences can be attributed to different edge-enhancement properties of the applied reconstruction filters. Moreover, when the GE scanner was operated with the facility's scanner settings for routine head exams, which apply 50% ASIR and use only approximately half of the 100%-FBP dose, the CNR of the images showed no significant change. Even though the CNR alone is not sufficient to characterize the image quality and justify any dose reduction claims, it can be useful as a constancy test metric.Conclusions: This work presents a straightforward method to connect direct measurements of CT dose with objective image metrics such as high-contrast resolution, noise, and CNR. It demonstrates that OSLD measurements in an anthropomorphic head phantom allow a realistic and locally precise estimation of magnitude and spatial distribution of dose in tissue delivered during a typical CT head scan. Additional objective analysis of the images of the ACR accreditation phantom can be used to relate the measured doses to high contrast resolution, noise, and CNR.

  1. CT Measurements of Two-Phase Flow in Fractured Porous Media

    SciTech Connect (OSTI)

    Brigham, William E.; Castanier Louis M.; Hughes, Richard G.

    1999-08-09T23:59:59.000Z

    This report describes the design, construction, and preliminary results of an experiment that studies imbibition displacement in two fracture blocks. Multiphase (oil/water) displacements will be conducted at the same rate on three core configurations. The configurations are a compact core, a two-block system with a 1 mm spacer between the blocks, and a two-block system with no spacer. The blocks are sealed in epoxy so that saturation measurements can be made throughout the displacement experiments using a Computed Tomography (CT) scanner. Preliminary results are presented from a water/air experiment. These results suggest that it is incorrect to assume negligible capillary continuity between matrix blocks as is often done.

  2. Improving Soft-Tissue Contrast in Four-Dimensional Computed Tomography Images of Liver Cancer Patients Using a Deformable Image Registration Method

    SciTech Connect (OSTI)

    Wang He [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Krishnan, Sunil [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Wang Xiaochun; Beddar, A. Sam; Briere, Tina M. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Crane, Christopher H. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Mohan, Radhe [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Dong Lei [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)], E-mail: ldong@mdanderson.org

    2008-09-01T23:59:59.000Z

    Purpose: To investigate a deformable image registration method to improve soft-tissue contrast in four-dimensional (4D) computed tomography (CT) images of the liver. Methods and Materials: Ten patients with hepatocellular carcinoma underwent 4D CT scan for radiotherapy treatment planning on a positron emission tomography/CT scanner. Four-dimensional CT images were binned into 10 equispaced phases. The exhale phase served as the reference phase, and images from the other nine phases were coregistered to the reference phase image using an intensity-based, automatic deformable image registration method. Then the coregistered images were combined to create a single, high-quality reconstructed CT image at exhale phase as the new reference for target delineation. The extent of image quality enhancement was quantified relative to the original CT by calculating the signal-to-noise ratio and the contrast-to-noise ratio. Results: The soft tissue image contrast was noticeably better after deformable image registration than in the original scans. Signal-to-noise ratios inside the liver region of interest increased for all patients by a factor of 3.0 (range, 2.3-3.7). The improvement in image quality was not linearly proportionate to the number of images averaged. Using only 6 phases can achieve at least 85% of the contrast enhancement that can be achieved using all 10 phases. We also found that contrast enhancement was inversely proportional to the original image quality (p = 0.006), and the contrast enhancement is attained with little loss of spatial resolution. Conclusions: This deformable image registration method is feasible to improve soft-tissue image quality in 4D CT images.

  3. Thoracic CT-PET Registration Using a 3D Breathing Model

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Thoracic CT-PET Registration Using a 3D Breathing Model Antonio Moreno1 , Sylvie Chambon1 , Anand P Orlando, USA Abstract. In the context of thoracic CT-PET volume registration, we present a novel method applications. We consider Computed Tomography (CT) and Positron Emission Tomography (PET) in thoracic regions

  4. Improvements to Existing Jefferson Lab Wire Scanners

    SciTech Connect (OSTI)

    McCaughan, Michael D. [JLAB; Tiefenback, Michael G. [JLAB; Turner, Dennis L. [JLAB

    2013-06-01T23:59:59.000Z

    This poster will detail the augmentation of selected existing CEBAF wire scanners with commercially available hardware, PMTs, and self created software in order to improve the scanners both in function and utility.

  5. Sclerosing angiomatoid nodular transformation of the spleen: CT, MR, PET, and 99mTc-sulfur colloid SPECT CT findings with gross and histopathological correlation

    E-Print Network [OSTI]

    Thacker, Curtis; Korn, Ronald; Millstine, John; Harvin, Howard; Lier Ribbink, Jeffrey A.; Gotway, Michael B.

    2010-01-01T23:59:59.000Z

    computed tomography-CT (FDG-PET CT) survey which revealed aof the spleen: CT, MR, PET, and 99m Tc-sulfur colloid SPECTT2, no enhancement US CT MR FDG-PET N/A › uptake N/A N/A N/A

  6. Experimental measurement of human head motion for high-resolution computed tomography

    E-Print Network [OSTI]

    Wang, Ge

    Experimental measurement of human head motion for high-resolution computed tomography system design experimentally measured for high-resolution computed tomography CT design using a Canon digital camera. Our goal-Optical Instrumentation Engineers. DOI: 10.1117/1.3454379 Subject terms: head motion; computed tomography CT ; image

  7. Reconstruction for proton computed tomography by tracing proton trajectories: A Monte Carlo study

    E-Print Network [OSTI]

    Reconstruction for proton computed tomography by tracing proton trajectories: A Monte Carlo study 11 January 2006; published 22 February 2006 Proton computed tomography pCT has been explored computed tomography pCT has several potential ad- vantages in medical applications. Its favorable dose

  8. Efficacy of Lower-Body Shielding in Computed Tomography Fluoroscopy-Guided Interventions

    SciTech Connect (OSTI)

    Mahnken, Andreas H., E-mail: mahnken@rad.rwth-aachen.de [RWTH Aachen, Department of Diagnostic and Interventional Radiology (Germany); Sedlmair, Martin [Siemens, Healthcare Sector (Germany); Ritter, Christine [University of Copenhagen, Niels Bohr Institute (Denmark); Banckwitz, Rosemarie; Flohr, Thomas [Siemens, Healthcare Sector (Germany)

    2012-12-15T23:59:59.000Z

    Purpose: Computed tomography (CT) fluoroscopy-guided interventions pose relevant radiation exposure to the interventionalist. The goal of this study was to analyze the efficacy of lower-body shielding as a simple structural method for decreasing radiation dose to the interventionalist without limiting access to the patient. Material and Methods: All examinations were performed with a 128-slice dual source CT scanner (12 Multiplication-Sign 1.2-mm collimation; 120 kV; and 20, 40, 60, and 80 mAs) and an Alderson-Rando phantom. Scatter radiation was measured with an ionization chamber and a digital dosimeter at standardized positions and heights with and without a lower-body lead shield (0.5-mm lead equivalent; Kenex, Harlow, UK). Dose decreases were computed for the different points of measurement. Results: On average, lower-body shielding decreased scatter radiation by 38.2% within a 150-cm radius around the shielding. This decrease is most significant close to the gantry opening and at low heights of 50 and 100 cm above the floor with a maximum decrease of scatter radiation of 95.9% close to the scanner's isocentre. With increasing distance to the gantry opening, the effect decreased. There is almost no dose decrease effect at {>=}150 above the floor. Scatter radiation and its decrease were linearly correlated with the tube current-time product (r{sup 2} = 0.99), whereas percent scatter radiation decrease was independent of the tube current-time product. Conclusion: Lower-body shielding is an effective way to decrease radiation exposure to the interventionalist and should routinely be used in CT fluoroscopy-guided interventions.

  9. Performance of Hull-Detection Algorithms For Proton Computed Tomography Reconstruction

    E-Print Network [OSTI]

    Schultze, Blake; Censor, Yair; Schulte, Reinhard; Schubert, Keith Evan

    2014-01-01T23:59:59.000Z

    Proton computed tomography (pCT) is a novel imaging modality developed for patients receiving proton radiation therapy. The purpose of this work was to investigate hull-detection algorithms used for preconditioning of the large and sparse linear system of equations that needs to be solved for pCT image reconstruction. The hull-detection algorithms investigated here included silhouette/space carving (SC), modified silhouette/space carving (MSC), and space modeling (SM). Each was compared to the cone-beam version of filtered backprojection (FBP) used for hull-detection. Data for testing these algorithms included simulated data sets of a digital head phantom and an experimental data set of a pediatric head phantom obtained with a pCT scanner prototype at Loma Linda University Medical Center. SC was the fastest algorithm, exceeding the speed of FBP by more than 100 times. FBP was most sensitive to the presence of noise. Ongoing work will focus on optimizing threshold parameters in order to define a fast and effic...

  10. Shape Filtering for False Positive Reduction at Computed Tomography Colonography

    E-Print Network [OSTI]

    Whelan, Paul F.

    Shape Filtering for False Positive Reduction at Computed Tomography Colonography Abhilash A) in the automatic detection of colorectal polyps at Computer Aided Detection in Computed Tomography Colonography of the images of the colon obtained using a Computed Tomography (CT) examination of the abdominal region

  11. Edge-Localized Iterative Reconstruction for Computed Tomography

    E-Print Network [OSTI]

    1 Edge-Localized Iterative Reconstruction for Computed Tomography Zhou Yu Student Member, IEEE) can greatly improve the quality of computed tomography (CT) images. In particular, MBR can recover at significantly reduced computational cost. Index Terms--Computed tomography, model based reconstruc- tion

  12. Edge-Localized Iterative Reconstruction for Computed Tomography

    E-Print Network [OSTI]

    Edge-Localized Iterative Reconstruction for Computed Tomography Zhou Yu Student Member, IEEE, Jean the quality of computed tomography (CT) images. In particular, MBR can recover fine details and small features reduced computational cost. Index Terms--Computed tomography, model based reconstruc- tion, coordinate

  13. Novel Application of X-ray Computed Tomography: Determination of Gas/Liquid Contact Area and Liquid Holdup in Structured Packing

    E-Print Network [OSTI]

    Eldridge, R. Bruce

    Novel Application of X-ray Computed Tomography: Determination of Gas/Liquid Contact Area and Liquid Company, 1 Neumann Way-M/D Q8, Cincinnati, Ohio 45215 X-ray computed tomography (CT) was utilized Principles of X-ray Computed Tomography. X-ray computed tomography (CT) is used to noninvasively

  14. Evaluation of the potential utility of flat panel CT for quantifying relative contrast enhancement

    SciTech Connect (OSTI)

    Jones, A. Kyle; Mahvash, Armeen [Department of Imaging Physics, Division of Diagnostic Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Interventional Radiology, Division of Diagnostic Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2012-07-15T23:59:59.000Z

    Purpose: Certain directed oncologic therapies seek to take advantage of the fact that tumors are typically more susceptible to directed therapeutic agents than normal tissue owing to their extensive networks of poorly formed, leaky vasculature. If differences between the vascularity of normal and tumor tissues could be quantified, patients could be selected for or excluded from directed treatments on the basis of this difference. However, angiographic imaging techniques such as digital subtraction angiography (DSA) yield two-dimensional data that may be inadequate for this task. As a first step, the authors evaluated the feasibility of using a commercial implementation of flat panel computed tomography (FPCT) to quantify differences in enhancement of a simulated tumor compared with normal tissue based on differences in CT number measured in precontrast and postcontrast scans. Methods: To evaluate the FPCT scanner studied, the authors scanned several phantoms containing simulated normal and tumor tissues. In the first experiment, the authors used an anthropomorphic phantom containing inclusions representing normal, tumor, and bone tissue to evaluate the constancy of CT numbers in scans repeated at clinically relevant intervals of 1 and 3 min. The authors then scanned gelatin phantoms containing dilutions of iodinated contrast to evaluate the accuracy of relative contrast enhancement measurements for a clinical FPCT system. Data were analyzed using widely available software. Results: CT numbers measured in identical locations were constant over both scan intervals evaluated. Measured relative contrast enhancement values were accurate compared with known relative contrast enhancement values. Care must be taken to avoid artifacts in reconstructed images when placing regions of interest. Conclusions: Despite its limitations, FPCT in the interventional laboratory can be used to quantify relative contrast enhancement in phantoms. This is accomplished by measuring CT number in simulated tumor and normal tissue on precontrast and postcontrast scans. This information opens the door for refinement of technique in an effort to use such a technique to plan directed therapies.

  15. Positron emission tomography wrist detector

    DOE Patents [OSTI]

    Schlyer, David J. (Bellport, NY); O'Connor, Paul (Bellport, NY); Woody, Craig (Setauket, NY); Junnarkar, Sachin Shrirang (Sound Beach, NY); Radeka, Veljko (Bellport, NY); Vaska, Paul (Sound Beach, NY); Pratte, Jean-Francois (Stony Brook, NY)

    2006-08-15T23:59:59.000Z

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal representing a time-of-occurrence of an annihilation event, generating an address signal representing a channel detecting the annihilation event, and generating a channel signal including the time and address signals. The method also includes generating a composite signal including the channel signal and another similarly generated channel signal concerning another annihilation event. An apparatus that serially transfers annihilation information includes a time signal generator, address signal generator, channel signal generator, and composite signal generator. The time signal is asynchronous and the address signal is synchronous to a clock signal. A PET scanner includes a scintillation array, detection array, front-end array, and a serial encoder. The serial encoders include the time signal generator, address signal generator, channel signal generator, and composite signal generator.

  16. Combined PET/MRI scanner

    DOE Patents [OSTI]

    Schlyer, David (Bellport, NY); Woody, Craig L. (Setauket, NY); Rooney, William (Miller Place, NY); Vaska, Paul (Sound Beach, NY); Stoll, Sean (Wading River, NY); Pratte, Jean-Francois (Stony Brook, NY); O'Connor, Paul (Bellport, NY)

    2007-10-23T23:59:59.000Z

    A combined PET/MRI scanner generally includes a magnet for producing a magnetic field suitable for magnetic resonance imaging, a radiofrequency (RF) coil disposed within the magnetic field produced by the magnet and a ring tomograph disposed within the magnetic field produced by the magnet. The ring tomograph includes a scintillator layer for outputting at least one photon in response to an annihilation event, a detection array coupled to the scintillator layer for detecting the at least one photon outputted by the scintillator layer and for outputting a detection signal in response to the detected photon and a front-end electronic array coupled to the detection array for receiving the detection signal, wherein the front-end array has a preamplifier and a shaper network for conditioning the detection signal.

  17. Development and application of a 4-dimensional Computed Tomography simulator

    E-Print Network [OSTI]

    Chu, Alan

    2007-01-01T23:59:59.000Z

    This thesis presents the development and application of a 4-Dimensional Computed Tomography (4D CT) simulation program. The simulation is used to understand and quantify the sources of image artifacts that arise from ...

  18. Using X-ray computed tomography in hydrology: systems, resolutions, and limitations

    E-Print Network [OSTI]

    Wildenschild, Dorthe

    Using X-ray computed tomography in hydrology: systems, resolutions, and limitations D to characterize phase distribution and pore geometry in porous media using non-destructive X-ray computed tomography (CT). We present qualitative and quantitative CT results for partially saturated media, obtained

  19. Automatic 3D Registration of Lung Surfaces in Computed Tomography Scans

    E-Print Network [OSTI]

    Automatic 3D Registration of Lung Surfaces in Computed Tomography Scans Margrit Betke, PhD 1 lung surfaces of 11 pairs of chest CT scans and report promising registration performance. 1 1 Introduction Chest computed tomography (CT) has become a well­established means of diag­ nosing primary lung

  20. Augmenting CT Cardiac Roadmaps with Segmented Streaming Qi Duan a,b

    E-Print Network [OSTI]

    Augmenting CT Cardiac Roadmaps with Segmented Streaming Ultrasound Qi Duan a,b , Guy Shechter Static X-ray computed tomography (CT) volumes are often used as anatomic roadmaps during catheter. Augmenting these static CT roadmaps with segmented myocardial borders extracted from live ultrasound (US

  1. Soft Classification with Gaussian Mixture Model for Clinical Dual-Energy CT Reconstructions

    E-Print Network [OSTI]

    1 Soft Classification with Gaussian Mixture Model for Clinical Dual-Energy CT Reconstructions, and Ken D. Sauer, Member, IEEE Abstract--We study the distribution of the clinical dual-energy CT (DECT material separation. Index Terms--Computed tomography (CT), dual energy, sta- tistical method, Gaussian

  2. Lung Nodule Detection in Screening Computed Tomography

    E-Print Network [OSTI]

    Gori, I; Cerello, P; Cheran, S C; De Nunzio, G; Fantacci, M E; Kasae, P; Masala, G L; Pérez-Martínez, A; Retico, A

    2007-01-01T23:59:59.000Z

    A computer-aided detection (CAD) system for the identification of pulmonary nodules in low-dose multi-detector helical Computed Tomography (CT) images with 1.25 mm slice thickness is presented. The basic modules of our lung-CAD system, a dot-enhancement filter for nodule candidate selection and a neural classifier for false-positive finding reduction, are described. The results obtained on the collected database of lung CT scans are discussed.

  3. Bioengineering 280ABioengineering 280A Principles ofPrinciples of

    E-Print Network [OSTI]

    Liu, Thomas T.

    for tomography, now called the Radon transform. 1972 Godfrey Hounsfield develops first CT system. Unaware://www.sprawls.org/resources/CTIMG/classroom.htm Thomas Liu, BE280A Fall 04, UCSD 9/23/04 Computed TomographyComputed Tomography Image from Siemens Siretom CT scanner, circa 1975. 128x128 matrix. Modern CT image acquired with a Siemens scanner. 512x512

  4. Nuclear Instruments and Methods in Physics Research A 571 (2007) 102105 Preliminary studies of a simultaneous PET/MRI scanner based on the

    E-Print Network [OSTI]

    of a simultaneous PET/MRI scanner based on the RatCAP small animal tomograph C. Woodya,Ã?, D. Schlyera , P. Vaskaa data using positron emission tomography (PET). The approach is based on the technology used for the RatCAP conscious small animal PET tomograph which utilizes block detectors consisting of pixelated arrays of LSO

  5. Bachelor of Science, Radiologic Sciences, Computed Tomography Emphasis, 2012-2013 Name ID# Date

    E-Print Network [OSTI]

    Barrash, Warren

    Bachelor of Science, Radiologic Sciences, Computed Tomography Emphasis, 2012-2013 Name ID# Date Imaging 3 RADSCI 431 CT Radiation Dose and Risk Analysis 1 RADSCI 450 Principles of Computed Tomography 3 RADSCI 450L Principles of Computed Tomography Lab 1 RADSCI 451 Procedural Case Studies in Computed

  6. The effects of gantry tilt on breast dose and image noise in cardiac CT

    SciTech Connect (OSTI)

    Hoppe, Michael E.; Gandhi, Diksha; Schmidt, Taly Gilat [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States)] [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States); Stevens, Grant M. [GE Healthcare, Waukesha, Wisconsin 53188 (United States)] [GE Healthcare, Waukesha, Wisconsin 53188 (United States); Foley, W. Dennis [Department of Radiology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee, Wisconsin 53226 (United States)] [Department of Radiology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee, Wisconsin 53226 (United States)

    2013-12-15T23:59:59.000Z

    Purpose: This study investigated the effects of tilted-gantry acquisition on image noise and glandular breast dose in females during cardiac computed tomography (CT) scans. Reducing the dose to glandular breast tissue is important due to its high radiosensitivity and limited diagnostic significance in cardiac CT scans.Methods: Tilted-gantry acquisition was investigated through computer simulations and experimental measurements. Upon IRB approval, eight voxelized phantoms were constructed from previously acquired cardiac CT datasets. Monte Carlo simulations quantified the dose deposited in glandular breast tissue over a range of tilt angles. The effects of tilted-gantry acquisition on breast dose were measured on a clinical CT scanner (CT750HD, GE Healthcare) using an anthropomorphic phantom with MOSFET dosimeters in the breast regions. In both simulations and experiments, scans were performed at gantry tilt angles of 0°–30°, in 5° increments. The percent change in breast dose was calculated relative to the nontilted scan for all tilt angles. The percent change in noise standard deviation due to gantry tilt was calculated in all reconstructed simulated and experimental images.Results: Tilting the gantry reduced the breast dose in all simulated and experimental phantoms, with generally greater dose reduction at increased gantry tilts. For example, at 30° gantry tilt, the dosimeters located in the superior, middle, and inferior breast regions measured dose reductions of 74%, 61%, and 9%, respectively. The simulations estimated 0%–30% total breast dose reduction across the eight phantoms and range of tilt angles. However, tilted-gantry acquisition also increased the noise standard deviation in the simulated phantoms by 2%–50% due to increased pathlength through the iodine-filled heart. The experimental phantom, which did not contain iodine in the blood, demonstrated decreased breast dose and decreased noise at all gantry tilt angles.Conclusions: Tilting the gantry reduced the dose to the breast, while also increasing noise standard deviation. Overall, the noise increase outweighed the dose reduction for the eight voxelized phantoms, suggesting that tilted gantry acquisition may not be beneficial for reducing breast dose while maintaining image quality.

  7. Effect on Lesion Detectability of Proximity to Anatomical Boundaries in Emission Tomography

    E-Print Network [OSTI]

    into the ET recon- struction. The increasing availability of PET-CT and SPECT- CT has engendered renewed of (idealized) lesion boundaries did indeed lead to enhanced detectability. To complicate matters, a PET-CT. Kulkarni, P. Khurd, I. Hsiao and G. Gindi Abstract-- In emission tomography (ET) comprising PET and SPECT

  8. LANSCE-R WIRE-SCANNER SYSTEM

    SciTech Connect (OSTI)

    Gruchalla, Michael E. [Los Alamos National Laboratory

    2011-01-01T23:59:59.000Z

    The National Instruments cRIO platform is used for the new LANSCE-R wire-scanner systems. All wire-scanner electronics are integrated into a single BiRa BiRIO 4U cRIO chassis specifically designed for the cRIO crate and all interface electronics. The BiRIO chassis, actuator and LabVIEW VIs provide a complete wire-scanner system integrated with EPICS. The new wire-scanner chassis includes an 8-slot cRIO crate with Virtex-5 LX 110 FPGA and Power-PC real-time controller, the LANL-developed cRIO 2-axis wire-sensor analog interface module (AFE), NI9222 cRIO 4-channel 16-bit digitizer, cRIO resolver demodulator, cRIO event receiver, front-panel touch panel display, motor driver, and all necessary software, interface wiring, connectors and ancillary components. This wirescanner system provides a complete, turn-key, 2-axis wire-scanner system including 2-channel low-noise sensewire interface with variable DC wire bias and wireintegrity monitor, 16-bit signal digitizers, actuator motor drive and control, actuator position sensing, limit-switch interfaces, event receiver, LabVIEW and EPICS interface, and both remote operation and full stand-alone operation using the touch panel.

  9. Laser Wire Scanner Compton Scattering Techniques for the Measurement of the Transverse Beam Size of Particle Beams at Future Linear Colliders

    E-Print Network [OSTI]

    Agapov, I; Blair, G A; Bosser, J; Braun, H H; Bravin, E; Boorman, G; Boogert, S T; Carter, J; D'amico, E; Delerue, N; Howell, D F; Doebert, S; Driouichi, C; Frisch, J; Hutchins, K Honkavaaram S; Kamps, T; Lefevre, T; Lewin, H; Paris, T; Poirier, F; Price, M T; Maccaferi, R; Malton, S; Penn, G; Ross, I N; Ross, M; Schlarb, H; Schmueser, P; Schreiber, S; Sertore, D; Walker, N; Wendt, M; Wittenburg, K

    2014-01-01T23:59:59.000Z

    This archive summarizes a working paper and conference proceedings related to laser wire scanner development for the Future Linear Collider (FLC) in the years 2001 to 2006. In particular the design, setup and data taking for the laser wire experiments at PETRA II and CT2 are described. The material is focused on the activities undertaken by Royal Holloway University of London (RHUL).

  10. 48 51(2) avril/April 2005 Canadian Medical Physics Newsletter / Le bulletin canadien physique mdical 30 Years Ago: First PET Scanner in Canada

    E-Print Network [OSTI]

    Thompson, Chris

    . To many or you reading this today, PET, and better still PET/CT, is something that your department "has médical 30 Years Ago: First PET Scanner in Canada Submitted by Chris Thompson Montreal Neurological (PET) in Canada. Thirty years ago, "PET" was a domestic animal, not a medical imaging technique

  11. Impact of tumor size and tracer uptake heterogeneity in F-FDG PET and CT NonSmall Cell Lung Cancer

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    heterogeneity on various PET uptake delineation approaches. Methods: 25 NSCLC cancer patients with 18F-FDG PET/CT increasingly used for staging Non-small Cell Lung Cancer (NSCLC) (1). In addition, the use of 18 F-FDG PET/CT F-FDG), associated with Computed Tomography (CT) since the development of PET/CT devices, has been

  12. LANSCE Wire Scanner System Prototype: Switchyard Test

    SciTech Connect (OSTI)

    Sedillo, James D [Los Alamos National Laboratory

    2012-04-11T23:59:59.000Z

    On November 19, 2011, the beam diagnostics team of Los Alamos National Laboratory's LANSCE accelerator facility conducted a test of a prototype wire scanner system for future deployment within the accelerator's switchyard area. The primary focus of this test was to demonstrate the wire scanner control system's ability to extend its functionality beyond acquiring lower energy linac beam profile measurements to acquiring data in the switchyard. This study summarizes the features and performance characteristics of the electronic and mechanical implementation of this system with details focusing on the test results.

  13. Addressing the risks of diagnostic radiology : what should be done about the increasing use of computed tomography in the United States

    E-Print Network [OSTI]

    Eastwick, Gary (Gary A.)

    2010-01-01T23:59:59.000Z

    Computed tomography (CT) is a prominent procedure in the US with larger radiation doses than traditional radiology. CT is a powerful tool in the diagnosis of a wide variety of conditions and its use has grown quickly because ...

  14. MagViz Bottled Liquid Scanner at Albuquerque International Sunport

    ScienceCinema (OSTI)

    Surko, Stephen; Dennis, Steve; Espy, Michelle

    2014-08-12T23:59:59.000Z

    The next-generation bottled liquid scanner, MagViz BLS, is demonstrated at the Albuquerque International Sunport, New Mexico

  15. Calibration and equivalency analysis of image plate scanners

    SciTech Connect (OSTI)

    Williams, G. Jackson, E-mail: williams270@llnl.gov; Maddox, Brian R.; Chen, Hui [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Kojima, Sadaoki [Institute of Laser Engineering, Osaka University, Yamada-oka, 2-6, Suita, Osaka 565-0871 (Japan); Millecchia, Matthew [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

    2014-11-15T23:59:59.000Z

    A universal procedure was developed to calibrate image plate scanners using radioisotope sources. Techniques to calibrate scanners and sources, as well as cross-calibrate scanner models, are described to convert image plate dosage into physical units. This allows for the direct comparison of quantitative data between any facility and scanner. An empirical relation was also derived to establish sensitivity response settings for arbitrary gain settings. In practice, these methods may be extended to any image plate scanning system.

  16. Miniature 'Wearable' PET Scanner Ready for Use

    ScienceCinema (OSTI)

    Paul Vaska

    2013-07-22T23:59:59.000Z

    Scientists from BNL, Stony Brook University, and collaborators have demonstrated the efficacy of a "wearable," portable PET scanner they've developed for rats. The device will give neuroscientists a new tool for simultaneously studying brain function and behavior in fully awake, moving animals.

  17. Current segmented gamma-ray scanner technology

    SciTech Connect (OSTI)

    Bjork, C.W.

    1987-01-01T23:59:59.000Z

    A new generation of segmented gamma-ray scanners has been developed at Los Alamos for scrap and waste measurements at the Savannah River Plant and the Los Alamos Plutonium Facility. The new designs are highly automated and exhibit special features such as good segmentation and thorough shielding to improve performance.

  18. Conventional wire scanners for TESLA K. Wittenburg

    E-Print Network [OSTI]

    in the undulator section. The heat load of the wires is calculated in the following for the TESLA parameters to the high heat load. At some locations in TESLA both beam diameters are larger than a few microns. The heat load defines the wire scanner parameters, mainly the scanning speed, and other limitations

  19. Wire scanner software and firmware issues

    SciTech Connect (OSTI)

    Gilpatrick, John Doug [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    The Los Alamos Neutron Science Center facility presently has 110 slow wire scanning profile measurement instruments located along its various beam lines. These wire scanners were developed and have been operating for at least 30 years. While the wire scanners solved many problems to operate and have served the facility well they have increasingly suffered from several problems or limitations, such as maintenance and reliability problems, antiquated components, slow data acquisition, and etc. In order to refurbish these devices, these wire scanners will be replaced with newer versions. The replacement will consist of a completely new beam line actuator, new cables, new electronics and brand new software and firmware. This note describes the functions and modes of operation that LabVIEW VI software on the real time controller and FPGA LabVIEW firmware will be required. It will be especially interesting to understand the overall architecture of these LabVIEW VIs. While this note will endeavor to describe all of the requirements and issues for the wire scanners, undoubtedly, there will be missing details that will be added as time progresses.

  20. Statistical CT noise reduction with multiscale decomposition and penalized weighted least squares in the projection domain

    SciTech Connect (OSTI)

    Tang Shaojie; Tang Xiangyang [Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Dr., C-5018, Atlanta, Georgia 30322 (United States); School of Automation, Xi'an University of Posts and Telecommunications, Xi'an, Shaanxi 710121 (China); Imaging and Medical Physics, Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1701 Uppergate Dr., C-5018, Atlanta, Georgia 30322 (United States)

    2012-09-15T23:59:59.000Z

    Purposes: The suppression of noise in x-ray computed tomography (CT) imaging is of clinical relevance for diagnostic image quality and the potential for radiation dose saving. Toward this purpose, statistical noise reduction methods in either the image or projection domain have been proposed, which employ a multiscale decomposition to enhance the performance of noise suppression while maintaining image sharpness. Recognizing the advantages of noise suppression in the projection domain, the authors propose a projection domain multiscale penalized weighted least squares (PWLS) method, in which the angular sampling rate is explicitly taken into consideration to account for the possible variation of interview sampling rate in advanced clinical or preclinical applications. Methods: The projection domain multiscale PWLS method is derived by converting an isotropic diffusion partial differential equation in the image domain into the projection domain, wherein a multiscale decomposition is carried out. With adoption of the Markov random field or soft thresholding objective function, the projection domain multiscale PWLS method deals with noise at each scale. To compensate for the degradation in image sharpness caused by the projection domain multiscale PWLS method, an edge enhancement is carried out following the noise reduction. The performance of the proposed method is experimentally evaluated and verified using the projection data simulated by computer and acquired by a CT scanner. Results: The preliminary results show that the proposed projection domain multiscale PWLS method outperforms the projection domain single-scale PWLS method and the image domain multiscale anisotropic diffusion method in noise reduction. In addition, the proposed method can preserve image sharpness very well while the occurrence of 'salt-and-pepper' noise and mosaic artifacts can be avoided. Conclusions: Since the interview sampling rate is taken into account in the projection domain multiscale decomposition, the proposed method is anticipated to be useful in advanced clinical and preclinical applications where the interview sampling rate varies.

  1. Pseudolocal tomography

    DOE Patents [OSTI]

    Katsevich, Alexander J. (Los Alamos, NM); Ramm, Alexander G. (Manhattan, KS)

    1996-01-01T23:59:59.000Z

    Local tomographic data is used to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. The relative attenuation data is input to a pseudo-local tomography function, where the difference between the internal density and the pseudo-local tomography function is computed across the discontinuity. The pseudo-local tomography function outputs the location of the discontinuity and the difference in density between the first density and the second density.

  2. Pseudolocal tomography

    DOE Patents [OSTI]

    Katsevich, A.J.; Ramm, A.G.

    1996-07-23T23:59:59.000Z

    Local tomographic data is used to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. The relative attenuation data is input to a pseudo-local tomography function, where the difference between the internal density and the pseudo-local tomography function is computed across the discontinuity. The pseudo-local tomography function outputs the location of the discontinuity and the difference in density between the first density and the second density. 7 figs.

  3. Scanning using the Axon GenePix scanner Time on the scanner is scheduled for both scanning and data

    E-Print Network [OSTI]

    Grünwald, Niklaus J.

    1 5/15/07 Scanning using the Axon GenePix scanner Time on the scanner is scheduled for both scanning and data extraction tasks at http://calendar.oregonstate.edu/cgrb-genepix/. To reserve time scanning. Turn on the scanner using the toggle switch (low center on the back of the instrument). Turn

  4. Low-Dose Spiral CT Scans for Early Lung Cancer Detection

    Broader source: Energy.gov [DOE]

    Low-dose spiral computed tomography (CT) scanning is a noninvasive medical imaging test that has been used for the early detection of lung cancer for over 16 years (Sone et al. 1998; Henschke et.al. 1999).

  5. Papers by Our Team Wang G, Vannier MW: Bolus-chasing angiography with adaptive real-time computed tomography. US

    E-Print Network [OSTI]

    Wang, Ge

    chasing computed tomography (CT) angiography. US patent publication 20060178836, Aug. 10, 2006 Ye Y, Wang:1-20, 2007 Cai Z, McCabe R, Wang G, Bai EW: Bolus chasing computed tomography angiography using local maximum, McCabe R, Wang G: An adaptive optimal control design for bolus chasing computed tomography

  6. Prospects for quantitative computed tomography imaging in the presence of foreign metal bodies using statistical image reconstruction

    E-Print Network [OSTI]

    O'Sullivan, Joseph A.

    Prospects for quantitative computed tomography imaging in the presence of foreign metal bodies September 2002 X-ray computed tomography CT images of patients bearing metal intracavitary applicators of Physicists in Medicine. DOI: 10.1118/1.1509443 Key words: x-ray transmission computed tomography, metal

  7. Doppler Tomography

    E-Print Network [OSTI]

    T. R. Marsh

    2000-11-01T23:59:59.000Z

    I review the method of Doppler tomography which translates binary-star line profiles taken at a series of orbital phases into a distribution of emission over the binary. I begin with a discussion of the basic principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the inversion. Following this I discuss the issue of noise in Doppler images and possible methods for coping with it. Then I move on to look at the results of Doppler Tomography applied to cataclysmic variable stars. Outstanding successes to date are the discovery of two-arm spiral shocks in cataclysmic variable accretion discs and the probing of the stream/magnetospheric interaction in magnetic cataclysmic variable stars. Doppler tomography has also told us much about the stream/disc interaction in non-magnetic systems and the irradiation of the secondary star in all systems. The latter indirectly reveals such effects as shadowing by the accretion disc or stream. I discuss all of these and finish with some musings on possible future directions for the method. At the end I include a tabulation of Doppler maps published in refereed journals.

  8. Bioengineering 280A Principles of

    E-Print Network [OSTI]

    Liu, Thomas T.

    the mathematical framework for tomography, now called the Radon transform. 1972 Godfrey Hounsfield develops first Tomography Image from Siemens Siretom CT scanner, circa 1975. 128x128 matrix. Modern CT image acquired with a Siemens scanner. 512x512 matrix. #12;7 Computed Tomography #12;8 #12;9 History of Ultrasound 1942 Dr

  9. Bioengineering 280A Principles of

    E-Print Network [OSTI]

    Liu, Thomas T.

    establishes the mathematical framework for tomography, now called the Radon transform. 1972 Godfrey://www.sprawls.org/resources/CTIMG/classroom.htm Computed Tomography Image from Siemens Siretom CT scanner, circa 1975. 128x128 matrix. Modern CT image acquired with a Siemens scanner. 512x512 matrix. #12;4 Computed Tomography #12;5 History of Ultrasound

  10. CT imaging of enhanced oil recovery experiments

    SciTech Connect (OSTI)

    Gall, B.L.

    1992-12-01T23:59:59.000Z

    X-ray computerized tomography (Cr) has been used to study fluid distributions during chemical enhanced oil recovery experiments. Four CT-monitored corefloods were conducted, and oil saturation distributions were calculated at various stages of the experiments. Results suggested that this technique could add significant information toward interpretation and evaluation of surfactant/polymer EOR recovery methods. CT-monitored tracer tests provided information about flow properties in the core samples. Nonuniform fluid advance could be observed, even in core that appeared uniform by visual inspection. Porosity distribution maps based on CT density calculations also showed the presence of different porosity layers that affected fluid movement through the cores. Several types of CT-monitored corefloods were conducted. Comparisons were made for CT-monitored corefloods using chemical systems that were highly successful in reducing residual oil saturations in laboratory experiments and less successful systems. Changes were made in surfactant formulation and in concentration of the mobility control polymer. Use of a poor mobility control agent failed to move oil that was not initially displaced by the injected surfactant solution; even when a good'' surfactant system was used. Use of a less favorable surfactant system with adequate mobility control could produce as much oil as the use of a good surfactant system with inadequate mobility control. The role of mobility control, therefore, becomes a critical parameter for successful application of chemical EOR. Continuation of efforts to use CT imaging in connection with chemical EOR evaluations is recommended.

  11. CT imaging of enhanced oil recovery experiments

    SciTech Connect (OSTI)

    Gall, B.L.

    1992-12-01T23:59:59.000Z

    X-ray computerized tomography (Cr) has been used to study fluid distributions during chemical enhanced oil recovery experiments. Four CT-monitored corefloods were conducted, and oil saturation distributions were calculated at various stages of the experiments. Results suggested that this technique could add significant information toward interpretation and evaluation of surfactant/polymer EOR recovery methods. CT-monitored tracer tests provided information about flow properties in the core samples. Nonuniform fluid advance could be observed, even in core that appeared uniform by visual inspection. Porosity distribution maps based on CT density calculations also showed the presence of different porosity layers that affected fluid movement through the cores. Several types of CT-monitored corefloods were conducted. Comparisons were made for CT-monitored corefloods using chemical systems that were highly successful in reducing residual oil saturations in laboratory experiments and less successful systems. Changes were made in surfactant formulation and in concentration of the mobility control polymer. Use of a poor mobility control agent failed to move oil that was not initially displaced by the injected surfactant solution; even when a ``good`` surfactant system was used. Use of a less favorable surfactant system with adequate mobility control could produce as much oil as the use of a good surfactant system with inadequate mobility control. The role of mobility control, therefore, becomes a critical parameter for successful application of chemical EOR. Continuation of efforts to use CT imaging in connection with chemical EOR evaluations is recommended.

  12. Multi-Material Decomposition Using Statistical Image Reconstruction in X-Ray CT

    E-Print Network [OSTI]

    Fessler, Jeffrey A.

    and Jeffrey A. Fessler Abstract--Dual-energy (DE) CT scans provide two sets of measurements at two different-mean-square (RMS) errors. Index Terms--Computed tomography, dual energy, multi- material decomposition, statistical image reconstruction I. INTRODUCTION Dual-energy (DE) CT reconstruction methods typically re- construct

  13. Hemorrhage Slices Detection in Brain CT Images Ruizhe Liu, Chew Lim Tan, Tze Yun Leong

    E-Print Network [OSTI]

    Tan, Chew Lim

    Hemorrhage Slices Detection in Brain CT Images Ruizhe Liu, Chew Lim Tan, Tze Yun Leong Department) scans are widely used in today's diagnosis of head traumas. It is effective to disclose the bleeding Tomography (CT) scans are widely used in today's diagnosis of head traumas. It is effective to disclose

  14. Automated segmentation of lungs with severe interstitial lung disease in CT

    E-Print Network [OSTI]

    Automated segmentation of lungs with severe interstitial lung disease in CT Jiahui Wang Department: Accurate segmentation of lungs with severe interstitial lung disease ILD in thoracic computed tomography CT developed in this study a texture analysis-based method for accurate segmentation of lungs with severe ILD

  15. Evaluation of Turbine Blades Using Computed Tomography

    E-Print Network [OSTI]

    C. Muralidhar; S. N. Lukose; M. P. Subramanian

    2006-01-01T23:59:59.000Z

    Turbine blades are high value castings having complex internal geometry. Computed Tomography has been employed on Turbine blades for finding out defects and internal details. The wall thickness, rib thickness and radius of curvature are measured from the CT slices. The discontinuities including blockages of cooling passages in the cast material can be detected. 3D visualization of the turbine blade provides in extracting its internal features including inaccessible areas nondestructively, which is not possible through conventional NDE methods. The salient features for evaluation of turbine blades using Tomography are brought out.

  16. Monte Carlo simulations of adult and pediatric computed tomography exams: Validation studies of organ doses with physical phantoms

    SciTech Connect (OSTI)

    Long, Daniel J.; Lee, Choonsik; Tien, Christopher; Fisher, Ryan; Hoerner, Matthew R.; Hintenlang, David; Bolch, Wesley E. [J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 (United States); National Cancer Institute, National Institute of Health, Bethesda, Maryland 20892-1502 (United States); J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 (United States); Department of Radiology, University of Florida, Gainesville, Florida 32610-0374 (United States); J Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611-6131 (United States)

    2013-01-15T23:59:59.000Z

    Purpose: To validate the accuracy of a Monte Carlo source model of the Siemens SOMATOM Sensation 16 CT scanner using organ doses measured in physical anthropomorphic phantoms. Methods: The x-ray output of the Siemens SOMATOM Sensation 16 multidetector CT scanner was simulated within the Monte Carlo radiation transport code, MCNPX version 2.6. The resulting source model was able to perform various simulated axial and helical computed tomographic (CT) scans of varying scan parameters, including beam energy, filtration, pitch, and beam collimation. Two custom-built anthropomorphic phantoms were used to take dose measurements on the CT scanner: an adult male and a 9-month-old. The adult male is a physical replica of University of Florida reference adult male hybrid computational phantom, while the 9-month-old is a replica of University of Florida Series B 9-month-old voxel computational phantom. Each phantom underwent a series of axial and helical CT scans, during which organ doses were measured using fiber-optic coupled plastic scintillator dosimeters developed at University of Florida. The physical setup was reproduced and simulated in MCNPX using the CT source model and the computational phantoms upon which the anthropomorphic phantoms were constructed. Average organ doses were then calculated based upon these MCNPX results. Results: For all CT scans, good agreement was seen between measured and simulated organ doses. For the adult male, the percent differences were within 16% for axial scans, and within 18% for helical scans. For the 9-month-old, the percent differences were all within 15% for both the axial and helical scans. These results are comparable to previously published validation studies using GE scanners and commercially available anthropomorphic phantoms. Conclusions: Overall results of this study show that the Monte Carlo source model can be used to accurately and reliably calculate organ doses for patients undergoing a variety of axial or helical CT examinations on the Siemens SOMATOM Sensation 16 scanner.

  17. Pulmonary fissure segmentation on CT Jingbin Wang a

    E-Print Network [OSTI]

    Betke, Margrit

    between the lobes in the lungs. Its segmentation is of clinical interest as it facilitates the assessment of lung disease on a lobar level. This paper describes a new approach for segmenting the major fissures in both lungs on thin-section computed tomography (CT). An image transformation called ``ridge map

  18. assisted laser scanner: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    pipeline Physics Websites Summary: measurements and finally its instantiation through 3D printing, are presented. Laser scanner acquisition, reconstruction and 3D printing lend...

  19. Reduction of Metal Artifacts in Computed Tomographies for the Planning and Simulation of Radiation Therapy

    E-Print Network [OSTI]

    Zerfowski, Detlef

    data histogram. Compared with continuous integral transform methods, iterative discrete reconstruction covering 180 . Acquisition of real patient data was performed using a Siemens Somatom Plus S CT scanner (Siemens Medical Engineering, Forchheim, Germany). For each slice, 1242 views covered a full rotation

  20. Estimation of the weighted CTDI{sub {infinity}} for multislice CT examinations

    SciTech Connect (OSTI)

    Li Xinhua; Zhang Da; Liu, Bob [Division of Diagnostic Imaging Physics, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)

    2012-02-15T23:59:59.000Z

    Purpose: The aim of this study was to examine the variations of CT dose index (CTDI) efficiencies, {epsilon}(CTDI{sub 100})=CTDI{sub 100}/CTDI{sub {infinity}}, with bowtie filters and CT scanner types. Methods: This was an extension of our previous study [Li, Zhang, and Liu, Phys. Med. Biol. 56, 5789-5803 (2011)]. A validated Monte Carlo program was used to calculate {epsilon}(CTDI{sub 100}) on a Siemens Somatom Definition scanner. The {epsilon}(CTDI{sub 100}) dependencies on tube voltages and beam widths were tested in previous studies. The influences of different bowtie filters and CT scanner types were examined in this work. The authors tested the variations of {epsilon}(CTDI{sub 100}) with bowtie filters on the Siemens Definition scanner. The authors also analyzed the published CTDI measurements of four independent studies on five scanners of four models from three manufacturers. Results: On the Siemens Definition scanner, the difference in {epsilon}(CTDI{sub W}) between using the head and body bowtie filters was 2.5% (maximum) in the CT scans of the 32-cm phantom, and 1.7% (maximum) in the CT scans of the 16-cm phantom. Compared with CTDI{sub W}, the weighted CTDI{sub {infinity}} increased by 30.5% (on average) in the 32-cm phantom, and by 20.0% (on average) in the 16-cm phantom. These results were approximately the same for 80-140 kV and 1-40 mm beam widths (4.2% maximum deviation). The differences in {epsilon}(CTDI{sub 100}) between the simulations and the direct measurements of four previous studies were 1.3%-5.0% at the center/periphery of the 16-cm/32-cm phantom (on average). Conclusions: Compared with CTDI{sub vol}, the equilibrium dose for large scan lengths is 30.5% higher in the 32-cm phantom, and is 20.0% higher in the 16-cm phantom. The relative increases are practically independent of tube voltages (80-140 kV), beam widths (up to 4 cm), and the CT scanners covered in this study.

  1. Transient foam flow in porous media with CAT Scanner

    SciTech Connect (OSTI)

    Liu, Dianbin; Brigham, W.E.

    1992-03-01T23:59:59.000Z

    Transient behavior is likely to dominate over most of the duration of a foam injection field project. Due to the lack of date, little is presently known about transient foam flow behavior. Foam flow does not follow established models such as the Buckley-Leverett theory, and no general predictive model has been derived. Therefore, both experimental data and a foam flow theory are needed. In this work, foam was injected at a constant mass rate into one-dimensional sandpacks of 1-in diameter and 24-in or 48-in length that had initially been saturate with distilled water. The system was placed in a cat Scanner. Data, obtained at room temperature and low pressure at various times, include both the pressure and saturation distributions. Pressure profiles showed that the pressure gradient is much greater behind the foam front than ahead of it. Moreover, the pressure gradients keep changing as the foam advances in the sandpack. This behavior differs from Buckley-Leverett theory. The CT scan results demonstrated gas channeling near the front, but eventually the foam block all these channels and sweeps the entire cross section after many pore volumes of injection. Three series of experiments were run: (1) surfactant adsorption measurements; (2) gas displacements of surfactant-laden solutions and (3) foam displacements. The first two series of experiments were made to provide the necessary parameters required to match the foam displacements. To this end, it was necessary to smooth the saturation history data, using a Langmuir-type formula. A theory was proposed based on the principles of the fractional flow curve construction method. This foam theory treats the foam as composed of infinitesimal slugs of gas of varying viscosities. The foam front has the lowest viscosity and foam at the injection end has the highest.

  2. PERTURBATION-BASED ERROR ANALYSIS OF ITERATIVE IMAGE RECONSTRUCTION ALGORITHM FOR X-RAY COMPUTED TOMOGRAPHY

    E-Print Network [OSTI]

    Fessler, Jeffrey A.

