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1

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

NLE Websites -- All DOE Office Websites (Extended Search)

Non-medical Uses of Computed Tomography (CT) Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR) Resources with Additional Information Computed Tomography (CT) Scanner CT Scanner - Courtesy Stanford University Department of Energy Resources Engineering Computed tomography (CT) and Nuclear Magnetic Resonance (NMR) have been used to resolve industrial problems, for materials characterizations, and to provide non-destructive evaluations for discovering flaws in parts before their use, resulting in greater reliability and greater safety for workers; to identify the presence and facilitate the recovery/extraction of oil, water, coal, and/or gas; and to provide non-destructive testing and quality control of fresh fruits and vegetables, enhancing the safety of food. These benefits of non-medical uses of CT and NMR contribute to the economy and improve people's lives.

2

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

Office of Scientific and Technical Information (OSTI)

Non-medical Uses of Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR) Resources with Additional Information Computed Tomography (CT) Scanner CT Scanner - Courtesy Stanford University Department of Energy Resources Engineering Computed tomography (CT) and Nuclear Magnetic Resonance (NMR) have been used to resolve industrial problems, for materials characterizations, and to provide non-destructive evaluations for discovering flaws in parts before their use, resulting in greater reliability and greater safety for workers; to identify the presence and facilitate the recovery/extraction of oil, water, coal, and/or gas; and to provide non-destructive testing and quality control of fresh fruits and vegetables, enhancing the safety of food. These benefits of non-medical uses of CT and NMR contribute to the economy and improve people's lives.

3

Quantitative comparison of noise texture across CT scanners from different manufacturers  

SciTech Connect

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.

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

4

Simultaneous CT and SPECT tomography using CZT detectors - Energy ...  

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 ...

5

Computed Tomography (CT) Scanning For Petrophysical Applications  

NLE Websites -- All DOE Office Websites (Extended Search)

R&D Fac R&D Fac ts Carbon Sequestration ContaCtS David Wildman Division Director Geosciences Division National Energy Technology Laboratory 626 Cochrans Mill Road P.O. Box 10940 Pittsburgh, PA 15236 412-386-4913 david.wildman@netl.doe.gov T. Robert McLendon Geosciences Division National Energy Technology Laboratory 3610 Collins Ferry Road P.O. Box 880 Morgantown, WV 26507 304-285-2008 t.mclen@netl.doe.gov Duane H. Smith Geosciences Division

6

Patient radiation dose in prospectively gated axial CT coronary angiography and retrospectively gated helical technique with a 320-detector row CT scanner  

Science Conference Proceedings (OSTI)

Purpose: The aim of this study was to evaluate radiation dose to patients undergoing computed tomography coronary angiography (CTCA) for prospectively gated axial (PGA) technique and retrospectively gated helical (RGH) technique. Methods: Radiation doses were measured for a 320-detector row CT scanner (Toshiba Aquilion ONE) using small sized silicon-photodiode dosimeters, which were implanted at various tissue and organ positions within an anthropomorphic phantom for a standard Japanese adult male. Output signals from photodiode dosimeters were read out on a personal computer, from which organ and effective doses were computed according to guidelines published in the International Commission on Radiological Protection Publication 103. Results: Organs that received high doses were breast, followed by lung, esophagus, and liver. Breast doses obtained with PGA technique and a phase window width of 16% at a simulated heart rate of 60 beats per minute were 13 mGy compared to 53 mGy with RGH technique using electrocardiographically dependent dose modulation at the same phase window width as that in PGA technique. Effective doses obtained in this case were 4.7 and 20 mSv for the PGA and RGH techniques, respectively. Conversion factors of dose length product to the effective dose in PGA and RGH were 0.022 and 0.025 mSv mGy{sup -1} cm{sup -1} with a scan length of 140 mm. Conclusions: CTCA performed with PGA technique provided a substantial effective dose reduction, i.e., 70%-76%, compared to RGH technique using the dose modulation at the same phase windows as those in PGA technique. Though radiation doses in CTCA with RGH technique were the same level as, or some higher than, those in conventional coronary angiography (CCA), the use of PGA technique reduced organ and effective doses to levels less than CCA except for breast dose.