    -ray computed tomography. The effects of the quantization error in forward-projection, back computed tomography (CT) have been proposed to improve image quality and reduce dose [1]. These methodsPERTURBATION-BASED ERROR ANALYSIS OF ITERATIVE IMAGE RECONSTRUCTION ALGORITHM FOR X-RAY COMPUTED

  3. Penalized Weighted Least-Squares Approach for Low-Dose X-Ray Computed Tomography

    E-Print Network [OSTI]

    Penalized Weighted Least-Squares Approach for Low-Dose X- Ray Computed Tomography Jing Wang*1, noise-resolution tradeoff, ROC curve. 1. INTRODUCTION Low-dose X-ray computed tomography (CT) imaging Military Medical University, Xi'an, Shaanxi 710032, China ABSTRACT The noise of low-dose computed

  4. Poly(iohexol) Nanoparticles As Contrast Agents for in Vivo Xray Computed Tomography Imaging

    E-Print Network [OSTI]

    Cheng, Jianjun

    Poly(iohexol) Nanoparticles As Contrast Agents for in Vivo Xray Computed Tomography Imaging Qian for in vivo X-ray computed tomography (CT) imaging. Compared to conventional small-molecule contrast agents with improved diagnosis accuracy over a broad time frame without multiple administrations. X-ray computed

  5. Automatic 3D Registration of Lung Surfaces in Computed Tomography Scans

    E-Print Network [OSTI]

    Automatic 3D Registration of Lung Surfaces in Computed Tomography Scans Margrit Betke, PhD1 scheme until the registration performance is sufficient. We applied our method to register the 3D lung computed tomography (CT) has become a well-established means of diag- nosing primary lung cancer

  6. CT measurements of two-phase flow in fractured porous media

    SciTech Connect (OSTI)

    Hughes, R.G.; Brigham, W.E.; Castanier, L.M.

    1997-06-01T23:59:59.000Z

    The simulation of flow in naturally fractured reservoirs commonly divides the reservoir into two continua - the matrix system and the fracture system. Flow equations are written presuming that the primary flow between grid blocks occurs through the fracture system and that the primary fluid storage is in the matrix system. The dual porosity formulation of the equations assumes that there is no flow between matrix blocks while the dual permeability formulation allows fluid movement between matrix blocks. Since most of the fluid storage is contained in the matrix, recovery is dominated by the transfer of fluid from the matrix to the high conductivity fractures. The physical mechanisms influencing this transfer have been evaluated primarily through numerical studies. Relatively few experimental studies have investigated the transfer mechanisms. Early studies focused on the prediction of reservoir recoveries from the results of scaled experiments on single reservoir blocks. Recent experiments have investigated some of the mechanisms that are dominant in gravity drainage situations and in small block imbibition displacements. The mechanisms active in multiphase flow in fractured media need to be further illuminated, since some of the experimental results appear to be contradictory. This report describes the design, construction, and preliminary results of an experiment that studies imbibition displacement in two fracture blocks. Multiphase (oil/water) displacements will be conducted at the same rate on three core configurations. The configurations are a compact core, a two-block system with a 1 mm spacer between the blocks, and a two-block system with no spacer. The blocks are sealed in epoxy so that saturation measurements can be made throughout the displacement experiments using a Computed Tomography (CT) scanner.

  7. Enlarged longitudinal dose profiles in cone-beam CT and the need for modified dosimetry

    SciTech Connect (OSTI)

    Mori, Shinichiro; Endo, Masahiro; Nishizawa, Kanae; Tsunoo, Takanori; Aoyama, Takahiko; Fujiwara, Hideaki; Murase, Kenya [National Institute of Radiological Sciences, Chiba 263-8555 (Japan); School of Health Sciences, Nagoya University, Nagoya 461-8673 (Japan); School of Allied Health Sciences, Faculty of Medicine, Osaka University, Osaka 565-0871 (Japan)

    2005-04-01T23:59:59.000Z

    In order to examine phantom length necessary to assess radiation dose delivered to patients in cone-beam CT with an enlarged beamwidth, we measured dose profiles in cylindrical phantoms of sufficient length using a prototype 256-slice CT-scanner developed at our institute. Dose profiles parallel to the rotation axis were measured at the central and peripheral positions in PMMA (polymethylmethacrylate) phantoms of 160 or 320 mm diameter and 900 mm length. For practical application, we joined unit cylinders (150 mm long) together to provide phantoms of 900 mm length. Dose profiles were measured with a pin photodiode sensor having a sensitive region of approximately 2.8x2.8 mm{sup 2} and 2.7 mm thickness. Beamwidths of the scanner were varied from 20 to 138 mm. Dose profile integrals (DPI) were calculated using the measured dose profiles for various beamwidths and integration ranges. For the body phantom (320-mm-diam phantom), 76% of the DPI was represented for a 20 mm beamwidth and 60% was represented for a 138 mm beamwidth if dose profiles were integrated over a 100 mm range, while more than 90% of the DPI was represented for beamwidths between 20 and 138 mm if integration was carried out over a 300 mm range. The phantom length and integration range for dosimetry of cone-beam CT needed to be more than 300 mm to represent more than 90% of the DPI for the body phantom with the beamwidth of more than 20 mm. Although we reached this conclusion using the prototype 256-slice CT-scanner, it may be applied to other multislice CT-scanners as well.

  8. Manifold Learning for 4D CT Reconstruction of the Lung Manfred Georg*, Richard Souvenir, Andrew Hope, Robert Pless*

    E-Print Network [OSTI]

    Pless, Robert

    Manifold Learning for 4D CT Reconstruction of the Lung Manfred Georg*, Richard Souvenir, Andrew, Canada Andrew.Hope@rmp.uhn.on.ca Abstract Computed Tomography is used to create models of lung dynamics because it provides high contrast images of lung tissue. Creating 4D CT models which capture dynamics

  9. SU-E-I-48: The Behavior of AEC in Scan Regions Outside the Localizer Radiograph FOV: An In Phantom Study of CT Systems From Four Vendors

    SciTech Connect (OSTI)

    Supanich, M [Rush University Medical Center, Chicago, IL (United States); Bevins, N [Henry Ford Health System, Detroit, MI (United States)

    2014-06-01T23:59:59.000Z

    Purpose: This review of scanners from 4 major manufacturers examines the clinical impact of performing CT scans that extend into areas of the body that were not acquired in the CT localizer radiograph. Methods: Anthropomorphic chest and abdomen phantoms were positioned together on the tables of CT scanners from 4 different vendors. All of the scanners offered an Automatic Exposure Control (AEC) option with both lateral and axial tube current modulation. A localizer radiograph was taken covering the entire extent of both phantoms and then the scanner's Chest-Abdomen-Pelvis (CAP) study was performed with the clinical AEC settings employed and the scan and reconstruction range extending from the superior portion of the chest phantom through the inferior portion of the abdomen phantom. A new study was then initiated with a localizer radiograph extending the length of the chest phantom (not covering the abdomen phantom). The same CAP protocol and AEC settings were then used to scan and reconstruct the entire length of both phantoms. Scan parameters at specific locations in the abdomen phantom from both studies were investigated using the information contained in the DICOM metadata of the reconstructed images. Results: The AEC systems on all scanners utilized different tube current settings in the abdomen phantom for the scan completed without the full localizer radiograph. The AEC system behavior was also scanner dependent with the default manual tube current, the maximum tube current and the tube current at the last known position observed as outcomes. Conclusion: The behavior of the AEC systems of CT scanners in regions not covered by the localizer radiograph is vendor dependent. To ensure optimal image quality and radiation exposure it is important to include the entire planned scan region in the localizer radiograph.

  10. airborne laser scanner: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 A glacier inventory for South Tyrol, Italy, based on airborne laser-scanner data Geosciences Websites...

  11. Automatic Channel Fault Detection and Diagnosis System for a Small Animal APD-Based Digital PET Scanner

    E-Print Network [OSTI]

    Jonathan Charest; Jean-François Beaudoin; Jules Cadorette; Roger Lecomte; Charles-Antoine Brunet; Réjean Fontaine

    2014-06-16T23:59:59.000Z

    Fault detection and diagnosis is critical to many applications in order to ensure proper operation and performance over time. Positron emission tomography (PET) systems that require regular calibrations by qualified scanner operators are good candidates for such continuous improvements. Furthermore, for scanners employing one-to-one coupling of crystals to photodetectors to achieve enhanced spatial resolution and contrast, the calibration task is even more daunting because of the large number of independent channels involved. To cope with the additional complexity of the calibration and quality control procedures of these scanners, an intelligent system (IS) was designed to perform fault detection and diagnosis (FDD) of malfunctioning channels. The IS can be broken down into four hierarchical modules: parameter extraction, channel fault detection, fault prioritization and diagnosis. Of these modules, the first two have previously been reported and this paper focuses on fault prioritization and diagnosis. The purpose of the fault prioritization module is to help the operator to zero in on the faults that need immediate attention. The fault diagnosis module will then identify the causes of the malfunction and propose an explanation of the reasons that lead to the diagnosis. The FDD system was implemented on a LabPET avalanche photodiode (APD)-based digital PET scanner. Experiments demonstrated a FDD Sensitivity of 99.3 % (with a 95% confidence interval (CI) of: [98.7, 99.9]) for major faults. Globally, the Balanced Accuracy of the diagnosis for varying fault severities is 92 %. This suggests the IS can greatly benefit the operators in their maintenance task.

  12. Bioengineering 280A Principles of

    E-Print Network [OSTI]

    Liu, Thomas T.

    the mathematical framework for tomography, now called the Radon transform. 1972 Godfrey Hounsfield develops first from Siemens Siretom CT scanner, circa 1975. 128x128 matrix. Modern CT image acquired with a Siemens

  13. Modulated Luminescent Tomography

    E-Print Network [OSTI]

    2015-01-28T23:59:59.000Z

    modalities behave differently than Photoacoustic and Thermoacoustic Tomography, where the ex- citation is highly diffusive but the emitted ultrasound signal ...

  14. Mathematics of thermoacoustic tomography

    E-Print Network [OSTI]

    Peter Kuchment; Leonid Kunyansky

    2007-10-21T23:59:59.000Z

    The paper presents a survey of mathematical problems, techniques, and challenges arising in the Thermoacoustic and Photoacoustic Tomography.

  15. SNR-weighted Sinogram Smoothing with Improved Noise-resolution Properties for Low-dose X-ray Computed Tomography

    E-Print Network [OSTI]

    -ray Computed Tomography T. Li*a , J. Wanga , J. Wena , X. Lib , H. Luc , J. Hsiehd , and Z. Lianga a State-beam, uniform attenuation, resolution variation. 1. INTRODUCTION It is well known that the quality of computed tomography (CT) images would be severely degraded by the excessive quantum noise under extremely low x

  16. Bioengineering 280A Principles of

    E-Print Network [OSTI]

    Liu, Thomas T.

    , now called the Radon transform. 1972 Godfrey Hounsfield develops first CT system. Unaware http://www.sprawls.org/resources/CTIMG/classroom.htm Computed Tomography Image from Siemens Siretom CT scanner, circa 1975. 128x128 matrix. Modern CT image acquired with a Siemens scanner. 512x512

  17. Bioengineering 280A Principles of

    E-Print Network [OSTI]

    Liu, Thomas T.

    , now called the Radon transform. 1972 Godfrey Hounsfield develops first CT system. Unaware of either http://www.sprawls.org/resources/CTIMG/classroom.htm Computed Tomography Image from Siemens Siretom CT scanner, circa 1975. 128x128 matrix. Modern CT image acquired with a Siemens scanner. 512x512

  18. Complications in CT-guided Procedures: Do We Really Need Postinterventional CT Control Scans?

    SciTech Connect (OSTI)

    Nattenmüller, Johanna, E-mail: johanna.nattenmueller@med.uni-heidelberg.de; Filsinger, Matthias, E-mail: Matthias_filsinger@web.de; Bryant, Mark, E-mail: mark.bryant@med.uni-heidelberg.de; Stiller, Wolfram, E-mail: Wolfram.Stiller@med.uni-heidelberg.de; Radeleff, Boris, E-mail: boris.radeleff@med.uni-heidelberg.de; Grenacher, Lars, E-mail: lars.grenacher@med.uni-heidelberg.de; Kauczor, Hans-Ullrich, E-mail: hu.kauczor@med.uni-heidelberg.de; Hosch, Waldemar, E-mail: waldemar.hosch@urz.uni-heidelberg.de [University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology (Germany)

    2013-06-19T23:59:59.000Z

    PurposeThe aim of this study is twofold: to determine the complication rate in computed tomography (CT)-guided biopsies and drainages, and to evaluate the value of postinterventional CT control scans.MethodsRetrospective analysis of 1,067 CT-guided diagnostic biopsies (n = 476) and therapeutic drainages (n = 591) in thoracic (n = 37), abdominal (n = 866), and musculoskeletal (ms) (n = 164) locations. Severity of any complication was categorized as minor or major. To assess the need for postinterventional CT control scans, it was determined whether complications were detected clinically, on peri-procedural scans or on postinterventional scans only.ResultsThe complication rate was 2.5 % in all procedures (n = 27), 4.4 % in diagnostic punctures, and 1.0 % in drainages; 13.5 % in thoracic, 2.0 % in abdominal, and 3.0 % in musculoskeletal procedures. There was only 1 major complication (0.1 %). Pneumothorax (n = 14) was most frequent, followed by bleeding (n = 9), paresthesia (n = 2), material damage (n = 1), and bone fissure (n = 1). Postinterventional control acquisitions were performed in 65.7 % (701 of 1,067). Six complications were solely detectable in postinterventional control acquisitions (3 retroperitoneal bleeds, 3 pneumothoraces); all other complications were clinically detectable (n = 4) and/or visible in peri-interventional controls (n = 21).ConclusionComplications in CT-guided interventions are rare. Of these, thoracic interventions had the highest rate, while pneumothoraces and bleeding were most frequent. Most complications can be detected clinically or peri-interventionally. To reduce the radiation dose, postinterventional CT controls should not be performed routinely and should be restricted to complicated or retroperitoneal interventions only.

  19. An RF dosimeter for independent SAR measurement in MRI scanners

    SciTech Connect (OSTI)

    Qian, Di; Bottomley, Paul A. [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)] [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 and Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); El-Sharkawy, AbdEl-Monem M.; Edelstein, William A., E-mail: w.edelstein@gmail.com [Division of MR Research, Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21287 (United States)

    2013-12-15T23:59:59.000Z

    Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B{sub 1}) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ?3%. With the torso landmarked at the xiphoid, human adult whole?body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on average independent of the imaging subject, albeit with fluctuations. Conclusions: Our 3T RF dosimeter and transducers accurately measure RF exposure in body-equivalent loads and provide scanner-independent assessments of whole-body RF power deposition for establishing safety compliance useful for MRI sequence and device testing.

  20. A Detector for Proton Computed Tomography

    SciTech Connect (OSTI)

    Blazey, G.; et al.,

    2013-12-06T23:59:59.000Z

    Radiation therapy is a widely recognized treatment for cancer. Energetic protons have distinct features that set them apart from photons and make them desirable for cancer therapy as well as medical imaging. The clinical interest in heavy ion therapy is due to the fact that ions deposit almost all of their energy in a sharp peak – the Bragg peak- at the very end of their path. Proton beams can be used to precisely localize a tumor and deliver an exact dose to the tumor with small doses to the surrounding tissue. Proton computed tomography (pCT) provides direct information on the location on the target tumor, and avoids position uncertainty caused by treatment planning based on imaging with X-ray CT. The pCT project goal is to measure and reconstruct the proton relative stopping power distribution directly in situ. To ensure the full advantage of cancer treatment with 200 MeV proton beams, pCT must be realized.

  1. CT Solar Loan

    Broader source: Energy.gov [DOE]

    The Clean Energy Finance and Investment Authority is offering a pilot loan program, CT Solar Loan, to provide homeowners with 15-year loans for solar PV equipment. The loans are administered...

  2. Turbocharging Quantum Tomography.

    SciTech Connect (OSTI)

    Blume-Kohout, Robin J; Gamble, John King,; Nielsen, Erik; Maunz, Peter Lukas Wilhelm; Scholten, Travis L.; Rudinger, Kenneth Michael

    2015-01-01T23:59:59.000Z

    Quantum tomography is used to characterize quantum operations implemented in quantum information processing (QIP) hardware. Traditionally, state tomography has been used to characterize the quantum state prepared in an initialization procedure, while quantum process tomography is used to characterize dynamical operations on a QIP system. As such, tomography is critical to the development of QIP hardware (since it is necessary both for debugging and validating as-built devices, and its results are used to influence the next generation of devices). But tomography su %7C ers from several critical drawbacks. In this report, we present new research that resolves several of these flaws. We describe a new form of tomography called gate set tomography (GST), which unifies state and process tomography, avoids prior methods critical reliance on precalibrated operations that are not generally available, and can achieve unprecedented accuracies. We report on theory and experimental development of adaptive tomography protocols that achieve far higher fidelity in state reconstruction than non-adaptive methods. Finally, we present a new theoretical and experimental analysis of process tomography on multispin systems, and demonstrate how to more e %7C ectively detect and characterize quantum noise using carefully tailored ensembles of input states.

  3. Validation of a Monte Carlo model used for simulating tube current modulation in computed tomography over a wide range of phantom conditions/challenges

    SciTech Connect (OSTI)

    Bostani, Maryam, E-mail: mbostani@mednet.ucla.edu; McMillan, Kyle; Cagnon, Chris H.; McNitt-Gray, Michael F. [Departments of Biomedical Physics and Radiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90024 (United States); DeMarco, John J. [Department of Radiation Oncology, University of California, Los Angeles, Los Angeles, California 90095 (United States)

    2014-11-01T23:59:59.000Z

    Purpose: Monte Carlo (MC) simulation methods have been widely used in patient dosimetry in computed tomography (CT), including estimating patient organ doses. However, most simulation methods have undergone a limited set of validations, often using homogeneous phantoms with simple geometries. As clinical scanning has become more complex and the use of tube current modulation (TCM) has become pervasive in the clinic, MC simulations should include these techniques in their methodologies and therefore should also be validated using a variety of phantoms with different shapes and material compositions to result in a variety of differently modulated tube current profiles. The purpose of this work is to perform the measurements and simulations to validate a Monte Carlo model under a variety of test conditions where fixed tube current (FTC) and TCM were used. Methods: A previously developed MC model for estimating dose from CT scans that models TCM, built using the platform of MCNPX, was used for CT dose quantification. In order to validate the suitability of this model to accurately simulate patient dose from FTC and TCM CT scan, measurements and simulations were compared over a wide range of conditions. Phantoms used for testing range from simple geometries with homogeneous composition (16 and 32 cm computed tomography dose index phantoms) to more complex phantoms including a rectangular homogeneous water equivalent phantom, an elliptical shaped phantom with three sections (where each section was a homogeneous, but different material), and a heterogeneous, complex geometry anthropomorphic phantom. Each phantom requires varying levels of x-, y- and z-modulation. Each phantom was scanned on a multidetector row CT (Sensation 64) scanner under the conditions of both FTC and TCM. Dose measurements were made at various surface and depth positions within each phantom. Simulations using each phantom were performed for FTC, detailed x–y–z TCM, and z-axis-only TCM to obtain dose estimates. This allowed direct comparisons between measured and simulated dose values under each condition of phantom, location, and scan to be made. Results: For FTC scans, the percent root mean square (RMS) difference between measurements and simulations was within 5% across all phantoms. For TCM scans, the percent RMS of the difference between measured and simulated values when using detailed TCM and z-axis-only TCM simulations was 4.5% and 13.2%, respectively. For the anthropomorphic phantom, the difference between TCM measurements and detailed TCM and z-axis-only TCM simulations was 1.2% and 8.9%, respectively. For FTC measurements and simulations, the percent RMS of the difference was 5.0%. Conclusions: This work demonstrated that the Monte Carlo model developed provided good agreement between measured and simulated values under both simple and complex geometries including an anthropomorphic phantom. This work also showed the increased dose differences for z-axis-only TCM simulations, where considerable modulation in the x–y plane was present due to the shape of the rectangular water phantom. Results from this investigation highlight details that need to be included in Monte Carlo simulations of TCM CT scans in order to yield accurate, clinically viable assessments of patient dosimetry.

  4. Electron tomography of defects

    E-Print Network [OSTI]

    Sharp, Joanne

    2010-10-12T23:59:59.000Z

    . . . . . . . . . . . . . . . . . . . 36 2.6 Limitations of electron tomography . . . . . . . . . . . . . . . 37 2.6.1 The missing wedge . . . . . . . . . . . . . . . . . . . . 37 2.6.2 Minimum reliable spacing of features . . . . . . . . . . 39 3 Tomography of dislocations using weak... ELECTRON TOMOGRAPHY OF DEFECTS This dissertation is submitted for the degree of Doctor of Philosophy by Joanne Sharp Of Wolfson College Submitted 26th April 2010 Acknowledgements This dissertation is the result of my own work and includes nothing...

  5. Utilizing a simple CT dosimetry phantom for the comprehension of the operational characteristics of CT AEC systems

    SciTech Connect (OSTI)

    Tsalafoutas, Ioannis A. [Medical Physics Department, Anticancer-Oncology Hospital of Athens “Agios Savvas,” 171 Alexandras Avenue, 115 22 Athens (Greece)] [Medical Physics Department, Anticancer-Oncology Hospital of Athens “Agios Savvas,” 171 Alexandras Avenue, 115 22 Athens (Greece); Varsamidis, Athanasios; Thalassinou, Stella; Efstathopoulos, Efstathios P. [Second Department of Radiology, Medical School, University of Athens, University General Hospital, “Attikon,” Rimini 1, 124 62 Athens (Greece)] [Second Department of Radiology, Medical School, University of Athens, University General Hospital, “Attikon,” Rimini 1, 124 62 Athens (Greece)

    2013-11-15T23:59:59.000Z

    Purpose: To investigate the utility of the nested polymethylacrylate (PMMA) phantom (which is available in many CT facilities for CTDI measurements), as a tool for the presentation and comparison of the ways that two different CT automatic exposure control (AEC) systems respond to a phantom when various scan parameters and AEC protocols are modified.Methods: By offsetting the two phantom's components (the head phantom and the body ring) half-way along their longitudinal axis, a phantom with three sections of different x-ray attenuation was created. Scan projection radiographs (SPRs) and helical scans of the three-section phantom were performed on a Toshiba Aquilion 64 and a Philips Brilliance 64 CT scanners, with different scan parameter selections [scan direction, pitch factor, slice thickness, and reconstruction interval (ST/RI), AEC protocol, and tube potential used for the SPRs]. The dose length product (DLP) values of each scan were recorded and the tube current (mA) values of the reconstructed CT images were plotted against the respective Z-axis positions on the phantom. Furthermore, measurements of the noise levels at the center of each phantom section were performed to assess the impact of mA modulation on image quality.Results: The mA modulation patterns of the two CT scanners were very dissimilar. The mA variations were more pronounced for Aquilion 64, where changes in any of the aforementioned scan parameters affected both the mA modulations curves and DLP values. However, the noise levels were affected only by changes in pitch, ST/RI, and AEC protocol selections. For Brilliance 64, changes in pitch affected the mA modulation curves but not the DLP values, whereas only AEC protocol and SPR tube potential selection variations affected both the mA modulation curves and DLP values. The noise levels increased for smaller ST/RI, larger weight category AEC protocol, and larger SPR tube potential selection.Conclusions: The nested PMMA dosimetry phantom can be effectively utilized for the comprehension of CT AEC systems performance and the way that different scan conditions affect the mA modulation patterns, DLP values, and image noise. However, in depth analysis of the reasons why these two systems exhibited such different behaviors in response to the same phantom requires further investigation which is beyond the scope of this study.

  6. TLD assessment of mouse dosimetry during microCT imaging

    SciTech Connect (OSTI)

    Figueroa, Said Daibes; Winkelmann, Christopher T.; Miller, William H.; Volkert, Wynn A.; Hoffman, Timothy J. [Harry S. Truman Memorial VA Hospital, Columbia, Missouri 65201 (United States) and Department of Radiology, University of Missouri, Columbia, Missouri 65201 (United States); Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri 65201 (United States); Nuclear Science and Engineering Institute, University of Missouri, Columbia, Missouri 65201 (United States); Department of Radiology, University of Missouri, Columbia, Missouri 65201 (United States); Harry S. Truman Memorial VA Hospital, Columbia, Missouri 65201 (United States) and Departments of Internal Medicine, Chemistry, and the Nuclear Science and Engineering Institute, University of Missouri, Columbia, Missouri 65201 (United States)

    2008-09-15T23:59:59.000Z

    Advances in laboratory animal imaging have provided new resources for noninvasive biomedical research. Among these technologies is microcomputed tomography (microCT) which is widely used to obtain high resolution anatomic images of small animals. Because microCT utilizes ionizing radiation for image formation, radiation exposure during imaging is a concern. The objective of this study was to quantify the radiation dose delivered during a standard microCT scan. Radiation dose was measured using thermoluminescent dosimeters (TLDs), which were irradiated employing an 80 kVp x-ray source, with 0.5 mm Al filtration and a total of 54 mA s for a full 360 deg rotation of the unit. The TLD data were validated using a 3.2 cm{sup 3} CT ion chamber probe. TLD results showed a single microCT scan air kerma of 78.0{+-}5.0 mGy when using a poly(methylmethacrylate) (PMMA) anesthesia support module and an air kerma of 92.0{+-}6.0 mGy without the use of the anesthesia module. The validation CT ion chamber study provided a measured radiation air kerma of 81.0{+-}4.0 mGy and 97.0{+-}5.0 mGy with and without the PMMA anesthesia module, respectively. Internal TLD analysis demonstrated an average mouse organ radiation absorbed dose of 76.0{+-}5.0 mGy. The author's results have defined x-ray exposure for a routine microCT study which must be taken into consideration when performing serial molecular imaging studies involving the microCT imaging modality.

  7. SCIPP 06/04 1 Prototype Tracking Studies for Proton CT

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    SCIPP 06/04 1 Prototype Tracking Studies for Proton CT Nate Blumenkrantz, Jason Feldt, Jason the feasibility of proton computed tomography, the most likely path (MLP) of protons inside an absorber resolution. The locations of 200 MeV protons were measured at three different absorber depth of PMMA (3.75, 6

  8. Surface Extraction from Multi-Material Components for Metrology using Dual Energy CT

    E-Print Network [OSTI]

    materials (e.g., carbon-fibre-reinforced plas- tics) induce manufacturers to design new functionSurface Extraction from Multi-Material Components for Metrology using Dual Energy CT Christoph surface models of multi-material components using dual energy com- puted tomography (DECT

  9. Automatic Lung Segmentation of Volumetric Low-Dose CT Scans Using Graph Cuts

    E-Print Network [OSTI]

    Farag, Aly A.

    Automatic Lung Segmentation of Volumetric Low-Dose CT Scans Using Graph Cuts Asem M. Ali and Aly A for unsupervised segmentation of the lung region from low dose computed tomography (LDCT) images. We follow distribution model. To better spec- ify region borders between lung and chest, each empirical distribution

  10. animal pet scanner: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    animal pet scanner First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Atlas-based attenuation correction...

  11. animal pet scanners: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    animal pet scanners First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Atlas-based attenuation correction...

  12. CHARACTERIZATION OF VIBRATIONINDUCED IMAGE DEFECTS IN INPUT SCANNERS

    E-Print Network [OSTI]

    Wolberg, George

    ) by dynamic errors of gears, timing bets, and motors, and indirectly by structural vibrations induced by gearsCHARACTERIZATION OF VIBRATION­INDUCED IMAGE DEFECTS IN INPUT SCANNERS Robert P. Loce George Wolberg. Keywords: image defects, digital documents, scanned documents, vibrations, motion quality 1. INTRODUCTION

  13. LANSCE wire scanner AFE: analysis, design, and fabrication

    SciTech Connect (OSTI)

    Gruchalla, Mike [Los Alamos National Laboratory; Chacon, Phillip [Los Alamos National Laboratory; Gilpatrick, John D [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory; Power, John F [Los Alamos National Laboratory; Smith, Brian [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    The goal of the design LANSCE-R Wire-Scanner Analog Front-end Electronics is to develop a high-performance, dual-axis wire-scanner analog front-end system implemented in a single cRIO module. This new design accommodates macropulse widths as wide as 700 {mu}s at a maximum pulse rate of 120Hz. A lossey integrator is utilized as the integration element to eliminate the requirement for providing gating signals to each wire scanner. The long macropulse and the high repetition rate present conflicting requirements for the design of the integrator. The long macropulse requires a long integration time constant to assure minimum integrator droop for accurate charge integration, and the high repetition rate requires a short time constant to assure adequate integrator reset between macropulses. Also, grounding is a serious concern due to the small signal levels. This paper reviews the basic Wire Scanner AFE system design implemented in the cRIO-module form factor to capture the charge information from the wire sensors and the grounding topology to assure minimum noise contamination of the wire signals.

  14. First Test Results of the New LANSCE Wire Scanner

    SciTech Connect (OSTI)

    Sedillo, James Daniel [Los Alamos National Laboratory

    2011-01-01T23:59:59.000Z

    The Beam Diagnostics and Instrumentation Team (BDIT) at Los Alamos National Laboratory's LANSCE facility is presently developing a new and improved wire scanner diagnostics system controlled by National Instrument's cRIO platform. This paper describes the current state of development of the control system along with the results gathered from the latest actuator motion performance and accelerator-beam data acquisition tests.

  15. Neutron computed tomography

    E-Print Network [OSTI]

    Russell, Clifford Marlow

    1992-01-01T23:59:59.000Z

    of tomography was discovered by Radon in 1917. Radon, a mathematician, solved the problem for an n-dimensional function with n-I dimensional projectors as related to gravitational equations. Radon's technique is not the only mathematical basis for tomography...

  16. Dual seven pinhole tomography

    SciTech Connect (OSTI)

    Bizais, Y.; Zubal, I.G.; Rowe, R.W.; Bennett, G.W.; Brill, A.B.

    1982-01-01T23:59:59.000Z

    Emission tomography using two orthogonal sets of projections through seven pinhole collimators is considered. This paper describes the acquisition system, the reconstruction algorithm, presents results obtained in phantom studies, and discusses the advantages and disadvantages of this method over conventional Seven Pinhole Tomography.

  17. Incorporation of motion information for tumour volume definition in PET Comparison of different methods of incorporating respiratory

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , respiratory motion, super-resolution, 4D PET imaging 1. Introduction Computed tomography (CT) is routinely Tomography (PET) for diagnosis and staging, as well as the widespread availability of combined PET/CT scanners, led to numerous studies investigating the potential of PET/CT for target volume delineation. Use

  18. Computerized method for evaluating diagnostic image quality of calcified plaque images in cardiac CT: Validation on a physical dynamic cardiac phantom

    SciTech Connect (OSTI)

    King, Martin; Rodgers, Zachary; Giger, Maryellen L.; Bardo, Dianna M. E.; Patel, Amit R. [Department of Radiology, Committee on Medical Physics, University of Chicago, 5841 South Maryland Avenue, MC 2026, Chicago, Illinois 60637 (United States); Department of Diagnostic Radiology, Oregon Health and Science University, 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239 (United States); Department of Medicine, University of Chicago, 5841 South Maryland Avenue, MC 5084, Chicago, Illinois 60637 (United States)

    2010-11-15T23:59:59.000Z

    Purpose: In cardiac computed tomography (CT), important clinical indices, such as the coronary calcium score and the percentage of coronary artery stenosis, are often adversely affected by motion artifacts. As a result, the expert observer must decide whether or not to use these indices during image interpretation. Computerized methods potentially can be used to assist in these decisions. In a previous study, an artificial neural network (ANN) regression model provided assessability (image quality) indices of calcified plaque images from the software NCAT phantom that were highly agreeable with those provided by expert observers. The method predicted assessability indices based on computer-extracted features of the plaque. In the current study, the ANN-predicted assessability indices were used to identify calcified plaque images with diagnostic calcium scores (based on mass) from a physical dynamic cardiac phantom. The basic assumption was that better quality images were associated with more accurate calcium scores. Methods: A 64-channel CT scanner was used to obtain 500 calcified plaque images from a physical dynamic cardiac phantom at different heart rates, cardiac phases, and plaque locations. Two expert observers independently provided separate sets of assessability indices for each of these images. Separate sets of ANN-predicted assessability indices tailored to each observer were then generated within the framework of a bootstrap resampling scheme. For each resampling iteration, the absolute calcium score error between the calcium scores of the motion-contaminated plaque image and its corresponding stationary image served as the ground truth in terms of indicating images with diagnostic calcium scores. The performances of the ANN-predicted and observer-assigned indices in identifying images with diagnostic calcium scores were then evaluated using ROC analysis. Results: Assessability indices provided by the first observer and the corresponding ANN performed similarly (AUC{sub OBS1}=0.80 [0.73,0.86] vs AUC{sub ANN1}=0.88 [0.82,0.92]) as that of the second observer and the corresponding ANN (AUC{sub OBS2}=0.87 [0.83,0.91] vs AUC{sub ANN2}=0.90 [0.85,0.94]). Moreover, the ANN-predicted indices were generated in a fraction of the time required to obtain the observer-assigned indices. Conclusions: ANN-predicted assessability indices performed similar to observer-assigned assessability indices in identifying images with diagnostic calcium scores from the physical dynamic cardiac phantom. The results of this study demonstrate the potential of using computerized methods for identifying images with diagnostic clinical indices in cardiac CT images.

  19. A Cost Effective Multi-Spectral Scanner for Natural Gas Detection

    SciTech Connect (OSTI)

    Yudaya Sivathanu; Jongmook Lim; Vinoo Narayanan; Seonghyeon Park

    2005-12-07T23:59:59.000Z

    The objective of this project is to design, fabricate and demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at EnUrga Inc. The multi-spectral scanner was also evaluated using a blind Department of Energy study at the Rocky Mountain Oilfield Testing Center. The performance of the scanner was inconsistent during the blind study. However, most of the leaks were outside the view of the multi-spectral scanner that was developed during the first year of the project. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, the optical design of the scanner was changed to improve the sensitivity of the system. Laboratory tests show that the system can reliably detect small leaks (20 SCFH) at 30 to 50 feet. A prototype scanner was built and evaluated during the second year of the project. Only laboratory evaluations were completed during the second year. The laboratory evaluations show the feasibility of using the scanner to determine natural gas pipeline leaks. Further field evaluations and optimization of the scanner are required before commercialization of the scanner can be initiated.

  20. Test of a single module of the J-PET scanner based on plastic scintillators

    E-Print Network [OSTI]

    P. Moskal; Sz. Nied?wiecki; T. Bednarski; E. Czerwi?ski; ?. Kap?on; E. Kubicz; I. Moskal; M. Pawlik-Nied?wiecka; N. G. Sharma; M. Silarski; M. Zieli?ski; N. Zo?; P. Bia?as; A. Gajos; A. Kochanowski; G. Korcyl; J. Kowal; P. Kowalski; T. Kozik; W. Krzemie?; M. Molenda; M. Pa?ka; L. Raczy?ski; Z. Rudy; P. Salabura; A. S?omski; J. Smyrski; A. Strzelecki; A. Wieczorek; W. Wi?licki

    2014-08-29T23:59:59.000Z

    Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this article we report on tests of a single detection module built out from BC-420 plastic scintillator strip (with dimensions of 5x19x300mm^3) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the 68Ge isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50ps intervals. The time resolution of the prototype module was established to be better than 80ps (sigma) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93cm (sigma) for the annihilation quanta. The fractional energy resolution for the energy E deposited by the annihilation quanta via the Compton scattering amounts to sigma(E)/E = 0.044/sqrt(E[MeV]) and corresponds to the sigma(E)/E of 7.5% at the Compton edge.

  1. Calculations of two new dose metrics proposed by AAPM Task Group 111 using the measurements with standard CT dosimetry phantoms

    SciTech Connect (OSTI)

    Li, Xinhua; Zhang, Da; Liu, Bob [Division of Diagnostic Imaging Physics and Webster Center for Advanced Research and Education in Radiation, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)] [Division of Diagnostic Imaging Physics and Webster Center for Advanced Research and Education in Radiation, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)

    2013-08-15T23:59:59.000Z

    Purpose: AAPM Task Group 111 proposed to measure the equilibrium dose-pitch product D-caret{sub eq} for scan modes involving table translation and the midpoint dose D{sub L}(0) for stationary-table modes on the central and peripheral axes of sufficiently long (e.g., at least 40 cm) phantoms. This paper presents an alternative approach to calculate both metrics using the measurements of scanning the standard computed tomographic (CT) dosimetry phantoms on CT scanners.Methods: D-caret{sub eq} was calculated from CTDI{sub 100} and ?(CTDI{sub 100}) (CTDI{sub 100} efficiency), and D{sub L}(0) was calculated from D-caret{sub eq} and the approach to equilibrium function H(L) =D{sub L}(0)/D{sub eq}, where D{sub eq} was the equilibrium dose. CTDI{sub 100} may be directly obtained from several sources (such as medical physicist's CT scanner performance evaluation or the IMPACT CT patient dosimetry calculator), or be derived from CTDI{sub Vol} using the central to peripheral CTDI{sub 100} ratio (R{sub 100}). The authors have provided the required ?(CTDI{sub 100}) and H(L) data in two previous papers [X. Li, D. Zhang, and B. Liu, Med. Phys. 39, 901–905 (2012); and ibid. 40, 031903 (10pp.) (2013)]. R{sub 100} was assessed for a series of GE, Siemens, Philips, and Toshiba CT scanners with multiple settings of scan field of view, tube voltage, and bowtie filter.Results: The calculated D{sub L}(0) and D{sub L}(0)/D{sub eq} in PMMA and water cylinders were consistent with the measurements on two GE CT scanners (LightSpeed 16 and VCT) by Dixon and Ballard [Med. Phys. 34, 3399–3413 (2007)], the measurements on a Siemens CT scanner (SOMATOM Spirit Power) by Descamps et al. [J. Appl. Clin. Med. Phys. 13, 293–302 (2012)], and the Monte Carlo simulations by Boone [Med. Phys. 36, 4547–4554 (2009)].Conclusions: D-caret{sub eq} and D{sub L}(0) can be calculated using the alternative approach. The authors have provided the required ?(CTDI{sub 100}) and H(L) data in two previous papers. R{sub 100} is presented for a majority of multidetector CT scanners currently on the market, and can be easily assessed for other CT scanners or operating conditions not covered in this study. The central to peripheral D{sub eq} ratio is about 1.50 and 1.12 times of R{sub 100} for the 32- and 16-cm diameter PMMA phantom, respectively.

  2. Data fusion in neutron and X-ray computed tomography

    SciTech Connect (OSTI)

    Schrapp, Michael J. [Siemens AG, Corporate Technology, Otto-Hahn-Ring 6, 81739 Munich (Germany); Physik Department E21, Technische Universität München, James-Franck-Strasse 1, 85747 Garching (Germany); Goldammer, Matthias [Siemens AG, Corporate Technology, Otto-Hahn-Ring 6, 81739 Munich (Germany); Schulz, Michael [Physik Department E21, Technische Universität München, James-Franck-Strasse 1, 85747 Garching (Germany); Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstrasse 1, 85747 Garching (Germany); Issani, Siraj; Bhamidipati, Suryanarayana [Siemens AG, Corporate Technology, Bangalore (India); Böni, Peter [Physik Department E21, Technische Universität München, James-Franck-Strasse 1, 85747 Garching (Germany)

    2014-10-28T23:59:59.000Z

    We present a fusion methodology between neutron and X-ray computed tomography (CT). On the one hand, the inspection by X-ray CT of a wide class of multimaterials in non-destructive testing applications suffers from limited information of object features. On the other hand, neutron imaging can provide complementary data in such a way that the combination of both data sets fully characterizes the object. In this contribution, a novel data fusion procedure, called Fusion Regularized Simultaneous Algebraic Reconstruction Technique, is developed where the X-ray reconstruction is modified to fulfill the available data from the imaging with neutrons. The experiments, which were obtained from an aluminum profile containing a steel screw, and attached carbon fiber plates demonstrate that the image quality in CT can be significantly improved when the proposed fusion method is used.

  3. Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development

    SciTech Connect (OSTI)

    Gilpatrick, John D. [Los Alamos National Laboratory; Batygin, Yuri K. [Los Alamos National Laboratory; Gonzales, Fermin [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Kutac, Vincent G. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

    2012-05-15T23:59:59.000Z

    The Los Alamos Neutron Science Center (LANSCE) is replacing Wire Scanner (WS) beam profile measurement systems. Three beam development tests have taken place to test the new wire scanners under beam conditions. These beam development tests have integrated the WS actuator, cable plant, electronics processors and associated software and have used H{sup -} beams of different beam energy and current conditions. In addition, the WS measurement-system beam tests verified actuator control systems for minimum profile bin repeatability and speed, checked for actuator backlash and positional stability, tested the replacement of simple broadband potentiometers with narrow band resolvers, and tested resolver use with National Instruments Compact Reconfigurable Input and Output (cRIO) Virtual Instrumentation. These beam tests also have verified how trans-impedance amplifiers react with various types of beam line background noise and how noise currents were not generated. This paper will describe these beam development tests and show some resulting data.

  4. Comparison of Fusion Imaging Using a Combined SPECT/CT System and Intra-arterial CT: Assessment of Drug Distribution by an Implantable Port System in Patients Undergoing Hepatic Arterial Infusion Chemotherapy

    SciTech Connect (OSTI)

    Ikeda, Osamu, E-mail: osamu-3643ik@do9.enjoy.ne.jp; Kusunoki, Shinichiroh; Nakaura, Takeshi; Shiraishi, Shinya; Kawanaka, Kouichi; Tomiguchi, Seiji; Yamashita, Yasuyuki [Kumamoto University Graduate School of Medical and Pharmaceutical Sciences, Department of Diagnostic Radiology (Japan); Takamori, Hiroshi; Chikamoto, Akira; Kanemitsu, Keiichiro [Kumamoto University Graduate School of Medical and Pharmaceutical Sciences, Gastroenterological Surgery (Japan)

    2006-06-15T23:59:59.000Z

    Hepatic arterial infusion (HAI) chemotherapy is effective for treating primary and metastatic carcinoma of the liver. We compared the perfusion patterns of HAI chemotherapy on intra-arterial port-catheter computed tomography (iapc-CT) and fused images obtained with a combined single-photon emission computed tomography/computed tomography (SPECT/CT) system. We studied 28 patients with primary or metastatic carcinoma of the liver who bore an implantable HAI port system. All underwent abdominal SPECT using Tc-99m-MAA (185 Mbq); the injection rate was 1 mL/min, identical to the chemotherapy infusion rate, and 0.5 mL/sec for iapc-CT. Delivery was through an implantable port. We compared the intrahepatic perfusion (IHP) and extrahepatic perfusion (EHP) patterns of HAI chemotherapy on iapc-CT images and fused images obtained with a combined SPECT/CT system. In 23 of 28 patients (82%), IHP patterns on iapc-CT images and fused images were identical. In 5 of the 28 patients (18%), IHP on fusion images was different from IHP on iapc-CT images. EHP was seen on fused images in 12 of the 28 patients (43%) and on iapc-CT images in 8 patients (29%). In 17 patients (61%), upper gastrointestinal endoscopy revealed gastroduodenal mucosal lesions. EHP was revealed on fused images in 10 of these patients; 9 of them manifested gastroduodenal toxicity at the time of subsequent HAI chemotherapy. Fusion imaging using the combined SPECT/CT system reflects the actual distribution of the infused anticancer agent. This information is valuable not only for monitoring adequate drug distribution but also for avoiding potential extrahepatic complications.

  5. Large-Scale User Facility Imaging and Scattering Techniques to Facilitate

    E-Print Network [OSTI]

    with the advent of computed tomography1. This pioneering work was done by 1979 Nobel Prize winners Godfrey Hounsfield and Allan McLeod Cormack which evolved into the first prototype Computed Tomography (CT) scanner the active user facilities, 1 Computed Tomography and History: http://en.wikipedia.org/wiki/Computed_tomography

  6. Pretreatment Staging Positron Emission Tomography/Computed Tomography in Patients With Inflammatory Breast Cancer Influences Radiation Treatment Field Designs

    SciTech Connect (OSTI)

    Walker, Gary V. [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Niikura, Naoki [Department of Breast and Endocrine Surgery, Tokai University School of Medicine, Kanagawa (Japan)] [Department of Breast and Endocrine Surgery, Tokai University School of Medicine, Kanagawa (Japan); Yang Wei [Department of Diagnostic Radiology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Diagnostic Radiology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rohren, Eric [Department of Nuclear Medicine, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Nuclear Medicine, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Valero, Vicente [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A. [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Alvarez, Ricardo H. [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lucci, Anthony [Department of Surgical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Surgical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ueno, Naoto T. [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Breast Medical Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Buchholz, Thomas A., E-mail: tbuchhol@mdanderson.org [Department of Radiation Oncology, Morgan Welch Inflammatory Breast Cancer Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-08-01T23:59:59.000Z

    Purpose: Positron emission tomography/computed tomography (PET/CT) is increasingly being utilized for staging of inflammatory breast cancer (IBC). The purpose of this study was to define how pretreatment PET/CT studies affected postmastectomy radiation treatment (PMRT) planning decisions for IBC. Methods and Materials: We performed a retrospective analysis of 62 patients diagnosed with IBC between 2004 and 2009, who were treated with PMRT in our institution and who had a staging PET/CT within 3 months of diagnosis. Patients received a baseline physical examination, staging mammography, ultrasonographic examination of breast and draining lymphatics, and chest radiography; most patients also had a bone scan (55 patients), liver imaging (52 patients), breast MRI (46 patients), and chest CT (25 patients). We compared how PET/CT findings affected PMRT, assuming that standard PMRT would target the chest wall, level III axilla, supraclavicular fossa, and internal mammary chain (IMC). Any modification of target volumes, field borders, or dose prescriptions was considered a change. Results: PET/CT detected new areas of disease in 27 of the 62 patients (44%). The areas of additional disease included the breast (1 patient), ipsilateral axilla (1 patient), ipsilateral supraclavicular (4 patients), ipsilateral infraclavicular (1 patient), ipsilateral IMC (5 patients), ipsilateral subpectoral (3 patients), mediastinal (8 patients), other distant/contralateral lymph nodes (15 patients), or bone (6 patients). One patient was found to have a non-breast second primary tumor. The findings of the PET/CT led to changes in PMRT in 11 of 62 patients (17.7%). These changes included additional fields in 5 patients, adjustment of fields in 2 patients, and higher doses to the supraclavicular fossa (2 patients) and IMC (5 patients). Conclusions: For patients with newly diagnosed IBC, pretreatment PET/CT provides important information concerning involvement of locoregional lymph nodes, mediastinal lymph nodes, and unsuspected sites of distant metastasis. This information is important in the design of radiotherapy treatment fields and, therefore, we recommend that PET/CT be a component of initial staging for IBC.

  7. Evaluation of scanners for C-scan imaging in nondestructive inspection of aircraft

    SciTech Connect (OSTI)

    Gieske, J.H.

    1994-04-01T23:59:59.000Z

    The goal of this project was to produce a document that contains information on the usability and performance of commercially available, fieldable, and portable scanner systems as they apply to aircraft NDI inspections. In particular, the scanners are used to generate images of eddy current, ultrasonic, or bond tester inspection data. The scanner designs include manual scanners, semiautomated scanners, and fully automated scanners. A brief description of the functionality of each scanner type, a sketch, and a fist of the companies that support the particular design are provided. Vendors of each scanner type provided hands-on demonstrations of their equipment on real aircraft samples in the FAA Aging Aircraft Nondestructive Inspection Validation Center (AANC) in Albuquerque, NM. From evaluations recorded during the demonstrations, a matrix of scanner features and factors and ranking of the capabilities and limitations of the design, portability, articulation, performance, usability, and computer hardware/software was constructed to provide a quick reference for comparing the different scanner types. Illustrations of C-scan images obtained during the demonstration are shown.

  8. Thermoacoustic tomography, variable sound speed Plamen Stefanov

    E-Print Network [OSTI]

    Stefanov, Plamen

    Thermoacoustic tomography, variable sound speed Plamen Stefanov Purdue University Based on a joint work with Gunther Uhlmann Plamen Stefanov (Purdue University ) Thermoacoustic tomography, variable sound speed 1 / 18 #12;Formulation Main Problem Thermoacoustic Tomography In thermoacoustic tomography

  9. X-ray Computed Tomography of coal: Final report

    SciTech Connect (OSTI)

    Maylotte, D.H.; Spiro, C.L.; Kosky, P.G.; Lamby, E.J.

    1986-12-01T23:59:59.000Z

    X-ray Computed Tomography (CT) is a method of mapping with x-rays the internal structures of coal. The technique normally produces 2-D images of the internal structures of an object. These images can be recast to create pseudo 3-D representations. CT of coal has been explored for a variety of different applications to coal and coal processing technology. In a comparison of CT data with conventional coal analyses and petrography, CT was found to offer a good indication of the total ash content of the coal. The spatial distribution of the coal mineral matter as seen with CT has been suggested as an indicator of coal washability. Studies of gas flow through coal using xenon gas as a tracer have shown the extremely complicated nature of the modes of penetration of gas through coal, with significant differences in the rates at which the gas can pass along and across the bedding planes of coal. In a special furnace designed to allow CT images to be taken while the coal was being heated, the pyrolysis and gasification of coal have been studied. Gasification rates with steam and CO/sub 2/ for a range of coal ranks have been obtained, and the location of the gasification reactions within the piece of coal can be seen. Coal drying and the progress of the pyrolysis wave into coal have been examined when the coal was subjected to the kind of sudden temperature jump that it might experience in fixed bed gasifier applications. CT has also been used to examine stable flow structures within model fluidized beds and the accessibility of lump coal to microbial desulfurization. 53 refs., 242 figs., 26 tabs.

  10. Factors Affecting Prostate Volume Estimation in Computed Tomography Images

    SciTech Connect (OSTI)

    Yang, Cheng-Hsiu [Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan (China); Wang, Shyh-Jen [Divisions of Experimental Surgery, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan (China); Institute of Biomedical Engineering, National Yang Ming University, Taipei, Taiwan (China); Lin, Alex Tong-Long [Divisions of Urology, Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan (China); Lin, Chao-An, E-mail: calin@pme.nthu.edu.t [Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan (China)

    2011-04-01T23:59:59.000Z

    The aim of this study was to investigate how apex-localizing methods and the computed tomography (CT) slice thickness affected the CT-based prostate volume estimation. Twenty-eight volunteers underwent evaluations of prostate volume by CT, where the contour segmentations were performed by three observers. The bottom of ischial tuberosities (ITs) and the bulb of the penis were used as reference positions to locate the apex, and the distances to the apex were recorded as 1.3 and 2.0 cm, respectively. Interobserver variations to locate ITs and the bulb of the penis were, on average, 0.10 cm (range 0.03-0.38 cm) and 0.30 cm (range 0.00-0.98 cm), respectively. The range of CT slice thickness varied from 0.08-0.48 cm and was adopted to examine the influence of the variation on volume estimation. The volume deviation from the reference case (0.08 cm), which increases in tandem with the slice thickness, was within {+-} 3 cm{sup 3}, regardless of the adopted apex-locating reference positions. In addition, the maximum error of apex identification was 1.5 times of slice thickness. Finally, based on the precise CT films and the methods of apex identification, there were strong positive correlation coefficients for the estimated prostate volume by CT and the transabdominal ultrasonography, as found in the present study (r > 0.87; p < 0.0001), and this was confirmed by Bland-Altman analysis. These results will help to identify factors that affect prostate volume calculation and to contribute to the improved estimation of the prostate volume based on CT images.

  11. CT NC0

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling Corp -KWatertowni5W 95.5x-L* d! CT NC0 - i , ,.

  12. High contrast, CdTe portal scanner for radiation therapy

    SciTech Connect (OSTI)

    Entine, G.; Squillante, M.R.; Hahn, R.; Cirignano, L.J.; McGann, W. (Radiation Monitoring Devices, Inc., Watertown, MA (United States)); Biggs, P.J. (Massachusetts General Hospital, Boston, MA (United States))

    1992-10-01T23:59:59.000Z

    This paper reports on one of the most promising new technologies for improving the qualify of radiation therapy, the use of real-time systems to produce portal images. In the authors' approach, they are constructing a linear array of 256 CdTe photovoltaic detectors attached to a very compact linear scanner, all of which will be mounted in a cassette shaped package to be located under the patient table. The high stopping power of the CdTe allows a high contrast image to be made using only a single Linac pulse per line, resulting in a high contrast image in under 5 seconds.

  13. Regularized Equally Sloped Tomography Algorithm for Low Dose X-Ray Computed Tomography

    E-Print Network [OSTI]

    Zhao, Yunzhe

    2012-01-01T23:59:59.000Z

    based imaging computed tomography extraction algorithms and10 2.2. Computed Tomography reconstruction theory andcontrast X-ray computed tomography for observing biological

  14. Regularized Equally Sloped Tomography Algorithm for Low Dose X-Ray Computed Tomography

    E-Print Network [OSTI]

    Zhao, Yunzhe

    2012-01-01T23:59:59.000Z

    based imaging computed tomography extraction algorithms andcontrast X-ray computed tomography for observing biological10 2.2. Computed Tomography reconstruction theory and

  15. Ionospheric Correction Using Tomography

    E-Print Network [OSTI]

    Stanford University

    re- quirements on the order of ones of meters with safety of life integrity requirements which delay algorithms. The capability of ionospheric tomography is demon- strated by a time series of 3D°N 30°N 30°N 40°N 40°N 50°N 50°N 60°N 60°N Figure 1: The NSTB reference network geometry is comprised

  16. Jet Tomography at RHIC

    E-Print Network [OSTI]

    J. C. Dunlop

    2007-07-10T23:59:59.000Z

    The status of the use of hard probes in heavy ion collisions at RHIC is reviewed. The discovery of strong jet quenching at RHIC is a major success. However, in order to make full use of this new phenomenon for full jet emission tomography of the properties of the collision zone further development is needed, both experimentally and theoretically.

  17. High Resolution Muon Computed Tomography at Neutrino Beam Facilities

    E-Print Network [OSTI]

    Suerfu, Burkhant

    2015-01-01T23:59:59.000Z

    X-ray computed tomography (CT) has an indispensable role in constructing 3D images of objects made from light materials. However, limited by absorption coefficients, X-rays cannot deeply penetrate materials such as copper and lead. Here we show via simulation that muon beams can provide high resolution tomographic images of dense objects and of structures within the interior of dense objects. The effects of resolution broadening from multiple scattering diminish with increasing muon momentum. As the momentum of the muon increases, the contrast of the image goes down and therefore requires higher resolution in the muon spectrometer to resolve the image. The variance of the measured muon momentum reaches a minimum and then increases with increasing muon momentum. The impact of the increase in variance is to require a higher integrated muon flux to reduce fluctuations. The flux requirements and level of contrast needed for high resolution muon computed tomography are well matched to the muons produced in the pio...

  18. Comparison of Physical Examination and Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography 4-6 Months After Radiotherapy to Assess Residual Head-and-Neck Cancer

    SciTech Connect (OSTI)

    Zundel, M. Tracy [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Michel, Michelle A. [Department of Radiology, Medical College of Wisconsin, Milwaukee, WI (United States); Schultz, Christopher J. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Maheshwari, Mohit [Department of Radiology, Medical College of Wisconsin, Milwaukee, WI (United States); Wong, Stuart J. [Department of Neoplastic and Related Disorders, Medical College of Wisconsin, Milwaukee, WI (United States); Campbell, Bruce H.; Massey, Becky L.; Blumin, Joel [Department of Otolaryngology, Medical College of Wisconsin, Milwaukee, WI (United States); Wilson, J. Frank [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Wang, Dian, E-mail: dwang@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)

    2011-12-01T23:59:59.000Z

    Purpose: To retrospectively compare fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and physical examination 4-6 months after radiotherapy for assessing residual head-and-neck cancer (HNC). Methods and Materials: From July 2002 through March 2006, 52 HNC patients underwent definitive radiotherapy or chemoradiotherapy. Categoric assessments of residual tumor by PET/CT and physical examination 4-6 months after therapy were correlated and compared with clinical outcomes. Pretreatment data, including tumor stage and primary site standardized uptake value, were also gathered retrospectively and correlated with clinical outcomes. Median follow-up time was 58 months. Results: Twenty-one patients had either locoregionally 'positive' (17 of 21) or 'equivocal' (4 of 21) PET/CT scans, whereas 31 patients had locoregionally negative scans. Four patients failed treatment and had biopsy-confirmed residual or recurrent local disease. All patients, including patients with locally suspicious scans or examinations who refused biopsies, were followed clinically for a minimum of 29 months after therapy, with no other cases of treatment failure detected during this time. No patient had residual nodal disease after therapy. Sensitivities of PET/CT vs. physical examination for early detection of treatment failure were 100% vs. 50%, whereas the specificities of the two modalities were 64.6% vs. 89.6%, respectively. Higher initial T stage and American Joint Commission on Cancer stage correlated with increased incidence of positive/equivocal PET/CT results and treatment failure. Maximal standardized uptake value was not predictive of any clinical outcome. Conclusions: A negative result on PET/CT obtained 4-6 months after radiotherapy is highly sensitive and correlates with successful locoregional control. Patients with negative scans may reasonably be spared invasive diagnostic procedures, such as biopsy and neck dissection, unless recurrent disease is suspected on clinical grounds. Close follow-up is prudent for HNC patients with abnormal findings on posttherapy PET/CT scan.

  19. CT reconstruction techniques for improved accuracy of lung CT airway measurement

    SciTech Connect (OSTI)

    Rodriguez, A. [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 (United States); Ranallo, F. N. [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792 (United States); Judy, P. F. [Brigham and Women’s Hospital, Boston, Massachusetts 02115 (United States); Gierada, D. S. [Department of Radiology, Washington University, St. Louis, Missouri 63110 (United States); Fain, S. B., E-mail: sfain@wisc.edu [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53792 (United States); Department of Biomedical Engineering,University of Wisconsin School of Engineering, Madison, Wisconsin 53706 (United States)

    2014-11-01T23:59:59.000Z

    Purpose: To determine the impact of constrained reconstruction techniques on quantitative CT (qCT) of the lung parenchyma and airways for low x-ray radiation dose. Methods: Measurement of small airways with qCT remains a challenge, especially for low x-ray dose protocols. Images of the COPDGene quality assurance phantom (CTP698, The Phantom Laboratory, Salem, NY) were obtained using a GE discovery CT750 HD scanner for helical scans at x-ray radiation dose-equivalents ranging from 1 to 4.12 mSv (12–100 mA s current–time product). Other parameters were 40 mm collimation, 0.984 pitch, 0.5 s rotation, and 0.625 mm thickness. The phantom was sandwiched between 7.5 cm thick water attenuating phantoms for a total length of 20 cm to better simulate the scatter conditions of patient scans. Image data sets were reconstructed using STANDARD (STD), DETAIL, BONE, and EDGE algorithms for filtered back projection (FBP), 100% adaptive statistical iterative reconstruction (ASIR), and Veo reconstructions. Reduced (half) display field of view (DFOV) was used to increase sampling across airway phantom structures. Inner diameter (ID), wall area percent (WA%), and wall thickness (WT) measurements of eight airway mimicking tubes in the phantom, including a 2.5 mm ID (42.6 WA%, 0.4 mm WT), 3 mm ID (49.0 WA%, 0.6 mm WT), and 6 mm ID (49.0 WA%, 1.2 mm WT) were performed with Airway Inspector (Surgical Planning Laboratory, Brigham and Women’s Hospital, Boston, MA) using the phase congruency edge detection method. The average of individual measures at five central slices of the phantom was taken to reduce measurement error. Results: WA% measures were greatly overestimated while IDs were underestimated for the smaller airways, especially for reconstructions at full DFOV (36 cm) using the STD kernel, due to poor sampling and spatial resolution (0.7 mm pixel size). Despite low radiation dose, the ID of the 6 mm ID airway was consistently measured accurately for all methods other than STD FBP. Veo reconstructions showed slight improvement over STD FBP reconstructions (4%–9% increase in accuracy). The most improved ID and WA% measures were for the smaller airways, especially for low dose scans reconstructed at half DFOV (18 cm) with the EDGE algorithm in combination with 100% ASIR to mitigate noise. Using the BONE + ASIR at half BONE technique, measures improved by a factor of 2 over STD FBP even at a quarter of the x-ray dose. Conclusions: The flexibility of ASIR in combination with higher frequency algorithms, such as BONE, provided the greatest accuracy for conventional and low x-ray dose relative to FBP. Veo provided more modest improvement in qCT measures, likely due to its compatibility only with the smoother STD kernel.

  20. A Laser Range Scanner Designed for Minimum Calibration Complexity James Davis, Xing Chen

    E-Print Network [OSTI]

    Stanford University

    A Laser Range Scanner Designed for Minimum Calibration Complexity James Davis, Xing Chen Computer are a popular method for acquiring three-dimensional geometry due to their accuracy and robustness. Maximizing a two camera range scanner design, specifically chosen to minimize calibration complexity and cost

  1. Instructions for Scanning with Public LC Scanners/Library-Side Use these instructions to

    E-Print Network [OSTI]

    Schweik, Charles M.

    Instructions for Scanning with Public LC Scanners/Library-Side Use these instructions to: · Scan a single document · Scan a document into editable text, rather than in a picture format · Email scanned light near the buttons on the scanner will be lit)** Scanning a Single (One-Page) Document 1.) Place

  2. REGOLAMENTO ed ISTRUZIONI per l'utilizzo delle fotocopiatrici/stampanti/scanner

    E-Print Network [OSTI]

    Garulli, Andrea

    (XEROX 7232) possono essere utilizzate oltre che come fotocopiatrici e scanner, anche come stampanti 7232, che si trova presso la portineria di ingresso al Palazzo San Niccolò può stampare a colori e;FOTOCOPIATRICE STAMPANTE SCANNER XEROX WORKCENTRE 7232 (portineria ingresso) Login: Inserire il proprio numero o

  3. Thermomechanical Actuator-Based Three-Axis Optical Scanner for High-Speed Two-Photon Endomicroscope Imaging

    E-Print Network [OSTI]

    Chen, Shih-Chi

    This paper presents the design and characterization of a three-axis thermomechanical actuator-based endoscopic scanner for obtaining ex vivo two-photon images. The scanner consisted of two sub-systems: 1) an optical system ...

  4. Wide-Bandwidth Capture of Wire-Scanner Signals

    SciTech Connect (OSTI)

    Gruchalla, Michael E. [Los Alamos National Laboratory; Gilpatrick, John D. [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory

    2012-05-16T23:59:59.000Z

    Integrated charge collected on the sense wires of wire-scanner systems utilized to determine beam profile is generally the parameter of interest. The LANSCE application requires capturing the charge information macropulse-by-macropulse with macropulse lengths as long as 700 {micro}s at a maximum macropulse rate of 120 Hz. Also, for the LANSCE application, it is required that the integration be performed in a manner that does not require integrator reset between macropulses. Due to the long macropulse which must be accommodated and the 8.33 ms minimum pulse period, a simple R-C integrator cannot be utilized since there is insufficient time between macropulses to allow the integrator to adequately recover. The application of wide analog bandwidth to provide accurate pulse-by-pulse capture of the wire signals with digital integration of the wire signals to determine captured charge at each macropulse in applications with comparatively long macropulses and high pulse repetition rates is presented.

  5. Data fusion in X-ray computed tomography using a superiorization approach

    SciTech Connect (OSTI)

    Schrapp, Michael J. [Siemens AG, CT Munich, Germany and Physics Department E21, Technical University of Munich, Munich (Germany)] [Siemens AG, CT Munich, Germany and Physics Department E21, Technical University of Munich, Munich (Germany); Herman, Gabor T. [Department of Computer Science, The Graduate Center, City University of New York, New York, New York 10016 (United States)] [Department of Computer Science, The Graduate Center, City University of New York, New York, New York 10016 (United States)

    2014-05-15T23:59:59.000Z

    X-ray computed tomography (CT) is an important and widespread inspection technique in industrial non-destructive testing. However, large-sized and heavily absorbing objects cause artifacts due to either the lack of penetration of the specimen in specific directions or by having data from only a limited angular range of views. In such cases, valuable information about the specimen is not revealed by the CT measurements alone. Further imaging modalities, such as optical scanning and ultrasonic testing, are able to provide data (such as an edge map) that are complementary to the CT acquisition. In this paper, a superiorization approach (a newly developed method for constrained optimization) is used to incorporate the complementary data into the CT reconstruction; this allows precise localization of edges that are not resolvable from the CT data by itself. Superiorization, as presented in this paper, exploits the fact that the simultaneous algebraic reconstruction technique (SART), often used for CT reconstruction, is resilient to perturbations; i.e., it can be modified to produce an output that is as consistent with the CT measurements as the output of unmodified SART, but is more consistent with the complementary data. The application of this superiorized SART method to measured data of a turbine blade demonstrates a clear improvement in the quality of the reconstructed image.

  6. Enhanced local tomography

    DOE Patents [OSTI]

    Katsevich, Alexander J. (Los Alamos, NM); Ramm, Alexander G. (Manhattan, KS)

    1996-01-01T23:59:59.000Z

    Local tomography is enhanced to determine the location and value of a discontinuity between a first internal density of an object and a second density of a region within the object. A beam of radiation is directed in a predetermined pattern through the region of the object containing the discontinuity. Relative attenuation data of the beam is determined within the predetermined pattern having a first data component that includes attenuation data through the region. In a first method for evaluating the value of the discontinuity, the relative attenuation data is inputted to a local tomography function .function..sub..LAMBDA. to define the location S of the density discontinuity. The asymptotic behavior of .function..sub..LAMBDA. is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA.. In a second method for evaluating the value of the discontinuity, a gradient value for a mollified local tomography function .gradient..function..sub..LAMBDA..epsilon. (x.sub.ij) is determined along the discontinuity; and the value of the jump of the density across the discontinuity curve (or surface) S is estimated from the gradient values.

  7. Semi-automatic delineation using weighted CT-MRI registered images for radiotherapy of nasopharyngeal cancer

    SciTech Connect (OSTI)

    Fitton, I. [European Georges Pompidou Hospital, Department of Radiology, 20 rue Leblanc, 75015, Paris (France); Cornelissen, S. A. P. [Image Sciences Institute, UMC, Department of Radiology, P.O. Box 85500, 3508 GA Utrecht (Netherlands); Duppen, J. C.; Rasch, C. R. N.; Herk, M. van [The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Radiotherapy, Plesmanlaan 121, 1066 CX Amsterdam (Netherlands); Steenbakkers, R. J. H. M. [University Medical Center Groningen, Department of Radiation Oncology, Hanzeplein 1, 9713 GZ Groningen (Netherlands); Peeters, S. T. H. [UZ Gasthuisberg, Herestraat 49, 3000 Leuven, Belgique (Belgium); Hoebers, F. J. P. [Maastricht University Medical Center, Department of Radiation Oncology (MAASTRO clinic), GROW School for Oncology and Development Biology Maastricht, 6229 ET Maastricht (Netherlands); Kaanders, J. H. A. M. [UMC St-Radboud, Department of Radiotherapy, Geert Grooteplein 32, 6525 GA Nijmegen (Netherlands); Nowak, P. J. C. M. [ERASMUS University Medical Center, Department of Radiation Oncology,Groene Hilledijk 301, 3075 EA Rotterdam (Netherlands)

    2011-08-15T23:59:59.000Z

    Purpose: To develop a delineation tool that refines physician-drawn contours of the gross tumor volume (GTV) in nasopharynx cancer, using combined pixel value information from x-ray computed tomography (CT) and magnetic resonance imaging (MRI) during delineation. Methods: Operator-guided delineation assisted by a so-called ''snake'' algorithm was applied on weighted CT-MRI registered images. The physician delineates a rough tumor contour that is continuously adjusted by the snake algorithm using the underlying image characteristics. The algorithm was evaluated on five nasopharyngeal cancer patients. Different linear weightings CT and MRI were tested as input for the snake algorithm and compared according to contrast and tumor to noise ratio (TNR). The semi-automatic delineation was compared with manual contouring by seven experienced radiation oncologists. Results: A good compromise for TNR and contrast was obtained by weighing CT twice as strong as MRI. The new algorithm did not notably reduce interobserver variability, it did however, reduce the average delineation time by 6 min per case. Conclusions: The authors developed a user-driven tool for delineation and correction based a snake algorithm and registered weighted CT image and MRI. The algorithm adds morphological information from CT during the delineation on MRI and accelerates the delineation task.

  8. Transhepatic Approach for Percutaneous Computed-Tomography-Guided Radiofrequency Ablation of Renal Cell Carcinoma

    SciTech Connect (OSTI)

    Iguchi, Toshihiro, E-mail: iguchi@cc.okayama-u.ac.jp; Hiraki, Takao; Gobara, Hideo; Mukai, Takashi; Hase, Soichiro; Fujiwara, Hiroyasu; Tajiri, Nobuhisa; Sakurai, Jun; Mimura, Hidefumi [Okayama University Medical School, Department of Radiology (Japan); Saika, Takashi; Kumon, Hiromi [Okayama University Medical School, Department of Urology (Japan); Kanazawa, Susumu [Okayama University Medical School, Department of Radiology (Japan)

    2007-07-15T23:59:59.000Z

    We performed percutaneously radiofrequency (RF) ablation of 5 renal cell carcinomas (mean diameter 26 {+-} 15 mm) with computed-tomography (CT) fluoroscopic guidance using the transhepatic route. The RF electrode was successfully advanced into all tumors. RF ablation caused one minor complication (small asymptomatic perirenal hematoma); no major complications occurred. The follow-up contrast-enhanced CT images showed no local tumor progression of any tumors in a median period of 10 months (range 3-14 months). In conclusion, it seems that this transhepatic approach is safe and can be an alternative method for electrode insertion during RF ablation of selected renal tumors.

  9. Computed tomography of the spleen and liver in sickle cell disease

    SciTech Connect (OSTI)

    Magid, D.; Fishman, E.K.; Siegelman, S.S.

    1984-08-01T23:59:59.000Z

    The spleen was assessed in 10 patients with sickle cell disease studied with computed tomography (CT) for abdominal pain and/or unexplained fever. Patients with homozygous sickle cell anemia were found to have small, densely calcified spleens with occasional low-density infarcts. Five of six had hepatomegaly, and there was one case each of hepatic abscess, infarcts, and hemochromatosis. All patients with heterozygous sickle cell disease were found to have splenomegaly, with a variety of findings including acute hemorrhage, acute and chronic infarcts, rupture, and possible sequestration. It was concluded that CT is useful for evaluating the status of the spleen and liver in symptomatic patients with sickle cell disease.

  10. Automatic CT simulation optimization for radiation therapy: A general strategy

    SciTech Connect (OSTI)

    Li, Hua, E-mail: huli@radonc.wustl.edu; Chen, Hsin-Chen; Tan, Jun; Gay, Hiram; Michalski, Jeff M.; Mutic, Sasa [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States)] [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Yu, Lifeng [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States)] [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Anastasio, Mark A. [Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63110 (United States)] [Department of Biomedical Engineering, Washington University, St. Louis, Missouri 63110 (United States); Low, Daniel A. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States)] [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States)

    2014-03-15T23:59:59.000Z

    Purpose: In radiation therapy, x-ray computed tomography (CT) simulation protocol specifications should be driven by the treatment planning requirements in lieu of duplicating diagnostic CT screening protocols. The purpose of this study was to develop a general strategy that allows for automatically, prospectively, and objectively determining the optimal patient-specific CT simulation protocols based on radiation-therapy goals, namely, maintenance of contouring quality and integrity while minimizing patient CT simulation dose. Methods: The authors proposed a general prediction strategy that provides automatic optimal CT simulation protocol selection as a function of patient size and treatment planning task. The optimal protocol is the one that delivers the minimum dose required to provide a CT simulation scan that yields accurate contours. Accurate treatment plans depend on accurate contours in order to conform the dose to actual tumor and normal organ positions. An image quality index, defined to characterize how simulation scan quality affects contour delineation, was developed and used to benchmark the contouring accuracy and treatment plan quality within the predication strategy. A clinical workflow was developed to select the optimal CT simulation protocols incorporating patient size, target delineation, and radiation dose efficiency. An experimental study using an anthropomorphic pelvis phantom with added-bolus layers was used to demonstrate how the proposed prediction strategy could be implemented and how the optimal CT simulation protocols could be selected for prostate cancer patients based on patient size and treatment planning task. Clinical IMRT prostate treatment plans for seven CT scans with varied image quality indices were separately optimized and compared to verify the trace of target and organ dosimetry coverage. Results: Based on the phantom study, the optimal image quality index for accurate manual prostate contouring was 4.4. The optimal tube potentials for patient sizes of 38, 43, 48, 53, and 58 cm were 120, 140, 140, 140, and 140 kVp, respectively, and the corresponding minimum CTDIvol for achieving the optimal image quality index 4.4 were 9.8, 32.2, 100.9, 241.4, and 274.1 mGy, respectively. For patients with lateral sizes of 43–58 cm, 120-kVp scan protocols yielded up to 165% greater radiation dose relative to 140-kVp protocols, and 140-kVp protocols always yielded a greater image quality index compared to the same dose-level 120-kVp protocols. The trace of target and organ dosimetry coverage and the ? passing rates of seven IMRT dose distribution pairs indicated the feasibility of the proposed image quality index for the predication strategy. Conclusions: A general strategy to predict the optimal CT simulation protocols in a flexible and quantitative way was developed that takes into account patient size, treatment planning task, and radiation dose. The experimental study indicated that the optimal CT simulation protocol and the corresponding radiation dose varied significantly for different patient sizes, contouring accuracy, and radiation treatment planning tasks.

  11. Brachial Plexus Injury from CT-Guided RF Ablation Under General Anesthesia

    SciTech Connect (OSTI)

    Shankar, Sridhar, E-mail: shankars@ummhc.org; Sonnenberg, Eric van; Silverman, Stuart G.; Tuncali, Kemal [Brigham and Women's Hospital, Department of Radiology (United States); Flanagan, Hugh L. [Brigham and Women's Hospital, Department of Anesthesia (United States); Whang, Edward E. [Brigham and Women's Hospital, Department of Surgery (United States)

    2005-06-15T23:59:59.000Z

    Brachial plexus injury in a patient under general anesthesia (GA) is not uncommon, despite careful positioning and, particularly, awareness of the possibility. The mechanism of injury is stretching and compression of the brachial plexus over a prolonged period. Positioning the patient within the computed tomography (CT) gantry for abdominal or chest procedures can simulate a surgical procedure, particularly when GA is used. The potential for brachial plexus injury is increased if the case is prolonged and the patient's arms are raised above the head to avoid CT image degradation from streak artifacts. We report a case of profound brachial plexus palsy following a CT-guided radiofrequency ablation procedure under GA. Fortunately, the patient recovered completely. We emphasize the mechanism of injury and detail measures to combat this problem, such that radiologists are aware of this potentially serious complication.

  12. Ten-Year Outcomes: The Clinical Utility of Single Photon Emission Computed Tomography/Computed Tomography Capromab Pendetide (Prostascint) in a Cohort Diagnosed With Localized Prostate Cancer

    SciTech Connect (OSTI)

    Ellis, Rodney J., E-mail: rodney.ellis@case.edu [Department of Radiation Oncology, University Hospitals, Case Medical Center and Case Western Reserve University School of Medicine, Cleveland, OH (United States); Department of Radiology, Northeastern Ohio Universities College of Medicine, Rootstown, OH (United States); Kaminsky, Deborah A. [Division of Radiation Therapy, Aultman Hospital, Canton, OH (United States); Zhou, Esther H. [Center for Drug Evaluation and Research, U.S.A. Food and Drug Administration, Silver spring, MD (United States); Fu, Pingfu [Department of Epidemiology and Biostatistics, Case Western Reserve University School of Medicine, Cleveland, OH (United States); Chen, Wei-Dong [Genetic Branch/Center for Cancer Research, National Cancer Institute/National Institutes of Health, and the National Naval Medical Center, Bethesda, MD (United States); Brelin, Alaina [Northeastern Ohio Universities College of Medicine, Rootstown, OH (United States); Faulhaber, Peter F. [Department of Radiology, University Hospitals, Case Medical Center and Case Western Reserve University School of Medicine, Cleveland, OH (United States); Bodner, Donald [Department of Urology, University Hospitals, Case Medical Center and Case Western Reserve University School of Medicine, Cleveland, OH (United States)

    2011-09-01T23:59:59.000Z

    Purpose: To evaluate the clinical utility of capromab pendetide imaging with single photon emission computed tomography coregistration with computed tomography (SPECT/CT) in primary prostate cancer (CaP) for pretreatment prognostic staging and localization of biologic target volumes (BTV) for individualized image-guided radiotherapy dose escalation (IGRT-DE). Methods and Materials: Patients consecutively presenting for primary radiotherapy (February 1997 to December 2002), having a clinical diagnosis of localized CaP, were evaluated for tumor stage using conventional staging and SPECT/CT (N = 239). Distant metastatic uptake (mets) were identified by SPECT/CT in 22 (9.2%). None of the suspected mets could be clinically confirmed. Thus, all subjects were followed without alteration in disease management. The SPECT/CT pelvic images defined BTV for IGRT-DE (+150% brachytherapy dose) without (n = 150) or with (n = 89) external radiation of 45 Gy. The National Comprehensive Cancer Network criteria defined risk groups (RG). The median survivor follow-up was 7 years. Biochemical disease-free survival (bDFS) was reported by clinical nadir +2 ng/mL (CN+2) criteria. Statistical analyses included Kaplan-Meier, multivariate analysis, and Concordance-index models. Results: At 10-year analyses, overall survival was 84.8% and bDFS was 84.6%. With stratification by RG, CN+2 bDFS was 93.5% for the low-RG (n = 116), 78.7% for the intermediate-RG (n = 94), and 68.8% for the high-RG (n = 29), p = 0.0002. With stratification by pretreatment SPECT/CT findings, bDFS was 65.5% in patients with suspected mets (n = 22) vs. 86.6% in patients with only localized uptake (n = 217), p = 0.0014. CaP disease-specific survival (DSS) was 97.7% for the cohort. With stratification by SPECT/CT findings, DSS was 86.4% (with suspected mets) vs. 99.0% (localized only), p = 0.0001. Using multivariate analysis, the DSS hazard ratio for SPECT/CT findings (mets vs. localized) was 3.58 (p = 0.0026). Concordance-index tests, based on all data, by CN+2 bDFS criteria were 0.710 for RG alone and 0.773 for SPECT/CT + RG. Conclusions: Through long-term outcomes we demonstrate statistically significant bDFS and DSS predictive value for pretreatment capromab pendetide SPECT/CT imaging in primary CaP. Dual clinical utility is demonstrated, using SPECT/CT to define BTV for individualized IGRT-DE.

  13. An indirect transmission measurement-based spectrum estimation method for computed tomography

    E-Print Network [OSTI]

    Zhao, Wei; Schafer, Sebastian; Royalty, Kevin

    2015-01-01T23:59:59.000Z

    The characteristics of an x-ray spectrum can greatly influence imaging and related tasks. In practice, due to the pile-up effect of the detector, it's difficult to directly measure the spectrum of a CT scanner using an energy resolved detector. An alternative solution is to estimate the spectrum using transmission measurements with a step phantom or other CT phantom. In this work, we present a new spectrum estimation method based on indirect transmission measurement and model spectra mixture approach. The estimated x-ray spectrum was expressed as weighted summation of a set of model spectra, which can significantly reduce the degrees of freedom (DOF) of the spectrum estimation problem. Next, an estimated projection can be calculated with the assumed spectrum. By iteratively updating the unknown weights, we minimized the difference between the estimated projection data and the raw projection data. The final spectrum was calculated with these calibrated weights and the model spectra. Both simulation and experim...

  14. Comparison of MRI-based and CT/MRI fusion-based postimplant dosimetric analysis of prostate brachytherapy

    SciTech Connect (OSTI)

    Tanaka, Osamu [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan)]. E-mail: osa-mu@umin.ac.jp; Hayashi, Shinya [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan); Matsuo, Masayuki [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan); Sakurai, Kota [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan); Department of Urology, Gifu University School of Medicine, Gifu City (Japan); Nakano, Masahiro [Department of Urology, Gifu University School of Medicine, Gifu City (Japan); Maeda, Sunaho [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan); Kajita, Kimihiro R.T. [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan); Deguchi, Takashi [Department of Urology, Gifu University School of Medicine, Gifu City (Japan); Hoshi, Hiroaki [Department of Radiology, Gifu University School of Medicine, Gifu City (Japan)

    2006-10-01T23:59:59.000Z

    Purpose: The aim of this study was to compare the outcomes between magnetic resonance imaging (MRI)-based and computed tomography (CT)/MRI fusion-based postimplant dosimetry methods in permanent prostate brachytherapy. Methods and Materials: Between October 2004 and March 2006, a total of 52 consecutive patients with prostate cancer were treated by brachytherapy, and postimplant dosimetry was performed using CT/MRI fusion. The accuracy and reproducibility were prospectively compared between MRI-based dosimetry and CT/MRI fusion-based dosimetry based on the dose-volume histogram (DVH) related parameters as recommended by the American Brachytherapy Society. Results: The prostate volume was 15.97 {+-} 6.17 cc (mean {+-} SD) in MRI-based dosimetry, and 15.97 {+-} 6.02 cc in CT/MRI fusion-based dosimetry without statistical difference. The prostate V100 was 94.5% and 93.0% in MRI-based and CT/MRI fusion-based dosimetry, respectively, and the difference was statistically significant (p = 0.002). The prostate D90 was 119.4% and 114.4% in MRI-based and CT/MRI fusion-based dosimetry, respectively, and the difference was statistically significant (p = 0.004). Conclusion: Our current results suggested that, as with fusion images, MR images allowed accurate contouring of the organs, but they tended to overestimate the analysis of postimplant dosimetry in comparison to CT/MRI fusion images. Although this MRI-based dosimetric discrepancy was negligible, MRI-based dosimetry was acceptable and reproducible in comparison to CT-based dosimetry, because the difference between MRI-based and CT/MRI fusion-based results was smaller than that between CT-based and CT/MRI fusion-based results as previously reported.

  15. Upright cone beam CT imaging using the onboard imager

    SciTech Connect (OSTI)

    Fave, Xenia, E-mail: xjfave@mdanderson.org; Martin, Rachael [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States)] [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States); Yang, Jinzhong; Balter, Peter; Court, Laurence [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)] [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Carvalho, Luis [Varian Medical Systems, Zug 6303 (Switzerland)] [Varian Medical Systems, Zug 6303 (Switzerland); Pan, Tinsu [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)] [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2014-06-15T23:59:59.000Z

    Purpose: Many patients could benefit from being treated in an upright position. The objectives of this study were to determine whether cone beam computed tomography (CBCT) could be used to acquire upright images for treatment planning and to demonstrate whether reconstruction of upright images maintained accurate geometry and Hounsfield units (HUs). Methods: A TrueBeam linac was programmed in developer mode to take upright CBCT images. The gantry head was positioned at 0°, and the couch was rotated to 270°. The x-ray source and detector arms were extended to their lateral positions. The x-ray source and gantry remained stationary as fluoroscopic projections were taken and the couch was rotated from 270° to 90°. The x-ray tube current was normalized to deposit the same dose (measured using a calibrated Farmer ion chamber) as that received during a clinical helical CT scan to the center of a cylindrical, polyethylene phantom. To extend the field of view, two couch rotation scans were taken with the detector offset 15 cm superiorly and then 15 cm inferiorly. The images from these two scans were stitched together before reconstruction. Upright reconstructions were compared to reconstructions from simulation CT scans of the same phantoms. Two methods were investigated for correcting the HUs, including direct calibration and mapping the values from a simulation CT. Results: Overall geometry, spatial linearity, and high contrast resolution were maintained in upright reconstructions. Some artifacts were created and HU accuracy was compromised; however, these limitations could be removed by mapping the HUs from a simulation CT to the upright reconstruction for treatment planning. Conclusions: The feasibility of using the TrueBeam linac to take upright CBCT images was demonstrated. This technique is straightforward to implement and could be of enormous benefit to patients with thoracic tumors or those who find a supine position difficult to endure.

  16. Mechanical optimisation of a high-precision fast wire scanner at CERN

    E-Print Network [OSTI]

    Samuelsson, Sebastian; Veness, Raymond

    Wire scanners are instruments used to measure the transverse beam prole in particle accelerators by passing a thin wire through the particle beam. To avoid the issues of vacuum leakage through the bellows and wire failure related to current designs of wire scanners, a new concept for a wire scanner has been developed at CERN. This design has all moving parts inside the beam vacuum and has a nominal wire scanning speed of 20 m/s. The demands on the design associated with this together with the high precision requirements create a need for\

  17. Thermoacoustic tomography with variable sound speed

    E-Print Network [OSTI]

    2009-10-26T23:59:59.000Z

    We study the mathematical model of thermoacoustic tomography in media with a ... In thermoacoustic tomography, a short electro-magnetic pulse is sent through ...

  18. Positron Emission Tomography (PET)

    DOE R&D Accomplishments [OSTI]

    Welch, M. J.

    1990-01-00T23:59:59.000Z

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

  19. Radial reflection diffraction tomography

    DOE Patents [OSTI]

    Lehman, Sean K.

    2012-12-18T23:59:59.000Z

    A wave-based tomographic imaging method and apparatus based upon one or more rotating radially outward oriented transmitting and receiving elements have been developed for non-destructive evaluation. At successive angular locations at a fixed radius, a predetermined transmitting element can launch a primary field and one or more predetermined receiving elements can collect the backscattered field in a "pitch/catch" operation. A Hilbert space inverse wave (HSIW) algorithm can construct images of the received scattered energy waves using operating modes chosen for a particular application. Applications include, improved intravascular imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts having existing access holes.

  20. Stored Luminescence Computed Tomography

    E-Print Network [OSTI]

    Cong, Wenxiang; Wang, Ge

    2013-01-01T23:59:59.000Z

    The phosphor nanoparticles made of doped semiconductors, pre-excited by well-collimated X-ray radiation, were recently reported for their light emission upon NIR light stimulation. The characteristics of X-ray energy storage and NIR stimulated emission is highly desirable to design targeting probes and improve molecular and cellular imaging. Here we propose stored luminescence computed tomography (SLCT), perform realistic numerical simulation, and demonstrate a much-improved spatial resolution in a preclinical research context. The future opportunities are also discussed along this direction.

  1. X-Ray Digital Radiography and Computed Tomography Characterization of Targets

    SciTech Connect (OSTI)

    Sain, J D; Brown, W D; Chinn, D J; Martz Jr., H E; Morales, K E; Schneberk, D J; Updike, E O

    2008-04-16T23:59:59.000Z

    The summary of this report is: (1) The Xradia Micro XCT and LLNL CCAT x-ray systems are used to nondestructively characterize a variety of materials, assemblies, and reference standard components; (2) The digital radiograph (DR) and computed tomography (CT) image data may be used for metrology, quality control, and defect detection; and (3) The ability to detect and characterize imperfections leads to improvements in the manufacturing processes for assemblies.

  2. DOE - Office of Legacy Management -- Seymour CT Site - CT 02

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling Corp -K Le BlondSanta SusanaSeymour CT Site - CT

  3. Semi-resonant operation of a fiber-cantilever piezotube scanner for stable optical coherence tomography endoscope imaging

    E-Print Network [OSTI]

    Moon, Sucbei; Lee, Sang-Won; Rubinstein, Marc; Wong, Brian J. F; Chen, Zhongping

    2010-01-01T23:59:59.000Z

    in-phase driving signals can be described as a line with aline were added for comparing the two in each column. Drivingdriving axes (X and Y) in the vicinity of their lowest resonance peaks. Solid lines

  4. Maximizing dose reductions with cardiac CT

    E-Print Network [OSTI]

    Budoff, Matthew J.

    2009-01-01T23:59:59.000Z

    for current scanners). The bowtie ?lter allows for smallerless photons. Thus, the bowtie ?lter allows less X-rays outsee #4 above). The bowtie ?lter allows more photons to go

  5. SU-E-J-113: The Influence of Optimizing Pediatric CT Simulator Protocols On the Treatment Dose Calculation in Radiotherapy

    SciTech Connect (OSTI)

    Zhang, Y; Zhang, J; Hu, Q; Tie, J; Wu, H [Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Radiotherapy, Peking University Cancer Hospital ' Institute, Beijing (China); Deng, J [Department of Therapeutic Radiology, Yale University, New Haven, CT (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To investigate the possibility of applying optimized scanning protocols for pediatric CT simulation by quantifying the dosimetric inaccuracy introduced by using a fixed HU to density conversion. Methods: The images of a CIRS electron density reference phantom (Model 062) were acquired by a Siemens CT simulator (Sensation Open) using the following settings of tube voltage and beam current: 120 kV/190mA (the reference protocol used to calibrate CT for our treatment planning system (TPS)); Fixed 190mA combined with all available kV: 80, 100, and 140; fixed 120 kV and various current from 37 to 444 mA (scanner extremes) with interval of 30 mA. To avoid the HU uncertainty of point sampling in the various inserts of known electron densities, the mean CT numbers of the central cylindrical volume were calculated using DICOMan software. The doses per 100 MU to the reference point (SAD=100cm, Depth=10cm, Field=10X10cm, 6MV photon beam) in a virtual cubic phantom (30X30X30cm) were calculated using Eclipse TPS (calculation model: AcurosXB-11031) by assigning the CT numbers to HU of typical materials acquired by various protocols. Results: For the inserts of densities less than muscle, CT number fluctuations of all protocols were within the tolerance of 10 HU as accepted by AAPM-TG66. For more condensed materials, fixed kV yielded stable HU with any mA combination where largest disparities were found in 1750mg/cc insert: HU{sub reference}=1801(106.6cGy), HU{sub minimum}=1799 (106.6cGy, error{sub dose}=0.00%), HU{sub maximum}=1815 (106.8cGy, error{sub dose}=0.19%). Yet greater disagreements were observed with increasing density when kV was modified: HU{sub minimum}=1646 (104.5cGy, error{sub dose}=- 1.97%), HU{sub maximum}=2487 (116.4cGy, error{sub dose}=9.19%) in 1750mg/cc insert. Conclusion: Without affecting treatment dose calculation, personalized mA optimization of CT simulator can be conducted by fixing kV for a better cost-effectiveness of imaging dose and quality especially for children. Unless recalibrated, kV should be constant for all anatomical sites if diagnostic CT scanner is used as a simulator. This work was partially supported by Capital Medical Development Scientific Research Fund of China.

  6. IEEE Transactions on Automation Science and Engineering Compensation of Scanner Creep and Hysteresis

    E-Print Network [OSTI]

    Southern California, University of

    IEEE Transactions on Automation Science and Engineering Compensation of Scanner Creep uncertainties associated with creep and hysteresis, and supports automated, computer-controlled manipulation) and by automation, which bypasses the time- consuming

  7. Aerosol analysis with the Coastal Zone Color Scanner (CZCS): the Australasian region

    E-Print Network [OSTI]

    Giondomenica, Gregory Michael

    1995-01-01T23:59:59.000Z

    The Channel 4 data from the Coastal Zone Color Scanner (CZCS), a space-borne radiometer, was analyzed to infer aerosol distributions in the Australasian region for 1979. Monthly, seasonal, and annual composites of the Channel 4 data were created...

  8. Comparison of CT, PET, and PET/CT for Staging of Patients with Indolent Non-Hodgkin’s Lymphoma

    E-Print Network [OSTI]

    Fueger, Barbara J.; Yeom, Kristen; Czernin, Johannes; Sayre, James W.; Phelps, Michael E.; Allen-Auerbach, Martin S.

    2009-01-01T23:59:59.000Z

    Differences between PET and CT were not significant forperformed significantly better than PET and CT in correctlyadditional information over PET and CT for the staging and

  9. Wire Scanner Beam Profile Measurements for the LANSCE Facility

    SciTech Connect (OSTI)

    Gilpatrick, John D. [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

    2012-05-15T23:59:59.000Z

    The Los Alamos Neutron Science Center (LANSCE) is replacing beam profile measurement systems, commonly known as Wire Scanners (WS). Using the principal of secondary electron emission, the WS measurement system moves a wire or fiber across an impinging particle beam, sampling a projected transverse-beam distribution. Because existing WS actuators and electronic components are either no longer manufactured or home-built with antiquated parts, a new WS beam profile measurement is being designed, fabricated, and tested. The goals for these new WS's include using off-the-shelf components while eliminating antiquated components, providing quick operation while allowing for easy maintainability, and tolerating external radioactivation. The WS measurement system consists of beam line actuators, a cable plant, an electronics processor chassis, and software located both in the electronics chassis (National Instruments LabVIEW) and in the Central Control Room (EPICS-based client software). This WS measurement system will measure Hand H{sup +} LANSCE-facility beams and will also measure less common beams. This paper describes these WS measurement systems.

  10. Using Synchrotron X-Ray Nano-CT to Characterize SOFC Electrode Microstructures in Three-Dimensions at Operating Temperature

    SciTech Connect (OSTI)

    Shearing, P.R.; Bradley, R.S.; Gelb, J.; Lee, S.N.; Atkinson, A.; Withers, P.J.; Brandon, N.P. (Manchester); (Xradia); (ICL)

    2012-01-20T23:59:59.000Z

    In recent years, developments in tomography tools have provided unprecedented insight into the microstructure of electrodes for solid oxide fuel cells, enabling researchers to establish direct links between electrode microstructure and electrochemical performance. Here we present results of high resolution, synchrotron X-ray nano computed tomography experiments, which have enabled microstructural characterisation of a mixed ionic electronic conducting lanthanum strontium cobalt iron oxide (LSCF) cathode with sub-50nm resolution at operating temperature. Using the uniquely non-destructive nano-CT platform, it is possible to characterise microstructural evolution processes associated with heating and operation in-situ.

  11. Relationship of brain imaging with radionuclides and with x-ray computed tomography

    SciTech Connect (OSTI)

    Kuhl, D.E.

    1981-03-03T23:59:59.000Z

    Because of high sensitivity and specificity for altered local cerebral structure, x-ray computed tomography (CT) is the preferred initial diagnostic imaging study under most circumstances when cerebral disease is suspected. CT has no competitor for detecting fresh intracerebral hemorrhage. Radionuclide imaging (RN) scan is preferred when relative perfusion is to be assessed, in patients allergic to contrast media, and when an adequate CT study is not technically possible. (RN) plays an important complementary role to CT, especially for patients suspected of subacute or chronic subdura hematoma, cerebral infarction, arteriovenous malformations, meningitis, encephalitis, normal pressure hydrocephalus, or when CT findings are inconclusive. When CT is not available, RN serves as a good screening study for suspected cerebral tumor, infection, recent infarction, arteriovenous malformation, and chronic subdural hematoma. Future improvement in radionuclide imaging by means of emission composition potential. The compound plating approacl threshold for all the investigated transistors and fast neutron spectra lies within the raal. The value of the potential slightly changes with the coordinate change in this region, i.e. the charge on a collecting electrode is not practically guided up to a certain moment of time during the movement of nonequilibrium carriers.