Seguchi, Shigenobu; Aoyama, Takahiko; Koyama, Shuji; Fujii, Keisuke; Yamauchi-Kawaura, Chiyo [Graduate School of Medicine, Nagoya University, Daikominami, Higashi-ku, Nagoya 461-8673 (Japan) and Department of Medical Technology, Nagoya Daini Red Cross Hospital, Myouken-chou, Showa-ku, Nagoya 466-8650 (Japan); Graduate School of Medicine, Nagoya University, Daikominami, Higashi-ku, Nagoya 461-8673 (Japan); Section of Radiological Protection, National Institute of Radiological Sciences, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Graduate School of Medicine, Nagoya University, Daikominami, Higashi-ku, Nagoya 461-8673 (Japan)

2010-11-15T23:59:59.000Z

7

Coronary artery wall imaging in mice using osmium tetroxide and micro-computed tomography (micro-CT)  

SciTech Connect

The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO{sub 4}) solution. As a tissue-staining contrast agent, OsO{sub 4} is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO{sub 4} preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE{sup -/-}) mice at 10 {mu}m resolution. The results show that walls of coronary arteries as small as 45 {mu}m in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO{sub 4} and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.

Pai, Vinay M.; Kozlowski, Megan; Donahue, Danielle; Miller, Elishiah; Xiao, Xianghui; Chen, Marcus Y.; Yu, Zu-Xi; Connelly, Patricia; Jeffries, Kenneth; Wen, Han (NIH)

2012-05-10T23:59:59.000Z

8

Simultaneous CT and SPECT tomography using CZT detectors  

DOE Patents (OSTI)

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.

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

9

Proton computed tomography  

SciTech Connect

The use of protons or other heavy charged particles instead of x rays in computed tomography (CT) is explored. The results of an experimental implementation of proton CT are presented. High quality CT reconstructions are obtained at an average dose reduction factor compared with an EMI 5005 x-ray scanner of 10:1 for a 30-cm-diameter phantom and 3.5:1 for a 20-cm diameter. The spatial resolution is limited by multiple Coulomb scattering to about 3.7 mm FWHM. Further studies are planned in which proton and x-ray images of fresh human specimens will be compared. Design considerations indicate that a clinically useful proton CT scanner is eminently feasible.

Hanson, K.M.

1978-01-01T23:59:59.000Z

10

Computed Tomography Status  

DOE R&D Accomplishments (OSTI)

Computed tomography (CT) is a relatively new radiographic technique which has become widely used in the medical field, where it is better known as computerized axial tomographic (CAT) scanning. This technique is also being adopted by the industrial radiographic community, although the greater range of densities, variation in samples sizes, plus possible requirement for finer resolution make it difficult to duplicate the excellent results that the medical scanners have achieved.

Hansche, B. D.

1983-00-00T23:59:59.000Z

11

Computed tomography status  

SciTech Connect

Computed tomography (CT) is a relatively new radiographic technique which has become widely used in the medical field, where it is better known as computerized axial tomographic (CAT) scanning. This technique is also being adopted by the industrial radiographic community, although the greater range of densities, variation in samples sizes, plus possible requirement for finer resolution make it difficult to duplicate the excellent results that the medical scanners have achieved.

Hansche, B.D.

1983-01-01T23:59:59.000Z

12

Artifacts in Conventional Computed Tomography (CT) and Free Breathing Four-Dimensional CT Induce Uncertainty in Gross Tumor Volume Determination  

Science Conference Proceedings (OSTI)