  12. Computed tomography of coals. Quarterly technical progress report No. 1, August 16, 1982-November 28, 1982

    SciTech Connect (OSTI)

    Maylotte, D. H.; Kosky, P. G.; Spiro, C. L.; Lamby, E. J.

    1982-01-01T23:59:59.000Z

    The purpose of this contract is to examine the utility and advantages of x-ray computed tomography (CT) for investigating the structure within coal and the changes that occur in these structures during such processes as combustion and gasification. The CT technique is noninvasive and nondestructive. It can produce interior views of the coal and, with a data acquisition time of ca 9 seconds, can be used for following many coal processes in real time. This is the first in-depth study of the application of the x-ray tomography technique to the problems in coal utilization, and consequently, considerable time will be spent in the early stages of this contract in examining CT pictures of coal and relating them to more conventional petrographic and mineral analyses. This phase of the work is being undertaken in Task 1 of the contract and is reported for this period. Building on this foundation, the succeeding tasks will follow changes in the coal structure during reaction. The first series of CT experiments is scheduled to take place on December 11-13, 1982, at the General Electric Company, Medical Systems Operation, Milwaukee, Wisconsin. 4 figures, 1 table.

  13. Positron Emission Tomography/Computed Tomography Imaging of Residual Skull Base Chordoma Before Radiotherapy Using Fluoromisonidazole and Fluorodeoxyglucose: Potential Consequences for Dose Painting

    SciTech Connect (OSTI)

    Mammar, Hamid, E-mail: hamid.mammar@unice.fr [Radiation Oncology Department, Antoine Lacassagne Center, Nice (France) [Radiation Oncology Department, Antoine Lacassagne Center, Nice (France); CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France); Kerrou, Khaldoun; Nataf, Valerie [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France)] [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France); Pontvert, Dominique [Proton Therapy Center of Orsay, Curie Institute, Paris (France)] [Proton Therapy Center of Orsay, Curie Institute, Paris (France); Clemenceau, Stephane [Department of Neurosurgery, Pitie-Salpetriere Hospital, Paris (France)] [Department of Neurosurgery, Pitie-Salpetriere Hospital, Paris (France); Lot, Guillaume [Department of Neurosurgery, Adolph De Rothschild Foundation, Paris (France)] [Department of Neurosurgery, Adolph De Rothschild Foundation, Paris (France); George, Bernard [Department of Neurosurgery, Lariboisiere Hospital, Paris (France)] [Department of Neurosurgery, Lariboisiere Hospital, Paris (France); Polivka, Marc [Department of Pathology, Lariboisiere Hospital, Paris (France)] [Department of Pathology, Lariboisiere Hospital, Paris (France); Mokhtari, Karima [Department of Pathology, Pitie-Salpetriere Hospital, Paris (France)] [Department of Pathology, Pitie-Salpetriere Hospital, Paris (France); Ferrand, Regis; Feuvret, Loiec; Habrand, Jean-louis [Proton Therapy Center of Orsay, Curie Institute, Paris (France)] [Proton Therapy Center of Orsay, Curie Institute, Paris (France); Pouyssegur, Jacques; Mazure, Nathalie [CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France)] [CNRS-UMR 6543, Institute of Developmental Biology and Cancer, University of Nice Sophia Antipolis, Nice (France); Talbot, Jean-Noeel [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France)] [Department of Nuclear Medicine and Radiopharmacy, Tenon Hospital, and University Pierre et Marie Curie, Paris (France)

    2012-11-01T23:59:59.000Z

    Purpose: To detect the presence of hypoxic tissue, which is known to increase the radioresistant phenotype, by its uptake of fluoromisonidazole (18F) (FMISO) using hybrid positron emission tomography/computed tomography (PET/CT) imaging, and to compare it with the glucose-avid tumor tissue imaged with fluorodeoxyglucose (18F) (FDG), in residual postsurgical skull base chordoma scheduled for radiotherapy. Patients and Methods: Seven patients with incompletely resected skull base chordomas were planned for high-dose radiotherapy (dose {>=}70 Gy). All 7 patients underwent FDG and FMISO PET/CT. Images were analyzed qualitatively by visual examination and semiquantitatively by computing the ratio of the maximal standardized uptake value (SUVmax) of the tumor and cerebellum (T/C R), with delineation of lesions on conventional imaging. Results: Of the eight lesion sites imaged with FDG PET/CT, only one was visible, whereas seven of nine lesions were visible on FMISO PET/CT. The median SUVmax in the tumor area was 2.8 g/mL (minimum 2.1; maximum 3.5) for FDG and 0.83 g/mL (minimum 0.3; maximum 1.2) for FMISO. The T/C R values ranged between 0.30 and 0.63 for FDG (median, 0.41) and between 0.75 and 2.20 for FMISO (median,1.59). FMISO T/C R >1 in six lesions suggested the presence of hypoxic tissue. There was no correlation between FMISO and FDG uptake in individual chordomas (r = 0.18, p = 0.7). Conclusion: FMISO PET/CT enables imaging of the hypoxic component in residual chordomas. In the future, it could help to better define boosted volumes for irradiation and to overcome the radioresistance of these lesions. No relationship was founded between hypoxia and glucose metabolism in these tumors after initial surgery.

  14. Ultrasound-modulated optical tomography 

    E-Print Network [OSTI]

    Nam, Haewon

    2004-09-30T23:59:59.000Z

    Ultrasound-modulated optical tomography is modeled by a linear integral equation and an inverse problem involving a diffusion equation in n spatial dimensions, n=2, 3. Based on measured data, the optical absorption coefficient ?...

  15. Teleseismic transmission and reflection tomography

    E-Print Network [OSTI]

    Burdick, Scott A. (Scott Anthony)

    2014-01-01T23:59:59.000Z

    The aim of seismic tomography is to determine a model of Earth properties that best explain observed seismic data. In practice, the limitations placed on our observations and computational capabilities force us to make a ...

  16. Mathematical Problems of Thermoacoustic Tomography 

    E-Print Network [OSTI]

    Nguyen, Linh V.

    2010-10-12T23:59:59.000Z

    Thermoacoustic tomography (TAT) is a newly emerging modality in biomedical imaging. It combines the good contrast of electromagnetic and good resolution of ultrasound imaging. The mathematical model of TAT is the observability problem for the wave...

  17. EMISSION AND TRANSMISSION NOISE PROPAGATION IN POSITRON EMISSION COMPUTED TOMOGRAPHY

    E-Print Network [OSTI]

    Gullberg, G.T.

    2010-01-01T23:59:59.000Z

    High Resolution Computed Tomography of Positron Emitters,"of Dynamic Emission Computed Tomography," J. Nucl. Med. ~:IN POSITRON EMISSION COMPUTED TOMOGRAPHY RECEIVED lAWRENCE

  18. SINGLE-PHOTON EMISSION COMPUTED TOMOGRAPHY: COMPENSATION FOR CONSTANT ATTENUATION

    E-Print Network [OSTI]

    Gullberg, Grant T.

    2013-01-01T23:59:59.000Z

    in radionuclide computed tomography," IEEE Trans. Nucl.49. M.E.Phelps, Emission computed tomography,~~ Seminars inSINGLE-PHOTON EMISSION COMPUTED TOMOGRAPHY: COMPENSATION FOR

  19. Thermal Neutron Computed Tomography of Soil Water and Plant Roots

    E-Print Network [OSTI]

    Leanne G. Tumlinson; Hungyuan Liu; Wendy K. Silk; Jan W. Hopmans

    2007-01-01T23:59:59.000Z

    2000. 3D neutron computed tomography: Requirements and2002. Using x-ray computed tomography in hydrology: Systems,of neutron computed tomography in the geosciences. Nucl.

  20. Frequency of Incidental Findings on Computed Tomography of Trauma Patients

    E-Print Network [OSTI]

    Devine, Alicia S; Jackson, Corinne S; Lyons, Lisa; Mason, Jon D

    2010-01-01T23:59:59.000Z

    findings on trauma computed tomography scans: experience atfindings in brain computed tomography scans of 3000 headfindings on chest computed tomography angiography performed

  1. Patient Attitudes Regarding Consent for Emergency Department Computed Tomographies

    E-Print Network [OSTI]

    Weigner, Michael B; Basham, Hilary F; Dewar, Kate M; Rupp, Valerie A; Cornelius, Llewellyn; Greenberg, Marna Rayl

    2014-01-01T23:59:59.000Z

    associated with common Computed Tomography examinations andRegarding Consent for Computed Tomographies ucm2007191.htm.for Emergency Department Computed Tomographies Lehigh Valley

  2. advanced computed tomography: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2007-01-01 4 Geometric Tomography: A Limited-View Approach for Computed Tomography Computer Technologies and Information Sciences Websites Summary: Geometric Tomography: A...

  3. Evaluation of Vascular Supply with Angio-Computed Tomography During Intra-Arterial Chemotherapy for Brain Tumors

    SciTech Connect (OSTI)

    Hirai, Toshinori, E-mail: toshinor@beige.ocn.ne.jp; Korogi, Yukunori [Kumamoto University School of Medicine, Department of Radiology (Japan); Ono, Ken [Amakusa Medical Center, Department of Radiology (Japan); Yamashita, Yasuyuki [Kumamoto University School of Medicine, Department of Radiology (Japan)

    2005-04-15T23:59:59.000Z

    We report the utility of a combined angiography and computed tomography (angio-CT) system in assessing drug distribution to the tumor during intra-arterial chemotherapy for metastatic brain tumors in a 65-year-old man. Although digital subtraction angiography did not clearly show tumor perfusion in two cerebellar tumors, angio-CT provided definite tumor perfusion in the complicated vascular territory, and anticancer agents were infused based on its findings. To our knowledge, however, this application for intra-arterial chemotherapy of brain tumors has not been previously described.

  4. High-speed digitization readout of silicon photomultipliers for time of flight positron emission tomography

    SciTech Connect (OSTI)

    Ronzhin, A.; Los, S.; Martens, M.; Ramberg, E.; /Fermilab; Kim, H.; Chen, C.; Kao, C.; /Chicago U.; Niessen, K.; /SUNY, Buffalo; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez; Mazzillo, M.; Carbone, B.; /SGS Thomson, Catania

    2011-02-01T23:59:59.000Z

    We report on work to develop a system with about 100 picoseconds (ps) time resolution for time of flight positron emission tomography [TOF-PET]. The chosen photo detectors for the study were Silicon Photomultipliers (SiPM's). This study was based on extensive experience in studying timing properties of SiPM's. The readout of these devices used the commercial high speed digitizer DRS4. We applied different algorithms to get the best time resolution of 155 ps Guassian (sigma) for a LYSO crystal coupled to a SiPM. We consider the work as a first step in building a prototype TOF-PET module. The field of positron-emission-tomography (PET) has been rapidly developing. But there are significant limitations in how well current PET scanners can reconstruct images, related to how fast data can be acquired, how much volume they can image, and the spatial and temporal resolution of the generated photons. Typical modern scanners now include multiple rings of detectors, which can image a large volume of the patient. In this type of scanner, one can treat each ring as a separate detector and require coincidences only within the ring, or treat the entire region viewed by the scanner as a single 3 dimensional volume. This 3d technique has significantly better sensitivity since more photon pair trajectories are accepted. However, the scattering of photons within the volume of the patient, and the effect of random coincidences limits the technique. The advent of sub-nanosecond timing resolution detectors means that there is potentially much better rejection of scattered photon events and random coincidence events in the 3D technique. In addition, if the timing is good enough, then the origin of photons pairs can be determined better, resulting in improved spatial resolution - so called 'Time-of-Flight' PET, or TOF-PET. Currently a lot of activity has occurred in applications of SiPMs for TOF-PET. This is due to the devices very good time resolution, low profile, lack of high voltage needed, and their non-sensitivity to magnetic fields. While investigations into this technique have begun elsewhere, we feel that the extensive SiPM characterization and data acquisition expertise of Fermilab, and the historical in-depth research of PET imaging at University of Chicago will combine to make significant strides in this field. We also benefit by a working relationship with the SiPM producer STMicroelectronics (STM).

  5. Preventive maintenance system for the photomultiplier detector blocks of PET scanners

    DOE Patents [OSTI]

    Levy, A.V.; Warner, D.

    1995-01-24T23:59:59.000Z

    A system including a method and apparatus for preventive maintenance of PET scanner photomultiplier detector blocks is disclosed. The qualitative comparisons used in the method of the present invention to provide an indication in the form of a display or printout advising the user that the photomultiplier block is stable, intermittently unstable, or drifting unstable, and also advising of the expected date of failure of a photomultiplier block in the PET scanner. The system alerts the user to replace the defective photomultiplier block prior to catastrophic failure in a scheduled preventative maintenance program, thus eliminating expensive and unscheduled downtime of the PET scanner due to photomultiplier failure. The apparatus for carrying out the method of the present invention preferably resides in the host computer controlling a PET scanner. It includes a memory adapted for storing a record of a number of iterative adjustments that are necessary to calibrate the gain of a photomultiplier detector block i at a time t[sub 0], a time t[sub 1] and a time T, where T>t[sub 1]>t[sub 0], which is designated as Histo(i,j(t)). The apparatus also includes a processor configured by a software program or a combination of programmed RAM and ROM devices to perform a number of calculations and operations on these values, and also includes a counter for analyzing each photomultiplier detector block i=1 through I of a PET scanner. 40 figures.

  6. Preventive maintenance system for the photomultiplier detector blocks of pet scanners

    DOE Patents [OSTI]

    Levy, Alejandro V. (Center Moriches, NY); Warner, Donald (Shirley, NY)

    1995-01-24T23:59:59.000Z

    A system including a method and apparatus for preventive maintenance of PET scanner photomultiplier detector blocks is disclosed. The quantitive comparisons used in the method of the present invention to provide an indication in the form of a display or printout advising the user that the photomultiplier block is stable, intermittently unstable, or drifting unstable, and also advising of the expected date of failure of a photomultiplier block in the PET scanner. The system alerts the user to replace the defective photomultiplier block prior to catastrophic failure in a scheduled preventative maintenance program, thus eliminating expensive and unscheduled downtime of the PET scanner due to photomultiplier failure. The apparatus for carrying out the method of the present invention preferably resides in the host computer controlling a PET scanner. It includes a memory adapted for storing a record of a number of iterative adjustments that are necessary to calibrate the gain of a photomultiplier detector block i at a time t.sub.0, a time t.sub.1 and a time T, where T>t.sub.1 >t.sub.0, which is designated as Histo(i,j(t)). The apparatus also includes a processor configured by a software program or a combination of programmed RAM and ROM devices to perform a number of calculations and operations on these values, and also includes a counter for analyzing each photomultiplier detector block i=1 through I of a PET scanner.

  7. Application of the optically stimulated luminescence (OSL) technique for mouse dosimetry in micro-CT imaging

    SciTech Connect (OSTI)

    Vrigneaud, Jean-Marc; Courteau, Alan; Oudot, Alexandra; Collin, Bertrand [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex (France)] [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex (France); Ranouil, Julien [Landauer Europe, 33 avenue du Général Leclerc, Fontenay-aux-Roses 92266 Cedex (France)] [Landauer Europe, 33 avenue du Général Leclerc, Fontenay-aux-Roses 92266 Cedex (France); Morgand, Loïc; Raguin, Olivier [Oncodesign, 20 rue Jean Mazen, Dijon 21076 Cedex (France)] [Oncodesign, 20 rue Jean Mazen, Dijon 21076 Cedex (France); Walker, Paul [LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France)] [LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France); Brunotte, François [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex, France and LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France)] [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex, France and LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France)

    2013-12-15T23:59:59.000Z

    Purpose: Micro-CT is considered to be a powerful tool to investigate various models of disease on anesthetized animals. In longitudinal studies, the radiation dose delivered by the micro-CT to the same animal is a major concern as it could potentially induce spurious effects in experimental results. Optically stimulated luminescence dosimeters (OSLDs) are a relatively new kind of detector used in radiation dosimetry for medical applications. The aim of this work was to assess the dose delivered by the CT component of a micro-SPECT (single-photon emission computed tomography)/CT camera during a typical whole-body mouse study, using commercially available OSLDs based on Al{sub 2}O{sub 3}:C crystals.Methods: CTDI (computed tomography dose index) was measured in micro-CT with a properly calibrated pencil ionization chamber using a rat-like phantom (60 mm in diameter) and a mouse-like phantom (30 mm in diameter). OSLDs were checked for reproducibility and linearity in the range of doses delivered by the micro-CT. Dose measurements obtained with OSLDs were compared to those of the ionization chamber to correct for the radiation quality dependence of OSLDs in the low-kV range. Doses to tissue were then investigated in phantoms and cadavers. A 30 mm diameter phantom, specifically designed to insert OSLDs, was used to assess radiation dose over a typical whole-body mouse imaging study. Eighteen healthy female BALB/c mice weighing 27.1 ± 0.8 g (1 SD) were euthanized for small animal measurements. OLSDs were placed externally or implanted internally in nine different locations by an experienced animal technician. Five commonly used micro-CT protocols were investigated.Results: CTDI measurements were between 78.0 ± 2.1 and 110.7 ± 3.0 mGy for the rat-like phantom and between 169.3 ± 4.6 and 203.6 ± 5.5 mGy for the mouse-like phantom. On average, the displayed CTDI at the operator console was underestimated by 1.19 for the rat-like phantom and 2.36 for the mouse-like phantom. OSLDs exhibited a reproducibility of 2.4% and good linearity was found between 60 and 450 mGy. The energy scaling factor was calculated to be between 1.80 ± 0.16 and 1.86 ± 0.16, depending on protocol used. In phantoms, mean doses to tissue over a whole-body CT examination were ranging from 186.4 ± 7.6 to 234.9 ± 7.1 mGy. In mice, mean doses to tissue in the mouse trunk (thorax, abdomen, pelvis, and flanks) were between 213.0 ± 17.0 and 251.2 ± 13.4 mGy. Skin doses (3 OSLDs) were much higher with average doses between 350.6 ± 25.3 and 432.5 ± 34.1 mGy. The dose delivered during a topogram was found to be below 10 mGy. Use of the multimouse bed of the system gave a significantly 20%–40% lower dose per animal (p < 0.05).Conclusions: Absorbed doses in micro-CT were found to be relatively high. In micro-SPECT/CT imaging, the micro-CT unit is mainly used to produce a localization frame. As a result, users should pay attention to adjustable CT parameters so as to minimize the radiation dose and avoid any adverse radiation effects which may interfere with biological parameters studied.

  8. A wire scanner system for characterizing the BNL energy recovery LINAC beam position monitor system

    SciTech Connect (OSTI)

    Michnoff R.; Biscardi, C.; Cerniglia, P.; Degen, C.; Gassner, D.; Hoff, L.; Hulsart, R.

    2012-04-15T23:59:59.000Z

    A stepper motor controlled wire scanner system has recently been modified to support testing of the Brookhaven National Laboratory (BNL) Collider-Accelerator department's Energy Recovery Linac (ERL) beam position monitor (BPM) system. The ERL BPM consists of four 9.33 mm diameter buttons mounted at 90 degree spacing in a cube with 1.875 inch inside diameter. The buttons were designed by BNL and fabricated by Times Microwave Systems. Libera brilliance single pass BPM electronic modules with 700 MHz bandpass filter, manufactured by Instrumentation Technologies, will be used to measure the transverse beam positions at 14 locations around the ERL. The wire scanner assembly provides the ability to measure the BPM button response to a pulsed wire, and evaluate and calibrate the Libera position measurement electronics. A description of the wire scanner system and test result data will be presented.

  9. SU-E-I-93: Improved Imaging Quality for Multislice Helical CT Via Sparsity Regularized Iterative Image Reconstruction Method Based On Tensor Framelet

    SciTech Connect (OSTI)

    Nam, H [Ewha Womans University, Seoul, Seoul (Korea, Republic of); Guo, M [Shanghai JiaoTong University, Shanghai, Shanghai (China); Lee, K [Stanford University, Stanford, CA (United States); Li, R [Stanford University, Palo Alto, CA (United States); Xing, L [Stanford UniversitySchool of Medicine, Stanford, CA (United States); Gao, H [Shanghai Jiao Tong University, Shanghai, Shanghai (China)

    2014-06-01T23:59:59.000Z

    Purpose: Inspired by compressive sensing, sparsity regularized iterative reconstruction method has been extensively studied. However, its utility pertinent to multislice helical 4D CT for radiotherapy with respect to imaging quality, dose, and time has not been thoroughly addressed. As the beginning of such an investigation, this work carries out the initial comparison of reconstructed imaging quality between sparsity regularized iterative method and analytic method through static phantom studies using a state-of-art 128-channel multi-slice Siemens helical CT scanner. Methods: In our iterative method, tensor framelet (TF) is chosen as the regularization method for its superior performance from total variation regularization in terms of reduced piecewise-constant artifacts and improved imaging quality that has been demonstrated in our prior work. On the other hand, X-ray transforms and its adjoints are computed on-the-fly through GPU implementation using our previous developed fast parallel algorithms with O(1) complexity per computing thread. For comparison, both FDK (approximate analytic method) and Katsevich algorithm (exact analytic method) are used for multislice helical CT image reconstruction. Results: The phantom experimental data with different imaging doses were acquired using a state-of-art 128-channel multi-slice Siemens helical CT scanner. The reconstructed image quality was compared between TF-based iterative method, FDK and Katsevich algorithm with the quantitative analysis for characterizing signal-to-noise ratio, image contrast, and spatial resolution of high-contrast and low-contrast objects. Conclusion: The experimental results suggest that our tensor framelet regularized iterative reconstruction algorithm improves the helical CT imaging quality from FDK and Katsevich algorithm for static experimental phantom studies that have been performed.

  10. Cholecystokinin-Assisted Hydrodissection of the Gallbladder Fossa during FDG PET/CT-guided Liver Ablation

    SciTech Connect (OSTI)

    Tewari, Sanjit O., E-mail: tewaris@mskcc.org [Memorial Sloan-Kettering Cancer Center, Molecular Imaging and Therapy Service, Department of Radiology (United States); Petre, Elena N., E-mail: petree@mskcc.org [Memorial Sloan-Kettering Cancer Center, Interventional Radiology Service, Department of Radiology (United States); Osborne, Joseph, E-mail: osbornej@mskcc.org [Memorial Sloan-Kettering Cancer Center, Molecular Imaging and Therapy Service, Department of Radiology (United States)] [Memorial Sloan-Kettering Cancer Center, Molecular Imaging and Therapy Service, Department of Radiology (United States); Sofocleous, Constantinos T., E-mail: sofoclec@mskcc.org [Memorial Sloan-Kettering Cancer Center, Interventional Radiology Service, Department of Radiology (United States)

    2013-12-15T23:59:59.000Z

    A 68-year-old female with colorectal cancer developed a metachronous isolated fluorodeoxyglucose-avid (FDG-avid) segment 5/6 gallbladder fossa hepatic lesion and was referred for percutaneous ablation. Pre-procedure computed tomography (CT) images demonstrated a distended gallbladder abutting the segment 5/6 hepatic metastasis. In order to perform ablation with clear margins and avoid direct puncture and aspiration of the gallbladder, cholecystokinin was administered intravenously to stimulate gallbladder contraction before hydrodissection. Subsequently, the lesion was ablated successfully with sufficient margins, of greater than 1.0 cm, using microwave with ultrasound and FDG PET/CT guidance. The patient tolerated the procedure very well and was discharged home the next day.

  11. The influence of glass fibers on elongational viscosity studied by means of optical coherence tomography and X-ray computed tomography

    SciTech Connect (OSTI)

    Aigner, M., E-mail: michael.aigner@jku.at; Köpplmayr, T., E-mail: thomas.koepplmayr@jku.at, E-mail: Christian.lang@jku.at; Lang, C., E-mail: thomas.koepplmayr@jku.at, E-mail: Christian.lang@jku.at; Burzic, I., E-mail: ivana.burzic@jku.at, E-mail: juergen.miethlinger@jku.at; Miethlinger, J., E-mail: ivana.burzic@jku.at, E-mail: juergen.miethlinger@jku.at [Institute of Polymer Extrusion and Compounding, Johannes Kepler University Linz (Austria); Salaberger, D., E-mail: dietmar.salaberger@fh-wels.at [University of Applied Sciences Upper Austria (Austria); Buchsbaum, A., E-mail: andreas.buchsbaum@recendt.at; Leitner, M. [Research Center for Non Destructive Testing GmbH (Austria); Heise, B., E-mail: bettina.heise@jku.at [Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterization, ZONA, Austria and Institute for Knowledge-based Mathematical Systems, Johannes Kepler University Linz (Austria); Schausberger, S. E., E-mail: stefan.schausberger@jku.at; Stifter, D. [Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterization, ZONA (Austria)

    2014-05-15T23:59:59.000Z

    We report on the flow characteristics of glass-fiber-reinforced polymers in elongational rheometry. Unlike polymers with geometrically isotropic fillers, glass-fiber-reinforced polymers exhibit flow behavior and rheology that depend heavily on the orientation, the length distribution and the content of the fibers. One of the primary objectives of this study was to determine the effect of fiber orientation, concentration and distribution on the entrance pressure drop by means of optical coherence tomography (OCT), full-field optical coherence microscopy (FF-OCM), and X-ray computed tomography (X-CT). Both pressure drop and melt flow were analyzed using a special elongation die (Thermo Scientific X-Die [3]) for inline measurements. Samples with a variety of fiber volume fractions, fiber lengths and processing temperatures were measured.

  12. A multispectral scanner survey of the Salmon Site and surrounding area, Lamar County, Mississippi

    SciTech Connect (OSTI)

    Blohm, J.D.; Brewster, S.B. Jr.; Shines, J.E.

    1994-06-01T23:59:59.000Z

    An airborne multispectral scanner survey was conducted over the Salmon Site and the surrounding area in Lamar County, Mississippi, on May 8, 1992. Twelve-channel daytime multispectral data were collected from altitudes of 2,000 feet, 4,000 feet, and 6,000 feet above ground level. Large-scale color photography was acquired simultaneously with the scanner data. Three different composite images have been prepared to demonstrate the digital image enhancement techniques that can be applied to the data. The data that were acquired offer opportunity for further standard and customized analysis based on any specific environmental characterization issues associated with this site.

  13. Tomography of a laser wakefield accelerator Tomography of a laser wakefield accelerator

    E-Print Network [OSTI]

    history of laser-plasma accelerators is reviewed. The excitation of plasma waves by ultra-short laser Tomography of a laser wakefield accelerator Tomography of a laser wakefield accelerator 692220024 #12; Tomography of a laser wakefield accelerator i #12; Tomography of a laser

  14. "EMM Region","PC","IGCC","PC","Conv. CT","Adv. CT","Conv. CC...

    U.S. Energy Information Administration (EIA) Indexed Site

    "EMM Region","PC","IGCC","PC","Conv. CT","Adv. CT","Conv. CC","Adv. CC","Adv. CC wCCS","Fuel Cell","Nuclear","Biomass","MSW","On-shore Wind","Off-shore Wind","Solar...

  15. Thermoacoustic and Photoacoustic Tomography ... - Purdue University

    E-Print Network [OSTI]

    Plamen Stefanov

    2010-11-09T23:59:59.000Z

    Thermoacoustic and Photoacoustic Tomography with a variable continuous or discontinuous sound speed. Plamen Stefanov. Purdue University. Based on a ...

  16. Mathematics of Thermoacoustic and Photoacoustic Tomography

    E-Print Network [OSTI]

    Kuchment, Peter

    2007-01-01T23:59:59.000Z

    The paper presents a survey of mathematical problems, techniques, and challenges arising in the Thermoacoustic and Photoacoustic Tomography.

  17. Electron tomography of dislocation structures

    SciTech Connect (OSTI)

    Liu, G.S.; House, S.D.; Kacher, J. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 W. Green St., Urbana, IL 61801 (United States); Tanaka, M.; Higashida, K. [Department of Materials Science and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Robertson, I.M., E-mail: irobertson@wisc.edu [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 W. Green St., Urbana, IL 61801 (United States); Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2014-01-15T23:59:59.000Z

    Recent developments in the application of electron tomography for characterizing microstructures in crystalline solids are described. The underlying principles for electron tomography are presented in the context of typical challenges in adapting the technique to crystalline systems and in using diffraction contrast imaging conditions. Methods for overcoming the limitations associated with the angular range, the number of acquired images, and uniformity of image contrast are introduced. In addition, a method for incorporating the real space coordinate system into the tomogram is presented. As the approach emphasizes development of experimental solutions to the challenges, the solutions developed and implemented are presented in the form of examples.

  18. CT Offshore | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2,AUDIT REPORT Americium/CuriumAguaBBBWind-BrizaHKC WindCT Offshore Place:

  19. Mathematics of thermoacoustic and photoacoustic tomography

    E-Print Network [OSTI]

    Mathematics of thermoacoustic and photoacoustic tomography Peter Kuchment and Leonid Kunyansky in the Thermoacoustic and Photoacoustic To- mography. 1 Introduction Medical tomography has had a huge impact on medical succesfull example of such a combination is the Thermoacoustic Tomography (TAT) (also abbreviated as TCT) [50

  20. PROGRAMME SPECIFICATION Programme name Radiography (Computed Tomography);

    E-Print Network [OSTI]

    Weyde, Tillman

    1 PROGRAMME SPECIFICATION KEY FACTS Programme name Radiography (Computed Tomography); Radiography in a clinical speciality, for example, Computed Tomography, you must successfully complete the Computed-time The postgraduate programmes in Radiography provide advanced education in #12;2 Computed Tomography and Medical

  1. High Resolution Muon Computed Tomography at Neutrino Beam Facilities

    E-Print Network [OSTI]

    Burkhant Suerfu; Christopher G. Tully

    2015-01-28T23:59:59.000Z

    X-ray computed tomography (CT) has an indispensable role in constructing 3D images of objects made from light materials. However, limited by absorption coefficients, X-rays cannot deeply penetrate materials such as copper and lead. Here we show via simulation that muon beams can provide high resolution tomographic images of dense objects and of structures within the interior of dense objects. The effects of resolution broadening from multiple scattering diminish with increasing muon momentum. As the momentum of the muon increases, the contrast of the image goes down and therefore requires higher resolution in the muon spectrometer to resolve the image. The variance of the measured muon momentum reaches a minimum and then increases with increasing muon momentum. The impact of the increase in variance is to require a higher integrated muon flux to reduce fluctuations. The flux requirements and level of contrast needed for high resolution muon computed tomography are well matched to the muons produced in the pion decay pipe at a neutrino beam facility and what can be achieved for momentum resolution in a muon spectrometer. Such an imaging system can be applied in archaeology, art history, engineering, material identification and whenever there is a need to image inside a transportable object constructed of dense materials.

  2. Fuzzy Modeling of Electrical Impedance Tomography Image of the Lungs

    E-Print Network [OSTI]

    Tanaka, Harki; Galizia, Mauricio Stanzione; Sobrinho, Joao Batista Borges; Amato, Marcelo Britto Passos

    2007-01-01T23:59:59.000Z

    Electrical Impedance Tomography (EIT) is a functional imaging method that is being developed for bedside use in critical care medicine. Aiming at improving the chest anatomical resolution of EIT images we developed a fuzzy model based on EIT high temporal resolution and the functional information contained in the pulmonary perfusion and ventilation signals. EIT data from an experimental animal model were collected during normal ventilation and apnea while an injection of hypertonic saline was used as a reference . The fuzzy model was elaborated in three parts: a modeling of the heart, a pulmonary map from ventilation images and, a pulmonary map from perfusion images. Image segmentation was performed using a threshold method and a ventilation/perfusion map was generated. EIT images treated by the fuzzy model were compared with the hypertonic saline injection method and CT-scan images, presenting good results in both qualitative (the image obtained by the model was very similar to that of the CT-scan) and quant...

  3. Applications of demand analysis for the dairy industry using household scanner data

    E-Print Network [OSTI]

    Stockton, Matthew C.

    2005-02-17T23:59:59.000Z

    of the represented cities. 9 Table 2. Percent of Households by Region Region Percent East 20.3 West 20.0 South 34.3 Central 25.3 The scanner information was collected by date of purchase and included only those panelist that purchased...

  4. A glacier inventory for South Tyrol, Italy, based on airborne laser-scanner data

    E-Print Network [OSTI]

    Kerschner, Hanns

    A glacier inventory for South Tyrol, Italy, based on airborne laser-scanner data Christoph KNOLL-mail: christoph.knoll@uibk.ac.at ABSTRACT. A new approach to glacier inventory, based on airborne laser supervision. Earlier inventories, from 1983 and 1997, are used to compare changes in area, volume

  5. 2D X-ray scanner and its uses in laboratory reservoir characterization measurements

    SciTech Connect (OSTI)

    Maloney, D.; Doggett, K.

    1997-08-01T23:59:59.000Z

    X-ray techniques are used in petroleum laboratories for a variety of reservoir characterization measurements. This paper describes the configuration of a 2D X-ray scanner and many of the ways in which it simplifies and improves accuracy`s of laboratory measurements. Linear X-ray scanners are most often used to provide descriptions of fluid saturations within core plugs during flow tests. We configured our linear scanner for both horizontal and vertical movement. Samples can be scanned horizontally, vertically, or according to horizontal and vertical grids. X-ray measurements are fast, allowing measurements of two- and three-phase fluid saturations during both steady- and unsteady-state flow processes. Rock samples can be scanned while they are subjected to stress, pore pressure, and temperature conditions simulating those of a petroleum reservoir. Many types of measurements are possible by selecting appropriate X-ray power settings, dopes, filters, and collimator configurations. The scanner has been used for a variety of applications besides fluid saturation measurements. It is useful for measuring porosity distributions in rocks, concentrations of X-ray dopes within flow streams during tracer tests, gap widths in fracture flow cells, fluid interface levels in PVT cells and fluid separators, and other features and phenomena.

  6. LOW POWER SCANNER FOR HIGH-DENSITY ELECTRODE ARRAY NEURAL RECORDING

    E-Print Network [OSTI]

    Mahmoodi, Hamid

    of this research is to design a low power integrated system that can be used in vivo for scanning the electrode. A model created in Python provides input vectors and output comparison for the verification processLOW POWER SCANNER FOR HIGH-DENSITY ELECTRODE ARRAY NEURAL RECORDING A Thesis work submitted

  7. Teaching geometric modeling algorithms and data structures through laser scanner acquisition pipeline

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    measurements and finally its instantiation through 3D printing, are presented. Laser scanner acquisition, reconstruction and 3D printing lend well to teaching general concepts in geometric modeling for several reasons. First, starting and ending with real physical 3D objects (the talus and its 3D print) provide

  8. Simulation of dynamics-coupling in piezoelectric tube scanners by reduced order finite element analysis

    E-Print Network [OSTI]

    Fleming, Andrew J.

    and imperfections during the manufactur- ing process of the tube on the dynamics-coupling-caused errors in openSimulation of dynamics-coupling in piezoelectric tube scanners by reduced order finite element as the compensation of dynamics-coupling effects. The present article gives a detailed description of the fully

  9. Iterative reconstruction using a Monte Carlo based system transfer matrix for dedicated breast positron emission tomography

    SciTech Connect (OSTI)

    Saha, Krishnendu [Ohio Medical Physics Consulting, Dublin, Ohio 43017 (United States); Straus, Kenneth J.; Glick, Stephen J. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Chen, Yu. [Department of Radiation Oncology, Columbia University, New York, New York 10032 (United States)

    2014-08-28T23:59:59.000Z

    To maximize sensitivity, it is desirable that ring Positron Emission Tomography (PET) systems dedicated for imaging the breast have a small bore. Unfortunately, due to parallax error this causes substantial degradation in spatial resolution for objects near the periphery of the breast. In this work, a framework for computing and incorporating an accurate system matrix into iterative reconstruction is presented in an effort to reduce spatial resolution degradation towards the periphery of the breast. The GATE Monte Carlo Simulation software was utilized to accurately model the system matrix for a breast PET system. A strategy for increasing the count statistics in the system matrix computation and for reducing the system element storage space was used by calculating only a subset of matrix elements and then estimating the rest of the elements by using the geometric symmetry of the cylindrical scanner. To implement this strategy, polar voxel basis functions were used to represent the object, resulting in a block-circulant system matrix. Simulation studies using a breast PET scanner model with ring geometry demonstrated improved contrast at 45% reduced noise level and 1.5 to 3 times resolution performance improvement when compared to MLEM reconstruction using a simple line-integral model. The GATE based system matrix reconstruction technique promises to improve resolution and noise performance and reduce image distortion at FOV periphery compared to line-integral based system matrix reconstruction.

  10. Introduction to Positron Emission Tomography

    E-Print Network [OSTI]

    Oakes, Terry

    range: 1-10 mm Gamma-Ray range: 10 mm - 8 positron annihilation #12;Positron Emission Tomography #12;P.E.T. measures Concentration of Radioactivity 1) Gamma-rays escape from body: External detection possible. 2) Two gamma rays emitted at 180 when a positron annihilates: The annihilation occured somewhere

  11. The color of X-rays Spectral X-ray computed tomography using energy sensitive pixel detectors

    E-Print Network [OSTI]

    Schioppa, Enrico Junior

    Energy sensitive X-ray imaging detectors are produced by connecting a semiconductor sensor to a spectroscopic pixel readout chip. In this thesis, the applicability of such detectors to X-ray Computed Tomography (CT) is studied. A prototype Medipix based silicon detector is calibrated using X-ray fluorescence. The charge transport properties of the sensor are characterized using a high energy beam of charged particles at the Super Proton Synchrotron (SPS) at the European Center for Nuclear Research (CERN). Monochromatic X-rays at the European Synchrotron Radiation Facility (ESRF) are used to determined the energy response function. These data are used to implement a physics-based CT projection operator that accounts for the transmission of the source spectrum through the sample and detector effects. Based on this projection operator, an iterative spectral CT reconstruction algorithm is developed by extending an Ordered Subset Expectation Maximization (OSEM) method. Subsequently, a maximum likelihood based algo...

  12. Statistical model based iterative reconstruction (MBIR) in clinical CT systems: Experimental assessment of noise performance

    SciTech Connect (OSTI)

    Li, Ke; Tang, Jie [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Chen, Guang-Hong, E-mail: gchen7@wisc.edu [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)] [Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin 53705 and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)

    2014-04-15T23:59:59.000Z

    Purpose: To reduce radiation dose in CT imaging, the statistical model based iterative reconstruction (MBIR) method has been introduced for clinical use. Based on the principle of MBIR and its nonlinear nature, the noise performance of MBIR is expected to be different from that of the well-understood filtered backprojection (FBP) reconstruction method. The purpose of this work is to experimentally assess the unique noise characteristics of MBIR using a state-of-the-art clinical CT system. Methods: Three physical phantoms, including a water cylinder and two pediatric head phantoms, were scanned in axial scanning mode using a 64-slice CT scanner (Discovery CT750 HD, GE Healthcare, Waukesha, WI) at seven different mAs levels (5, 12.5, 25, 50, 100, 200, 300). At each mAs level, each phantom was repeatedly scanned 50 times to generate an image ensemble for noise analysis. Both the FBP method with a standard kernel and the MBIR method (Veo{sup ®}, GE Healthcare, Waukesha, WI) were used for CT image reconstruction. Three-dimensional (3D) noise power spectrum (NPS), two-dimensional (2D) NPS, and zero-dimensional NPS (noise variance) were assessed both globally and locally. Noise magnitude, noise spatial correlation, noise spatial uniformity and their dose dependence were examined for the two reconstruction methods. Results: (1) At each dose level and at each frequency, the magnitude of the NPS of MBIR was smaller than that of FBP. (2) While the shape of the NPS of FBP was dose-independent, the shape of the NPS of MBIR was strongly dose-dependent; lower dose lead to a “redder” NPS with a lower mean frequency value. (3) The noise standard deviation (?) of MBIR and dose were found to be related through a power law of ????(dose){sup ??} with the component ? ? 0.25, which violated the classical ????(dose){sup ?0.5} power law in FBP. (4) With MBIR, noise reduction was most prominent for thin image slices. (5) MBIR lead to better noise spatial uniformity when compared with FBP. (6) A composite image generated from two MBIR images acquired at two different dose levels (D1 and D2) demonstrated lower noise than that of an image acquired at a dose level of D1+D2. Conclusions: The noise characteristics of the MBIR method are significantly different from those of the FBP method. The well known tradeoff relationship between CT image noise and radiation dose has been modified by MBIR to establish a more gradual dependence of noise on dose. Additionally, some other CT noise properties that had been well understood based on the linear system theory have also been altered by MBIR. Clinical CT scan protocols that had been optimized based on the classical CT noise properties need to be carefully re-evaluated for systems equipped with MBIR in order to maximize the method's potential clinical benefits in dose reduction and/or in CT image quality improvement.

  13. Julie A. Arruda R.T.(R) Woods Hole Oceanographic Institution Massachusetts Eye & Ear Infirmary

    E-Print Network [OSTI]

    and necropsies of specimens. Equipment and Training: · Siemens Volume Zoom CT scanner · Siemens Emotion CT hours. Equipment and Training: · 3.0 T Philips Achieva MRI scanner · 1.5T Siemens Magnatom Vision MRI scanner · Siemens Sensation CT scanner · Siemens Volume Zoom CT scanner · Siemens Plus-4 CT scanner 1986

  14. Siemens AG, CT, September 2001 CORPORATETECHNOLOGY

    E-Print Network [OSTI]

    s © Siemens AG, CT, September 2001 CORPORATETECHNOLOGY Research and Technology at Siemens Transportation Power Information & Communications Health Automation & Control #12;2© Siemens AGResearch and Technology at Siemens CORPORATETECHNOLOGY CT / E 020 a - 02.01 Key Figures for 2000 Amounts in billions

  15. A comparison of CT- and ultrasound-based imaging to localize the prostate for external beam radiotherapy

    SciTech Connect (OSTI)

    McNair, Helen A. [Department of Radiotherapy, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom)]. E-mail: Helen.McNair@rmh.nhs.uk; Mangar, Stephen A. [Department of Academic Urology Unit, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Coffey, Jerome [Department of Academic Urology Unit, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Shoulders, Beverley [Department of Radiotherapy, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Hansen, Vibeke N. [Department of Physics, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Norman, Andrew [Department of Radiotherapy, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Department of Physics, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Department of Radiology, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Department of Academic Urology Unit, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Staffurth, John [Department of Academic Urology Unit, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Sohaib, S. Aslam [Department of Radiology, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Warrington, Alan P. [Department of Physics, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom); Dearnaley, David P. [Department of Academic Urology Unit, Royal Marsden NHS Foundation Trust, Sutton (United Kingdom)

    2006-07-01T23:59:59.000Z

    Purpose: This study assesses the accuracy of NOMOS B-mode acquisition and targeting system (BAT) compared with computed tomography (CT) in localizing the prostate. Methods and Materials: Twenty-six patients were CT scanned, and the prostate was localized by 3 observers using the BAT system. The BAT couch shift measurements were compared with the CT localization. Six of the patients had gold markers present in the prostate, and the prostate movement determined by BAT was compared with the movement determined by the gold markers. Results: Using the BAT system, the 3 observers determined the prostate position to be a mean of 1-5 mm over all directions with respect to the CT. The proportion of readings with a difference >3 mm between the observers was in the range of 25% to 44%. The prostate movement based on gold markers was an average of 3-5 mm different from that measured by BAT. The literature assessing the accuracy and reproducibility on BAT is summarized and compared with our findings. Conclusions: We have found that there are systematic differences between the BAT-defined prostate position compared with that estimated on CT using gold grain marker seeds.

  16. A Fast local Reconstruction algorithm by selective backprojection for Low-Dose in Dental Computed Tomography

    E-Print Network [OSTI]

    Bin, Yan; Yu, Han; Feng, Zhang; Chao, Wang Xian; Lei, Li

    2013-01-01T23:59:59.000Z

    High radiation dose in computed tomography (CT) scans increases the lifetime risk of cancer, which become a major clinical concern. The backprojection-filtration (BPF) algorithm could reduce radiation dose by reconstructing images from truncated data in a short scan. In dental CT, it could reduce radiation dose for the teeth by using the projection acquired in a short scan, and could avoid irradiation to other part by using truncated projection. However, the limit of integration for backprojection varies per PI-line, resulting in low calculation efficiency and poor parallel performance. Recently, a tent BPF (T-BPF) has been proposed to improve calculation efficiency by rearranging projection. However, the memory-consuming data rebinning process is included. Accordingly, the chose-BPF (C-BPF) algorithm is proposed in this paper. In this algorithm, the derivative of projection is backprojected to the points whose x coordinate is less than that of the source focal spot to obtain the differentiated backprojection...

  17. Correlation between internal fiducial tumor motion and external marker motion for liver tumors imaged with 4D-CT

    SciTech Connect (OSTI)

    Beddar, A. Sam [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)]. E-mail: abeddar@mdanderson.org; Kainz, Kristofer [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Briere, Tina Marie [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Tsunashima, Yoshikazu [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Pan Tinsu [Department of Diagnostic Imaging, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Prado, Karl [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Mohan, Radhe [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Gillin, Michael [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Krishnan, Sunil [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

    2007-02-01T23:59:59.000Z

    Purpose: We investigated the correlation between the motions of an external marker and internal fiducials implanted in the liver for 8 patients undergoing respiratory-based computed tomography (four-dimensional CT [4D-CT]) procedures. Methods and Materials: The internal fiducials were gold seeds, 3 mm in length and 1.2 mm in diameter. Four patients each had one implanted fiducial, and the other four had three implanted fiducials. The external marker was a plastic box, which is part of the Real-Time Position Management System (RPM) used to track the patient's respiration. Each patient received a standard helical CT scan followed by a time-correlated CT-image acquisition (4D-CT). The 4D-CT images were reconstructed in 10 separate phases covering the entire respiratory cycle. Results: The internal fiducial motion is predominant in the superior-inferior direction, with a range of 7.5-17.5 mm. The correlation between external respiration and internal fiducial motion is best during expiration. For 2 patients with their three fiducials separated by a maximum of 3.2 cm, the motions of the fiducials were well correlated, whereas for 2 patients with more widely spaced fiducials, there was less correlation. Conclusions: In general, there is a good correlation between internal fiducial motion imaged by 4D-CT and external marker motion. We have demonstrated that gating may be best performed at the end of the respiratory cycle. Special attention should be paid to gating for patients whose fiducials do not move in synchrony, because targeting on the correct respiratory amplitude alone would not guarantee that the entire tumor volume is within the treatment field.

  18. Impact of Computed Tomography Image Quality on Image-Guided Radiation Therapy Based on Soft Tissue Registration

    SciTech Connect (OSTI)

    Morrow, Natalya V.; Lawton, Colleen A. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Qi, X. Sharon [Department of Radiation Oncology, University of Colorado Denver, Denver, Colorado (United States); Li, X. Allen, E-mail: ali@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin (United States)

    2012-04-01T23:59:59.000Z

    Purpose: In image-guided radiation therapy (IGRT), different computed tomography (CT) modalities with varying image quality are being used to correct for interfractional variations in patient set-up and anatomy changes, thereby reducing clinical target volume to the planning target volume (CTV-to-PTV) margins. We explore how CT image quality affects patient repositioning and CTV-to-PTV margins in soft tissue registration-based IGRT for prostate cancer patients. Methods and Materials: Four CT-based IGRT modalities used for prostate RT were considered in this study: MV fan beam CT (MVFBCT) (Tomotherapy), MV cone beam CT (MVCBCT) (MVision; Siemens), kV fan beam CT (kVFBCT) (CTVision, Siemens), and kV cone beam CT (kVCBCT) (Synergy; Elekta). Daily shifts were determined by manual registration to achieve the best soft tissue agreement. Effect of image quality on patient repositioning was determined by statistical analysis of daily shifts for 136 patients (34 per modality). Inter- and intraobserver variability of soft tissue registration was evaluated based on the registration of a representative scan for each CT modality with its corresponding planning scan. Results: Superior image quality with the kVFBCT resulted in reduced uncertainty in soft tissue registration during IGRT compared with other image modalities for IGRT. The largest interobserver variations of soft tissue registration were 1.1 mm, 2.5 mm, 2.6 mm, and 3.2 mm for kVFBCT, kVCBCT, MVFBCT, and MVCBCT, respectively. Conclusions: Image quality adversely affects the reproducibility of soft tissue-based registration for IGRT and necessitates a careful consideration of residual uncertainties in determining different CTV-to-PTV margins for IGRT using different image modalities.

  19. Reconstruction for proton computed tomography by tracing proton trajectories: A Monte Carlo study

    SciTech Connect (OSTI)

    Li Tianfang; Liang Zhengrong; Singanallur, Jayalakshmi V.; Satogata, Todd J.; Williams, David C.; Schulte, Reinhard W. [Departments of Radiology, Computer Science, and Physics and Astronomy, State University of New York at Stony Brook, Stony Brook, New York 11794 (United States); Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States); Santa Cruz Institute for Particle Physics, University of California at Santa Cruz, Santa Cruz, California 95064 (United States); Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, California 92354 (United States)

    2006-03-15T23:59:59.000Z

    Proton computed tomography (pCT) has been explored in the past decades because of its unique imaging characteristics, low radiation dose, and its possible use for treatment planning and on-line target localization in proton therapy. However, reconstruction of pCT images is challenging because the proton path within the object to be imaged is statistically affected by multiple Coulomb scattering. In this paper, we employ GEANT4-based Monte Carlo simulations of the two-dimensional pCT reconstruction of an elliptical phantom to investigate the possible use of the algebraic reconstruction technique (ART) with three different path-estimation methods for pCT reconstruction. The first method assumes a straight-line path (SLP) connecting the proton entry and exit positions, the second method adapts the most-likely path (MLP) theoretically determined for a uniform medium, and the third method employs a cubic spline path (CSP). The ART reconstructions showed progressive improvement of spatial resolution when going from the SLP [2 line pairs (lp) cm{sup -1}] to the curved CSP and MLP path estimates (5 lp cm{sup -1}). The MLP-based ART algorithm had the fastest convergence and smallest residual error of all three estimates. This work demonstrates the advantage of tracking curved proton paths in conjunction with the ART algorithm and curved path estimates.

  20. Measurement of breast tissue composition with dual energy cone-beam computed tomography: A postmortem study

    SciTech Connect (OSTI)

    Ding Huanjun; Ducote, Justin L.; Molloi, Sabee [Department of Radiological Sciences, University of California, Irvine, California 92697 (United States)

    2013-06-15T23:59:59.000Z

    Purpose: To investigate the feasibility of a three-material compositional measurement of water, lipid, and protein content of breast tissue with dual kVp cone-beam computed tomography (CT) for diagnostic purposes. Methods: Simulations were performed on a flat panel-based computed tomography system with a dual kVp technique in order to guide the selection of experimental acquisition parameters. The expected errors induced by using the proposed calibration materials were also estimated by simulation. Twenty pairs of postmortem breast samples were imaged with a flat-panel based dual kVp cone-beam CT system, followed by image-based material decomposition using calibration data obtained from a three-material phantom consisting of water, vegetable oil, and polyoxymethylene plastic. The tissue samples were then chemically decomposed into their respective water, lipid, and protein contents after imaging to allow direct comparison with data from dual energy decomposition. Results: Guided by results from simulation, the beam energies for the dual kVp cone-beam CT system were selected to be 50 and 120 kVp with the mean glandular dose divided equally between each exposure. The simulation also suggested that the use of polyoxymethylene as the calibration material for the measurement of pure protein may introduce an error of -11.0%. However, the tissue decomposition experiments, which employed a calibration phantom made out of water, oil, and polyoxymethylene, exhibited strong correlation with data from the chemical analysis. The average root-mean-square percentage error for water, lipid, and protein contents was 3.58% as compared with chemical analysis. Conclusions: The results of this study suggest that the water, lipid, and protein contents can be accurately measured using dual kVp cone-beam CT. The tissue compositional information may improve the sensitivity and specificity for breast cancer diagnosis.

  1. Correlation between model observer and human observer performance in CT imaging when lesion location is uncertain

    SciTech Connect (OSTI)

    Leng, Shuai; Yu, Lifeng; Zhang, Yi; McCollough, Cynthia H. [Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States)] [Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States); Carter, Rickey [Department of Biostatistics, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States)] [Department of Biostatistics, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States); Toledano, Alicia Y. [Biostatistics Consulting, LLC, 10606 Wheatley Street, Kensington, Maryland 20895 (United States)] [Biostatistics Consulting, LLC, 10606 Wheatley Street, Kensington, Maryland 20895 (United States)

    2013-08-15T23:59:59.000Z

    Purpose: The purpose of this study was to investigate the correlation between model observer and human observer performance in CT imaging for the task of lesion detection and localization when the lesion location is uncertain.Methods: Two cylindrical rods (3-mm and 5-mm diameters) were placed in a 35 × 26 cm torso-shaped water phantom to simulate lesions with ?15 HU contrast at 120 kV. The phantom was scanned 100 times on a 128-slice CT scanner at each of four dose levels (CTDIvol = 5.7, 11.4, 17.1, and 22.8 mGy). Regions of interest (ROIs) around each lesion were extracted to generate images with signal-present, with each ROI containing 128 × 128 pixels. Corresponding ROIs of signal-absent images were generated from images without lesion mimicking rods. The location of the lesion (rod) in each ROI was randomly distributed by moving the ROIs around each lesion. Human observer studies were performed by having three trained observers identify the presence or absence of lesions, indicating the lesion location in each image and scoring confidence for the detection task on a 6-point scale. The same image data were analyzed using a channelized Hotelling model observer (CHO) with Gabor channels. Internal noise was added to the decision variables for the model observer study. Area under the curve (AUC) of ROC and localization ROC (LROC) curves were calculated using a nonparametric approach. The Spearman's rank order correlation between the average performance of the human observers and the model observer performance was calculated for the AUC of both ROC and LROC curves for both the 3- and 5-mm diameter lesions.Results: In both ROC and LROC analyses, AUC values for the model observer agreed well with the average values across the three human observers. The Spearman's rank order correlation values for both ROC and LROC analyses for both the 3- and 5-mm diameter lesions were all 1.0, indicating perfect rank ordering agreement of the figures of merit (AUC) between the average performance of the human observers and the model observer performance.Conclusions: In CT imaging of different sizes of low-contrast lesions (?15 HU), the performance of CHO with Gabor channels was highly correlated with human observer performance for the detection and localization tasks with uncertain lesion location in CT imaging at four clinically relevant dose levels. This suggests the ability of Gabor CHO model observers to meaningfully assess CT image quality for the purpose of optimizing scan protocols and radiation dose levels in detection and localization tasks for low-contrast lesions.

  2. Self-guided quantum tomography

    E-Print Network [OSTI]

    Christopher Ferrie

    2014-11-10T23:59:59.000Z

    We introduce a self-learning tomographic technique in which the experiment guides itself to an estimate of its own state. Self-guided quantum tomography (SGQT) uses measurements to directly test hypotheses in an iterative algorithm which converges to the true state. We demonstrate through simulation on many qubits that SGQT is a more efficient and robust alternative to the usual paradigm of taking a large amount of informationally complete data and solving the inverse problem of post-processed state estimation.

  3. Clinical Evaluation of Spatial Accuracy of a Fusion Imaging Technique Combining Previously Acquired Computed Tomography and Real-Time Ultrasound for Imaging of Liver Metastases

    SciTech Connect (OSTI)

    Hakime, Antoine, E-mail: thakime@yahoo.com; Deschamps, Frederic; Garcia Marques de Carvalho, Enio; Teriitehau, Christophe; Auperin, Anne; De Baere, Thierry [Gustave Roussy Institute (France)

    2011-04-15T23:59:59.000Z

    Purpose: This study was designed to evaluate the spatial accuracy of matching volumetric computed tomography (CT) data of hepatic metastases with real-time ultrasound (US) using a fusion imaging system (VNav) according to different clinical settings. Methods: Twenty-four patients with one hepatic tumor identified on enhanced CT and US were prospectively enrolled. A set of three landmarks markers was chosen on CT and US for image registration. US and CT images were then superimposed using the fusion imaging display mode. The difference in spatial location between the tumor visible on the CT and the US on the overlay images (reviewer no. 1, comment no. 2) was measured in the lateral, anterior-posterior, and vertical axis. The maximum difference (Dmax) was evaluated for different predictive factors.CT performed 1-30 days before registration versus immediately before. Use of general anesthesia for CT and US versus no anesthesia.Anatomic landmarks versus landmarks that include at least one nonanatomic structure, such as a cyst or a calcificationResultsOverall, Dmax was 11.53 {+-} 8.38 mm. Dmax was 6.55 {+-} 7.31 mm with CT performed immediately before VNav versus 17.4 {+-} 5.18 with CT performed 1-30 days before (p < 0.0001). Dmax was 7.05 {+-} 6.95 under general anesthesia and 16.81 {+-} 6.77 without anesthesia (p < 0.0015). Landmarks including at least one nonanatomic structure increase Dmax of 5.2 mm (p < 0.0001). The lowest Dmax (1.9 {+-} 1.4 mm) was obtained when CT and VNav were performed under general anesthesia, one immediately after the other. Conclusions: VNav is accurate when adequate clinical setup is carefully selected. Only under these conditions (reviewer no. 2), liver tumors not identified on US can be accurately targeted for biopsy or radiofrequency ablation using fusion imaging.

  4. Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated CodesTransparencyDOE Project Taps HPCNew4Organic Materials and

  5. Computed tomography image using sub-terahertz waves generated from a high-T{sub c} superconducting intrinsic Josephson junction oscillator

    SciTech Connect (OSTI)

    Kashiwagi, T., E-mail: kashiwagi@ims.tsukuba.ac.jp; Minami, H.; Kadowaki, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba (Japan); Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Nakade, K.; Saiwai, Y.; Kitamura, T.; Watanabe, C.; Ishida, K.; Sekimoto, S.; Asanuma, K.; Yasui, T.; Shibano, Y. [Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba (Japan); Tsujimoto, M. [Department of Electronic Science and Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510 (Japan); Yamamoto, T. [Wide Bandgap Materials Group, Optical and Electronic Materials Unit, Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Markovi?, B. [Faculty of Sciences, University of Montenegro, George Washington Str., 81000 Podgorica (Montenegro); Mirkovi?, J. [Faculty of Science, University of Montenegro, and CETI, Put Radomira Ivanovica, 81000 Podgorica (Montenegro); Klemm, R. A. [Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Orlando, Florida 32816-2385 (United States)

    2014-02-24T23:59:59.000Z

    A computed tomography (CT) imaging system using monochromatic sub-terahertz coherent electromagnetic waves generated from a device constructed from the intrinsic Josephson junctions in a single crystalline mesa structure of the high-T{sub c} superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+?} was developed and tested on three samples: Standing metallic rods supported by styrofoam, a dried plant (heart pea) containing seeds, and a plastic doll inside an egg shell. The images obtained strongly suggest that this CT imaging system may be useful for a variety of practical applications.

  6. STRIP-PET: a novel detector concept for the TOF-PET scanner

    E-Print Network [OSTI]

    Moskal, P; Bia?as, P; Ciszewska, M; Czerwi?ski, E; Heczko, A; Kajetanowicz, M; Kap?on, ?; Kochanowski, A; Konopka-Cupia?, G; Korcyl, G; Krzemie?, W; ?ojek, K; Majewski, J; Migda?, W; Molenda, M; Nied?wiecki, Sz; Pa?ka, M; Rudy, Z; Salabura, P; Silarski, M; S?omski, A; Smyrski, J; Zdebik, J; Zieli?ski, M

    2013-01-01T23:59:59.000Z

    We briefly present a design of a new PET scanner based on strips of polymer scintillators arranged in a barrel constituting a large acceptance detector. The solution proposed is based on the superior timing properties of the polymer scintillators. The position and time of the reaction of the gamma quanta in the detector material will be determined based on the time of arrival of light signals to the edges of the scintillator strips.

  7. A modified commercial scanner as an image plate for table-top optical applications

    SciTech Connect (OSTI)

    Casado-Rojo, S; Lorenzana, H E; Baonza, V G

    2008-12-09T23:59:59.000Z

    A reliable, accurate, and inexpensive optical detector for table-top applications is described here. Based on a commercial high resolution office scanner coupled to a projection on plate, it enables a large image plate surface, allowing recording of large images without systematic errors associated to coupling optics' aberrations. Several tests on distance-dependent and steady interference patterns will be presented and discussed. The extension to other types of optical measurement by substituting the projection on plate is proposed.

  8. A multispectral scanner survey of the United States Department of Energy's Paducah Gaseous Diffusion Plant

    SciTech Connect (OSTI)

    Not Available

    1991-06-01T23:59:59.000Z

    Airborne multispectral scanner data of the Paducah Gaseous Diffusion Plant (PGDP) and surrounding area were acquired during late spring 1990. This survey was conducted by the Remote Sensing Laboratory (RSL) which is operated by EG G Energy Measurements (EG G/EM) for the US Department of Energy (DOE) Nevada Operations Office. It was requested by the US Department of Energy (DOE) Environmental Audit Team which was reviewing environmental conditions at the facility. The objectives of this survey were to: (1) Acquire 12-channel, multispectral scanner data of the PGDP from an altitude of 3000 feet above ground level (AGL); (2) Acquire predawn, digital thermal infrared (TIR) data of the site from the same altitude; (3) Collect color and color-infrared (CIR) aerial photographs over the facilities; and (4) Illustrate how the analyses of these data could benefit environmental monitoring at the PGDP. This report summarizes the two multispectral scanner and aerial photographic missions at the Paducah Gaseous Diffusion Plant. Selected examples of the multispectral data are presented to illustrate its potential for aiding environmental management at the site. 4 refs., 1 fig., 2 tabs.

  9. LANSCE-R WIRE-SCANNER ANALOG FRONT-END ELECTRONICS

    SciTech Connect (OSTI)

    Gruchalla, Michael E. [Los Alamos National Laboratory

    2011-01-01T23:59:59.000Z

    A new AFE is being developed for the new LANSCE-R wire-scanner systems. The new AFE is implemented in a National Instruments Compact RIO (cRIO) module installed a BiRa 4U BiRIO cRIO chassis specifically designed to accommodate the cRIO crate and all the wire-scanner interface, control and motor-drive electronics. A single AFE module provides interface to both X and Y wire sensors using true DC coupled transimpedance amplifiers providing collection of the wire charge signals, real-time wire integrity verification using the normal dataacquisition system, and wire bias of 0V to +/-50V. The AFE system is designed to accommodate comparatively long macropulses (>1ms) with high PRF (>120Hz) without the need to provide timing signals. The basic AFE bandwidth is flat from true DC to 50kHz with a true first-order pole at 50kHz. Numeric integration in the cRIO FPGA provides real-time pulse-to-pulse numeric integration of the AFE signal to compute the total charge collected in each macropulse. This method of charge collection eliminates the need to provide synchronization signals to the wire-scanner AFE while providing the capability to accurately record the charge from long macropulses at high PRF.

  10. THERMOACOUSTIC TOMOGRAPHY ARISING IN BRAIN IMAGING ...

    E-Print Network [OSTI]

    2011-02-21T23:59:59.000Z

    In this paper, we study the mathematical model of thermoacoustic and photoacoustic tomography for a sound speed that jumps across a smooth closed surface.

  11. Imaging and sensing based on muon tomography

    DOE Patents [OSTI]

    Morris, Christopher L; Saunders, Alexander; Sossong, Michael James; Schultz, Larry Joe; Green, J. Andrew; Borozdin, Konstantin N; Hengartner, Nicolas W; Smith, Richard A; Colthart, James M; Klugh, David C; Scoggins, Gary E; Vineyard, David C

    2012-10-16T23:59:59.000Z

    Techniques, apparatus and systems for detecting particles such as muons for imaging applications. Subtraction techniques are described to enhance the processing of the muon tomography data.

  12. Algorithm for Rapid Tomography of Gas Concentrations

    E-Print Network [OSTI]

    Price, P.N.

    2008-01-01T23:59:59.000Z

    sensing and computed tomography in industrial hygiene.American Industrial Hygiene Association Journal 51: 1165-indoor air. American Industrial Hygiene Association Journal

  13. On reconstruction and time reversal in thermoacoustic tomography in acoustically

    E-Print Network [OSTI]

    Kuchment, Peter

    On reconstruction and time reversal in thermoacoustic tomography in acoustically homogeneous of recent approaches to the reconstruction in thermoacoustic/photoacoustic tomography: backprojection of the problem of sound speed recovery is also provided. Keywords: Tomography, thermoacoustic, wave equation. AMS

  14. Two-dimensional ultrasonic computed tomography of growing bones.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Two-dimensional ultrasonic computed tomography of growing bones. P. Lasaygues, E. Franceschini, R: Ultrasonic Computed Tomography, Bone imaging, Born approximation, iterative distorted method I. INTRODUCTION imaging process, using ultrasonic computed tomography. Although this method is known to provide

  15. Computational confocal tomography for simultaneous reconstruction of objects, occlusions,

    E-Print Network [OSTI]

    Fainman, Yeshaiahu

    Computational confocal tomography for simultaneous reconstruction of objects, occlusions computationally intense and novel reconstruction methods that we called "compu- tational confocal tomography." The key to computed tomography is the collection of projections of the data over a range of angles

  16. CLINICAL RESEARCH Clinical Trials Coronary Computed Tomography Angiography

    E-Print Network [OSTI]

    CLINICAL RESEARCH Clinical Trials Coronary Computed Tomography Angiography for Early Triage computed tomography angiography (CTA) in patients with acute chest pain. Background Triage of chest pain disease (CAD), 31% had nonobstructive disease, and 19% had inconclusive or positive computed tomography

  17. Dynamic Computed Tomography, an algebraic reconstruction method with

    E-Print Network [OSTI]

    Promayon, Emmanuel

    Dynamic Computed Tomography, an algebraic reconstruction method with deformation compensation Sofia . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.2 Computed Tomography . . . . . . . . . . . . . . . . . . . . . . 8 1.3 Dynamic Computed . . . . . . . . . . . . . . . . . . . . . 9 2 Basic tools for Computed Tomography 10 2.1 The Radon Transform

  18. SU-E-I-82: Improving CT Image Quality for Radiation Therapy Using Iterative Reconstruction Algorithms and Slightly Increasing Imaging Doses

    SciTech Connect (OSTI)

    Noid, G; Chen, G; Tai, A; Li, X [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)

    2014-06-01T23:59:59.000Z

    Purpose: Iterative reconstruction (IR) algorithms are developed to improve CT image quality (IQ) by reducing noise without diminishing spatial resolution or contrast. For CT in radiation therapy (RT), slightly increasing imaging dose to improve IQ may be justified if it can substantially enhance structure delineation. The purpose of this study is to investigate and to quantify the IQ enhancement as a result of increasing imaging doses and using IR algorithms. Methods: CT images were acquired for phantoms, built to evaluate IQ metrics including spatial resolution, contrast and noise, with a variety of imaging protocols using a CT scanner (Definition AS Open, Siemens) installed inside a Linac room. Representative patients were scanned once the protocols were optimized. Both phantom and patient scans were reconstructed using the Sinogram Affirmed Iterative Reconstruction (SAFIRE) and the Filtered Back Projection (FBP) methods. IQ metrics of the obtained CTs were compared. Results: IR techniques are demonstrated to preserve spatial resolution as measured by the point spread function and reduce noise in comparison to traditional FBP. Driven by the reduction in noise, the contrast to noise ratio is doubled by adopting the highest SAFIRE strength. As expected, increasing imaging dose reduces noise for both SAFIRE and FBP reconstructions. The contrast to noise increases from 3 to 5 by increasing the dose by a factor of 4. Similar IQ improvement was observed on the CTs for selected patients with pancreas and prostrate cancers. Conclusion: The IR techniques produce a measurable enhancement to CT IQ by reducing the noise. Increasing imaging dose further reduces noise independent of the IR techniques. The improved CT enables more accurate delineation of tumors and/or organs at risk during RT planning and delivery guidance.

  19. Utilization of Computed Tomography Angiography in the Evaluation of Acute Pulmonary Embolus

    E-Print Network [OSTI]

    Constantino, Mary; Randall, Geneva; Gosselin, Marc; Vegas, Carl; Brandt, Marissa; Spinning, Kristopher

    2007-01-01T23:59:59.000Z

    providers. Utilization of Computed Tomography Angiography inappropriate use of computed tomography angiography (CTA) in

  20. Frequency and Clinical Significance of Previously Undetected Incidental Findings Detected on Computed Tomography Simulation Scans for Breast Cancer Patients

    SciTech Connect (OSTI)

    Nakamura, Naoki, E-mail: naokinak@luke.or.jp [Department of Radiation Oncology, St. Luke's International Hospital, Tokyo (Japan)] [Department of Radiation Oncology, St. Luke's International Hospital, Tokyo (Japan); Tsunoda, Hiroko [Department of Radiology, St. Luke's International Hospital, Tokyo (Japan)] [Department of Radiology, St. Luke's International Hospital, Tokyo (Japan); Takahashi, Osamu [Division of General Internal Medicine, Department of Medicine, St. Luke's International Hospital, Tokyo (Japan)] [Division of General Internal Medicine, Department of Medicine, St. Luke's International Hospital, Tokyo (Japan); Kikuchi, Mari; Honda, Satoshi [Department of Radiology, St. Luke's International Hospital, Tokyo (Japan)] [Department of Radiology, St. Luke's International Hospital, Tokyo (Japan); Shikama, Naoto [Department of Radiation Oncology, Saitama Medical University International Medical Center, Hidaka (Japan)] [Department of Radiation Oncology, Saitama Medical University International Medical Center, Hidaka (Japan); Akahane, Keiko; Sekiguchi, Kenji [Department of Radiation Oncology, St. Luke's International Hospital, Tokyo (Japan)] [Department of Radiation Oncology, St. Luke's International Hospital, Tokyo (Japan)

    2012-11-01T23:59:59.000Z

    Purpose: To determine the frequency and clinical significance of previously undetected incidental findings found on computed tomography (CT) simulation images for breast cancer patients. Methods and Materials: All CT simulation images were first interpreted prospectively by radiation oncologists and then double-checked by diagnostic radiologists. The official reports of CT simulation images for 881 consecutive postoperative breast cancer patients from 2009 to 2010 were retrospectively reviewed. Potentially important incidental findings (PIIFs) were defined as any previously undetected benign or malignancy-related findings requiring further medical follow-up or investigation. For all patients in whom a PIIF was detected, we reviewed the clinical records to determine the clinical significance of the PIIF. If the findings from the additional studies prompted by a PIIF required a change in management, the PIIF was also recorded as a clinically important incidental finding (CIIF). Results: There were a total of 57 (6%) PIIFs. The 57 patients in whom a PIIF was detected were followed for a median of 17 months (range, 3-26). Six cases of CIIFs (0.7% of total) were detected. Of the six CIIFs, three (50%) cases had not been noted by the radiation oncologist until the diagnostic radiologist detected the finding. On multivariate analysis, previous CT examination was an independent predictor for PIIF (p = 0.04). Patients who had not previously received chest CT examinations within 1 year had a statistically significantly higher risk of PIIF than those who had received CT examinations within 6 months (odds ratio, 3.54; 95% confidence interval, 1.32-9.50; p = 0.01). Conclusions: The rate of incidental findings prompting a change in management was low. However, radiation oncologists appear to have some difficulty in detecting incidental findings that require a change in management. Considering cost, it may be reasonable that routine interpretations are given to those who have not received previous chest CT examinations within 1 year.

  1. Methane hydrate distribution from prolonged and repeated formation in natural and compacted sand samples: X-ray CT observations

    SciTech Connect (OSTI)

    Rees, E.V.L.; Kneafsey, T.J.; Seol, Y.

    2010-07-01T23:59:59.000Z

    To study physical properties of methane gas hydrate-bearing sediments, it is necessary to synthesize laboratory samples due to the limited availability of cores from natural deposits. X-ray computed tomography (CT) and other observations have shown gas hydrate to occur in a number of morphologies over a variety of sediment types. To aid in understanding formation and growth patterns of hydrate in sediments, methane hydrate was repeatedly formed in laboratory-packed sand samples and in a natural sediment core from the Mount Elbert Stratigraphic Test Well. CT scanning was performed during hydrate formation and decomposition steps, and periodically while the hydrate samples remained under stable conditions for up to 60 days. The investigation revealed the impact of water saturation on location and morphology of hydrate in both laboratory and natural sediments during repeated hydrate formations. Significant redistribution of hydrate and water in the samples was observed over both the short and long term.

  2. Cone-Beam CT with Flat-Panel-Detector Digital Angiography System: Early Experience in Abdominal Interventional Procedures

    SciTech Connect (OSTI)

    Hirota, Shozo, E-mail: hirota-s@hyo-med.ac.jp; Nakao, Norio; Yamamoto, Satoshi; Kobayashi, Kaoru; Maeda, Hiroaki; Ishikura, Reiichi; Miura, Koui; Sakamoto, Kiyoshi [Hyogo College of Medicine, Department of Radiology (Japan); Ueda, Ken [Hitachi Medical Corporation, Research and Development Center (Japan); Baba, Rika [Hitachi Limited, Central Research Laboratory (Japan)

    2006-12-15T23:59:59.000Z

    We developed a cone-beam computed tomography (CBCT) system equipped with a large flat-panel detector. Data obtained by 200{sup o} rotation imaging are reconstructed by means of CBCT to generate three-dimensional images. We report the use of CBCT angiography using CBCT in 10 patients with 8 liver malignancies and 2 hypersplenisms during abdominal interventional procedures. CBCT was very useful for interventional radiologists to confirm a perfusion area of the artery catheter wedged on CT by injection of contrast media through the catheter tip, although the image quality was slightly degraded, scoring as 2.60 on average by streak artifacts. CBCT is space-saving because it does not require a CT system with a gantry, and it is also time-saving because it does not require the transfer of patients.

  3. ADAPTIVE AND ROBUST TECHNIQUES (ART) FOR THERMOACOUSTIC TOMOGRAPHY

    E-Print Network [OSTI]

    Xie, Yao

    ADAPTIVE AND ROBUST TECHNIQUES (ART) FOR THERMOACOUSTIC TOMOGRAPHY By YAO XIE A DISSERTATION.1 Thermoacoustic Tomography . . . . . . . . . . . . . . . . . . . . . 1 1.2 Image Reconstruction Algorithms for TAT

  4. HEAVY-ION RADIOGRAPHY AND HEAVY-ION COMPUTED TOMOGRAPHY

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01T23:59:59.000Z

    RADIOGRAPHY AND HEAVY-ION COMPUTED TOMOGRAPHY 1,2 Jacob I .RADIOGRAPHY AND HEAVY-ION COMPUTED TOMOGRAPHY J I Fabrikant,

  5. Using X-Ray Computed Tomography in Pore Structure Characterization...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Using X-Ray Computed Tomography in Pore Structure Characterization for a Berea Sandstone: Resolution Effect. Using X-Ray Computed Tomography in Pore Structure Characterization for...

  6. Lung Tumors Treated With Percutaneous Radiofrequency Ablation: Computed Tomography Imaging Follow-Up

    SciTech Connect (OSTI)

    Palussiere, Jean, E-mail: palussiere@bergonie.org; Marcet, Benjamin; Descat, Edouard [Institut Bergonie, Regional Cancer Center, Department of Interventional Radiology (France); Deschamps, Frederic; Rao, Pramod [Institut Gustave Roussy, Department of Interventional Radiology (France); Ravaud, Alain [Hopital Saint-Andre, Department of Medical Oncology (France); Brouste, Veronique [Institut Bergonie, Department of Biostatistics (France); Baere, Thierry de [Institut Gustave Roussy, Department of Interventional Radiology (France)

    2011-10-15T23:59:59.000Z

    Purpose: To describe the morphologic evolution of lung tumors treated with radiofrequency ablation (RFA) by way of computed tomography (CT) images and to investigate patterns of incomplete RFA at the site of ablation. Materials and Methods: One hundred eighty-nine patients with 350 lung tumors treated with RFA underwent CT imaging at 2, 4, 6, and 12 months. CT findings were interpreted separately by two reviewers with consensus. Five different radiologic patterns were predefined: fibrosis, cavitation, nodule, atelectasis, and disappearance. The appearance of the treated area was evaluated at each follow-up CT using the predefined patterns. Results: At 1 year after treatment, the most common evolutions were fibrosis (50.5%) or nodules (44.8%). Differences were noted depending on the initial size of the tumor, with fibrosis occurring more frequently for tumors <2 cm (58.6% vs. 22.9%, P = 1 Multiplication-Sign 10{sup -5}). Cavitation and atelectasis were less frequent patterns (2.4% and 1.4%, respectively, at 1 year). Tumor location (intraparenchymatous, with pleural contact <50% or >50%) was not significantly correlated with follow-up image pattern. Local tumor progressions were observed with each type of evolution. At 1 year, 12 local recurrences were noted: 2 cavitations, which represented 40% of the cavitations noted at 1 year; 2 fibroses (1.9%); 7 nodules (7.4%); and 1 atelectasis (33.3%). Conclusion: After RFA of lung tumors, follow-up CT scans show that the shape of the treatment zone can evolve in five different patterns. None of these patterns, however, can confirm the absence of further local tumor progression at subsequent follow-up.

  7. Thermoacoustic Tomography in Elastic Media

    E-Print Network [OSTI]

    Justin Tittelfitz

    2011-10-11T23:59:59.000Z

    We investigate the problem of recovering the initial displacement f for a solution u of a linear, isotropic, non-homogeneous elastic wave equation, given measurements of u on [0,T] x \\partial \\Omega, where \\Omega\\subset\\R^3 is some bounded domain containing the support of f. For the acoustic wave equation, this problem is known as thermoacoustic tomography (TAT), and has been well-studied; for the elastic wave equation, the situation is somewhat more subtle, and we give sufficient conditions on the Lam\\'e parameters to ensure that recovery is possible.

  8. Fourier Transform Quantum State Tomography

    E-Print Network [OSTI]

    Mohammadreza Mohammadi; Agata M. Branczyk; Daniel F. V. James

    2013-01-17T23:59:59.000Z

    We propose a technique for performing quantum state tomography of photonic polarization-encoded multi-qubit states. Our method uses a single rotating wave plate, a polarizing beam splitter and two photon-counting detectors per photon mode. As the wave plate rotates, the photon counters measure a pseudo-continuous signal which is then Fourier transformed. The density matrix of the state is reconstructed using the relationship between the Fourier coefficients of the signal and the Stokes' parameters that represent the state. The experimental complexity, i.e. different wave plate rotation frequencies, scales linearly with the number of qubits.

  9. Surface Impedance Tomography for Antarctic Sea Ice

    E-Print Network [OSTI]

    Golden, Kenneth M.

    Surface Impedance Tomography for Antarctic Sea Ice C. Sampsona , K. M. Goldena , A. Gullya , A. P, Australia Abstract During the 2007 SIPEX expedition in pack ice off the coast of East Antarctica, we measured the electrical conductivity of sea ice via surface impedance tomography. Resistance data from

  10. Efficiency of quantum state tomography for qubits

    E-Print Network [OSTI]

    Koichi Yamagata

    2011-05-19T23:59:59.000Z

    The efficiency of quantum state tomography is discussed from the point of view of quantum parameter estimation theory, in which the trace of the weighted covariance is to be minimized. It is shown that tomography is optimal only when a special weight is adopted.

  11. Implementation and commissioning of an integrated micro-CT/RT system with computerized independent jaw collimation

    SciTech Connect (OSTI)

    Jensen, Michael D. [Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada)] [Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Hrinivich, W. Thomas; Jung, Jongho A. [Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada)] [Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Holdsworth, David W. [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8 (Canada) [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8 (Canada); Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Surgery, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Drangova, Maria [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8, Canada and Department of Medical Biophysics, The University of Western Ontario 1151 Richmond Street, London, Ontario N6A 3K7 (Canada)] [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Ontario N6A 5K8, Canada and Department of Medical Biophysics, The University of Western Ontario 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Chen, Jeff [Department of Physics and Engineering, London Regional Cancer Program, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 5W9 (Canada) [Department of Physics and Engineering, London Regional Cancer Program, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 5W9 (Canada); Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Oncology, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Wong, Eugene [Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada) [Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Medical Biophysics, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Oncology, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 3K7 (Canada); Department of Physics and Engineering, London Regional Cancer Program, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario N6A 5W9 (Canada)

    2013-08-15T23:59:59.000Z

    Purpose: To design, construct, and commission a set of computer-controlled motorized jaws for a micro-CT/RT system to perform conformal image-guided small animal radiotherapy.Methods: The authors designed and evaluated a system of custom-built motorized orthogonal jaws, which allows the delivery of off-axis rectangular fields on a GE eXplore CT 120 preclinical imaging system. The jaws in the x direction are independently driven, while the y-direction jaws are symmetric. All motors have backup encoders, verifying jaw positions. Mechanical performance of the jaws was characterized. Square beam profiles ranging from 2 × 2 to 60 × 60 mm{sup 2} were measured using EBT2 film in the center of a 70 × 70 × 22 mm{sup 3} solid water block. Similarly, absolute depth dose was measured in a solid water and EBT2 film stack 50 × 50 × 50 mm{sup 3}. A calibrated Farmer ion chamber in a 70 × 70 × 20 mm{sup 3} solid water block was used to measure the output of three field sizes: 50 × 50, 40 × 40, and 30 × 30 mm{sup 2}. Elliptical target plans were delivered to films to assess overall system performance. Respiratory-gated treatment was implemented on the system and initially proved using a simple sinusoidal motion phantom. All films were scanned on a flatbed scanner (Epson 1000XL) and converted to dose using a fitted calibration curve. A Monte Carlo beam model of the micro-CT with the jaws has been created using BEAMnrc for comparison with the measurements. An example image-guided partial lung irradiation in a rat is demonstrated.Results: The averaged random error of positioning each jaw is less than 0.1 mm. Relative output factors measured with the ion chamber agree with Monte Carlo simulations within 2%. Beam profiles and absolute depth dose curves measured from the films agree with simulations within measurement uncertainty. Respiratory-gated treatments applied to a phantom moving with a peak-to-peak amplitude of 5 mm showed improved beam penumbra (80%–20%) from 3.9 to 0.8 mm.Conclusions: A set of computer-controlled motorized jaws for a micro-CT/RT system were constructed with position reliably better than a tenth of a millimeter. The hardware system is ready for image-guided conformal radiotherapy for small animals with capability of respiratory-gated delivery.

  12. Friction Reduction for Microhole CT Drilling

    SciTech Connect (OSTI)

    Ken Newman; Patrick Kelleher; Edward Smalley

    2007-03-31T23:59:59.000Z

    The objective of this 24 month project focused on improving microhole coiled tubing drilling bottom hole assembly (BHA) reliability and performance, while reducing the drilling cost and complexity associated with inclined/horizontal well sections. This was to be accomplished by eliminating the need for a downhole drilling tractor or other downhole coiled tubing (CT) friction mitigation techniques when drilling long (>2,000 ft.) of inclined/horizontal wellbore. The technical solution to be developed and evaluated in this project was based on vibrating the coiled tubing at surface to reduce the friction along the length of the downhole CT drillstring. The Phase 1 objective of this project centered on determining the optimum surface-applied vibration system design for downhole CT friction mitigation. Design of the system would be based on numerical modeling and laboratory testing of the CT friction mitigation achieved with various types of surface-applied vibration. A numerical model was developed to predict how far downhole the surface-applied vibration would travel. A vibration test fixture, simulating microhole CT drilling in a horizontal wellbore, was constructed and used to refine and validate the numerical model. Numerous tests, with varying surface-applied vibration parameters were evaluated in the vibration test fixture. The data indicated that as long as the axial force on the CT was less than the helical buckling load, axial vibration of the CT was effective at mitigating friction. However, surface-applied vibration only provided a small amount of friction mitigation as the helical buckling load on the CT was reached or exceeded. Since it would be impractical to assume that routine field operations be conducted at less than the helical buckling load of the CT, it was determined that this technical approach did not warrant the additional cost and maintenance issues that would be associated with the surface vibration equipment. As such, the project was concluded following completion of Phase 1, and Phase 2 (design, fabrication, and testing of a prototype surface vibration system) was not pursued.

  13. Assessment of Pen Branch delta and corridor vegetation changes using multispectral scanner data 1992--1994

    SciTech Connect (OSTI)

    NONE

    1996-01-01T23:59:59.000Z

    Airborne multispectral scanner data were used to monitor natural succession of wetland vegetation species over a three-year period from 1992 through 1994 for Pen Branch on the Savannah River Site in South Carolina. Image processing techniques were used to identify and measure wetland vegetation communities in the lower portion of the Pen Branch corridor and delta. The study provided a reliable means for monitoring medium- and large-scale changes in a diverse environment. Findings from the study will be used to support decisions regarding remediation efforts following the cessation of cooling water discharge from K reactor at the Department of Energy`s Savannah River Site in South Carolina.

  14. Software Development for a CompactRIO-Based Wire Scanner Control and Data Acquisition SYstem

    SciTech Connect (OSTI)

    Sedillo, James Daniel [Los Alamos National Laboratory

    2012-05-16T23:59:59.000Z

    The Beam Diagnostics and Instrumentation Team at the Los Alamos Neutron Science Center is developing a wire scanner data acquisition and control system with a National Instrument's compactRIO at its core. For this application, the compactRIO controller not only requires programming the FPGA and RT computer internal to the compactRIO, but also requires programming a client computer and a touch panel display. This article will summarize the hardware interfaces and describe the software design approach utilized for programming and interfacing the four systems together in order to fulfill the design requirements and promote reliable interoperability.

  15. Idiopathic juvenile osteoporosis: a cross-sectional single-centre experience with bone histomorphometry and quantitative computed tomography

    E-Print Network [OSTI]

    Bacchetta, Justine; Wesseling-Perry, Katherine; Gilsanz, Vicente; Gales, Barbara; Pereira, Renata C; Salusky, Isidro B

    2013-01-01T23:59:59.000Z

    and quantitative computed tomography. Pediatric Rheumatologyand quantitative computed tomography Justine Bacchetta 1 ,by quantitative computed tomography (QCT) and their

  16. Reconstruction Algorithm for Single Photon Emission Computed Tomography and its

    E-Print Network [OSTI]

    Fokas, A. S.

    Reconstruction Algorithm for Single Photon Emission Computed Tomography and its Numerical Emission Tomography and of Single Photon Emission Computed Tomography are not only two of the most measured by the usual computed tomography. Thus the basic mathematical problem in SPECT is to determine

  17. State tomography via weak measurements

    E-Print Network [OSTI]

    Shengjun Wu

    2013-02-01T23:59:59.000Z

    Recent work has revealed that the wave function of a pure state can be measured directly and that complementary knowledge of a quantum system can be obtained simultaneously by weak measurements. However, the original scheme applies only to pure states, and it is not efficient because most of the data are discarded by post-selection. Here, we propose tomography schemes for pure states and for mixed states via weak measurements, and our schemes are more efficient because we do not discard any data. Furthermore, we demonstrate that any matrix element of a general state can be directly read from an appropriate weak measurement. The density matrix (with all of its elements) represents all that is directly accessible from a general measurement.

  18. Collimator-free photon tomography

    DOE Patents [OSTI]

    Dilmanian, F. Avraham (Yaphank, NY); Barbour, Randall L. (Westbury, NY)

    1998-10-06T23:59:59.000Z

    A method of uncollimated single photon emission computed tomography includes administering a radioisotope to a patient for producing gamma ray photons from a source inside the patient. Emissivity of the photons is measured externally of the patient with an uncollimated gamma camera at a plurality of measurement positions surrounding the patient for obtaining corresponding energy spectrums thereat. Photon emissivity at the plurality of measurement positions is predicted using an initial prediction of an image of the source. The predicted and measured photon emissivities are compared to obtain differences therebetween. Prediction and comparison is iterated by updating the image prediction until the differences are below a threshold for obtaining a final prediction of the source image.

  19. Collimator-free photon tomography

    DOE Patents [OSTI]

    Dilmanian, F.A.; Barbour, R.L.

    1998-10-06T23:59:59.000Z

    A method of uncollimated single photon emission computed tomography includes administering a radioisotope to a patient for producing gamma ray photons from a source inside the patient. Emissivity of the photons is measured externally of the patient with an uncollimated gamma camera at a plurality of measurement positions surrounding the patient for obtaining corresponding energy spectrums thereat. Photon emissivity at the plurality of measurement positions is predicted using an initial prediction of an image of the source. The predicted and measured photon emissivities are compared to obtain differences therebetween. Prediction and comparison is iterated by updating the image prediction until the differences are below a threshold for obtaining a final prediction of the source image. 6 figs.

  20. Comparison of CT and MR-CT Fusion for Prostate Post-Implant Dosimetry

    SciTech Connect (OSTI)

    Maletz, Kristina L. [Department of Radiation Oncology, St. Luke's-Roosevelt Hospital Center, Beth Israel Medical Center, Continuum Health Partners, New York, NY (Israel); Columbia University College of Physicians and Surgeons, New York, NY (United States); Ennis, Ronald D., E-mail: REnnis@chpnet.org [Department of Radiation Oncology, St. Luke's-Roosevelt Hospital Center, Beth Israel Medical Center, Continuum Health Partners, New York, NY (Israel); Ostenson, Jason; Pevsner, Alexander [Department of Radiation Oncology, St. Luke's-Roosevelt Hospital Center, Beth Israel Medical Center, Continuum Health Partners, New York, NY (Israel); Kagen, Alexander [Department of Radiology, Beth Israel Medical Center, St. Luke's-Roosevelt Hospital, Continuum Health Partners, New York, NY (Israel); Wernick, Iddo [Department of Radiation Oncology, St. Luke's-Roosevelt Hospital Center, Beth Israel Medical Center, Continuum Health Partners, New York, NY (Israel)

    2012-04-01T23:59:59.000Z

    Purpose: The use of T2 MR for postimplant dosimetry (PID) after prostate brachytherapy allows more anatomically accurate and precise contouring but does not readily permit seed identification. We developed a reproducible technique for performing MR-CT fusion and compared the resulting dosimetry to standard CT-based PID. Methods and Materials: CT and T1-weighted MR images for 45 patients were fused and aligned based on seed distribution. The T2-weighted MR image was then fused to the aligned T1. Reproducibility of the fusion technique was tested by inter- and intraobserver variability for 13 patients. Dosimetry was computed for the prostate as a whole and for the prostate divided into anterior and posterior sectors of the base, mid-prostate, and apex. Results: Inter- and intraobserver variability for the fusion technique showed less than 1% variation in D90. MR-CT fusion D90 and CT D90 were nearly equivalent for the whole prostate, but differed depending on the identification of superior extent of the base (p = 0.007) and on MR/CT prostate volume ratio (p = 0.03). Sector analysis showed a decrease in MR-CT fusion D90 in the anterior base (ratio 0.93 {+-}0.25, p < 0.05) and an increase in MR-CT fusion D90 in the apex (p < 0.05). The volume of extraprostatic tissue encompassed by the V100 is greater on MR than CT. Factors associated with this difference are the MR/CT volume ratio (p < 0.001) and the difference in identification of the inferior extent of the apex (p = 0.03). Conclusions: We developed a reproducible MR-CT fusion technique that allows MR-based dosimetry. Comparing the resulting postimplant dosimetry with standard CT dosimetry shows several differences, including adequacy of coverage of the base and conformity of the dosimetry around the apex. Given the advantage of MR-based tissue definition, further study of MR-based dosimetry is warranted.

  1. Computed tomography and optical remote sensing: Development for the study of indoor air pollutant transport and dispersion

    SciTech Connect (OSTI)

    Drescher, A.C.

    1995-06-01T23:59:59.000Z

    This thesis investigates the mixing and dispersion of indoor air pollutants under a variety of conditions using standard experimental methods. It also extensively tests and improves a novel technique for measuring contaminant concentrations that has the potential for more rapid, non-intrusive measurements with higher spatial resolution than previously possible. Experiments conducted in a sealed room support the hypothesis that the mixing time of an instantaneously released tracer gas is inversely proportional to the cube root of the mechanical power transferred to the room air. One table-top and several room-scale experiments are performed to test the concept of employing optical remote sensing (ORS) and computed tomography (CT) to measure steady-state gas concentrations in a horizontal plane. Various remote sensing instruments, scanning geometries and reconstruction algorithms are employed. Reconstructed concentration distributions based on existing iterative CT techniques contain a high degree of unrealistic spatial variability and do not agree well with simultaneously gathered point-sample data.

  2. Statistical models and regularization strategies in statistical image reconstruction of low-dose X-ray computed tomography: a survey

    E-Print Network [OSTI]

    Zhang, Hao; Ma, Jianhua; Lu, Hongbing; Liang, Zhengrong

    2014-01-01T23:59:59.000Z

    Statistical image reconstruction (SIR) methods have shown potential to substantially improve the image quality of low-dose X-ray computed tomography (CT) as compared to the conventional filtered back-projection (FBP) method for various clinical tasks. According to the maximum a posterior (MAP) estimation, the SIR methods can be typically formulated by an objective function consisting of two terms: (1) data-fidelity (or equivalently, data-fitting or data-mismatch) term modeling the statistics of projection measurements, and (2) regularization (or equivalently, prior or penalty) term reflecting prior knowledge or expectation on the characteristics of the image to be reconstructed. Existing SIR methods for low-dose CT can be divided into two groups: (1) those that use calibrated transmitted photon counts (before log-transform) with penalized maximum likelihood (pML) criterion, and (2) those that use calibrated line-integrals (after log-transform) with penalized weighted least-squares (PWLS) criterion. Accurate s...

  3. Pressurized subsampling system for pressured gas-hydrate-bearing sediment: Microscale imaging using X-ray computed tomography

    SciTech Connect (OSTI)

    Jin, Yusuke, E-mail: u-jin@aist.go.jp; Konno, Yoshihiro; Nagao, Jiro [Production Technology Team, Methane Hydrate Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Sapporo 062-8517 (Japan)

    2014-09-01T23:59:59.000Z

    A pressurized subsampling system was developed for pressured gas hydrate (GH)-bearing sediments, which have been stored under pressure. The system subsamples small amounts of GH sediments from cores (approximately 50 mm in diameter and 300 mm in height) without pressure release to atmospheric conditions. The maximum size of the subsamples is 12.5 mm in diameter and 20 mm in height. Moreover, our system transfers the subsample into a pressure vessel, and seals the pressure vessel by screwing in a plug under hydraulic pressure conditions. In this study, we demonstrated pressurized subsampling from artificial xenon-hydrate sediments and nondestructive microscale imaging of the subsample, using a microfocus X-ray computed tomography (CT) system. In addition, we estimated porosity and hydrate saturation from two-dimensional X-ray CT images of the subsamples.

  4. abdominal ct images: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    methods establish microCT imaging as a useful tool for comparative Metscher, Brian 31 CT-PET Landmark-based Lung Registration Using a Dynamic Breathing Model S. Chambon1 Physics...