Purpose: Artifacts impacting the imaged tumor volume can be seen in conventional three-dimensional CT (3DCT) scans for planning of lung cancer radiotherapy but can be reduced with the use of respiration-correlated imaging, i.e., 4DCT or breathhold CT (BHCT) scans. The aim of this study was to compare delineated gross tumor volume (GTV) sizes in 3DCT, 4DCT, and BHCT scans of patients with lung tumors. Methods and Materials: A total of 36 patients with 46 tumors referred for stereotactic radiotherapy of lung tumors were included. All patients underwent positron emission tomography (PET)/CT, 4DCT, and BHCT scans. GTVs in all CT scans of individual patients were delineated during one session by a single physician to minimize systematic delineation uncertainty. The GTV size from the BHCT was considered the closest to true tumor volume and was chosen as the reference. The reference GTV size was compared to GTV sizes in 3DCT, at midventilation (MidV), at end-inspiration (Insp), and at end-expiration (Exp) bins from the 4DCT scan. Results: The median BHCT GTV size was 4.9 cm{sup 3} (0.1-53.3 cm{sup 3}). Median deviation between 3DCT and BHCT GTV size was 0.3 cm{sup 3} (-3.3 to 30.0 cm{sup 3}), between MidV and BHCT size was 0.2 cm{sup 3} (-5.7 to 19.7 cm{sup 3}), between Insp and BHCT size was 0.3 cm{sup 3} (-4.7 to 24.8 cm{sup 3}), and between Exp and BHCT size was 0.3 cm{sup 3} (-4.8 to 25.5 cm{sup 3}). The 3DCT, MidV, Insp, and Exp median GTV sizes were all significantly larger than the BHCT median GTV size. Conclusions: In the present study, the choice of CT method significantly influenced the delineated GTV size, on average, leading to an increase in GTV size compared to the reference BHCT. The uncertainty caused by artifacts is estimated to be in the same magnitude as delineation uncertainty and should be considered in the design of margins for radiotherapy.

Fredberg Persson, Gitte, E-mail: gitte.persson@rh.regionh.dk [Department of Radiation Oncology, Copenhagen University Hospital, Rigshospitalet, Copenhagen (Denmark); Nygaard, Ditte Eklund; Munch af Rosenschoeld, Per; Richter Vogelius, Ivan; Josipovic, Mirjana [Department of Radiation Oncology, Copenhagen University Hospital, Rigshospitalet, Copenhagen (Denmark); Specht, Lena [Department of Radiation Oncology, Copenhagen University Hospital, Rigshospitalet, Copenhagen (Denmark); Faculty of Health Sciences, University of Copenhagen, Copenhagen (Denmark); Korreman, Stine Sofia [Department of Radiation Oncology, Copenhagen University Hospital, Rigshospitalet, Copenhagen (Denmark); Department of Human Oncology, University of Wisconsin-Madison, Madison, Wisconsin (United States); Niels Bohr Institute, Faculty of Sciences, University of Copenhagen, Copenhagen (Denmark)

2011-08-01T23:59:59.000Z

13

Automated size-specific CT dose monitoring program: Assessing variability in CT dose  

SciTech Connect

Purpose: The potential health risks associated with low levels of ionizing radiation have created a movement in the radiology community to optimize computed tomography (CT) imaging protocols to use the lowest radiation dose possible without compromising the diagnostic usefulness of the images. Despite efforts to use appropriate and consistent radiation doses, studies suggest that a great deal of variability in radiation dose exists both within and between institutions for CT imaging. In this context, the authors have developed an automated size-specific radiation dose monitoring program for CT and used this program to assess variability in size-adjusted effective dose from CT imaging. Methods: The authors radiation dose monitoring program operates on an independent health insurance portability and accountability act compliant dosimetry server. Digital imaging and communication in medicine routing software is used to isolate dose report screen captures and scout images for all incoming CT studies. Effective dose conversion factors (k-factors) are determined based on the protocol and optical character recognition is used to extract the CT dose index and dose-length product. The patient's thickness is obtained by applying an adaptive thresholding algorithm to the scout images and is used to calculate the size-adjusted effective dose (ED{sub adj}). The radiation dose monitoring program was used to collect data on 6351 CT studies from three scanner models (GE Lightspeed Pro 16, GE Lightspeed VCT, and GE Definition CT750 HD) and two institutions over a one-month period and to analyze the variability in ED{sub adj} between scanner models and across institutions. Results: No significant difference was found between computer measurements of patient thickness and observer measurements (p= 0.17), and the average difference between the two methods was less than 4%. Applying the size correction resulted in ED{sub adj} that differed by up to 44% from effective dose estimates that were not adjusted by patient size. Additionally, considerable differences were noted in ED{sub adj} distributions between scanners, with scanners employing iterative reconstruction exhibiting significantly lower ED{sub adj} (range: 9%-64%). Finally, a significant difference (up to 59%) in ED{sub adj} distributions was observed between institutions, indicating the potential for dose reduction. Conclusions: The authors developed a robust automated size-specific radiation dose monitoring program for CT. Using this program, significant differences in ED{sub adj} were observed between scanner models and across institutions. This new dose monitoring program offers a unique tool for improving quality assurance and standardization both within and across institutions.