  5. Binary Tomography with Deblurring Stefan Weber1

    E-Print Network [OSTI]

    Schnörr, Christoph

    Binary Tomography with Deblurring Stefan Weber1 , Thomas Sch¨ule1,3 , Attila Kuba2 , and Christoph-Verlag Berlin Heidelberg 2006 #12;376 S. Weber et al. quality of the reconstructed images. The correction

  6. Anatomic measurement accuracy: CT parameters and 3D rendering effects

    E-Print Network [OSTI]

    Vorperian, Houri K.

    Anatomic measurement accuracy: CT parameters and 3D rendering effects Brian J Whyms a, E Michael of Neuroscience #12;INTRODUCTION · Measurements from 3D-CT rendering are used in research and clinical management-CT rendering techniques on measurements #12;METHODS Scanned: · 3 human mandibles · a phantom object Phantom

  7. ECG-edit function in multidetector-row computed tomography coronary arteriography for patients with arrhythmias.

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    multi- detector row computed tomography for the evaluationwith multislice computed tomography. J Am Coll Cardiol 2001;multi- detector-row computed tomography: Results in 102

  8. Reduction in downstream test utilization following introduction of coronary computed tomography in a cardiology practice

    E-Print Network [OSTI]

    Karlsberg, Ronald P.; Budoff, Matthew J.; Thomson, Louise E.; Friedman, John D.; Berman, Daniel S.

    2010-01-01T23:59:59.000Z

    introduction of coronary computed tomography in a cardiologyphoton emission computed tomography (SPECT) myocardialÁ Multi-slice computed tomography Á Multi-detector computed

  9. Evaluation of a EMCCD detector for emission-transmission computed tomography

    E-Print Network [OSTI]

    Teo, B K; Shestakova, I; Sun, M; Barber, W C; Nagarkar, V V; Hasegawa, B H

    2006-01-01T23:59:59.000Z

    emission-transmission computed-tomography imaging system,”for Emission-Transmission Computed Tomography B. K. Teo, I.sion-transmission computed tomography. The detector has an

  10. Characterization of Biological Effects of Computed Tomography by Assessing the DNA Damage Response

    E-Print Network [OSTI]

    Elgart, Shona Robin

    2014-01-01T23:59:59.000Z

    Brenner DJ, Hall EJ. Computed Tomography - An IncreasingSmith-Bindman R. Is Computed Tomography Safe? New Englandof X-ray Trends: Computed Tomography 2005 – 06 Preliminary

  11. Coronary computed tomography angiography predicts subsequent cardiac outcome events: results of the Visipaque CCTA registry study.

    E-Print Network [OSTI]

    Budoff, MJ; Bloom, SA; Chow, BJ; Chandler, AB; Cole, JH

    2015-01-01T23:59:59.000Z

    Event CCTA= Coronary computed tomography angiography; MACE=CONFIRM (COroNary computed tomography angiography evaluationcalcium scoring and computed tomography angiography: current

  12. Statistical Estimation of Quantum Tomography Protocols Quality

    E-Print Network [OSTI]

    Yu. I. Bogdanov; G. Brida; M. Genovese; S. P. Kulik; E. V. Moreva; A. P. Shurupov

    2010-02-18T23:59:59.000Z

    A novel operational method for estimating the efficiency of quantum state tomography protocols is suggested. It is based on a-priori estimation of the quality of an arbitrary protocol by means of universal asymptotic fidelity distribution and condition number, which takes minimal value for better protocol. We prove the adequacy of the method both with numerical modeling and through the experimental realization of several practically important protocols of quantum state tomography.

  13. A Novel Time-Based Readout Scheme for a Combined PET-CT Detector Using APDs

    E-Print Network [OSTI]

    Powolny, F; Hillemanns, H; Jarron, P; Lecoq, P; Meyer, T C; Moraes, D

    2008-01-01T23:59:59.000Z

    This paper summarizes CERN R&D work done in the framework of the European Commission's FP6 BioCare Project. The objective was to develop a novel "time-based" signal processing technique to read out LSO-APD photodetectors for medical imaging. An important aspect was to employ the technique in a combined scenario for both computer tomography (CT) and positron emission tomography (PET) with effectively no tradeoffs in efficiency and resolution compared to traditional single mode machines. This made the use of low noise and yet very high-speed monolithic front-end electronics essential so as to assure the required timing characteristics together with a high signal-to-noise ratio. Using APDs for photon detection, two chips, traditionally employed for particle physics, could be identified to meet the above criteria. Although both were not optimized for their intended new medical application, excellent performance in conjunction with LSO-APD sensors could be derived. Whereas a measured energy resolution of 16% (...

  14. Introduction of heat map to fidelity assessment of compressed CT images

    SciTech Connect (OSTI)

    Lee, Hyunna; Kim, Bohyoung; Seo, Jinwook; Park, Seongjin; Shin, Yeong-Gil [School of Computer Science and Engineering, Seoul National University, 599 Kwanak-ro, Kwanak-gu, Seoul 151-742 (Korea, Republic of); Kim, Kil Joong [Department of Radiation Applied Life Science, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of); Lee, Kyoung Ho [Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Institute of Radiation Medicine and Seoul National University Medical Research Center, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707 (Korea, Republic of)

    2011-08-15T23:59:59.000Z

    Purpose: This study aimed to introduce heat map, a graphical data presentation method widely used in gene expression experiments, to the presentation and interpretation of image fidelity assessment data of compressed computed tomography (CT) images. Methods: The authors used actual assessment data that consisted of five radiologists' responses to 720 computed tomography images compressed using both Joint Photographic Experts Group 2000 (JPEG2000) 2D and JPEG2000 3D compressions. They additionally created data of two artificial radiologists, which were generated by partly modifying the data from two human radiologists. Results: For each compression, the entire data set, including the variations among radiologists and among images, could be compacted into a small color-coded grid matrix of the heat map. A difference heat map depicted the advantage of 3D compression over 2D compression. Dendrograms showing hierarchical agglomerative clustering results were added to the heat maps to illustrate the similarities in the data patterns among radiologists and among images. The dendrograms were used to identify two artificial radiologists as outliers, whose data were created by partly modifying the responses of two human radiologists. Conclusions: The heat map can illustrate a quick visual extract of the overall data as well as the entirety of large complex data in a compact space while visualizing the variations among observers and among images. The heat map with the dendrograms can be used to identify outliers or to classify observers and images based on the degree of similarity in the response patterns.

  15. Comparison of CT, PET, and PET/CT for Staging of Patients with Indolent Non-Hodgkin’s Lymphoma

    E-Print Network [OSTI]

    Fueger, Barbara J.; Yeom, Kristen; Czernin, Johannes; Sayre, James W.; Phelps, Michael E.; Allen-Auerbach, Martin S.

    2009-01-01T23:59:59.000Z

    B. J. Fueger et al. : PET/CT for indolent lymphoma Table 2.Performance for detection of nodal disease Sensitivity PETCT PET/CT pG0.001 vs PET, CT Specificity pG0.001 vs PET

  16. Percutaneous Extraction of Cement Leakage After Vertebroplasty Under CT and Fluoroscopy Guidance: A New Technique

    SciTech Connect (OSTI)

    Amoretti, Nicolas, E-mail: amorettinicolas@yahoo.fr; Huwart, Laurent, E-mail: huwart.laurent@wanadoo.fr [Centre Hospitalo-Universitaire de Nice, Department of Radiology (France)

    2012-12-15T23:59:59.000Z

    Purpose: We report a new minimally invasive technique of extraction of cement leakage following percutaneous vertebroplasty in adults. Methods: Seven adult patients (five women, two men; mean age: 81 years) treated for vertebral compression fractures by percutaneous vertebroplasty had cement leakage into perivertebral soft tissues along the needle route. Immediately after vertebroplasty, the procedure of extraction was performed under computed tomography (CT) and fluoroscopy guidance: a Chiba needle was first inserted using the same route as the vertebroplasty until contact was obtained with the cement fragment. This needle was then used as a guide for an 11-gauge Trocar t'am (Thiebaud, France). After needle withdrawal, a 13-gauge endoscopy clamp was inserted through the cannula to extract the cement fragments. The whole procedure was performed under local anesthesia. Results: In each patient, all cement fragments were withdrawn within 10 min, without complication. Conclusions: This report suggests that this CT- and fluoroscopy-guided percutaneous technique of extraction could reduce the rate of cement leakage-related complications.

  17. Sparse signal reconstruction from polychromatic X-ray CT measurements via mass attenuation discretization

    SciTech Connect (OSTI)

    Gu, Renliang; Dogandži?, Aleksandar [Iowa State University, Center for Nondestructive Evaluation, 1915 Scholl Road, Ames, IA 50011 (United States)

    2014-02-18T23:59:59.000Z

    We propose a method for reconstructing sparse images from polychromatic x-ray computed tomography (ct) measurements via mass attenuation coefficient discretization. The material of the inspected object and the incident spectrum are assumed to be unknown. We rewrite the Lambert-Beer’s law in terms of integral expressions of mass attenuation and discretize the resulting integrals. We then present a penalized constrained least-squares optimization approach for reconstructing the underlying object from log-domain measurements, where an active set approach is employed to estimate incident energy density parameters and the nonnegativity and sparsity of the image density map are imposed using negative-energy and smooth ?{sub 1}-norm penalty terms. We propose a two-step scheme for refining the mass attenuation discretization grid by using higher sampling rate over the range with higher photon energy, and eliminating the discretization points that have little effect on accuracy of the forward projection model. This refinement allows us to successfully handle the characteristic lines (Dirac impulses) in the incident energy density spectrum. We compare the proposed method with the standard filtered backprojection, which ignores the polychromatic nature of the measurements and sparsity of the image density map. Numerical simulations using both realistic simulated and real x-ray ct data are presented.

  18. Determination of lung segments in computed tomography images using the Euclidean distance to the pulmonary artery

    SciTech Connect (OSTI)

    Stoecker, Christina; Moltz, Jan H.; Lassen, Bianca; Kuhnigk, Jan-Martin; Krass, Stefan [Fraunhofer MEVIS, Institute for Medical Image Computing, Universitaetsallee 29, 28359 Bremen (Germany)] [Fraunhofer MEVIS, Institute for Medical Image Computing, Universitaetsallee 29, 28359 Bremen (Germany); Welter, Stefan [Ruhrlandklinik, Department of Thoracic Surgery, Tueschener Weg 40, 45239 Essen (Germany)] [Ruhrlandklinik, Department of Thoracic Surgery, Tueschener Weg 40, 45239 Essen (Germany); Peitgen, Heinz-Otto [Jacobs University Bremen, Campus Ring 1, 28759 Bremen (Germany)] [Jacobs University Bremen, Campus Ring 1, 28759 Bremen (Germany)

    2013-09-15T23:59:59.000Z

    Purpose: Computed tomography (CT) imaging is the modality of choice for lung cancer diagnostics. With the increasing number of lung interventions on sublobar level in recent years, determining and visualizing pulmonary segments in CT images and, in oncological cases, reliable segment-related information about the location of tumors has become increasingly desirable. Computer-assisted identification of lung segments in CT images is subject of this work.Methods: The authors present a new interactive approach for the segmentation of lung segments that uses the Euclidean distance of each point in the lung to the segmental branches of the pulmonary artery. The aim is to analyze the potential of the method. Detailed manual pulmonary artery segmentations are used to achieve the best possible segment approximation results. A detailed description of the method and its evaluation on 11 CT scans from clinical routine are given.Results: An accuracy of 2–3 mm is measured for the segment boundaries computed by the pulmonary artery-based method. On average, maximum deviations of 8 mm are observed. 135 intersegmental pulmonary veins detected in the 11 test CT scans serve as reference data. Furthermore, a comparison of the presented pulmonary artery-based approach to a similar approach that uses the Euclidean distance to the segmental branches of the bronchial tree is presented. It shows a significantly higher accuracy for the pulmonary artery-based approach in lung regions at least 30 mm distal to the lung hilum.Conclusions: A pulmonary artery-based determination of lung segments in CT images is promising. In the tests, the pulmonary artery-based determination has been shown to be superior to the bronchial tree-based determination. The suitability of the segment approximation method for application in the planning of segment resections in clinical practice has already been verified in experimental cases. However, automation of the method accompanied by an evaluation on a larger number of test cases is required before application in the daily clinical routine.

  19. Brain Imaging with Positron Emission Tomography: Quantification and Biomedical Applications in Alzheimer's Disease and Brain Tumors

    E-Print Network [OSTI]

    Wardak, Mirwais

    2013-01-01T23:59:59.000Z

    and the combination of PET and CT into one imaging system (dose (35). Since the PET and CT components are attachedionizing radiation (unlike PET and CT), provides excellent

  20. The effect of spatial micro-CT image resolution and surface complexity on the morphological 3D analysis of open porous structures

    SciTech Connect (OSTI)

    Pyka, Grzegorz, E-mail: gregory.pyka@mtm.kuleuven.be [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 – PB2450, B-3001 Leuven (Belgium); Kerckhofs, Greet [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 – PB2450, B-3001 Leuven (Belgium); Biomechanics Research Unit, Université de Liege, Chemin des Chevreuils 1 - BAT 52/3, B-4000 Liège (Belgium); Schrooten, Jan; Wevers, Martine [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 – PB2450, B-3001 Leuven (Belgium)

    2014-01-15T23:59:59.000Z

    In material science microfocus X-ray computed tomography (micro-CT) is one of the most popular non-destructive techniques to visualise and quantify the internal structure of materials in 3D. Despite constant system improvements, state-of-the-art micro-CT images can still hold several artefacts typical for X-ray CT imaging that hinder further image-based processing, structural and quantitative analysis. For example spatial resolution is crucial for an appropriate characterisation as the voxel size essentially influences the partial volume effect. However, defining the adequate image resolution is not a trivial aspect and understanding the correlation between scan parameters like voxel size and the structural properties is crucial for comprehensive material characterisation using micro-CT. Therefore, the objective of this study was to evaluate the influence of the spatial image resolution on the micro-CT based morphological analysis of three-dimensional (3D) open porous structures with a high surface complexity. In particular the correlation between the local surface properties and the accuracy of the micro-CT-based macro-morphology of 3D open porous Ti6Al4V structures produced by selective laser melting (SLM) was targeted and revealed for rough surfaces a strong dependence of the resulting structure characteristics on the scan resolution. Reducing the surface complexity by chemical etching decreased the sensitivity of the overall morphological analysis to the spatial image resolution and increased the detection limit. This study showed that scan settings and image processing parameters need to be customized to the material properties, morphological parameters under investigation and the desired final characteristics (in relation to the intended functional use). Customization of the scan resolution can increase the reliability of the micro-CT based analysis and at the same time reduce its operating costs. - Highlights: • We examine influence of the image resolution on ?CT-based morphological analysis. • Surface properties influence accuracy of ?CT-based morphology of porous structures. • Total porosity was the least sensitive to surface complexity and scan voxel size. • The beam thickness analysis was overestimated by the surface roughness. • Voxel size customization can significantly reduce a cost of the ?CT-based analysis.

  1. Wind Scanner: A full-scale Laser Facility for Wind and Turbulence Measurements around large Wind Turbines

    E-Print Network [OSTI]

    Wind Scanner: A full-scale Laser Facility for Wind and Turbulence Measurements around large Wind Turbines Torben Mikkelsen, Jakob Mann and Michael Courtney Wind Energy Department, Risø National Laboratory:Torben.Mikkelsen@Risoe.dk Summary RISØ DTU has started to build a newly designed laser-based lidar scanning facility for remote wind

  2. Scanner-Free and Wide-Field Endoscopic Imaging by Using a Single Multimode Optical Fiber Youngwoon Choi,1

    E-Print Network [OSTI]

    Fang-Yen, Christopher

    Scanner-Free and Wide-Field Endoscopic Imaging by Using a Single Multimode Optical Fiber Youngwoon November 2012) A single multimode fiber is considered an ideal optical element for endoscopic imaging due fiber has been an important turning point. Especially, a multimode optical fiber has drawn interest

  3. Journal of Neuroscience Methods 169 (2008) 7683 Visual stimulus presentation using fiber optics in the MRI scanner

    E-Print Network [OSTI]

    Sereno, Martin

    2008-01-01T23:59:59.000Z

    Journal of Neuroscience Methods 169 (2008) 76­83 Visual stimulus presentation using fiber optics-face space using fiber optics in the MRI scanner. The feasibility of fiber-optic based displays-encoded paradigms in both experiments. The results suggest that fiber-optic based displays can be a complementary

  4. Title: NMR scanner with motion zeugmatography Patent Number: 04516075 (U.S. patents which cite this patent)

    E-Print Network [OSTI]

    Walker, Thad G.

    Title: NMR scanner with motion zeugmatography Patent Number: 04516075 (U.S. patents which cite this patent) Issue Date: 05-07-1985 Application Date: 01-04-1983 Application Number: 455596 Inventor(s): Name Patents Number Date Inventor 04015196 1977-03 Moore et al. 04021726 1977-05 Garroway et al. 04070611 1978

  5. CAPITAL ASSET MANAGEMENT (CAM) NEWS 2014 CAM has barcode scanners available for use when inventorying your equipment.

    E-Print Network [OSTI]

    records can be updated at any time via the Capital Asset Management section (CAMs) within EBS - FinanceCAPITAL ASSET MANAGEMENT (CAM) NEWS 2014 CAM has barcode scanners available for use when. You must have Role 6 ­ CAM Processor, in EBS - Finance, to edit/update asset records. For more

  6. Wavelet based characterization of ex vivo vertebral trabecular bone structure with 3T MRI compared to microCT

    SciTech Connect (OSTI)

    Krug, R; Carballido-Gamio, J; Burghardt, A; Haase, S; Sedat, J W; Moss, W C; Majumdar, S

    2005-04-11T23:59:59.000Z

    Trabecular bone structure and bone density contribute to the strength of bone and are important in the study of osteoporosis. Wavelets are a powerful tool to characterize and quantify texture in an image. In this study the thickness of trabecular bone was analyzed in 8 cylindrical cores of the vertebral spine. Images were obtained from 3 Tesla (T) magnetic resonance imaging (MRI) and micro-computed tomography ({micro}CT). Results from the wavelet based analysis of trabecular bone were compared with standard two-dimensional structural parameters (analogous to bone histomorphometry) obtained using mean intercept length (MR images) and direct 3D distance transformation methods ({micro}CT images). Additionally, the bone volume fraction was determined from MR images. We conclude that the wavelet based analyses delivers comparable results to the established MR histomorphometric measurements. The average deviation in trabecular thickness was less than one pixel size between the wavelet and the standard approach for both MR and {micro}CT analysis. Since the wavelet based method is less sensitive to image noise, we see an advantage of wavelet analysis of trabecular bone for MR imaging when going to higher resolution.

  7. Studying Brazil-Nut Effect History Line using Disk-Formed Objects, Scanner, and Web Browser

    E-Print Network [OSTI]

    Sparisoma Viridi; Siti Nurul Khotimah; Novitrian; Widayani; Luman Haris; Dimas Praja Purwa Aji

    2014-08-07T23:59:59.000Z

    Grains configuration snapshots of Brazil-nut effect (BNE) in two-dimension are physically modeled using disk-formed objects, e.g., buttons and magnetic pin. These BNE configurations are artificially designed to mimic the real ones observed in experiments. A computer scanner is used to capture the configurations. Obtained images are then digitized using web browser running a HTML equipped with a JavaScript code, which is built mainly only for this work. From digitization process all grains positions (granular bed and intruder) are obtained, which is later analyzed using the simplest model, i.e., potential energy. Since the minimum energy principle (MEP) suggests that a closed system should go to its state with minimum internal energy, our BNE system must also obey it. Evolution of only the intruder seems to violate MEP but not for the whole system. Grains compaction plays important role, so that the system can achieve its configuration with minimum potential energy.

  8. Ionisation losses and wire scanner heating evaluation, possible solutions, application to the LHC

    E-Print Network [OSTI]

    Fischer, C

    2000-01-01T23:59:59.000Z

    Harmful heating mechanisms, resulting in wire breakage, limit the utilisation of wire scanner monitors to below a given beam intensity. This threshold depends on the accelerator design parameters. In lepton colliders, the short beam bunches generate strong wake-fields inside the vacuum pipe which are sensed by the wire and are the predominant current limit. These effects can be minimised by a smooth design of the monitor cross section and by choosing a wire made of an insulating material [1]. A second source of energy deposition inside the wire, also present in hadron machines, and even when the wire material is insulating, results from collision and ionisation of the wire material atoms by the incident beam particles. Calculations are presented to evaluate the efficiency of this process and a possible solution is suggested which may reduce this limitation. An example is given for the case of the LHC.

  9. Does Preinterventional Flat-Panel Computer Tomography Pooled Blood Volume Mapping Predict Final Infarct Volume After Mechanical Thrombectomy in Acute Cerebral Artery Occlusion?

    SciTech Connect (OSTI)

    Wagner, Marlies, E-mail: marlies.wagner@kgu.de [Hospital of Goethe University, Institute of Neuroradiology (Germany); Kyriakou, Yiannis, E-mail: yiannis.kyriakou@siemens.com [Siemens AG, Health Care Sector (Germany); Mesnil de Rochemont, Richard du, E-mail: mesnil@em.uni-frankfurt.de [Hospital of Goethe University, Institute of Neuroradiology (Germany); Singer, Oliver C., E-mail: o.singer@em.uni-frankfurt.de [Hospital of Goethe University, Department of Neurology (Germany); Berkefeld, Joachim, E-mail: berkefeld@em.uni-frankfurt.de [Hospital of Goethe University, Institute of Neuroradiology (Germany)

    2013-08-01T23:59:59.000Z

    PurposeDecreased cerebral blood volume is known to be a predictor for final infarct volume in acute cerebral artery occlusion. To evaluate the predictability of final infarct volume in patients with acute occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA) and successful endovascular recanalization, pooled blood volume (PBV) was measured using flat-panel detector computed tomography (FPD CT).Materials and MethodsTwenty patients with acute unilateral occlusion of the MCA or distal ACI without demarcated infarction, as proven by CT at admission, and successful Thrombolysis in cerebral infarction score (TICI 2b or 3) endovascular thrombectomy were included. Cerebral PBV maps were acquired from each patient immediately before endovascular thrombectomy. Twenty-four hours after recanalization, each patient underwent multislice CT to visualize final infarct volume. Extent of the areas of decreased PBV was compared with the final infarct volume proven by follow-up CT the next day.ResultsIn 15 of 20 patients, areas of distinct PBV decrease corresponded to final infarct volume. In 5 patients, areas of decreased PBV overestimated final extension of ischemia probably due to inappropriate timing of data acquisition and misery perfusion.ConclusionPBV mapping using FPD CT is a promising tool to predict areas of irrecoverable brain parenchyma in acute thromboembolic stroke. Further validation is necessary before routine use for decision making for interventional thrombectomy.

  10. PET/CT shielding design comparisons

    E-Print Network [OSTI]

    Coker, Audra Lee

    2007-09-17T23:59:59.000Z

    moving through the gantry (with permission from Bushong 2001). 7 Positron Emission Tomography (PET) is a noninvasive diagnostic imaging tool that takes advantage of certain radiopharmaceuticals and allows abnormal metabolic... activity in and around organs to be examined by injection of a radionuclide into a patient (Radiology 2006). These radiopharmaceuticals, biological compounds linked to radiation-emitting radionuclides, can in some cases be tailored for concentration...

  11. Stabilizing dual-energy X-ray computed tomography reconstructions using patch-based regularization

    E-Print Network [OSTI]

    Tracey, Brian H

    2014-01-01T23:59:59.000Z

    Recent years have seen growing interest in exploiting dual- and multi-energy measurements in computed tomography (CT) in order to characterize material properties as well as object shape. Material characterization is performed by decomposing the scene into constitutive basis functions, such as Compton scatter and photoelectric absorption functions. While well motivated physically, the joint recovery of the spatial distribution of photoelectric and Compton properties is severely complicated by the fact that the data are several orders of magnitude more sensitive to Compton scatter coefficients than to photoelectric absorption, so small errors in Compton estimates can create large artifacts in the photoelectric estimate. To address these issues, we propose a model-based iterative approach which uses patch-based regularization terms to stabilize inversion of photoelectric coefficients, and solve the resulting problem though use of computationally attractive Alternating Direction Method of Multipliers (ADMM) solu...

  12. Scanning microwave-induced thermoacoustic tomography: Signal, resolution, and contrast

    E-Print Network [OSTI]

    Wang, Lihong

    Scanning microwave-induced thermoacoustic tomography: Signal, resolution, and contrast Geng Ku Scanning thermoacoustic tomography was explored in the microwave region of the electromagnetic spectrum ultrasonic transducer detected the time-resolved thermoacoustic signals. Based on the microwave

  13. Photoacoustic and thermoacoustic tomography: system development for biomedical applications 

    E-Print Network [OSTI]

    Ku, Geng

    2006-04-12T23:59:59.000Z

    Photoacoustic tomography (PAT), as well as thermoacoustic tomography (TAT), utilize electromagnetic radiation in its visible, near infrared, microwave, and radiofrequency forms, respectively, to induce acoustic waves in biological tissues...

  14. Understanding Why Patients Return to the Emergency Department after Mild Traumatic Brain Injury within 72 hours of Discharge

    E-Print Network [OSTI]

    2015-01-01T23:59:59.000Z

    a bleed on head computed tomography (CT) (p=0.0334). EDafter injury. A computed tomography (CT) was performed indepartment; CT, computed tomography Western Journal of

  15. Renal infarction: CT diagnosis and correlation between CT findings and etiologies

    SciTech Connect (OSTI)

    Wong, W.S.; Moss, A.A.; Federle, M.P.; Cochran, S.T.; London, S.S.

    1984-01-01T23:59:59.000Z

    The CT scans and the clinical records of 12 patients who had renal infarction were reviewed. The renal infarcts were classified as either focal or global. The CT findings were correlated with the etiologies of renal infarction. Embolism was the most common cause of renal infarcts that were multifocal with involvement of both kidneys. Trauma caused a unilateral global type of infract. A case of sickle cell anemia presented with multiple ''slit-like'' focal infarcts and enlarged kidneys. Forty-seven per cent of infarcts demonstrated the cortical rim sign, 11% were acapsular fluid collection, and 6% had an abnormally thickened renal fascia.

  16. Three-dimensional multiphase segmentation of X-ray CT data of porous materials using a Bayesian Markov random field framework

    SciTech Connect (OSTI)

    Kulkarni, Ramaprasad; Tuller, Markus; Fink, Wolfgang; Wildschild, Dorthe (Oregon State U.); (Ariz)

    2012-07-27T23:59:59.000Z

    Advancements in noninvasive imaging methods such as X-ray computed tomography (CT) have led to a recent surge of applications in porous media research with objectives ranging from theoretical aspects of pore-scale fluid and interfacial dynamics to practical applications such as enhanced oil recovery and advanced contaminant remediation. While substantial efforts and resources have been devoted to advance CT technology, microscale analysis, and fluid dynamics simulations, the development of efficient and stable three-dimensional multiphase image segmentation methods applicable to large data sets is lacking. To eliminate the need for wet-dry or dual-energy scans, image alignment, and subtraction analysis, commonly applied in X-ray micro-CT, a segmentation method based on a Bayesian Markov random field (MRF) framework amenable to true three-dimensional multiphase processing was developed and evaluated. Furthermore, several heuristic and deterministic combinatorial optimization schemes required to solve the labeling problem of the MRF image model were implemented and tested for computational efficiency and their impact on segmentation results. Test results for three grayscale data sets consisting of dry glass beads, partially saturated glass beads, and partially saturated crushed tuff obtained with synchrotron X-ray micro-CT demonstrate great potential of the MRF image model for three-dimensional multiphase segmentation. While our results are promising and the developed algorithm is stable and computationally more efficient than other commonly applied porous media segmentation models, further potential improvements exist for fully automated operation.

  17. Routine Repeat Head CT may not be Indicated in Patients on Anticoagulant/Antiplatelet Therapy Following Mild Traumatic Brain Injury

    E-Print Network [OSTI]

    McCammack, Kevin C.; Sadler, Charlotte; Guo, Yueyang; Ramaswamy, Raja S; Farid, Nikdokht

    2015-01-01T23:59:59.000Z

    needed when the computed tomography scan is normal. Acadof noncontrast cranial computed tomography for the emergencyMcCammack et al. Head Computed Tomography anticoagulant and

  18. Determination and distribution of left ventricular size as measured by noncontrast CT in the Multi-Ethnic Study of Atherosclerosis.

    E-Print Network [OSTI]

    2015-01-01T23:59:59.000Z

    of Cardiovascular Computed Tomography. Bild DE, Bluemke DA,filtration rate and computed tomography based leftof 4 th quartile of computed tomography derived left

  19. Routine Repeat Head CT may not be Indicated in Patients on Anticoagulant/Antiplatelet Therapy Following Mild Traumatic Brain Injury

    E-Print Network [OSTI]

    McCammack, Kevin C.; Sadler, Charlotte; Guo, Yueyang; Ramaswamy, Raja S; Farid, Nikdokht

    2015-01-01T23:59:59.000Z

    needed when the computed tomography scan is normal. AcadMcCammack et al. Head Computed Tomography anticoagulant andof sequential computed tomography scanning in anticoagulated

  20. Seismic Tomography: Definitions Lapo Boschi (lapo@erdw.ethz.ch)

    E-Print Network [OSTI]

    Boschi, Lapo

    Tomography Seismic tomography is the science of interpreting seismic measurements (seismograms) to derive; that is to say, solve the seismological inverse problem. Seismic data and their interpretation Seismic stationsSeismic Tomography: Definitions Lapo Boschi (lapo@erdw.ethz.ch) September 14, 2009 Seismic

  1. PHOTOACOUSTIC AND THERMOACOUSTIC TOMOGRAPHY WITH AN UNCERTAIN WAVE SPEED

    E-Print Network [OSTI]

    Uhlmann, Gunther

    PHOTOACOUSTIC AND THERMOACOUSTIC TOMOGRAPHY WITH AN UNCERTAIN WAVE SPEED LAURI OKSANEN AND GUNTHER UHLMANN Abstract. We consider the mathematical model of photoacoustic and thermoacoustic tomography. In Thermoacoustic tomography (TAT), see e.g. [8], low frequency microwaves, with wavelengths on the order of 1m

  2. THERMOACOUSTIC TOMOGRAPHY WITH AN ARBITRARY ELLIPTIC OPERATOR MICHAEL V. KLIBANOV

    E-Print Network [OSTI]

    1 THERMOACOUSTIC TOMOGRAPHY WITH AN ARBITRARY ELLIPTIC OPERATOR MICHAEL V. KLIBANOV Abstract. Thermoacoustic tomography is a term for the inverse problem of determining of one of initial conditions. In thermoacoustic tomography (TAT) a short radio frequency pulse is sent in a biological tissue [1, 9]. Some energy

  3. Application of a nudging technique to thermoacoustic tomography

    E-Print Network [OSTI]

    Boyer, Edmond

    Application of a nudging technique to thermoacoustic tomography Xavier Bonnefond and Sébastien Marinesque December 3, 2011 Abstract ThermoAcoustic Tomography (TAT) is a promising, non invasive, medical inversion method. 1 Introduction ThermoAcoustic Tomography (TAT) is a hybrid imaging technique that uses

  4. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with AAS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with AAS Radiologic Technology] Note: Admission to the program is required to enroll in RIS courses RIS 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography 2

  5. Kinetic Model for Motion Compensation in Computed Tomography

    E-Print Network [OSTI]

    1 Kinetic Model for Motion Compensation in Computed Tomography Zhou Yu, Jean-Baptiste Thibault- gorithms have recently been applied to computed tomography and demonstrated superior image quality. MBIR to computed tomography and demonstrated superior image quality performance [1], [2], [3]. These methods

  6. A new correction method serving to eliminate the parabola effect of flatbed scanners used in radiochromic film dosimetry

    SciTech Connect (OSTI)

    Poppinga, D., E-mail: daniela.poppinga@uni-oldenburg.de; Schoenfeld, A. A.; Poppe, B. [Medical Radiation Physics, Carl v. Ossietzky University, Oldenburg 26127, Germany and Department for Radiation Oncology, Pius Hospital, Oldenburg 26121 (Germany)] [Medical Radiation Physics, Carl v. Ossietzky University, Oldenburg 26127, Germany and Department for Radiation Oncology, Pius Hospital, Oldenburg 26121 (Germany); Doerner, K. J. [Radiotherapy Department, General Hospital, Celle 29223 (Germany)] [Radiotherapy Department, General Hospital, Celle 29223 (Germany); Blanck, O. [CyberKnife Center Northern Germany, Güstrow 18273, Germany and Department for Radiation Oncology, University Clinic Schleswig-Holstein, Lübeck 23562 (Germany)] [CyberKnife Center Northern Germany, Güstrow 18273, Germany and Department for Radiation Oncology, University Clinic Schleswig-Holstein, Lübeck 23562 (Germany); Harder, D. [Medical Physics and Biophysics, Georg-August-University, Göttingen 37073 (Germany)] [Medical Physics and Biophysics, Georg-August-University, Göttingen 37073 (Germany)

    2014-02-15T23:59:59.000Z

    Purpose: The purpose of this study is the correction of the lateral scanner artifact, i.e., the effect that, on a large homogeneously exposed EBT3 film, a flatbed scanner measures different optical densities at different positions along thex axis, the axis parallel to the elongated light source. At constant dose, the measured optical densitiy profiles along this axis have a parabolic shape with significant dose dependent curvature. Therefore, the effect is shortly called the parabola effect. The objective of the algorithm developed in this study is to correct for the parabola effect. Any optical density measured at given position x is transformed into the equivalent optical density c at the apex of the parabola and then converted into the corresponding dose via the calibration of c versus dose. Methods: For the present study EBT3 films and an Epson 10000XL scanner including transparency unit were used for the analysis of the parabola effect. The films were irradiated with 6 MV photons from an Elekta Synergy accelerator in a RW3 slab phantom. In order to quantify the effect, ten film pieces with doses graded from 0 to 20.9 Gy were sequentially scanned at eight positions along thex axis and at six positions along the z axis (the movement direction of the light source) both for the portrait and landscape film orientations. In order to test the effectiveness of the new correction algorithm, the dose profiles of an open square field and an IMRT plan were measured by EBT3 films and compared with ionization chamber and ionization chamber array measurement. Results: The parabola effect has been numerically studied over the whole measuring field of the Epson 10000XL scanner for doses up to 20.9 Gy and for both film orientations. The presented algorithm transforms any optical density at positionx into the equivalent optical density that would be measured at the same dose at the apex of the parabola. This correction method has been validated up to doses of 5.2 Gy all over the scanner bed with 2D dose distributions of an open square photon field and an IMRT distribution. Conclusions: The algorithm presented in this study quantifies and corrects the parabola effect of EBT3 films scanned in commonly used commercial flatbed scanners at doses up to 5.2 Gy. It is easy to implement, and no additional work steps are necessary in daily routine film dosimetry.

  7. aneurysm ct evaluation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    die Magnetresonanztomographie und die Positronen-Emissionstomographie ( CT, MRT, PET) sind heute, neben der Ultraschalltechnik, die wichtigsten nicht-invasiven bildgebenden...

  8. Segmentation of artifacts and anatomy in CT metal artifact reduction

    E-Print Network [OSTI]

    Karimi, Seemeen; Cosman, Pamela; Wald, Christoph; Martz, Harry

    2012-01-01T23:59:59.000Z

    Maximum- likelihood dual-energy tomographic imageartifact reduction by dual energy CT using monoenergetictive reconstruction of dual energy data 21 has the potential

  9. CT. L-2 United States Government

    Office of Legacy Management (LM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group currentBradleyTableSelling Corp -KWatertowni5W 95.5x-L* d! CT NC0 - i ,

  10. Global transition zone tomography Jeroen Ritsema1

    E-Print Network [OSTI]

    Ritsema, Jeroen

    Global transition zone tomography Jeroen Ritsema1 and Hendrik Jan van Heijst Seismological on accurate models of seismic velocity variation in the upper mantle transition zone (400­1000 km depth. Such data provide new global transition zone constraints. We combined more than a million measurements

  11. Reconstruction in tomography with diffracting sources

    E-Print Network [OSTI]

    Xu, Yuan

    2005-02-17T23:59:59.000Z

    Homogeneous Model . . . . . . . . . . . . . . . . . . . 22 III LIMITED-VIEW THERMOACOUSTIC TOMOGRAPHY1 . . . 24 A. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . 24 1. Analysis of Singularities in Circular Radon Trans- form and Limited-view TAT... . . . . . . . . . . . . . . 26 a. Circular Radon Transform . . . . . . . . . . . . . 26 b. TAT . . . . . . . . . . . . . . . . . . . . . . . . . 27 c. Reconstruction Methods . . . . . . . . . . . . . . 30 2. Numerical Implementation . . . . . . . . . . . . . . . 35 viii CHAPTER...

  12. Single-Shot Quantum Process Tomography

    E-Print Network [OSTI]

    Abhishek Shukla; T. S. Mahesh

    2014-05-27T23:59:59.000Z

    The standard procedure for quantum process tomography (QPT) involves applying the quantum process on a system initialized in each of a complete set of orthonormal states. The corresponding outputs are then characterized by quantum state tomography (QST), which itself requires the measurement of non-commuting observables realized by independent experiments on identically prepared system states. Thus QPT procedure demands a number of independent measurements, and moreover, this number increases rapidly with the size of the system. However, the total number of independent measurements can be greatly reduced with the availability of ancilla qubits. Ancilla assisted process tomography (AAPT) has earlier been shown to require a single QST of system-ancilla space. Ancilla assisted quantum state tomography (AAQST) has also been shown to perform QST in a single measurement. Here we combine AAPT with AAQST to realize a `single-shot QPT' (SSPT), a procedure to characterize a general quantum process in a single collective measurement of a set of commuting observables. We demonstrate experimental SSPT by characterizing several single-qubit processes using a three-qubit NMR quantum register. Furthermore, using the SSPT procedure we experimentally characterize the twirling process and compare the results with theory.

  13. Regularized Equally Sloped Tomography Algorithm for Low Dose X-Ray Computed Tomography

    E-Print Network [OSTI]

    Zhao, Yunzhe

    2012-01-01T23:59:59.000Z

    of the central slice of Siemens SOMATOM sensation 64 CT3.6. The three inserts from Siemens’ image quality phantom,3.6. The three inserts from Siemens’ image quality EMMA

  14. Mechanical Design and Evaluation of the MP-11-Like Wire Scanner Prototype

    SciTech Connect (OSTI)

    Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Maestas, Alfred J. [Los Alamos National Laboratory; Gilpatrick, John D. [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory; Raybun, Joseph L. [Los Alamos National Laboratory; Martinez, Jason P. [Los Alamos National Laboratory; Sattler, F. D. [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory

    2012-05-16T23:59:59.000Z

    A wire scanner (WS) is a linearly actuated diagnostic device that uses fiber wires (such as Tungsten or Silicon Carbide) to obtain the position and intensity profile of the proton beam at the Los Alamos Neutron Science Center (LANSCE) particle accelerator. LANSCE will be installing approximately 86 new WS in the near future as part of the LANSCE Risk Mitigation project. These 86 new WS include the replacement of many current WS and some newly added to the current linear accelerator and other beam lines. The reason for the replacement and addition of WS is that many of the existing actuators have parts that are no longer readily available and are difficult to find, thus making maintenance very difficult. One of the main goals is to construct the new WS with as many commercially-available-off-the-shelf components as possible. In addition, faster beam scans (both mechanically and in term of data acquisition) are desired for better operation of the accelerator. This document outlines the mechanical design of the new MP-11-like WS prototype and compares it to a previously built and tested SNS-like WS prototype.

  15. Recent results with a CdTe imaging portal scanner for radiation therapy

    SciTech Connect (OSTI)

    Entine, G.; Redus, R.H.; Feyder, A. (Radiation Monitoring Devices, Inc., Watertown, MA (United States)); Biggs, P.J. (Massachusetts General Hospital, Boston, MA (United States))

    1993-08-01T23:59:59.000Z

    One of the most promising means for improving the quality of radiation therapy is the use of real-time imaging systems for routine portal position verification. The authors have constructed a prototype portal imager using a linear array of 256 CdTe photovoltaic detectors, each 2X2X2 mm. The array is attached to a compact linear scanner which is to be mounted in a cassette shaped package located below the patient table. The array of detectors is moved under the patient during image acquisition. The high stopping power of the CdTe allows a high contrast image to be made using a single linac pulse for each array position. In tests conducted with a 4 MV linac, this system produced 50 cm x 35 cm images with an open field signal-to-noise ratio of 143 and 2 mm spatial resolution in less than 3 seconds. This corresponds to a signal-to-noise ratio of 1 for 1% contrast objects. Ultimately, a signal-to-noise ratio greater than 5 at 1% contrast should be achievable with no loss of spatial resolution or increase in acquisition time.

  16. Fluorodeoxyglucose Positron Emission Tomography Response and Normal Tissue Regeneration After Stereotactic Body Radiotherapy to Liver Metastases

    SciTech Connect (OSTI)

    Stinauer, Michelle A., E-mail: Michelle.Stinauer@ucdenver.edu [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Diot, Quentin; Westerly, David C.; Schefter, Tracey E.; Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)] [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)

    2012-08-01T23:59:59.000Z

    Purpose: To characterize changes in standardized uptake value (SUV) in positron emission tomography (PET) scans and determine the pace of normal tissue regeneration after stereotactic body radiation therapy (SBRT) for solid tumor liver metastases. Methods and Materials: We reviewed records of patients with liver metastases treated with SBRT to {>=}40 Gy in 3-5 fractions. Evaluable patients had pretreatment PET and {>=}1 post-treatment PET. Each PET/CT scan was fused to the planning computed tomography (CT) scan. The maximum SUV (SUV{sub max}) for each lesion and the total liver volume were measured on each PET/CT scan. Maximum SUV levels before and after SBRT were recorded. Results: Twenty-seven patients with 35 treated liver lesions were studied. The median follow-up was 15.7 months (range, 1.5-38.4 mo), with 5 PET scans per patient (range, 2-14). Exponential decay curve fitting (r=0.97) showed that SUV{sub max} declined to a plateau of 3.1 for controlled lesions at 5 months after SBRT. The estimated SUV{sub max} decay half-time was 2.0 months. The SUV{sub max} in controlled lesions fluctuated up to 4.2 during follow-up and later declined; this level is close to 2 standard deviations above the mean normal liver SUV{sub max} (4.01). A failure cutoff of SUV{sub max} {>=}6 is twice the calculated plateau SUV{sub max} of controlled lesions. Parenchymal liver volume decreased by 20% at 3-6 months and regenerated to a new baseline level approximately 10% below the pretreatment level at 12 months. Conclusions: Maximum SUV decreases over the first months after SBRT to plateau at 3.1, similar to the median SUV{sub max} of normal livers. Transient moderate increases in SUV{sub max} may be observed after SBRT. We propose a cutoff SUV{sub max} {>=}6, twice the baseline normal liver SUV{sub max}, to score local failure by PET criteria. Post-SBRT values between 4 and 6 would be suspicious for local tumor persistence or recurrence. The volume of normal liver reached nadir 3-6 months after SBRT and regenerated within the next 6 months.

  17. Automated movement correction for dynamic PET/CT images: Evaluation with phantom and patient data

    E-Print Network [OSTI]

    2014-01-01T23:59:59.000Z

    co- registration between PET and CT and for between frameco-registration between PET and CT, the PET images with ACregistration between PET and CT. Figure 3 shows that small

  18. Customized Computed Tomography-Based Boost Volumes in Breast-Conserving Therapy: Use of Three-Dimensional Histologic Information for Clinical Target Volume Margins

    SciTech Connect (OSTI)

    Hanbeukers, Bianca [Department of Radiation Oncology, MAASTRO Clinic, Maastricht (Netherlands); Borger, Jacques; Ende, Piet van den [Department of Radiation Oncology, MAASTRO Clinic, Maastricht (Netherlands); Department of Radiation Oncology, Maastricht University Medical Center, Maastricht (Netherlands); Ent, Fred van der [Department of Surgery, Maasland Hospital, Sittard (Netherlands); Houben, Ruud [Department of Radiation Oncology, MAASTRO Clinic, Maastricht (Netherlands); Jager, Jos [Department of Radiation Oncology, MAASTRO Clinic, Maastricht (Netherlands); Department of Radiation Oncology, Maastricht University Medical Center, Maastricht (Netherlands); Keymeulen, Kristien [Department of Surgery, Maastricht University Medical Center, Maastricht (Netherlands); Murrer, Lars [Department of Radiation Oncology, MAASTRO Clinic, Maastricht (Netherlands); Department of Radiation Oncology, Maastricht University Medical Center, Maastricht (Netherlands); Sastrowijoto, Suprapto [Department of Pathology, Maasland Hospital, Sittard (Netherlands); Vijver, Koen van de [Department of Pathology, Maastricht University Medical Center, Maastricht (Netherlands); Boersma, Liesbeth, E-mail: liesbeth.boersma@maastro.n [Department of Radiation Oncology, Maastricht University Medical Center, Maastricht (Netherlands); Department of Radiation Oncology, MAASTRO Clinic, Maastricht (Netherlands)

    2009-11-01T23:59:59.000Z

    Purpose: To determine the difference in size between computed tomography (CT)-based irradiated boost volumes and simulator-based irradiated volumes in patients treated with breast-conserving therapy and to analyze whether the use of anisotropic three-dimensional clinical target volume (CTV) margins using the histologically determined free resection margins allows for a significant reduction of the CT-based boost volumes. Patients and Methods: The CT data from 49 patients were used to delineate a planning target volume (PTV) with isotropic CTV margins and to delineate a PTV{sub sim} that mimicked the PTV as delineated in the era of conventional simulation. For 17 patients, a PTV with anisotropic CTV margins was defined by applying customized three-dimensional CTV margins, according to the free excision margins in six directions. Boost treatment plans consisted of conformal portals for the CT-based PTVs and rectangular fields for the PTV{sub sim}. Results: The irradiated volume (volume receiving >=95% of the prescribed dose [V{sub 95}]) for the PTV with isotropic CTV margins was 1.6 times greater than that for the PTV{sub sim}: 228 cm{sup 3} vs. 147 cm{sup 3} (p < .001). For the 17 patients with a PTV with anisotropic CTV margins, the V{sub 95} was similar to the V{sub 95} for the PTV{sub sim} (190 cm{sup 3} vs. 162 cm{sup 3}; p = NS). The main determinant for the irradiated volume was the size of the excision cavity (p < .001), which was mainly related to the interval between surgery and the planning CT scan (p = .029). Conclusion: CT-based PTVs with isotropic margins for the CTV yield much greater irradiated volumes than fluoroscopically based PTVs. Applying individualized anisotropic CTV margins allowed for a significant reduction of the irradiated boost volume.