Christianson, Olav; Li Xiang; Frush, Donald; Samei, Ehsan [Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States) and Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States)

2012-11-15T23:59:59.000Z

14

Anatomical database generation for radiation transport modeling from computed tomography (CT) scan data  

SciTech Connect

Geometric models of the anatomy are used routinely in calculations of the radiation dose in organs and tissues of the body. Development of such models has been hampered by lack of detailed anatomical information on children, and models themselves have been limited to quadratic conic sections. This summary reviews the development of an image processing workstation used to extract anatomical information from routine diagnostic CT procedure. A standard IBM PC/AT microcomputer has been augmented with an automatically loading 9-track magnetic tape drive, an 8-bit 1024 {times} 1024 pixel graphics adapter/monitor/film recording package, a mouse/trackball assembly, dual 20 MB removable cartridge media, a 72 MB disk drive, and a printer. Software utilized by the workstation includes a Geographic Information System (modified for manipulation of CT images), CAD software, imaging software, and various modules to ease data transfer among the software packages. 5 refs., 3 figs.

Margle, S.M.; Tinnel, E.P.; Till, L.E.; Eckerman, K.F.; Durfee, R.C.

1989-01-01T23:59:59.000Z

15

Practical CT technology and techniques  

SciTech Connect

This handbook equips both radiologists and radiologists in training with a thorough working knowledge of the mechanisms and processes of computed tomography (CT) image generation, the common causes of image artifacts, and useful examination protocols for each area of the body. The author explains the fundamental technological principles of CT, focusing on those concepts crucial to successful CT examinations. The first part of the book succinctly reviews the fundamentals of CT technology. It begins with a methodical introduction to key principles of X-ray physics and technology, in which topics such as the modulation transfer function, magnification, and the X-ray tube are discussed in understandable, nonmathematical terms. The author then explains the basic technology of CT scanners, the principles of scan projection radiography, and the essential rules for radiation dosage determination and radiation protection. Careful attention is given to selectable scan factors in both routine and dynamic scanning, as well as to the processes involved in image creation and refinement and the chief determinants of image quality. Basic and specialized program features and the technology of image display, recording, and storage are also thoroughly described.

Berland, L.L.

1987-01-01T23:59:59.000Z

16

Ion Stopping Powers and CT Numbers  

SciTech Connect

One of the advantages of ion beam therapy is the steep dose gradient produced near the ion's range. Use of this advantage makes knowledge of the stopping powers for all materials through which the beam passes critical. Most treatment planning systems calculate dose distributions using depth dose data measured in water and an algorithm that converts the kilovoltage X-ray computed tomography (CT) number of a given material to its linear stopping power relative to water. Some materials present in kilovoltage scans of patients and simulation phantoms do not lie on the standard tissue conversion curve. The relative linear stopping powers (RLSPs) of 21 different tissue substitutes and positioning, registration, immobilization, and beamline materials were measured in beams of protons accelerated to energies of 155, 200, and 250 MeV; carbon ions accelerated to 290 MeV/n; and iron ions accelerated to 970 MeV/n. These same materials were scanned with both kilovoltage and megavoltage CT scanners to obtain their CT numbers. Measured RLSPs and CT numbers were compared with calculated and/or literature values. Relationships of RLSPs to physical densities, electronic densities, kilovoltage CT numbers, megavoltage CT numbers, and water equivalence values converted by a treatment planning system are given. Usage of CT numbers and substitution of measured values into treatment plans to provide accurate patient and phantom simulations are discussed.

Moyers, Michael F., E-mail: MFMoyers@roadrunner.co [Department of Proton Therapy, Inc., Colton, CA (United States); Sardesai, Milind [Department of Long Beach Memorial Medical Center, Long Beach, CA (United States); Sun, Sean [Department of City of Hope National Medical Center, Duarte, CA (United States); Miller, Daniel W. [Department of Loma Linda University Medical Center, Loma Linda, CA (United States)

2010-10-01T23:59:59.000Z

17

Task force report on computerized tomographic scanners  

SciTech Connect

Computerized axial tomography (CAT) scanning was the focus of a task force established by the Bergen-Passaic Health Systems Agency in New Jersey. The task force reviewed the literature on CAT technology and its applications, surveyed four northeastern hospitals with operating CAT scanning installations, and created three working subcommittees which produced written reports. It was agreed by task force members that certain criteria should be used when evaluating applications for CAT scanners, e.g., service area, staff resources, emergency room activity, radiotherapy, 24-hour scanner coverage, the medically indigent, and cost. Overall, it was determined that CAT is a proven diagnostic tool of significant value and that it should be available to residents of the Bergen-Passaic health service area. Since the CAT field is rapidly evolving and changing, however, it was not possible to define quantitatively the long-term need for and supply of CAT scanners in the region. Appendixes present supporting data on the task force findings.

1978-10-01T23:59:59.000Z

18

Improved image quality for x-ray CT imaging of gel dosimeters  

Science Conference Proceedings (OSTI)

Purpose: This study provides a simple method for improving precision of x-ray computed tomography (CT) scans of irradiated polymer gel dosimetry. The noise affecting CT scans of irradiated gels has been an impediment to the use of clinical CT scanners for gel dosimetry studies. Methods: In this study, it is shown that multiple scans of a single PAGAT gel dosimeter can be used to extrapolate a ''zero-scan'' image which displays a similar level of precision to an image obtained by averaging multiple CT images, without the compromised dose measurement resulting from the exposure of the gel to radiation from the CT scanner. Results: When extrapolating the zero-scan image, it is shown that exponential and simple linear fits to the relationship between Hounsfield unit and scan number, for each pixel in the image, provide an accurate indication of gel density. Conclusions: It is expected that this work will be utilized in the analysis of three-dimensional gel volumes irradiated using complex radiotherapy treatments.

Kakakhel, M. B.; Kairn, T.; Kenny, J.; Trapp, J. V. [Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Queesland 4001, Australia and Department of Physics and Applied Mathematics, DPAM, Pakistan Institute of Engineering and Applied Sciences, PO Nilore, Islamabad 45450 (Pakistan); Premion, The Wesley Medical Centre, Suite 1, 40 Chasely St, Auchenflower, Queensland 4066 (Australia); Premion, The Wesley Medical Centre, Suite 1, 40 Chasely St, Auchenflower, Queensland 4066, Australia and Australian Clinical Dosimetry Service, ARPANSA, Yallambie, Vic 3085 (Australia); Faculty of Science and Technology, Queensland University of Technology, GPO Box 2434, Brisbane, Ql d 4001 (Australia)

2011-09-15T23:59:59.000Z

19

Optical fuel pin scanner  

DOE Patents (OSTI)

An optical scanner for indicia arranged in a focal plane at a cylindrical outside surface by use of an optical system including a rotatable dove prism. The dove prism transmits a rotating image of an encircled cylindrical surface area to a stationary photodiode array.

Kirchner, Tommy L. (Richland, WA); Powers, Hurshal G. (Richland, WA)

1983-01-01T23:59:59.000Z

20

High throughput optical scanner  

SciTech Connect

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.