  19. A general framework and review of scatter correction methods in x-ray cone-beam computerized tomography. Part 1: Scatter compensation approaches

    SciTech Connect (OSTI)

    Ruehrnschopf, Ernst-Peter; Klingenbeck, Klaus [Siemens AG, Healthcare Sector, Imaging and Therapy Division, Forchheim (Germany)

    2011-07-15T23:59:59.000Z

    Since scattered radiation in cone-beam volume CT implies severe degradation of CT images by quantification errors, artifacts, and noise increase, scatter suppression is one of the main issues related to image quality in CBCT imaging. The aim of this review is to structurize the variety of scatter suppression methods, to analyze the common structure, and to develop a general framework for scatter correction procedures. In general, scatter suppression combines hardware techniques of scatter rejection and software methods of scatter correction. The authors emphasize that scatter correction procedures consist of the main components scatter estimation (by measurement or mathematical modeling) and scatter compensation (deterministic or statistical methods). The framework comprises most scatter correction approaches and its validity also goes beyond transmission CT. Before the advent of cone-beam CT, a lot of papers on scatter correction approaches in x-ray radiography, mammography, emission tomography, and in Megavolt CT had been published. The opportunity to avail from research in those other fields of medical imaging has not yet been sufficiently exploited. Therefore additional references are included when ever it seems pertinent. Scatter estimation and scatter compensation are typically intertwined in iterative procedures. It makes sense to recognize iterative approaches in the light of the concept of self-consistency. The importance of incorporating scatter compensation approaches into a statistical framework for noise minimization has to be underscored. Signal and noise propagation analysis is presented. A main result is the preservation of differential-signal-to-noise-ratio (dSNR) in CT projection data by ideal scatter correction. The objective of scatter compensation methods is the restoration of quantitative accuracy and a balance between low-contrast restoration and noise reduction. In a synopsis section, the different deterministic and statistical methods are discussed with respect to their properties and applications. The current paper is focused on scatter compensation algorithms. The multitude of scatter estimation models will be dealt with in a separate paper.

  20. Radioimmuntherapie3 Radioimmundiagnostik (Immuno-PET/CT)3

    E-Print Network [OSTI]

    Gollisch, Tim

    Radioimmuntherapie3 Radioimmundiagnostik (Immuno-PET/CT)3 Entzündungsdiagnostik mit [18F]FDG3 of Inflammatory Diseases with [18F]FDG3 Characterisation of Multinodular Toxic Goiter3 Radioactive tracers onkologischer Therapiekonzepte Radioimmunotherapy3 Radioimmunodiagnostics (Immuno-PET/CT)3 Diagnosis

  1. CT imaging during microwave ablation: Analysis of spatial and temporal tissue contraction

    SciTech Connect (OSTI)

    Liu, Dong; Brace, Christopher L., E-mail: clbrace@wisc.edu [Departments of Radiology and Biomedical Engineering, University of Wisconsin, Madison, Wisconsin 53705 (United States)

    2014-11-01T23:59:59.000Z

    Purpose: To analyze the spatial distribution and temporal development of liver tissue contraction during high-temperature ablation by using intraprocedural computed tomography (CT) imaging. Methods: A total of 46 aluminum fiducial markers were positioned in a 60 × 45 mm grid, in a single plane, around a microwave ablation antenna in each of six ex vivo bovine liver samples. Ablations were performed for 10 min at 100 W. CT data of the liver sample were acquired every 30 s during ablation. Fiducial motion between acquisitions was tracked in postprocessing and used to calculate measures of tissue contraction and contraction rates. The spatial distribution and temporal evolution of contraction were analyzed. Results: Fiducial displacement indicated that the zone measured postablation was 8.2 ± 1.8 mm (?20%) smaller in the radial direction and 7.1 ± 1.0 mm (?10%) shorter in the longitudinal direction than the preablation tissue dimension. Therefore, the total ablation volume was reduced from its preablation value by approximately 45%. Very little longitudinal contraction was noted in the distal portion of the ablation zone. Central tissues contracted more than 60%, which was near an estimated limit of ?70% based on initial water content. More peripheral tissues contracted only 15% in any direction. Contraction rates peaked during the first 60 s of heating with a roughly exponential decay over time. Conclusions: Ablation zones measured posttreatment are significantly smaller than the pretreatment tissue dimensions. Tissue contraction is spatially dependent, with the greatest effect occurring in the central ablation zone. Contraction rate peaks early and decays over time.

  2. Contouring Variability of the Penile Bulb on CT Images: Quantitative Assessment Using a Generalized Concordance Index

    SciTech Connect (OSTI)

    Carillo, Viviana [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Cozzarini, Cesare [Department of Radiotherapy, San Raffaele Scientific Institute, Milano (Italy)] [Department of Radiotherapy, San Raffaele Scientific Institute, Milano (Italy); Perna, Lucia; Calandra, Mauro [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Gianolini, Stefano [Medical Software Solutions GmbH, Hagendorn (Switzerland)] [Medical Software Solutions GmbH, Hagendorn (Switzerland); Rancati, Tiziana [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy)] [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy); Spinelli, Antonello Enrico [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Vavassori, Vittorio [Department of Radiotherapy, Cliniche Gavazzeni Humanitas, Bergamo (Italy)] [Department of Radiotherapy, Cliniche Gavazzeni Humanitas, Bergamo (Italy); Villa, Sergio [Department of Radiotherapy 1, IRCCS National Institute of Cancer, Milano (Italy)] [Department of Radiotherapy 1, IRCCS National Institute of Cancer, Milano (Italy); Valdagni, Riccardo [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy) [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy); Department of Radiotherapy 1, IRCCS National Institute of Cancer, Milano (Italy); Fiorino, Claudio, E-mail: fiorino.claudio@hsr.it [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)

    2012-11-01T23:59:59.000Z

    Purpose: Within a multicenter study (DUE-01) focused on the search of predictors of erectile dysfunction and urinary toxicity after radiotherapy for prostate cancer, a dummy run exercise on penile bulb (PB) contouring on computed tomography (CT) images was carried out. The aim of this study was to quantitatively assess interobserver contouring variability by the application of the generalized DICE index. Methods and Materials: Fifteen physicians from different Institutes drew the PB on CT images of 10 patients. The spread of DICE values was used to objectively select those observers who significantly disagreed with the others. The analyses were performed with a dedicated module in the VODCA software package. Results: DICE values were found to significantly change among observers and patients. The mean DICE value was 0.67, ranging between 0.43 and 0.80. The statistics of DICE coefficients identified 4 of 15 observers who systematically showed a value below the average (p value range, 0.013 - 0.059): Mean DICE values were 0.62 for the 4 'bad' observers compared to 0.69 of the 11 'good' observers. For all bad observers, the main cause of the disagreement was identified. Average DICE values were significantly worse from the average in 2 of 10 patients (0.60 vs. 0.70, p < 0.05) because of the limited visibility of the PB. Excluding the bad observers and the 'bad' patients,' the mean DICE value increased from 0.67 to 0.70; interobserver variability, expressed in terms of standard deviation of DICE spread, was also reduced. Conclusions: The obtained values of DICE around 0.7 shows an acceptable agreement, considered the small dimension of the PB. Additional strategies to improve this agreement are under consideration and include an additional tutorial of the so-called bad observers with a recontouring procedure, or the recontouring by a single observer of the PB for all patients included in the DUE-01 study.

  3. Multi-energy CT Based on a Prior Rank, Intensity and Sparsity Model (PRISM)

    E-Print Network [OSTI]

    Soatto, Stefano

    -color, as a natural extension of dual energy CT [1], the future of CT will be multi-energy, generating much richer

  4. The Relationship between Organ Dose and Patients Size in Multidetector Computed Tomography (MDCT) Scans Utilizing Tube Current Modulation (TCM)

    E-Print Network [OSTI]

    Khatonabadi, Maryam

    2013-01-01T23:59:59.000Z

    Dose Reduction With Chest Computed Tomography Using AdaptiveDose reduction in computed tomography by attenuation-baseddose from cardiac computed tomography before and after

  5. Comments on “Sensitivity of Emergency Bedside Ultrasound to Detect Hydronephrosis in Patients with Computed Tomography-proven Stones”

    E-Print Network [OSTI]

    K?z?lca, Özgür; Oztek, Alp; Senol, Utku

    2014-01-01T23:59:59.000Z

    al. Ultrasonography versus computed tomography for suspectedin Patients with Computed Tomography-proven Stones” Özgürin Patients with Computed Tomography-proven Stones. West J

  6. Usefulness of Computed Tomography Perfusion in Treatment of an Acute Stroke Patient with Unknown Time of Symptom Onset

    E-Print Network [OSTI]

    Fesmire, Francis M; England, Bryan S; Shell, Jared S; Devlin, Thomas G; Buchheit, Ron C

    2014-01-01T23:59:59.000Z

    ischemic stroke using computed tomography perfusion-derivedUsefulness of Computed Tomography Perfusion in Treatment oftime of symptom onset. Computed tomography angiogram (CTA)

  7. Reply to Comments Regarding “Sensitivity of Emergency Bedside Ultrasound to Detect Hydronephrosis in Patients with Computed Tomography-proven Stones”

    E-Print Network [OSTI]

    Riddell, Jeff; Swadron, Stuart

    2014-01-01T23:59:59.000Z

    al. Ultrasonography versus computed tomography for suspectedin Patients with Computed Tomography-proven Stones” Özgürin Patients with Computed Tomography-proven Stones. West J

  8. A Novel Immunofluorescent Computed Tomography (ICT) Method to Localise and Quantify Multiple Antigens in Large Tissue Volumes at High Resolution

    E-Print Network [OSTI]

    2012-01-01T23:59:59.000Z

    Immunofluorescent Computed Tomography Figure 1. IterativeImmunofluorescent Computed Tomography 31. Freund I, DeutschNovel Immunofluorescent Computed Tomography (ICT) Method to

  9. THE ATTENUATED RADON TRANSFORM: APPLICATION TO SINGLE-PHOTON EMISSION COMPUTED TOMOGRAPHY IN THE PRESENCE OF A VARIABLE ATTENUATING MEDIUM

    E-Print Network [OSTI]

    Gullberg, Grant T.

    2013-01-01T23:59:59.000Z

    PHOTON EMISSION COMPUTED TOMOGRAPHY IN THE PRESENCE OF APHOTON EMISSION COMPUTED TOMOGRAPHY IN THE PRESENCE OF APHOTON EMISSION COMPUTED TOMOGRAPHY IN THE PRESENCE OF A

  10. Automated simulation of areal bone mineral density assessment in the distal radius from high-resolution peripheral quantitative computed tomography

    E-Print Network [OSTI]

    Burghardt, A. J.; Kazakia, G. J.; Link, T. M.; Majumdar, S.

    2009-01-01T23:59:59.000Z

    quantitative computed tomography A. J. Burghardt & G. J.2017–2024 Micro-computed tomography has become an importantperipheral quantitative computed tomography (HR-pQCT) is a

  11. Analysis of in-situ rock joint strength using digital borehole scanner images

    SciTech Connect (OSTI)

    Thapa, B.B.

    1994-09-01T23:59:59.000Z

    The availability of high resolution digital images of borehole walls using the Borehole Scanner System has made it possible to develop new methods of in-situ rock characterization. This thesis addresses particularly new approaches to the characterization of in-situ joint strength arising from surface roughness. An image processing technique is used to extract the roughness profile from joints in the unrolled image of the borehole wall. A method for estimating in-situ Rengers envelopes using this data is presented along with results from using the method on joints in a borehole in porphyritic granite. Next, an analysis of the joint dilation angle anisotropy is described and applied to the porphyritic granite joints. The results indicate that the dilation angle of the joints studied are anisotropic at small scales and tend to reflect joint waviness as scale increases. A procedure to unroll the opposing roughness profiles to obtain a two dimensional sample is presented. The measurement of apertures during this process is shown to produce an error which increases with the dip of the joint. The two dimensional sample of opposing profiles is used in a new kinematic analysis of the joint shear stress-shear deformation behavior. Examples of applying these methods on the porphyritic granite joints are presented. The unrolled opposing profiles were used in a numerical simulation of a direct shear test using Discontinuous Deformation Analysis. Results were compared to laboratory test results using core samples containing the same joints. The simulated dilatancy and shear stress-shear deformation curves were close to the laboratory curves in the case of a joint in porphyritic granite.

  12. Process tomography for unitary quantum channels

    SciTech Connect (OSTI)

    Gutoski, Gus [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada)] [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada); Johnston, Nathaniel [Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)] [Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2014-03-15T23:59:59.000Z

    We study the number of measurements required for quantum process tomography under prior information, such as a promise that the unknown channel is unitary. We introduce the notion of an interactive observable and we show that any unitary channel acting on a d-level quantum system can be uniquely identified among all other channels (unitary or otherwise) with only O(d{sup 2}) interactive observables, as opposed to the O(d{sup 4}) required for tomography of arbitrary channels. This result generalizes to the problem of identifying channels with at most q Kraus operators, and slight improvements can be obtained if we wish to identify such a channel only among unital channels or among other channels with q Kraus operators. These results are proven via explicit construction of large subspaces of Hermitian matrices with various conditions on rank, eigenvalues, and partial trace. Our constructions are built upon various forms of totally nonsingular matrices.

  13. Bachelor of Science, Radiologic Sciences, Computed Tomography Emphasis, 2014-2015 Name ID# Date

    E-Print Network [OSTI]

    Barrash, Warren

    Bachelor of Science, Radiologic Sciences, Computed Tomography Emphasis, 2014-2015 Name ID# Date RADSCI 450 Principles of Computed Tomography RADSCI 450L Principles of Computed Tomography Lab RADSCI 451 Procedural Case Studies in Computed Tomography RADSCI 455 Clinical Experience in Computed Tomography 1 3 1 3

  14. Bachelor of Science, Radiologic Sciences, Computed Tomography Emphasis, 2013-2014 Name ID# Date

    E-Print Network [OSTI]

    Barrash, Warren

    Bachelor of Science, Radiologic Sciences, Computed Tomography Emphasis, 2013-2014 Name ID# Date RADSCI 450 Principles of Computed Tomography RADSCI 450L Principles of Computed Tomography Lab RADSCI 451 Procedural Case Studies in Computed Tomography RADSCI 455 Clinical Experience in Computed Tomography 1 3 1 3

  15. Thermoacoustic tomography arising in brain imaging

    E-Print Network [OSTI]

    Stefanov, Plamen

    2010-01-01T23:59:59.000Z

    We study the mathematical model of thermoacoustic and photoacoustic tomography when the sound speed has a jump across a smooth surface. This models the change of the sound speed in the skull when trying to image the human brain. We derive an explicit inversion formula in the form of a convergent Neumann series under the assumptions that all singularities from the support of the source reach the boundary.

  16. Thermoacoustic tomography arising in brain imaging

    E-Print Network [OSTI]

    Plamen Stefanov; Gunther Uhlmann

    2010-09-09T23:59:59.000Z

    We study the mathematical model of thermoacoustic and photoacoustic tomography when the sound speed has a jump across a smooth surface. This models the change of the sound speed in the skull when trying to image the human brain. We derive an explicit inversion formula in the form of a convergent Neumann series under the assumptions that all singularities from the support of the source reach the boundary.

  17. Thermoacoustic tomography with variable sound speed

    E-Print Network [OSTI]

    Stefanov, Plamen

    2009-01-01T23:59:59.000Z

    We study the mathematical model of thermoacoustic tomography in media with a variable speed for a fixed time interval, greater than the diameter of the domain. In case of measurements on the whole boundary, we give an explicit solution in terms of a Neumann series expansion. We give necessary and sufficient conditions for uniqueness and stability when the measurements are taken on a part of the boundary.

  18. Thermoacoustic tomography with variable sound speed

    E-Print Network [OSTI]

    Plamen Stefanov; Gunther Uhlmann

    2009-05-30T23:59:59.000Z

    We study the mathematical model of thermoacoustic tomography in media with a variable speed for a fixed time interval, greater than the diameter of the domain. In case of measurements on the whole boundary, we give an explicit solution in terms of a Neumann series expansion. We give necessary and sufficient conditions for uniqueness and stability when the measurements are taken on a part of the boundary.

  19. Tomography and spectroscopy as quantum computations

    E-Print Network [OSTI]

    Cesar Miquel; Juan Pablo Paz; Marcos Saraceno; Emmanuel Knill; Raymond Laflamme; Camille Negrevergne

    2001-09-14T23:59:59.000Z

    Determining the state of a system and measuring properties of its evolution are two of the most important tasks a physicist faces. For the first purpose one can use tomography, a method that after subjecting the system to a number of experiments determines all independent elements of the density matrix. For the second task, one can resort to spectroscopy, a set of techniques used to determine the spectrum of eigenvalues of the evolution operator. In this letter, we show that tomography and spectroscopy can be naturally interpreted as dual forms of quantum computation. We show how to adapt the simplest case of the well-known phase estimation quantum algorithm to perform both tasks, giving it a natural interpretation as a simulated scattering experiment. We show how this algorithm can be used to implement an interesting form of tomography by performing a direct measurement of the Wigner function of a quantum system. We present results of such measurements performed on a system of three qubits using liquid state NMR quantum computation techniques in a sample of trichloroethylene. Remarkable analogies with other experiments are discussed.

  20. Radiofrequency Ablation of Non-Small-Cell Carcinoma of the Lung Under Real-Time FDG PET CT Guidance

    SciTech Connect (OSTI)

    Schoellnast, Helmut; Larson, Steven M. [Memorial Sloan-Kettering Cancer Center, Department of Radiology (United States); Nehmeh, Sadek A. [Memorial Sloan-Kettering Cancer Center, Department of Medical Physics (United States); Carrasquillo, Jorge A.; Thornton, Raymond H.; Solomon, Stephen B., E-mail: solomons@mskcc.org [Memorial Sloan-Kettering Cancer Center, Department of Radiology (United States)

    2011-02-15T23:59:59.000Z

    Radiofrequency ablation (RFA) is a well-established method in treatment of patients with lung carcinomas who are not candidates for surgical resection. Usually computed tomographic (CT) guidance is used for the procedure, thus enabling needle placement and permitting evaluation of complications such as pneumothorax and bleeding. {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is generally used for tumor activity assessment and is therefore useful in follow-up after tumor treatment. A method that provides real-time image-based monitoring of RFA to ensure complete tumor ablation would be a valuable tool. In this report, we describe the behavior of preinjected FDG during PET CT-guided RFA of a non-small-cell lung carcinoma and discuss the value of FDG as a tool to provide intraprocedure monitor ablation. The size and the form of the activity changed during ablation. Ablation led to increase of the size and blurring and irregularity of the contour compared to pretreatment imaging. The maximal standardized uptake value decreased only slightly during the procedure. Therefore, before RFA, FDG PET can guide initial needle placement, but it does not serve as a monitoring tool to evaluate residual viable tissue during the procedure.

  1. Objective index of image fidelity for JPEG2000 compressed body CT images

    SciTech Connect (OSTI)

    Kim, Kil Joong; Lee, Kyoung Ho; Kang, Heung-Sik; Kim, So Yeon; Kim, Young Hoon; Kim, Bohyoung; Seo, Jinwook; Mantiuk, Rafal [Department of Radiation Applied Life Science, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul, 110-744 (Korea, Republic of); Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Institute of Radiation Medicine, and Seoul National University Medical Research Center, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggido, 463-707 (Korea, Republic of); School of Computer Science and Engineering, Seoul National University, 599 Gwanak-Ro, Gwanak-Gu, Seoul, 151-744 (Korea, Republic of); Department of Computer Science, University of British Columbia, 201-2366 Main Mall, Vancouver, British Columbia V6T 1Z4 (Canada)

    2009-07-15T23:59:59.000Z

    Compression ratio (CR) has been the de facto standard index of compression level for medical images. The aim of the study is to evaluate the CR, peak signal-to-noise ratio (PSNR), and a perceptual quality metric (high-dynamic range visual difference predictor HDR-VDP) as objective indices of image fidelity for Joint Photographic Experts Group (JPEG) 2000 compressed body computed tomography (CT) images, from the viewpoint of visually lossless compression approach. A total of 250 body CT images obtained with five different scan protocols (5-mm-thick abdomen, 0.67-mm-thick abdomen, 5-mm-thick lung, 0.67-mm-thick lung, and 5-mm-thick low-dose lung) were compressed to one of five CRs (reversible, 6:1, 8:1, 10:1, and 15:1). The PSNR and HDR-VDP values were calculated for the 250 pairs of the original and compressed images. By alternately displaying an original and its compressed image on the same monitor, five radiologists independently determined if the pair was distinguishable or indistinguishable. The kappa statistic for the interobserver agreement among the five radiologists' responses was 0.70. According to the radiologists' responses, the number of distinguishable image pairs tended to significantly differ among the five scan protocols at 6:1-10:1 compressions (Fisher-Freeman-Halton exact tests). Spearman's correlation coefficients between each of the CR, PSNR, and HDR-VDP and the number of radiologists who responded as distinguishable were 0.72, -0.77, and 0.85, respectively. Using the radiologists' pooled responses as the reference standards, the areas under the receiver-operating-characteristic curves for the CR, PSNR, and HDR-VDP were 0.87, 0.93, and 0.97, respectively, showing significant differences between the CR and PSNR (p=0.04), or HDR-VDP (p<0.001), and between the PSNR and HDR-VDP (p<0.001). In conclusion, the CR is less suitable than the PSNR or HDR-VDP as an objective index of image fidelity for JPEG2000 compressed body CT images. The HDR-VDP is more promising than the PSNR as such an index.

  2. Abstract--Proton computed tomography (pCT) has the potential to improve the accuracy of dose calculations for proton

    E-Print Network [OSTI]

    Mueller, Klaus

    calculations for proton treatment planning, and will also be useful for pretreatment verification of patient Installation time Data acquisition time Reconstruction time energy to penetrate the body part to be imaged. According to the NIST PSTAR data base [1], the continuous

  3. Lack of Gender Disparities in Emergency Department Triage of Acute Stroke Patients

    E-Print Network [OSTI]

    Madsen, Tracy E.; Choo, Esther K.; Seigel, Todd A.; Palms, Danielle; Silver, Brian

    2015-01-01T23:59:59.000Z

    have non-contrast computed tomography (CT) within 25 minutesmedical services; CT, computed tomography non-critical care

  4. Mathematics Master acadmique

    E-Print Network [OSTI]

    Thalmaier, Anton

    , cosmos) to Geology (oil reserves), from Medical Technology (computerized axial tomography scanners

  5. Tumor Tracking Method Based on a Deformable 4D CT Breathing Motion Model Driven by an External Surface Surrogate

    SciTech Connect (OSTI)

    Fassi, Aurora, E-mail: aurora.fassi@mail.polimi.it [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Schaerer, Joël; Fernandes, Mathieu [CREATIS, CNRS UMR 5220, INSERM U1044, Université Lyon 1, INSA-Lyon, Villeurbanne (France); Department of Radiotherapy, Centre Léon Bérard, Lyon (France); Riboldi, Marco [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy); Sarrut, David [CREATIS, CNRS UMR 5220, INSERM U1044, Université Lyon 1, INSA-Lyon, Villeurbanne (France); Department of Radiotherapy, Centre Léon Bérard, Lyon (France); Baroni, Guido [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy)

    2014-01-01T23:59:59.000Z

    Purpose: To develop a tumor tracking method based on a surrogate-driven motion model, which provides noninvasive dynamic localization of extracranial targets for the compensation of respiration-induced intrafraction motion in high-precision radiation therapy. Methods and Materials: The proposed approach is based on a patient-specific breathing motion model, derived a priori from 4-dimensional planning computed tomography (CT) images. Model parameters (respiratory baseline, amplitude, and phase) are retrieved and updated at each treatment fraction according to in-room radiography acquisition and optical surface imaging. The baseline parameter is adapted to the interfraction variations obtained from the daily cone beam (CB) CT scan. The respiratory amplitude and phase are extracted from an external breathing surrogate, estimated from the displacement of the patient thoracoabdominal surface, acquired with a noninvasive surface imaging device. The developed method was tested on a database of 7 lung cancer patients, including the synchronized information on internal and external respiratory motion during a CBCT scan. Results: About 30 seconds of simultaneous acquisition of CBCT and optical surface images were analyzed for each patient. The tumor trajectories identified in CBCT projections were used as reference and compared with the target trajectories estimated from surface displacement with the a priori motion model. The resulting absolute differences between the reference and estimated tumor motion along the 2 image dimensions ranged between 0.7 and 2.4 mm; the measured phase shifts did not exceed 7% of the breathing cycle length. Conclusions: We investigated a tumor tracking method that integrates breathing motion information provided by the 4-dimensional planning CT with surface imaging at the time of treatment, representing an alternative approach to point-based external–internal correlation models. Although an in-room radiograph-based assessment of the reliability of the motion model is envisaged, the developed technique does not involve the estimation and continuous update of correlation parameters, thus requiring a less intense use of invasive imaging.

  6. A Fully Automated Method for CT-on-Rails-Guided Online Adaptive Planning for Prostate Cancer Intensity Modulated Radiation Therapy

    SciTech Connect (OSTI)

    Li, Xiaoqiang; Quan, Enzhuo M.; Li, Yupeng [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Pan, Xiaoning [Department of Radiation Oncology, University of Texas Health Science Center at Tyler, Tyler, Texas (United States); Zhou, Yin [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Wang, Xiaochun [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Du, Weiliang [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kudchadker, Rajat J.; Johnson, Jennifer L. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kuban, Deborah A.; Lee, Andrew K. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhang, Xiaodong, E-mail: xizhang@mdanderson.org [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2013-08-01T23:59:59.000Z

    Purpose: This study was designed to validate a fully automated adaptive planning (AAP) method which integrates automated recontouring and automated replanning to account for interfractional anatomical changes in prostate cancer patients receiving adaptive intensity modulated radiation therapy (IMRT) based on daily repeated computed tomography (CT)-on-rails images. Methods and Materials: Nine prostate cancer patients treated at our institution were randomly selected. For the AAP method, contours on each repeat CT image were automatically generated by mapping the contours from the simulation CT image using deformable image registration. An in-house automated planning tool incorporated into the Pinnacle treatment planning system was used to generate the original and the adapted IMRT plans. The cumulative dose–volume histograms (DVHs) of the target and critical structures were calculated based on the manual contours for all plans and compared with those of plans generated by the conventional method, that is, shifting the isocenters by aligning the images based on the center of the volume (COV) of prostate (prostate COV-aligned). Results: The target coverage from our AAP method for every patient was acceptable, while 1 of the 9 patients showed target underdosing from prostate COV-aligned plans. The normalized volume receiving at least 70 Gy (V{sub 70}), and the mean dose of the rectum and bladder were reduced by 8.9%, 6.4 Gy and 4.3%, 5.3 Gy, respectively, for the AAP method compared with the values obtained from prostate COV-aligned plans. Conclusions: The AAP method, which is fully automated, is effective for online replanning to compensate for target dose deficits and critical organ overdosing caused by interfractional anatomical changes in prostate cancer.

  7. Constrained optimization in seismic reflection tomography: an SQP ...

    E-Print Network [OSTI]

    2004-07-06T23:59:59.000Z

    Seismic reflection tomography is a method for determining a subsurface velocity model from the traveltimes of seismic waves reflecting on geological interfaces.

  8. Three-Dimensional Thermal Tomography Advances Cancer Treatment...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Three-Dimensional Thermal Tomography Advances Cancer Treatment Technology available for licensing: A 3D technique to detect early skin changes due to radiation treatment in breast...

  9. Minimally invasive diagnostic imaging using high resolution Optical Coherence Tomography

    E-Print Network [OSTI]

    Herz, Paul Richard, 1972-

    2004-01-01T23:59:59.000Z

    Advances in medical imaging have given researchers unprecedented capabilities to visualize, characterize and understand biological systems. Optical Coherence Tomography (OCT) is a high speed, high resolution imaging technique ...

  10. assisted tomography romicat: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the...

  11. abdominal computerized tomography: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the...

  12. Mathematical modeling of positron emission tomography (PET) data to assess radiofluoride transport in living plants following petiolar administration

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Converse, Alexander K.; Ahlers, Elizabeth O.; Bryan, Tom W.; Hetue, Jackson D.; Lake, Katherine A.; Ellison, Paul A.; Engle, Jonathan W.; Barnhart, Todd E.; Nickles, Robert J.; Williams, Paul H.; et al

    2015-01-01T23:59:59.000Z

    Background: Ion transport is a fundamental physiological process that can be studied non-invasively in living plants with radiotracer imaging methods. Fluoride is a known phytotoxic pollutant and understanding its transport in plants after leaf absorption is of interest to those in agricultural areas near industrial sources of airborne fluoride. Here we report the novel use of a commercial, high-resolution, animal positron emission tomography (PET) scanner to trace a bolus of [¹?F]fluoride administered via bisected petioles of Brassica oleracea, an established model species, to simulate whole plant uptake of atmospheric fluoride. This methodology allows for the first time mathematical compartmental modelingmore »of fluoride transport in the living plant. Radiotracer kinetics in the stem were described with a single-parameter free- and trapped-compartment model and mean arrival times at different stem positions were calculated from the free-compartment time-activity curves. Results: After initiation of administration at the bisected leaf stalk, [¹?F] radioactivity climbed for approximately 10 minutes followed by rapid washout from the stem and equilibration within leaves. Kinetic modeling of transport in the stem yielded a trapping rate of 1.5 +/- 0.3%/min (mean +/- s.d., n = 3), velocity of 2.2 +/- 1.1 cm/min, and trapping fraction of 0.8 +/- 0.5%/cm. Conclusion: Quantitative assessment of physiologically meaningful transport parameters of fluoride in living plants is possible using standard positron emission tomography in combination with petiolar radiotracer administration. Movement of free fluoride was observed to be consistent with bulk flow in xylem, namely a rapid and linear change in position with respect to time. Trapping, likely in the apoplast, was observed. Future applications of the methods described here include studies of transport of other ions and molecules of interest in plant physiology.« less

  13. A New Numerical Algorithm for Thermoacoustic and Photoacoustic Tomography with Variable Sound Speed

    E-Print Network [OSTI]

    Uhlmann, Gunther

    A New Numerical Algorithm for Thermoacoustic and Photoacoustic Tomography with Variable Sound Speed algorithm for reconstructing an unknown source in Thermoacoustic and Photoacoustic Tomography based Thermoacoustic (TAT) and Photoacoustic (PAT) Tomography are emerging medical imaging modal- ities [32, 30

  14. Reduction of radiation dose to radiosensitive organs and its tradeoff with image quality in Computed Tomography

    E-Print Network [OSTI]

    Zhang, Di

    2012-01-01T23:59:59.000Z

    helical multislice computed tomography examination. MedicalRadiation Dose in X-Ray Computed Tomography. AAPM report NO.of X-ray equipment for computed tomography. (2002). American

  15. Edge Localized Image Sharpening via Reassignment with Application to Computed Tomography

    E-Print Network [OSTI]

    Bhashyam, Srikrishna

    Edge Localized Image Sharpening via Reassignment with Application to Computed Tomography Timothy computed tomography. Practical implementations limit the amount of high frequency content. Keywords: Image enhancement, edge sharpening, computed tomography, wavelets, reassignment 1. INTRODUCTION

  16. Optimizing Cone Beam Computed Tomography (CBCT) System for Image Guided Radiation Therapy

    E-Print Network [OSTI]

    Park, Chun Joo

    Four-Dimensional Cone-Beam Computed Tomography. Submitted.Four-dimensional cone-beam computed tomography and digitalFlat-panel cone-beam computed tomography for image-guided

  17. FAST MARCHING METHOD TO CORRECT FOR REFRACTION IN ULTRASOUND COMPUTED TOMOGRAPHY

    E-Print Network [OSTI]

    Mueller, Klaus

    FAST MARCHING METHOD TO CORRECT FOR REFRACTION IN ULTRASOUND COMPUTED TOMOGRAPHY Shengying Li Detection Systems ABSTRACT A significant obstacle in the advancement of Ultrasound Computed Tomography has ultrasound breast phantom. 1. INTRODUCTION Ultrasound computed tomography (UCT) has a long history

  18. Non-linear inversion modeling for Ultrasound Computer Tomography: transition from soft to hard tissues imaging

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Non-linear inversion modeling for Ultrasound Computer Tomography: transition from soft to hard Marseille cedex 20, France ABSTRACT Ultrasound Computer Tomography (UCT) is an imaging technique which has experiments. Keyword: Ultrasound Computer Tomography, Inverse Born Approximation, Elliptical Projection

  19. Feasibility and value of fully 3D Monte Carlo reconstruction in Single Photon Emission Computed Tomography

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Emission Computed Tomography (SPECT) images is degraded by physical effects, namely photon attenuation datasets are currently under investigation. Keywords : single photon emission computed tomography; Monte Emission Computed Tomography (SPECT), the qualitative and quantitative accuracy of images is degraded

  20. Contrast Enhanced Computed Tomography can predict the glycosaminoglycan content and biomechanical properties

    E-Print Network [OSTI]

    Contrast Enhanced Computed Tomography can predict the glycosaminoglycan content and biomechanical in this work is to establish the feasibility of using Contrast Enhanced Computed Tomography (CECT peripheral quantitative computed tomography (pQCT), subjected to an unconfined compressive stress relaxation

  1. In-line x-ray phase-contrast tomography and diffraction-contrast tomography study of the ferrite-cementite microstructure in steel

    E-Print Network [OSTI]

    van Vliet, Lucas J.

    In-line x-ray phase-contrast tomography and diffraction-contrast tomography study of the ferrite;In-line X-ray phase-contrast tomography and diffraction-contrast tomography study of the ferrite embedded in a ferrite matrix of medium-carbon steel. The measurements were carried out at the material

  2. 28,183HUSEN ET AL.: TOMOGRAPHY OF SHALLOW SUBDUCTION IN CHILE Local earthquake tomography of shallow subduction in north Chile: A

    E-Print Network [OSTI]

    Boschi, Lapo

    [Graeber and Asch, 1999; C. Haberland and A. Rietbrock, Attenuation tomography in the western central Andes

  3. CT-scan-monitored electrical-resistivity measurements show problems achieving homogeneous saturation

    SciTech Connect (OSTI)

    Sprunt, E.S.; Davis, R.M.; Muegge, E.L. (Mobil R and D Corp. (US)); Desai, K.P. (Saudi Aramco (SA))

    1991-06-01T23:59:59.000Z

    This paper reports on x-ray computerized tomography (CT) scans obtained during measurement of the electrical resistivity of core samples which revealed some problems in obtaining uniform saturation along the lengths of the samples. The electrical resistivity of core samples is measured as a function of water saturation to determine the saturation exponent used in electric-log interpretation. An assumption in such tests is that the water saturation is uniformly distributed. Failure of this assumption can result in errors in the determination of the saturation exponent. Three problems were identified in obtaining homogeneous water saturation in two samples of a Middle Eastern carbonate grainstone: a stationary front formed in one sample at 1-psi oil/brine capillary pressure, a moving front formed at oil/brine capillary pressure {le}4 psi in samples tested in fresh mixed-wettability and cleaned water-wet states, and the heterogeneous fluid distribution caused by a rapidly moving front did not dissipate when the capillary pressure was eliminated in the samples.

  4. Radiation doses in cone-beam breast computed tomography: A Monte Carlo simulation study

    SciTech Connect (OSTI)

    Yi Ying; Lai, Chao-Jen; Han Tao; Zhong Yuncheng; Shen Youtao; Liu Xinming; Ge Shuaiping; You Zhicheng; Wang Tianpeng; Shaw, Chris C. [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2011-02-15T23:59:59.000Z

    Purpose: In this article, we describe a method to estimate the spatial dose variation, average dose and mean glandular dose (MGD) for a real breast using Monte Carlo simulation based on cone beam breast computed tomography (CBBCT) images. We present and discuss the dose estimation results for 19 mastectomy breast specimens, 4 homogeneous breast models, 6 ellipsoidal phantoms, and 6 cylindrical phantoms. Methods: To validate the Monte Carlo method for dose estimation in CBBCT, we compared the Monte Carlo dose estimates with the thermoluminescent dosimeter measurements at various radial positions in two polycarbonate cylinders (11- and 15-cm in diameter). Cone-beam computed tomography (CBCT) images of 19 mastectomy breast specimens, obtained with a bench-top experimental scanner, were segmented and used to construct 19 structured breast models. Monte Carlo simulation of CBBCT with these models was performed and used to estimate the point doses, average doses, and mean glandular doses for unit open air exposure at the iso-center. Mass based glandularity values were computed and used to investigate their effects on the average doses as well as the mean glandular doses. Average doses for 4 homogeneous breast models were estimated and compared to those of the corresponding structured breast models to investigate the effect of tissue structures. Average doses for ellipsoidal and cylindrical digital phantoms of identical diameter and height were also estimated for various glandularity values and compared with those for the structured breast models. Results: The absorbed dose maps for structured breast models show that doses in the glandular tissue were higher than those in the nearby adipose tissue. Estimated average doses for the homogeneous breast models were almost identical to those for the structured breast models (p=1). Normalized average doses estimated for the ellipsoidal phantoms were similar to those for the structured breast models (root mean square (rms) percentage difference=1.7%; p=0.01), whereas those for the cylindrical phantoms were significantly lower (rms percentage difference=7.7%; p<0.01). Normalized MGDs were found to decrease with increasing glandularity. Conclusions: Our results indicate that it is sufficient to use homogeneous breast models derived from CBCT generated structured breast models to estimate the average dose. This investigation also shows that ellipsoidal digital phantoms of similar dimensions (diameter and height) and glandularity to actual breasts may be used to represent a real breast to estimate the average breast dose with Monte Carlo simulation. We have also successfully demonstrated the use of structured breast models to estimate the true MGDs and shown that the normalized MGDs decreased with the glandularity as previously reported by other researchers for CBBCT or mammography.

  5. Low-Dose Dual-Energy CT for PET Attenuation Correction with Statistical Sinogram Restoration

    E-Print Network [OSTI]

    Fessler, Jeffrey A.

    1 Low-Dose Dual-Energy CT for PET Attenuation Correction with Statistical Sinogram Restoration. of Michigan & Univ. of Washington Outline Introduction - PET/CT background - CT-based attenuation correction for PET Conventional sinogram decomposition in DE-CT Statistically motivated sinogram restoration in DE

  6. Coronary dominance and prognosis in patients undergoing coronary computed tomographic angiography: results from the CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter) registry.

    E-Print Network [OSTI]

    2015-01-01T23:59:59.000Z

    of 64-slice computed tomography coronary angiography: avalue of cardiac computed tomography angiography: aangiography using computed tomography versus magnetic

  7. Dynamic Bowtie for Fan-beam CT

    E-Print Network [OSTI]

    Liu, Fenglin; Cong, Wenxiang; Hsieh, Scott; Pelc, Norbert

    2013-01-01T23:59:59.000Z

    A bowtie is a filter used to shape an x-ray beam and equalize its flux reaching different detector channels. For development of spectral CT with energy-discriminative photon-counting (EDPC) detectors, here we propose and evaluate a dynamic bowtie for performance optimization based on a patient model or a scout scan. Our dynamic bowtie modifies an x-ray beam intensity profile by mechanical rotation and adaptive adjustment of the x-ray source flux. First, a mathematical model for dynamic bowtie filtering is established for an elliptical section in fan-beam geometry, and the contour of the optimal bowtie is derived. Then, numerical simulation is performed to compare the performance of the dynamic bowtie in the cases of an ideal phantom and a realistic cross-section relative to the counterparts without any bowtie and with a fixed bowtie respectively. Our dynamic bowtie can equalize the expected numbers of photons in the case of an ideal phantom. In practical cases, our dynamic bowtie can effectively reduce the dy...

  8. Development of new deoxycytidine kinase inhibitors and noninvasive in vivo evaluation using positron emission tomography

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    Imaging and an Appraisal of PET/CT Scanning. Nat. Clin.R. ; Allen-Auerbach, M. S. PET/CT Imaging: The Incrementalfor their assistance with PET/CT imaging studies, the UCLA

  9. Comparison of pressure-saturation characteristics derived from computed tomography and lattice Boltzmann simulations

    E-Print Network [OSTI]

    Wildenschild, Dorthe

    Comparison of pressure-saturation characteristics derived from computed tomography and lattice), Comparison of pressure-saturation characteristics derived from computed tomography and lattice Boltzmann

  10. The Role of Computed Tomography in the Management of the Neck After Chemoradiotherapy in Patients With Head-and-Neck Cancer

    SciTech Connect (OSTI)

    Clavel, Sebastien, E-mail: sebastien.clavel@umontreal.ca [Department of Radiation Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Charron, Marie-Pierre [Faculte de medicine, Universite de Montreal, Montreal, Quebec (Canada); Belair, Manon [Department of Radiology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Delouya, Guila; Fortin, Bernard; Despres, Philippe [Department of Radiation Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Soulieres, Denis [Department of Medical Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Filion, Edith [Department of Radiation Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Guertin, Louis [Department of Head and Neck Surgery, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); and others

    2012-02-01T23:59:59.000Z

    Purpose: The aim of this study was to describe the outcome in patients with head-and neck-squamous cell carcinoma (HNSCC) followed up without neck dissection (ND) after concomitant chemoradiotherapy (CRT) based on computed tomography (CT) response. The second objective was to establish CT characteristics that can predict which patients can safely avoid ND. Methods and Materials: Between 1998 and 2007, 369 patients with node-positive HNSCC were treated with primary CRT at our institution. After a clinical and a radiologic evaluation based on CT done 6 to 8 weeks after CRT, patients were labeled with a complete neck response (CR) or with a partial neck response (PR). Results: The median follow-up was 44 months. The number of patients presenting with N3, N2, or N1 disease were 54 (15%), 268 (72%), and 47 (13%), respectively. After CRT, 263 (71%) patients reached a CR, and 253 of them did not undergo ND. Ninety-six patients reached a PR and underwent ND. Of those, 34 (35%) had residual disease on pathologic evaluation. A regression of the diameter of {>=}80% and a residual largest diameter of 15 mm of nodes had negative pathologic predictive values of 100% and 86%, respectively. The 3-year regional control and survival rates were not different between patients with CR who had no ND and patients with PR followed by ND. Conclusion: Node-positive patients presenting a CR as determined by CT evaluation 6 to 8 weeks after CRT had a low rate of regional recurrence without ND. This study also suggests that lymph node residual size and percentage of regression on CT after CRT may be useful criteria to guide clinical decisions regarding neck surgery. Those results can help diminish the number of ND procedures with negative results and their associated surgical complications.

  11. Cryo-electron tomography of bacterial viruses

    SciTech Connect (OSTI)

    Guerrero-Ferreira, Ricardo C. [Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA 30322 (United States)] [Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA 30322 (United States); Wright, Elizabeth R., E-mail: erwrigh@emory.edu [Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children's Healthcare of Atlanta, Atlanta, GA 30322 (United States)

    2013-01-05T23:59:59.000Z

    Bacteriophage particles contain both simple and complex macromolecular assemblages and machines that enable them to regulate the infection process under diverse environmental conditions with a broad range of bacterial hosts. Recent developments in cryo-electron tomography (cryo-ET) make it possible to observe the interactions of bacteriophages with their host cells under native-state conditions at unprecedented resolution and in three-dimensions. This review describes the application of cryo-ET to studies of bacteriophage attachment, genome ejection, assembly and egress. Current topics of investigation and future directions in the field are also discussed.

  12. Characterizing aquifer heterogeneity using hydraulic tomography

    E-Print Network [OSTI]

    Wachter, Brian James

    2008-07-29T23:59:59.000Z

    such as sands and gravels because these materials drain the water so quickly. The K value is highly localized and only represents the portion of the aquifer in which the core was taken. When working with unconsolidated sediments, care must be taken to pack...?????. .?????.1 17 vi LIST OF FIGURES Figure 1: Map of field site and layout of wells used in study (figure modified from Engard, 2006). Figure 2: MOG setup for tomography study. Figure 3: Packed versus unpacked response in an observation well...

  13. Mathematics of Photoacoustic and Thermoacoustic Tomography

    E-Print Network [OSTI]

    Kuchment, Peter

    2009-01-01T23:59:59.000Z

    This is the manuscript of the chapter for a planned Handbook of Mathematical Methods in Imaging that surveys the mathematical models, problems, and algorithms of the Thermoacoustic (TAT) and Photoacoustic (PAT) Tomography. TAT and PAT represent probably the most developed of the several novel ``hybrid'' methods of medical imaging. These new modalities combine different physical types of waves (electromagnetic and acoustic in case of TAT and PAT) in such a way that the resolution and contrast of the resulting method are much higher than those achievable using only acoustic or electromagnetic measurements.

  14. Thermoacoustic tomography with an arbitrary elliptic operator

    E-Print Network [OSTI]

    Michael V. Klibanov

    2012-08-26T23:59:59.000Z

    Thermoacoustic tomography is a term for the inverse problem of determining of one of initial conditions of a hyperbolic equation from boundary measurements. In the past publications both stability estimates and convergent numerical methods for this problem were obtained only under some restrictive conditions imposed on the principal part of the elliptic operator. In this paper logarithmic stability estimates are obatined for an arbitrary variable principal part of that operator. Convergence of the Quasi-Reversibility Method to the exact solution is also established for this case. Both complete and incomplete data collection cases are considered.

  15. Mathematics of Photoacoustic and Thermoacoustic Tomography

    E-Print Network [OSTI]

    Peter Kuchment; Leonid Kunyansky

    2009-12-10T23:59:59.000Z

    This is the manuscript of the chapter for a planned Handbook of Mathematical Methods in Imaging that surveys the mathematical models, problems, and algorithms of the Thermoacoustic (TAT) and Photoacoustic (PAT) Tomography. TAT and PAT represent probably the most developed of the several novel ``hybrid'' methods of medical imaging. These new modalities combine different physical types of waves (electromagnetic and acoustic in case of TAT and PAT) in such a way that the resolution and contrast of the resulting method are much higher than those achievable using only acoustic or electromagnetic measurements.

  16. Momentum computed tomography of charged particles

    E-Print Network [OSTI]

    Yu, Deyang

    2013-01-01T23:59:59.000Z

    The principle of the momentum computed tomography of charged particles is presented. It may be useful for momentum spectroscopy of various beam-matter interactions, especially when very intense beams are involved. It is able to collect the shower of charged particles with the 4Pi solid angle, and suitable for measuring the overall perspective of the arbitrary momentum distribution of the outgoing charged particles induced by arbitrary beams, especially when the other techniques are invalid. The extended collisional region, the strong field approximation and the case without magnetic field are discussed.

  17. Adaptive schemes for incomplete quantum process tomography

    SciTech Connect (OSTI)

    Teo, Yong Siah [Centre for Quantum Technologies, National University of Singapore, Singapore 117543 (Singapore); NUS Graduate School for Integrative Sciences and Engineering, Singapore 117597 (Singapore); Englert, Berthold-Georg [Centre for Quantum Technologies, National University of Singapore, Singapore 117543 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Rehacek, Jaroslav; Hradil, Zdenek [Department of Optics, Palacky University, 17. listopadu 12, CZ-77146 Olomouc (Czech Republic)

    2011-12-15T23:59:59.000Z

    We propose an iterative algorithm for incomplete quantum process tomography with the help of quantum state estimation. The algorithm, which is based on the combined principles of maximum likelihood and maximum entropy, yields a unique estimator for an unknown quantum process when one has less than a complete set of linearly independent measurement data to specify the quantum process uniquely. We apply this iterative algorithm adaptively in various situations and so optimize the amount of resources required to estimate a quantum process with incomplete data.

  18. Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem

    SciTech Connect (OSTI)

    William Charlton

    2007-07-01T23:59:59.000Z

    Neutron radiography and computed tomography are commonly used techniques to non-destructively examine materials. Tomography refers to the cross-sectional imaging of an object from either transmission or reflection data collected by illuminating the object from many different directions.