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

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Organ doses for reference pediatric and adolescent patients undergoing computed tomography estimated by Monte Carlo simulation  

SciTech Connect

Purpose: To establish an organ dose database for pediatric and adolescent reference individuals undergoing computed tomography (CT) examinations by using Monte Carlo simulation. The data will permit rapid estimates of organ and effective doses for patients of different age, gender, examination type, and CT scanner model. Methods: The Monte Carlo simulation model of a Siemens Sensation 16 CT scanner previously published was employed as a base CT scanner model. A set of absorbed doses for 33 organs/tissues normalized to the product of 100 mAs and CTDI{sub vol} (mGy/100 mAs mGy) was established by coupling the CT scanner model with age-dependent reference pediatric hybrid phantoms. A series of single axial scans from the top of head to the feet of the phantoms was performed at a slice thickness of 10 mm, and at tube potentials of 80, 100, and 120 kVp. Using the established CTDI{sub vol}- and 100 mAs-normalized dose matrix, organ doses for different pediatric phantoms undergoing head, chest, abdomen-pelvis, and chest-abdomen-pelvis (CAP) scans with the Siemens Sensation 16 scanner were estimated and analyzed. The results were then compared with the values obtained from three independent published methods: CT-Expo software, organ dose for abdominal CT scan derived empirically from patient abdominal circumference, and effective dose per dose-length product (DLP). Results: Organ and effective doses were calculated and normalized to 100 mAs and CTDI{sub vol} for different CT examinations. At the same technical setting, dose to the organs, which were entirely included in the CT beam coverage, were higher by from 40 to 80% for newborn phantoms compared to those of 15-year phantoms. An increase of tube potential from 80 to 120 kVp resulted in 2.5-2.9-fold greater brain dose for head scans. The results from this study were compared with three different published studies and/or techniques. First, organ doses were compared to those given by CT-Expo which revealed dose differences up to several-fold when organs were partially included in the scan coverage. Second, selected organ doses from our calculations agreed to within 20% of values derived from empirical formulae based upon measured patient abdominal circumference. Third, the existing DLP-to-effective dose conversion coefficients tended to be smaller than values given in the present study for all examinations except head scans. Conclusions: A comprehensive organ/effective dose database was established to readily calculate doses for given patients undergoing different CT examinations. The comparisons of our results with the existing studies highlight that use of hybrid phantoms with realistic anatomy is important to improve the accuracy of CT organ dosimetry. The comprehensive pediatric dose data developed here are the first organ-specific pediatric CT scan database based on the realistic pediatric hybrid phantoms which are compliant with the reference data from the International Commission on Radiological Protection (ICRP). The organ dose database is being coupled with an adult organ dose database recently published as part of the development of a user-friendly computer program enabling rapid estimates of organ and effective dose doses for patients of any age, gender, examination types, and CT scanner model.

Lee, Choonsik; Kim, Kwang Pyo; Long, Daniel J.; 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, Gyeonggi-do, 446906 (Korea, Republic of); J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2012-04-15T23:59:59.000Z

22

High resolution computed tomography for solid modeling and computer aided design  

SciTech Connect

Input of solid objects to a CAD/CAM system has been accomplished using serial sections and 3-D surface reconstructions obtained with an unmodified medical CT scanner.

Vannier, M.W.; Dye, D.M.; Knapp, R.H.; Gayou, D.E.; Sammon, N.P.; Dzik, S.; Butterfield, R.L.; Larson, J.; Ellingson, W.A.

1984-09-01T23:59:59.000Z

23

An adaptive approach to metal artifact reduction in helical computed tomography for radiation therapy treatment planning: Experimental and clinical studies  

SciTech Connect

Purpose: In this article, an approach to metal artifact reduction is proposed that is practical for clinical use in radiation therapy. It is based on a new interpolation scheme of the projections associated with metal implants in helical computed tomography (CT) scanners. Methods and Materials: A three-step approach was developed consisting of an automatic algorithm for metal implant detection, a correction algorithm for helical projections, and a new, efficient algorithm for projection interpolation. The modified raw projection data are transferred back to the CT scanner device where CT slices are regenerated using the built-in reconstruction operator. The algorithm was tested on a CT calibration phantom in which the density of inserted objects are known and on clinical prostate cases with two hip prostheses. The results are evaluated using the CT number and shape of the objects. Results: The validations on a CT calibration phantom with various inserts of known densities show that the algorithm improved the overall image quality by restoring the shape and the representative CT number of the objects in the image. For the clinical hip replacement cases, a large fraction of the bladder, rectum, and prostate that were not visible on the original CT slices were recovered using the algorithm. Precise contouring of the target volume was thus feasible. Without this enhancement, physicians would have drawn bigger margins to be sure to include the target and, at the same time, could have prescribed a lower dose to keep the same level of normal tissue toxicity. Conclusions: In both phantom experiment and patient studies, the algorithm resulted in significant artifact reduction with increases in the reliability of planning procedure for the case of metallic hip prostheses. This algorithm is now clinically used as a preprocessing before treatment planning for metal artifact reduction.

Yazdia, Mehran [Departement de radio-onoclogie and Centre de Recherche en Cancerologie de l' Universite Laval, Hotel-Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec City, Quebec (Canada); Gingras, Luc [Departement de radio-onoclogie and Centre de Recherche en Cancerologie de l' Universite Laval, Hotel-Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec City, Quebec (Canada); Departement de Physique, Genie Physique et d' Optique, Universite Laval, Quebec City, Quebec (Canada); Beaulieu, Luc [Departement de radio-onoclogie and Centre de Recherche en Cancerologie de l' Universite Laval, Hotel-Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec City, Quebec (Canada) and Departement de Physique, Genie Physique et d' Optique, Universite Laval, Quebec City, Quebec (Canada)]. E-mail: beaulieu@phy.ulaval.ca

2005-07-15T23:59:59.000Z

24

Validation of ERBS Scanner Radiances  

Science Conference Proceedings (OSTI)

The earth radiation budget satellite (ERBS) has made broadband scanner measurements of the earth radiance for over 5 years. The redundancy between the shortwave, longwave, and total scanning radiometers and data averages have been used to ...

Richard N. Green; Lee M. Avis

1996-08-01T23:59:59.000Z

25

A robust geometry estimation method for spiral, sequential and circular cone-beam micro-CT  

Science Conference Proceedings (OSTI)

Purpose: The authors propose a novel method for misalignment estimation of micro-CT scanners using an adaptive genetic algorithm. Methods: The proposed algorithm is able to estimate the rotational geometry, the direction vector of table movement and the displacement between different imaging threads of a dual source or even multisource scanner. The calibration procedure does not rely on dedicated calibration phantoms and a sequence scan of a single metal bead is sufficient to geometrically calibrate the whole imaging system for spiral, sequential, and circular scan protocols. Dual source spiral and sequential scan protocols in micro-computed tomography result in projection data that-besides the source and detector positions and orientations-also require a precise knowledge of the table direction vector to be reconstructed properly. If those geometric parameters are not known accurately severe artifacts and a loss in spatial resolution appear in the reconstructed images as long as no geometry calibration is performed. The table direction vector is further required to ensure that consecutive volumes of a sequence scan can be stitched together and to allow the reconstruction of spiral data at all. Results: The algorithm's performance is evaluated using simulations of a micro-CT system with known geometry and misalignment. To assess the quality of the algorithm in a real world scenario the calibration of a micro-CT scanner is performed and several reconstructions with and without geometry estimation are presented. Conclusions: The results indicate that the algorithm successfully estimates all geometry parameters, misalignment artifacts in the reconstructed volumes vanish, and the spatial resolution is increased as can be shown by the evaluation of modulation transfer function measurements.

Sawall, Stefan; Knaup, Michael; Kachelriess, Marc [Institute of Medical Physics (IMP), University of Erlangen-Nuernberg, 91052 Erlangen (Germany); Institute of Medical Physics (IMP), University of Erlangen-Nuernberg, 91052 Erlangen (Germany) and Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)

2012-09-15T23:59:59.000Z

26

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

Science Conference Proceedings (OSTI)

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.