  19. Signal processing in scanning thermoacoustic tomography in biological tissues

    E-Print Network [OSTI]

    Wang, Lihong

    Signal processing in scanning thermoacoustic tomography in biological tissues Yuan Xu and Lihong V Microwave-induced thermoacoustic tomography was explored to image biological tissues. Short microwave pulses-induced thermoacoustic waves were detected with a focused ultrasonic transducer to obtain two-dimensional tomographic

  20. Microwave-induced thermoacoustic tomography: Reconstruction by synthetic aperture

    E-Print Network [OSTI]

    Wang, Lihong

    Microwave-induced thermoacoustic tomography: Reconstruction by synthetic aperture Dazi Feng, Yuan thermoacoustic signals, to which the delay-and-sum algorithm was applied for image reconstruc- tion. We greatly-induced thermoacoustic tomography based on focused transducers. Two mi- crowave sources, which had frequencies of 9 and 3

  1. Propagation Beam Consideration for 3D THz Computed Tomography

    E-Print Network [OSTI]

    Boyer, Edmond

    Propagation Beam Consideration for 3D THz Computed Tomography B. Recur, 1, J.P. Guillet, 2 I. Manek, "Refraction losses in terahertz computed tomography," Opt. Commun. 283, 2050­2055 (2010). 8. S. Nadar, H of the beam propagation is developed according to the physical properties of THz waves used in THz computed

  2. High-Resolution Computed Tomography Study of the Cranium of

    E-Print Network [OSTI]

    Allman, John M.

    High-Resolution Computed Tomography Study of the Cranium of a Fossil Anthropoid Primate of these characteristics may have important implications for brain evolution. Here computed tomography is used to examine in the evolutionary development of anthropoids did these characteristics evolve? We recently used X-ray computed

  3. Optimal control techniques for thermo-acoustic tomography Maitine Bergounioux

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . These hybrid systems use an electromagnetic pulse as an input and record ultrasound waves as an output-acoustic tomography (TAT) when the heating is realized by means of microwaves, and of photo-acoustic tomography (PAT) when optical heating is used. While in TAT waves of radio frequency range are used to trigger

  4. Rectus Sheath Hematoma: An Unfortunate Consequence of Novel Anticoagulants

    E-Print Network [OSTI]

    Stillman, Kimberly Diane; Kellar, Jesse

    2015-01-01T23:59:59.000Z

    Ultrasonography and computed tomography reduce unnecessarynormal limits. A computed tomography (CT) of the abdomen and

  5. Double-Difference Tomography for Sequestration MVA

    SciTech Connect (OSTI)

    Westman, Erik

    2008-12-31T23:59:59.000Z

    Analysis of synthetic data was performed to determine the most cost-effective tomographic monitoring system for a geologic carbon sequestration injection site. Double-difference tomographic inversion was performed on 125 synthetic data sets: five stages of CO2 plume growth, five seismic event regions, and five geophone arrays. Each resulting velocity model was compared quantitatively to its respective synthetic velocity model to determine an accuracy value. The results were examined to determine a relationship between cost and accuracy in monitoring, verification, and accounting applications using double-difference tomography. The geophone arrays with widely-varying geophone locations, both laterally and vertically, performed best. Additionally, double difference seismic tomography was performed using travel time data from a carbon sequestration site at the Aneth oil field in southeast Utah as part of a Department of Energy initiative on monitoring, verification, and accounting (MVA) of sequestered CO2. A total of 1,211 seismic events were recorded from a borehole array consisting of 22 geophones. Artificial velocity models were created to determine the ease with which different CO2 plume locations and sizes can be detected. Most likely because of the poor geophone arrangement, a low velocity zone in the Desert Creek reservoir can only be detected when regions of test site containing the highest ray path coverage are considered. MVA accuracy and precision may be improved through the use of a receiver array that provides more comprehensive ray path coverage.

  6. SU-E-T-121: Dosimetric Characterization of Gafchromic Film EBT3 Using Vidar DosimetryPro Advantage RED and EPSON Expression 10000XL Scanners

    SciTech Connect (OSTI)

    Medina, L; Adrada, A; Filipuzzi, M; Garrigo, E; Venencia, C [Instituto Privado de Radioterapia - Fundacion Marie Curie, Cordoba (Argentina)

    2014-06-01T23:59:59.000Z

    Purpose: The purpose of this paper is to characterize EBT3 using two types of scanner, analyzing the factors of influence of each dosimetry system. Methods: The film used in this study was GAFCHROMIC EBT3, the films were exposed at a dose range between 0Gy a 9Gy in a solid water phantom, SSD=100cm, 5cm depth and perpendicularly to the 6MV photon beam generated by a Novalis TX linear accelerator equipped with an HDMLC. A Farmer type ion chamber TN30013 (PTW) was used to determine the dose delivered to the film. The films were digitized with a scanner EPSON expression 10000XL and the VIDAR DosimetryPro Adventage RED. Software RIT113v6.1 was used for construction of the calibration curve and analysis. The film characteristics investigated were: response at different dose levels, sensitivity to orientation and side and resolution through the results of the spatial response function by analyzing a step pattern. Additionally, 20 IMRT treatment fields were measured with both scanner and compared with calculated dose using gamma index analysis (3%-3mm). Results: The OD obtained for dose level 2Gy in the orientation portrait of the film on the scanner EPSON is (0,222±0,19) and for Vidar RED (0,252±0,10) and landscape is for EPSON (0,211±0,25) and for Vidar RED (0,250±0,11) . The orientation dependence with respect to film side is about 0,09% for EPSON and about 0.03% for VIDAR. The spatial response function increase in response to the Gaussian function FWHM EPSON scanner (0.18mm) compared with VIDAR scanner function (less than 0.06mm) was observed. We analyzed 20 total plan dose distributions the number of pixels with gamma>1 (3%-3mm) was 0.7%±1.2 [0.1%; 2.82%] for EBT3-VIDAR y 2%±2.9 [0.2%; 3.5%] for EBT3-EPSON. Conclusion: VIDAR scanner shows better sensitivity. EBT3 film shows a different response between portrait and landscape orientation. Step pattern is better reproduce by VIDAR scanner.

  7. 1st World Congress on Industrial Process Tomography, Buxton, Greater Manchester 1417 April 1999. Eddy Current Tomography for Metal

    E-Print Network [OSTI]

    Hua, Yingbo

    . 451 Eddy Current Tomography for Metal Solidification Imaging Minh H. Pham* , Yingbo Hua* , Neil B of molten metal inside a pipe by eddy currents. A complete mathematical model is developed which reveals functions in multiple layered media. Keywords: eddy current tomography, electromagnetic field, numerical

  8. Image and Signal Processing with Non-Gaussian Noise: EM-Type Algorithms and Adaptive Outlier Pursuit

    E-Print Network [OSTI]

    Yan, Ming

    2012-01-01T23:59:59.000Z

    reconstruction from PET and CT with undersampled data, wetomography (PET) and computed tomography (CT), analytical

  9. Influence of radiation therapy on the lung-tissue in breast cancer patients: CT-assessed density changes and associated symptoms

    SciTech Connect (OSTI)

    Rotstein, S.; Lax, I.; Svane, G. (Karolinska Hospital, Stockholm (Sweden))

    1990-01-01T23:59:59.000Z

    The relative electron density of lung tissue was measured from computer tomography (CT) slices in 33 breast cancer patients treated by various techniques of adjuvant radiotherapy. The measurements were made before radiotherapy, 3 months and 9 months after completion of radiation therapy. The changes in lung densities at 3 months and 9 months were compared to radiation induced radiological (CT) findings. In addition, subjective symptoms such as cough and dyspnoea were assessed before and after radiotherapy. It was observed that the mean of the relative electron density of lung tissue varied from 0.25 when the whole lung was considered to 0.17 when only the anterior lateral quarter of the lung was taken into account. In patients with positive radiological (CT) findings the mean lung density of the anterior lateral quarter increased 2.1 times 3 months after radiotherapy and was still increased 1.6 times 6 months later. For those patients without findings, in the CT pictures the corresponding values were 1.2 and 1.1, respectively. The standard deviation of the pixel values within the anterior lateral quarter of the lung increased 3.8 times and 3.2 times at 3 months and 9 months, respectively, in the former group, as opposed to 1.2 and 1.1 in the latter group. Thirteen patients had an increase in either cough or dyspnoea as observed 3 months after completion of radiotherapy. In eleven patients these symptoms persisted 6 months later. No significant correlation was found between radiological findings and subjective symptoms. However, when three different treatment techniques were compared among 29 patients the highest rate of radiological findings was observed in patients in which the largest lung volumes received the target dose. A tendency towards an increased rate of subjective symptoms was also found in this group.

  10. X-ray computed-tomography observations of water flow through anisotropic methane hydrate-bearing sand

    SciTech Connect (OSTI)

    Seol, Yongkoo; Kneafsey, Timothy J.

    2009-06-01T23:59:59.000Z

    We used X-ray computed tomography (CT) to image and quantify the effect of a heterogeneous sand grain-size distribution on the formation and dissociation of methane hydrate, as well as the effect on water flow through the heterogeneous hydrate-bearing sand. A 28 cm long sand column was packed with several segments having vertical and horizontal layers with sands of different grain-size distributions. During the hydrate formation, water redistribution occurred. Observations of water flow through the hydrate-bearing sands showed that water was imbibed more readily into the fine sand, and that higher hydrate saturation increased water imbibition in the coarse sand due to increased capillary strength. Hydrate dissociation induced by depressurization resulted in different flow patterns with the different grain sizes and hydrate saturations, but the relationships between dissociation rates and the grain sizes could not be identified using the CT images. The formation, presence, and dissociation of hydrate in the pore space dramatically impact water saturation and flow in the system.

  11. Permeability of laboratory-formed methane-hydrate-bearing sand: Measurements and observations using x-ray computed tomography

    SciTech Connect (OSTI)

    Kneafsey, T. J.; Seol, Y.; Gupta, A.; Tomutsa, L.

    2010-09-15T23:59:59.000Z

    Methane hydrate was formed in two moist sands and a sand/silt mixture under a confining stress in an X-ray-transparent pressure vessel. Three initial water saturations were used to form three different methane-hydrate saturations in each medium. X-ray computed tomography (CT) was used to observe location-specific density changes caused by hydrate formation and flowing water. Gas-permeability measurements in each test for the dry, moist, frozen, and hydrate-bearing states are presented. As expected, the effective permeabilities (intrinsic permeability of the medium multiplied by the relative permeability) of the moist sands decreased with increasing moisture content. In a series of tests on a single sample, the effective permeability typically decreased as the pore space became more filled, in the order of dry, moist, frozen, and hydrate-bearing. In each test, water was flowed through the hydrate-bearing medium and we observed the location-specific changes in water saturation using CT scanning. We compared our data to a number of models, and our relative permeability data compare most favorably with models in which hydrate occupies the pore bodies rather than the pore throats. Inverse modeling (using the data collected from the tests) will be performed to extend the relative permeability measurements.

  12. SU-D-12A-07: Optimization of a Moving Blocker System for Cone-Beam Computed Tomography Scatter Correction

    SciTech Connect (OSTI)

    Ouyang, L; Yan, H; Jia, X; Jiang, S; Wang, J [UT Southwestern Medical Center, Dallas, TX (United States); Zhang, H [Southern Medical University, Guangzhou, Guang Dong (China)

    2014-06-01T23:59:59.000Z

    Purpose: A moving blocker based strategy has shown promising results for scatter correction in cone-beam computed tomography (CBCT). Different parameters of the system design affect its performance in scatter estimation and image reconstruction accuracy. The goal of this work is to optimize the geometric design of the moving block system. Methods: In the moving blocker system, a blocker consisting of lead strips is inserted between the x-ray source and imaging object and moving back and forth along rotation axis during CBCT acquisition. CT image of an anthropomorphic pelvic phantom was used in the simulation study. Scatter signal was simulated by Monte Carlo calculation with various combinations of the lead strip width and the gap between neighboring lead strips, ranging from 4 mm to 80 mm (projected at the detector plane). Scatter signal in the unblocked region was estimated by cubic B-spline interpolation from the blocked region. Scatter estimation accuracy was quantified as relative root mean squared error by comparing the interpolated scatter to the Monte Carlo simulated scatter. CBCT was reconstructed by total variation minimization from the unblocked region, under various combinations of the lead strip width and gap. Reconstruction accuracy in each condition is quantified by CT number error as comparing to a CBCT reconstructed from unblocked full projection data. Results: Scatter estimation error varied from 0.5% to 2.6% as the lead strip width and the gap varied from 4mm to 80mm. CT number error in the reconstructed CBCT images varied from 12 to 44. Highest reconstruction accuracy is achieved when the blocker lead strip width is 8 mm and the gap is 48 mm. Conclusions: Accurate scatter estimation can be achieved in large range of combinations of lead strip width and gap. However, image reconstruction accuracy is greatly affected by the geometry design of the blocker.

  13. Out-of-Plane Computed-Tomography-Guided Biopsy Using a Magnetic-Field-Based Navigation System

    SciTech Connect (OSTI)

    Wallace, Michael J., E-mail: mwallace@di.mdacc.tmc.edu; Gupta, Sanjay; Hicks, Marshall E. [University of Texas M. D. Anderson Cancer Center, Departments of Diagnostic Radiology, Section of Vascular and Interventional Radiology (United States)

    2006-02-15T23:59:59.000Z

    The purpose of this article is to report our clinical experience with out-of-plane computed-tomography (CT)-guided biopsies using a magnetic-field-based navigation system. Between February 2002 and March 2003, 20 patients underwent CT-guided biopsy in which an adjunct magnetic-field-based navigation system was used to aid an out-of-plane biopsy approach. Eighteen patients had an underlying primary malignancy. All biopsies involved the use of a coaxial needle system in which an outer 18G guide needle was inserted to the lesion using the navigation system and an inner 22G needle was then used to obtain fine-needle aspirates. Complications and technical success were recorded. Target lesions were located in the adrenal gland (n = 7), liver (n = 6), pancreas (n = 3), lung (n = 2), retroperitoneal lymph node (n = 1), and pelvis (n = 1). The mean lesion size (maximum transverse diameter) was 26.5 mm (range: 8-70 mm) and the mean and median cranial-caudal distance, between the transaxial planes of the final needle tip location and the needle insertion site, was 40 mm (range: 18-90 mm). Needle tip positioning was successfully placed within the lesion in all 20 biopsies. A diagnosis of malignancy was obtained in 14 biopsies. Benign diagnoses were encountered in the remaining six biopsies and included a benign adrenal gland (n = 2), fibroelastic tissue (n = 1), hepocytes with steatosis (n = 2) and reactive hepatocytes (n = 1). No complications were encountered. A magnetic-field-based navigation system is an effective adjunct tool for accurate and safe biopsy of lesions that require an out-of-plane CT approach.

  14. Prostate Postbrachytherapy Seed Distribution: Comparison of High-Resolution, Contrast-Enhanced, T1- and T2-Weighted Endorectal Magnetic Resonance Imaging Versus Computed Tomography: Initial Experience

    SciTech Connect (OSTI)

    Bloch, B. Nicolas [Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna (Austria)], E-mail: nbloch@bidmc.harvard.edu; Lenkinski, Robert E. [Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Helbich, Thomas H. [Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna (Austria); Ngo, Long [Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Oismueller, Renee [Institute for Radio-Oncology, Danube Hospital, Vienna (Austria); Jaromi, Silvia; Kubin, Klaus [Department of Radiology, General Hospital Vienna, Medical University Vienna, Vienna (Austria); Hawliczek, Robert [Institute for Radio-Oncology, Danube Hospital, Vienna (Austria); Kaplan, Irving D. [Department of Radiation Oncology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States); Rofsky, Neil M. [Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA (United States)

    2007-09-01T23:59:59.000Z

    Purpose: To compare contrast-enhanced, T1-weighted, three-dimensional magnetic resonance imaging (CEMR) and T2-weighted magnetic resonance imaging (T2MR) with computed tomography (CT) for prostate brachytherapy seed location for dosimetric calculations. Methods and Materials: Postbrachytherapy prostate MRI was performed on a 1.5 Tesla unit with combined surface and endorectal coils in 13 patients. Both CEMR and T2MR used a section thickness of 3 mm. Spiral CT used a section thickness of 5 mm with a pitch factor of 1.5. All images were obtained in the transverse plane. Two readers using CT and MR imaging assessed brachytherapy seed distribution independently. The dependency of data read by both readers for a specific subject was assessed with a linear mixed effects model. Results: The mean percentage ({+-} standard deviation) values of the readers for seed detection and location are presented. Of 1205 implanted seeds, CEMR, T2MR, and CT detected 91.5% {+-} 4.8%, 78.5% {+-} 8.5%, and 96.1% {+-} 2.3%, respectively, with 11.8% {+-} 4.5%, 8.5% {+-} 3.5%, 1.9% {+-} 1.0% extracapsular, respectively. Assignment to periprostatic structures was not possible with CT. Periprostatic seed assignments for CEMR and T2MR, respectively, were as follows: neurovascular bundle, 3.5% {+-} 1.6% and 2.1% {+-} 0.9%; seminal vesicles, 0.9% {+-} 1.8% and 0.3% {+-} 0.7%; periurethral, 7.1% {+-} 3.3% and 5.8% {+-} 2.9%; penile bulb, 0.6% {+-} 0.8% and 0.3% {+-} 0.6%; Denonvillier's Fascia/rectal wall, 0.5% {+-} 0.6% and 0%; and urinary bladder, 0.1% {+-} 0.3% and 0%. Data dependency analysis showed statistical significance for the type of imaging but not for reader identification. Conclusion: Both enumeration and localization of implanted seeds are readily accomplished with CEMR. Calculations with MRI dosimetry do not require CT data. Dose determinations to specific extracapsular sites can be obtained with MRI but not with CT.

  15. Roadmap: Radiologic Imaging Sciences -Computed Tomography (with certification and ATS Radiologic Technology) -

    E-Print Network [OSTI]

    Sheridan, Scott

    Roadmap: Radiologic Imaging Sciences - Computed Tomography (with certification and ATS Radiologic 34084 Computed Tomography and Magnetic Resonance Imaging Sectional Anatomy I 2 C RIS 44021 Patient Management in Computed Tomography 2 C RIS 44025 Computed Tomography Clinical Education I 3 C RIS 44030

  16. Flow Velocity Estimation in Optical Doppler Tomography and A Preliminary Study on Radiation Detection for Hybrid

    E-Print Network [OSTI]

    Piao, Daqing

    Tomography and A Preliminary Study on Radiation Detection for Hybrid Optical Coherence TomographyFlow Velocity Estimation in Optical Doppler Tomography and A Preliminary Study on Radiation Detection for Hybrid Optical Coherence Tomography/Scintigraphy Daqing Piao B.S., Tsinghua University, 1990 M

  17. Ultra-high resolution computed tomography imaging

    DOE Patents [OSTI]

    Paulus, Michael J. (Knoxville, TN); Sari-Sarraf, Hamed (Knoxville, TN); Tobin, Jr., Kenneth William (Harriman, TN); Gleason, Shaun S. (Knoxville, TN); Thomas, Jr., Clarence E. (Knoxville, TN)

    2002-01-01T23:59:59.000Z

    A method for ultra-high resolution computed tomography imaging, comprising the steps of: focusing a high energy particle beam, for example x-rays or gamma-rays, onto a target object; acquiring a 2-dimensional projection data set representative of the target object; generating a corrected projection data set by applying a deconvolution algorithm, having an experimentally determined a transfer function, to the 2-dimensional data set; storing the corrected projection data set; incrementally rotating the target object through an angle of approximately 180.degree., and after each the incremental rotation, repeating the radiating, acquiring, generating and storing steps; and, after the rotating step, applying a cone-beam algorithm, for example a modified tomographic reconstruction algorithm, to the corrected projection data sets to generate a 3-dimensional image. The size of the spot focus of the beam is reduced to not greater than approximately 1 micron, and even to not greater than approximately 0.5 microns.

  18. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, VOL. 5, NO. 1, JANUARY/FEBRUARY 1999 75 Diffraction Grating Scanners Using

    E-Print Network [OSTI]

    Merat, Francis L.

    THERE is an increasing need in today's marketplace to develop low-cost high-precision optical scanners for a variety with single and pyramidal diffraction grating elements fabricated on the polished surface of large-area rotors, the technology has advanced toward optical applications [2]. A 20- m-tall reflective nickel polygon, plated

  19. Realistic simulation of reduced-dose CT with noise modeling and sinogram synthesis using DICOM CT images

    SciTech Connect (OSTI)

    Won Kim, Chang [Interdisciplinary Program of Bioengineering Major Seoul National University College of Engineering, San 56-1, Silim-dong, Gwanak-gu, Seoul 152-742, South Korea and Institute of Radiation Medicine, Seoul National University College of Medicine, 28, Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of)] [Interdisciplinary Program of Bioengineering Major Seoul National University College of Engineering, San 56-1, Silim-dong, Gwanak-gu, Seoul 152-742, South Korea and Institute of Radiation Medicine, Seoul National University College of Medicine, 28, Yongon-dong, Chongno-gu, Seoul 110-744 (Korea, Republic of); Kim, Jong Hyo, E-mail: kimjhyo@snu.ac.kr [Department of Radiology, Institute of Radiation Medicine, Seoul National University College of Medicine, 28, Yongon-dong, Chongno-gu, Seoul, 110-744 (Korea, Republic of); Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Suwon, Gyeonggi-do, 443-270 (Korea, Republic of); Advanced Institutes of Convergence Technology, Seoul National University, Suwon, Gyeonggi-do, 443-270 (Korea, Republic of)

    2014-01-15T23:59:59.000Z

    Purpose: Reducing the patient dose while maintaining the diagnostic image quality during CT exams is the subject of a growing number of studies, in which simulations of reduced-dose CT with patient data have been used as an effective technique when exploring the potential of various dose reduction techniques. Difficulties in accessing raw sinogram data, however, have restricted the use of this technique to a limited number of institutions. Here, we present a novel reduced-dose CT simulation technique which provides realistic low-dose images without the requirement of raw sinogram data. Methods: Two key characteristics of CT systems, the noise equivalent quanta (NEQ) and the algorithmic modulation transfer function (MTF), were measured for various combinations of object attenuation and tube currents by analyzing the noise power spectrum (NPS) of CT images obtained with a set of phantoms. Those measurements were used to develop a comprehensive CT noise model covering the reduced x-ray photon flux, object attenuation, system noise, and bow-tie filter, which was then employed to generate a simulated noise sinogram for the reduced-dose condition with the use of a synthetic sinogram generated from a reference CT image. The simulated noise sinogram was filtered with the algorithmic MTF and back-projected to create a noise CT image, which was then added to the reference CT image, finally providing a simulated reduced-dose CT image. The simulation performance was evaluated in terms of the degree of NPS similarity, the noise magnitude, the bow-tie filter effect, and the streak noise pattern at photon starvation sites with the set of phantom images. Results: The simulation results showed good agreement with actual low-dose CT images in terms of their visual appearance and in a quantitative evaluation test. The magnitude and shape of the NPS curves of the simulated low-dose images agreed well with those of real low-dose images, showing discrepancies of less than +/?3.2% in terms of the noise power at the peak height and +/?1.2% in terms of the spatial frequency at the peak height. The magnitudes of the noise measured for 12 different combinations the phantom size, tube current, and reconstruction kernel for the simulated and real low-dose images were very similar, with differences of 0.1 to 4.7%. Thep value for a statistical testing of the difference in the noise magnitude ranged from 0.99 to 0.11, showing that there was no difference statistically between the noise magnitudes of the real and simulated low-dose images using our method. The strength and pattern of the streak noise in an anthropomorphic phantom was also consistent with expectations. Conclusions: A novel reduced-dose CT simulation technique was developed which uses only CT images while not requiring raw sinogram data. Our method can provide realistic simulation results under reduced-dose conditions both in terms of the noise magnitude and the textual appearance. This technique has the potential to promote clinical research for patient dose reductions.

  20. Note: Reliable and non-contact 6D motion tracking system based on 2D laser scanners for cargo transportation

    SciTech Connect (OSTI)

    Kim, Young-Keun, E-mail: ykkim@handong.edu [Department of Mechanical and Control Engineering, Handong Global University, Pohang (Korea, Republic of); Kim, Kyung-Soo [Department of Mechanical Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

    2014-10-15T23:59:59.000Z

    Maritime transportation demands an accurate measurement system to track the motion of oscillating container boxes in real time. However, it is a challenge to design a sensor system that can provide both reliable and non-contact methods of 6-DOF motion measurements of a remote object for outdoor applications. In the paper, a sensor system based on two 2D laser scanners is proposed for detecting the relative 6-DOF motion of a crane load in real time. Even without implementing a camera, the proposed system can detect the motion of a remote object using four laser beam points. Because it is a laser-based sensor, the system is expected to be highly robust to sea weather conditions.

  1. Volumetric quantification of lung nodules in CT with iterative reconstruction (ASiR and MBIR)

    SciTech Connect (OSTI)

    Chen, Baiyu [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States)] [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Barnhart, Huiman [Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina 27705 (United States)] [Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina 27705 (United States); Richard, Samuel [Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke University, Durham, North Carolina 27705 (United States)] [Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Robins, Marthony [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States)] [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Colsher, James [Department of Radiology, Duke University, Durham, North Carolina 27705 (United States)] [Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Samei, Ehsan [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States) [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University, Durham, North Carolina 27705 (United States); Department of Physics, Department of Biomedical Engineering, and Department of Electronic and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States)

    2013-11-15T23:59:59.000Z

    Purpose: Volume quantifications of lung nodules with multidetector computed tomography (CT) images provide useful information for monitoring nodule developments. The accuracy and precision of the volume quantification, however, can be impacted by imaging and reconstruction parameters. This study aimed to investigate the impact of iterative reconstruction algorithms on the accuracy and precision of volume quantification with dose and slice thickness as additional variables.Methods: Repeated CT images were acquired from an anthropomorphic chest phantom with synthetic nodules (9.5 and 4.8 mm) at six dose levels, and reconstructed with three reconstruction algorithms [filtered backprojection (FBP), adaptive statistical iterative reconstruction (ASiR), and model based iterative reconstruction (MBIR)] into three slice thicknesses. The nodule volumes were measured with two clinical software (A: Lung VCAR, B: iNtuition), and analyzed for accuracy and precision.Results: Precision was found to be generally comparable between FBP and iterative reconstruction with no statistically significant difference noted for different dose levels, slice thickness, and segmentation software. Accuracy was found to be more variable. For large nodules, the accuracy was significantly different between ASiR and FBP for all slice thicknesses with both software, and significantly different between MBIR and FBP for 0.625 mm slice thickness with Software A and for all slice thicknesses with Software B. For small nodules, the accuracy was more similar between FBP and iterative reconstruction, with the exception of ASIR vs FBP at 1.25 mm with Software A and MBIR vs FBP at 0.625 mm with Software A.Conclusions: The systematic difference between the accuracy of FBP and iterative reconstructions highlights the importance of extending current segmentation software to accommodate the image characteristics of iterative reconstructions. In addition, a calibration process may help reduce the dependency of accuracy on reconstruction algorithms, such that volumes quantified from scans of different reconstruction algorithms can be compared. The little difference found between the precision of FBP and iterative reconstructions could be a result of both iterative reconstruction's diminished noise reduction at the edge of the nodules as well as the loss of resolution at high noise levels with iterative reconstruction. The findings do not rule out potential advantage of IR that might be evident in a study that uses a larger number of nodules or repeated scans.

  2. Magnified Weak Lensing Cross Correlation Tomography

    SciTech Connect (OSTI)

    Ulmer, Melville P., Clowe, Douglas I.

    2010-11-30T23:59:59.000Z

    This project carried out a weak lensing tomography (WLT) measurement around rich clusters of galaxies. This project used ground based photometric redshift data combined with HST archived cluster images that provide the WLT and cluster mass modeling. The technique has already produced interesting results (Guennou et al, 2010,Astronomy & Astrophysics Vol 523, page 21, and Clowe et al, 2011 to be submitted). Guennou et al have validated that the necessary accuracy can be achieved with photometric redshifts for our purposes. Clowe et al titled "The DAFT/FADA survey. II. Tomographic weak lensing signal from 10 high redshift clusters," have shown that for the **first time** via this purely geometrical technique, which does not assume a standard rod or candle, that a cosmological constant is **required** for flat cosmologies. The intent of this project is not to produce the best constraint on the value of the dark energy equation of state, w. Rather, this project is to carry out a sustained effort of weak lensing tomography that will naturally feed into the near term Dark Energy Survey (DES) and to provide invaluable mass calibration for that project. These results will greatly advance a key cosmological method which will be applied to the top-rated ground-based project in the Astro2020 decadal survey, LSST. Weak lensing tomography is one of the key science drivers behind LSST. CO-I Clowe is on the weak lensing LSST committee, and senior scientist on this project, at FNAL James Annis, plays a leading role in the DES. This project has built on successful proposals to obtain ground-based imaging for the cluster sample. By 1 Jan, it is anticipated the project will have accumulated complete 5-color photometry on 30 (or about 1/3) of the targeted cluster sample (public webpage for the survey is available at http://cencos.oamp.fr/DAFT/ and has a current summary of the observational status of various clusters). In all, the project has now been awarded the equivalent of over 60 nights on 4-m class telescopes, which gives concrete evidence of strong community support for this project. The WLT technique is based on the dependence of the gravitational shear signal on the angular diameter distances between the observer, the lens, and the lensed galaxy to measure cosmological parameters. By taking the ratio of measured shears of galaxies with different redshifts around the same lens, one obtains a measurement of the ratios of the angular diameter distances involved. Making these observations over a large range of lenses and background galaxy redshifts will measure the history of the expansion rate of the universe. Because this is a purely geometric measurement, it is insensitive to any form of evolution of objects or the necessity to understand the physics in the early universe. Thus, WLT was identified by the Dark Energy Task Force as perhaps the best method to measure the evolution of DE. To date, however, the conjecture of the DETF has not been experimentally verified, but will be by the proposed project. The primary reason for the lack of tomography measurements is that one must have an exceptional data-set to attempt the measurement. One needs both extremely good seeing (or space observations) in order to minimize the point spread function smearing corrections on weak lensing shear measurements and deep, multi-color data, from B to z, to measure reliable photometric redshifts of the background galaxies being lensed (which are typically too faint to obtain spectroscopic redshifts). Because the entire process from multi-drizzling the HST images, and then creating shear maps, to gathering the necessary ground based observations, to generating photo-zs and then carrying out the tomography is a complicated task, until the creation of our team, nobody has taken the time to connect all the levels of expertise necessary to carry out this project based on HST archival data. Our data are being used in 2 Ph.D. theses. Kellen Murphy, at Ohio University, is using the tomography data along with simulations in a thesis expected to be completed in Jun

  3. High-resolution 18F-FDG PET with MRI for monitoring response to treatment in rheumatoid arthritis

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    of a dedicated breast PET/CT scanner during human imaging. J2]. A high-resolution PET/CT scanner for imaging extremitiesOA). An extremity 18 F-FDG PET/CT scan immediately following

  4. Long-term Neurological Outcomes in Adults with Traumatic Intracranial Hemorrhage Admitted to ICU versus Floor

    E-Print Network [OSTI]

    2015-01-01T23:59:59.000Z

    and immediate computed tomography or admission forseverity; CT, computed tomography *Adjusted coefficients foron initial head CT (computed tomography). Clinical data were

  5. Headache in Pregnancy: An Approach to Emergency Department Evaluation and Management

    E-Print Network [OSTI]

    Schoen, Jessica C.; Campbell, Ronna L.; Sadosty, Annie T.

    2015-01-01T23:59:59.000Z

    characteristics of head computed tomography in patientsA non- contrast computed tomography (CT) of the head wasCO, carbon monoxide; CT, computed tomography; CBC, complete

  6. SU-E-I-02: A Framework to Perform Batch Simulations of Computational Voxel Phantoms to Study Organ Doses in Computed Tomography Using a Commercial Monte Carlo Software Package

    SciTech Connect (OSTI)

    Bujila, R; Nowik, P; Poludniowski, G [Karolinska University Hospital, Stockholm, Stockholm (Sweden)

    2014-06-01T23:59:59.000Z

    Purpose: ImpactMC (CT Imaging, Erlangen, Germany) is a Monte Carlo (MC) software package that offers a GPU enabled, user definable and validated method for 3D dose distribution calculations for radiography and Computed Tomography (CT). ImpactMC, in and of itself, offers limited capabilities to perform batch simulations. The aim of this work was to develop a framework for the batch simulation of absorbed organ dose distributions from CT scans of computational voxel phantoms. Methods: The ICRP 110 adult Reference Male and Reference Female computational voxel phantoms were formatted into compatible input volumes for MC simulations. A Matlab (The MathWorks Inc., Natick, MA) script was written to loop through a user defined set of simulation parameters and 1) generate input files required for the simulation, 2) start the MC simulation, 3) segment the absorbed dose for organs in the simulated dose volume and 4) transfer the organ doses to a database. A demonstration of the framework is made where the glandular breast dose to the adult Reference Female phantom, for a typical Chest CT examination, is investigated. Results: A batch of 48 contiguous simulations was performed with variations in the total collimation and spiral pitch. The demonstration of the framework showed that the glandular dose to the right and left breast will vary depending on the start angle of rotation, total collimation and spiral pitch. Conclusion: The developed framework provides a robust and efficient approach to performing a large number of user defined MC simulations with computational voxel phantoms in CT (minimal user interaction). The resulting organ doses from each simulation can be accessed through a database which greatly increases the ease of analyzing the resulting organ doses. The framework developed in this work provides a valuable resource when investigating different dose optimization strategies in CT.

  7. Unusual association of alveolar rhabdomyosarcoma with pancreatic metastasis: emerging role of PET-CT in tumor staging

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    Christie R, Daw NC et al ( 2005) PET/CT in the evaluation ofComparative study of FDG PET/CT and conventional imaging inet al (2009) Diagnostic value of PET/CT for the staging and

  8. Estimated cumulative radiation dose from PET/CT in children with malignancies: reply to Gelfand et al

    E-Print Network [OSTI]

    Chawla, Soni C.; Boechat, M. Ines; McNitt-Gray, Michael

    2010-01-01T23:59:59.000Z

    radiation dose from PET/CT in children with malignancies.radiation dose from PET/CT in children with malig- nancies:radiation dose from PET/CT in children with malignancies:

  9. Molecular imaging in oncology: the acceptance of PET/CT and the emergence of MR/PET imaging

    E-Print Network [OSTI]

    Schiepers, Christiaan; Dahlbom, Magnus

    2011-01-01T23:59:59.000Z

    only [2] to combining PET and CT [3] and PET and MRI [4].varies widely between PET and CT, e.g. arms up or down,body imaging with MRI or PET/CT: the future for single-

  10. Estimated cumulative radiation dose from PET/CT in children with malignancies: a 5-year retrospective review

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    N, Feig SA (2007) PET/CT in the evaluating pediatriccan be used for both PET and CT studies. The ALARA principleMB, Christie R, Daw NC (2005) PET/CT in the evaluation of

  11. Unusual association of alveolar rhabdomyosarcoma with pancreatic metastasis: emerging role of PET-CT in tumor staging

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    The combination of PET and CT provided a mean effective doseChristie R, Daw NC et al ( 2005) PET/CT in the evaluation ofComparative study of FDG PET/CT and conventional imaging in

  12. Characterizing Low-Permeable Granitic Rock From Micrometer to Centimeter Scale: X-ray Micro-computed Tomography, Confocal Laser Scanning Microscopy and {sup 14}C-PMMA Method

    SciTech Connect (OSTI)

    Laehdemaeki, T.; Kelokaski, M.; Siitari-Kauppi, M. [Laboratory of Radiochemistry, University of Helsinki, P.O.Box 55, University of Helsinki, FIN- 00014 (Finland); Voutilainen, M.; Myllys, M.; Turpeinen, T.; Timonen, J. [Department of Physics, University of Jyvaeskylae, P.O.Box 35, Jyvaeskylae, FIN-40351 (Finland); Mateos, F.; Montoto, M. [Department of Geology, University of Oviedo, Oviedo, 33005 (Spain)

    2007-07-01T23:59:59.000Z

    First results of combining X-ray micro-computed tomography ({mu}CT), confocal laser-scanning microscopy (CLSM) and {sup 14}C-poly-methyl-methacrylate ({sup 14}C-PMMA) impregnation techniques in the study of granitic rock samples are reported. Combining results of {mu}CT and CLSM with those of the {sup 14}C-PMMA technique, the mineral-specific porosity and morphology of the open pore space, as well as its connectivity, could be analyzed from a micrometer up to a decimeter scale. Three different types of granite were studied. In two cases part of the micro-fissure and pore apertures were found to be in a micrometer scale, but in one case all grain-boundary openings were below the detection limit. Micrometer-scale apertures could be analyzed by CLSM and {mu}CT. The benefit of {mu}CT is that it can also provide the heterogeneous distribution of minerals in 3D. The 2D porosity distributions in the mineral phases, consisting of nanometer-scale pores, could be measured by the {sup 14}C-PMMA method together with the micro-fissures. This method does not, however, give the exact pore apertures. The limitations and applicability of the methods are discussed. (authors)

  13. Thermal Neutron Computed Tomography of Soil Water and Plant Roots

    E-Print Network [OSTI]

    Leanne G. Tumlinson; Hungyuan Liu; Wendy K. Silk; Jan W. Hopmans

    2007-01-01T23:59:59.000Z

    images in the McClellan Nuclear Radiation Center tomographyPap. NCT5. McClellan Nuclear Radiation Ctr. , Univ. of1991. McClellan Nuclear Radiation Center safety analysis

  14. Advances in Inverse Transport Methods and Applications to Neutron Tomography

    E-Print Network [OSTI]

    Wu, Zeyun

    2011-02-22T23:59:59.000Z

    and postulated constraints. We illustrate our approach using some neutron-tomography model problems that are several mean-free paths thick and contain highly scattering materials. In these problems we impose reasonable constraints, similar to those...

  15. Scattered neutron tomography based on a neutron transport problem 

    E-Print Network [OSTI]

    Scipolo, Vittorio

    2005-11-01T23:59:59.000Z

    scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...

  16. Properties of Some Integral Transforms Arising in Tomography 

    E-Print Network [OSTI]

    Moon, Sunghwan

    2013-10-11T23:59:59.000Z

    introduce a different Radon-type transform arising in photo acoustic tomography with circular detectors, and study mathematically similar object, a toroidal Radon transform. We also consider the cone transform arising in Compton camera imaging as well...

  17. 3D optical tomography in the presence of void regions

    E-Print Network [OSTI]

    Lorenzo, Jorge Ripoll

    reconstruction scheme for optical tomography based on the equation of radiative transfer," Med. Phys. 26 1698 and F. W¨ubbeling, Mathematical Methods in Image Reconstruction (SIAM, Philadel- phia, 2001). 15. J. Sch

  18. Functional lung imaging in humans using Positron Emission Tomography

    E-Print Network [OSTI]

    Layfield, Dominick, 1971-

    2003-01-01T23:59:59.000Z

    This thesis deals with a method of functional lung imaging using Positron Emission Tomography (PET). In this technique, a radioactive tracer, nitrogen-13, is dissolved in saline solution, and injected into a peripheral ...

  19. Time-dependent seismic tomography and its application to the...

    Open Energy Info (EERE)

    geothermal area, 1996-2006 Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: Time-dependent seismic tomography and its application to...

  20. Purely optical tomography : atlas-based reconstruction of brain activation

    E-Print Network [OSTI]

    Custo, Anna

    2008-01-01T23:59:59.000Z

    Diffuse Optical Tomography (DOT) is a relatively new method used to image blood volume and oxygen saturation in vivo. Because of its relatively poor spatial resolution (typically no better than 1-2 cm), DOT is increasingly ...

  1. Anatomical atlas-guided diffuse optical tomography of brain activation

    E-Print Network [OSTI]

    Custo, Anna

    We describe a neuroimaging protocol that utilizes an anatomical atlas of the human head to guide diffuse optical tomography of human brain activation. The protocol is demonstrated by imaging the hemodynamic response to ...

  2. Ultrahigh speed optical coherence tomography for ophthalmic imaging applications

    E-Print Network [OSTI]

    Liu, Jonathan Jaoshin

    2014-01-01T23:59:59.000Z

    Optical coherence tomography (OCT) is a non-contact, non-invasive, micron-scale optical imaging technology that has become a standard clinical tool in ophthalmology. Fourier domain OCT detection methods have enabled higher ...

  3. Embrittlement of RPV steels; An atom probe tomography perspective

    SciTech Connect (OSTI)

    Miller, Michael K [ORNL; Russell, Kaye F [ORNL

    2007-01-01T23:59:59.000Z

    Atom probe tomography has played a key role in the understanding of the embrittlement of neutron irradiated reactor pressure vessel steels through the atomic level characterization of the microstructure. Atom probe tomography has been used to demonstrate the importance of the post weld stress relief treatment in reducing the matrix copper content in high copper alloys, the formation of {approx}-nm-diameter copper-, nickel-, manganese- and silicon-enriched precipitates during neutron irradiation in copper containing RPV steels, and the coarsening of these precipitates during post irradiation heat treatments. Atom probe tomography has been used to detect {approx}2-nm-diameter nickel-, silicon- and manganese-enriched clusters in neutron irradiated low copper and copper free alloys. Atom probe tomography has also been used to quantify solute segregation to, and precipitation on, dislocations and grain boundaries.

  4. Microwave-induced thermoacoustic tomography: reconstruction by synthetic aperture 

    E-Print Network [OSTI]

    Feng, Dazi

    2001-01-01T23:59:59.000Z

    We have applied the synthetic-aperture method to linear-scanning microwave-induced thermoacoustic tomography in biological tissues. A non-focused ultrasonic transducer was used to receive thermoacoustic signals, to which the delay-and-sum algorithm...

  5. Spherical radon transforms and mathematical problems of thermoacoustic tomography 

    E-Print Network [OSTI]

    Ambartsoumian, Gaik

    2009-06-02T23:59:59.000Z

    including approximation theory, integral geometry, inverse problems for PDEs, etc. In Chapter I we give a brief description of thermoacoustic tomography (TAT or TCT) and introduce the SRT. In Chapter II we consider the injectivity problem for SRT. A major...

  6. Iron oxide nanoparticles as a contrast agent for thermoacoustic tomography 

    E-Print Network [OSTI]

    Keho, Aaron Lopez

    2009-06-02T23:59:59.000Z

    An exogenous contrast agent has been developed to enhance the contrast achievable in Thermoacoustic Tomography (TAT). TAT utilizes the penetration depth of microwave energy while producing high resolution images through acoustic waves. A sample...

  7. Scattered neutron tomography based on a neutron transport problem

    E-Print Network [OSTI]

    Scipolo, Vittorio

    2005-11-01T23:59:59.000Z

    scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...

  8. Revisiting Stopping Rules for Iterative Methods used in Emission Tomography

    E-Print Network [OSTI]

    Renaut, Rosemary

    Stopping Rules for Iterative Methods used in Emission Tomography Hongbin Guo,a, Rosemary A Renautb a Insta.guo@gmail.com (Hongbin Guo) Preprint submitted to Computerized Medical Imaging and Graphics September 28, 2010

  9. aids computed tomography: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Computer-aided diagnosis of rheumatoid arthritis with optical tomography, Part Computer...

  10. Assessment of the relationship between stenosis severity and distribution of coronary artery stenoses on multislice computed tomographic angiography and myocardial ischemia detected by single photon emission computed tomography

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    photon emission computed tomography Balaji K. Tamarappoo,of 64-slice computed tomography coronary angiography: Aphoton emission computed tomography for the prediction of

  11. Optimal phase for coronary interpretations and correlation of ejection fraction using late-diastole and end-diastole imaging in cardiac computed tomography angiography: implications for prospective triggering

    E-Print Network [OSTI]

    2009-01-01T23:59:59.000Z

    of multidetector computed tomography versus echocardiog-diastole imaging in cardiac computed tomography angiography:multi- row detector computed tomography (MDCT) angiog- raphy

  12. Assessment of the relationship between stenosis severity and distribution of coronary artery stenoses on multislice computed tomographic angiography and myocardial ischemia detected by single photon emission computed tomography

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    of 64-slice computed tomography coronary angiography: Aphoton emission computed tomography for the prediction ofphoton emission computed tomography. Circu- lation 2003;107:

  13. Ultrasonic Tomography for Detecting and Locating Defects in Concrete Structures 

    E-Print Network [OSTI]

    White, Joshua

    2012-07-16T23:59:59.000Z

    acquisition has grown from single-point 3 3 evaluations to automated scanning of larger areas (Streicher et al. 2006; De La Haza et al. n.d.). The tomography system used in this proposed research belongs to this family of phased-array transducers... at ACS working in collaboration with the Federal Institute of Materials Research and Testing in Berlin, Germany (BAM), developed the first ultrasonic tomography system that required no coupling agent (Acoustic Control Systems n.d.). The tomograph, a...

  14. Simultaneous Detection and Registration for Ileo-Cecal Valve Detection in 3D CT Colonography

    E-Print Network [OSTI]

    Barbu, Adrian

    Simultaneous Detection and Registration for Ileo-Cecal Valve Detection in 3D CT Colonography Le Lu1-Cecal Valve (ICV) detection in both clean and tagged 3D CT colonography scans. Our final ICV detection system

  15. CT Poison Control Center 2014 Video Contest Rules

    E-Print Network [OSTI]

    Kim, Duck O.

    CT Poison Control Center 2014 Video Contest Rules To Enter: 1) Record and upload a video to your an immediate family member who is an employee of the Connecticut Poison Control Center. Video Requirements: · DO NOT HANDLE, INGEST OR USE ANY ACTUAL POISONOUS OR HAZARDOUSSUBSTANCES. IF YOU HAVE QUESTIONS ABOUT

  16. Status and Promise CT's and Magnetized Target Fusion

    E-Print Network [OSTI]

    . Hill (LLNL) #12;CT's: Spheromaks & Field Reversed Configurations At LLNL, the SSPX experiment is investigating spheromak formation, sustainment, and confinement issues. (Hill, Mclean, Wood, Ryutov). At UC-Davis, formation and acceleration of spheromaks. (Hwang) At the U of Washington, field reversed configuration

  17. Collapsibility of Lung Volume by Paired Inspiratory and Expiratory CT

    E-Print Network [OSTI]

    Collapsibility of Lung Volume by Paired Inspiratory and Expiratory CT Scans: Correlations with Lung Function and Mean Lung Density Tsuneo Yamashiro, MD, Shin Matsuoka, MD, PhD, Brian J. Bartholmai, MD, Rau: To evaluate the relationship between measurements of lung volume (LV) on inspiratory/expiratory computed

  18. Measurements from 3D-CT renderings are used in research and clinical management

    E-Print Network [OSTI]

    Vorperian, Houri K.

    Measurements from 3D-CT renderings are used in research and clinical management: · Characterization for the prism]) RENDERING TECHNIQUES USED in ANALYZE 10.0: - Volume Render - (2) Volumes of Interest 1) VOI-Auto & 2) VOI-Manual TOTAL 3D-CT MODELS: 3 mandibles X 18 CT series X 3 rendering techniques = 162 mandible

  19. Automated Tumour Delineation Using Joint PET/CT Information Vaclav Potesil 1,2

    E-Print Network [OSTI]

    Huang, Xiaolei

    Automated Tumour Delineation Using Joint PET/CT Information Vaclav Potesil 1,2 , Xiaolei Huang 1 for automated delineation of tumor boundaries in whole-body PET/CT by jointly using information from both PET. Keywords: Tumor delineation, PET-CT, segmentation, radiation therapy planning 1. INTRODUCTION

  20. The New Oncology: Cost-effectiveness and Matchless Impactof PET-CT in Cancer Management CME

    E-Print Network [OSTI]

    Jadvar, Hossein

    The New Oncology: Cost-effectiveness and Matchless Impactof PET-CT in Cancer Management CME Author in integrating cost-effective FDG-PET and PET-CT fusion techniques into their clinical armamentarium to refine the clinical impact and cost-effectiveness of advanced imaging studies such as FDG-PET scanning and PET-CT