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

27

Automatic heart isolation for CT coronary visualization using graph-cuts  

E-Print Network (OSTI)

We describe a means to automatically and efficiently isolate the outer surface of the entire heart in Computer Tomography (CT) cardiac scans. Isolating the entire heart allows the coronary vessels on the surface of the heart to be easily visualized despite the proximity of surrounding organs such as the ribs and pulmonary blood vessels. Numerous techniques have been described for segmenting the left ventricle of the heart in images from various types of medical scanners but rarely has the entire heart been segmented. We make use of graphcuts to do the segmentation and introduce a novel means of initiating and constraining the graph-cut technique for heart isolation. The technique has been tested on 70 patient data sets. Results are compares with hand labeled results. 1.

G. Funka-lea; Y. Boykov; C. Florin; M. -p. Jolly; R. Moreau-gobard; R. Ramaraj; D. Rinck

2006-01-01T23:59:59.000Z

28

Impact of computed tomography and {sup 18}F-deoxyglucose coincidence detection emission tomography image fusion for optimization of conformal radiotherapy in non-small-cell lung cancer  

SciTech Connect

Purpose: To report a retrospective study concerning the impact of fused {sup 18}F-fluoro-deoxy-D-glucose (FDG)-hybrid positron emission tomography (PET) and CT images on three-dimensional conformal radiotherapy planning for patients with non-small-cell lung cancer. Methods and Materials: A total of 101 patients consecutively treated for Stage I-III non-small-cell lung cancer were studied. Each patient underwent CT and FDG-hybrid PET for simulation treatment in the same treatment position. Images were coregistered using five fiducial markers. Target volume delineation was initially performed on the CT images, and the corresponding FDG-PET data were subsequently used as an overlay to the CT data to define the target volume. Results: {sup 18}F-fluoro-deoxy-D-glucose-PET identified previously undetected distant metastatic disease in 8 patients, making them ineligible for curative conformal radiotherapy (1 patient presented with some positive uptake corresponding to concomitant pulmonary tuberculosis). Another patient was ineligible for curative treatment because the fused PET-CT images demonstrated excessively extensive intrathoracic disease. The gross tumor volume (GTV) was decreased by CT-PET image fusion in 21 patients (23%) and was increased in 24 patients (26%). The GTV reduction was {>=}25% in 7 patients because CT-PET image fusion reduced the pulmonary GTV in 6 patients (3 patients with atelectasis) and the mediastinal nodal GTV in 1 patient. The GTV increase was {>=}25% in 14 patients owing to an increase in the pulmonary GTV in 11 patients (4 patients with atelectasis) and detection of occult mediastinal lymph node involvement in 3 patients. Of 81 patients receiving a total dose of {>=}60 Gy at the International Commission on Radiation Units and Measurements point, after CT-PET image fusion, the percentage of total lung volume receiving >20 Gy increased in 15 cases and decreased in 22. The percentage of total heart volume receiving >36 Gy increased in 8 patients and decreased in 14. The spinal cord volume receiving at least 45 Gy (2 patients) decreased. Multivariate analysis showed that tumor with atelectasis was the single independent factor that resulted in a significant effect on the modification of the size of the GTV by FDG-PET: tumor with atelectasis (with vs. without atelectasis, p = 0.0001). Conclusion: The results of our study have confirmed that integrated hybrid PET/CT in the treatment position and coregistered images have an impact on treatment planning and management of non-small-cell lung cancer. However, FDG images using dedicated PET scanners and respiration-gated acquisition protocols could improve the PET-CT image coregistration. Furthermore, the impact on treatment outcome remains to be demonstrated.

Deniaud-Alexandre, Elisabeth [Department of Radiation Oncology, Tenon Hospital A.P.-H.P., Paris (France); Touboul, Emmanuel [Department of Radiation Oncology, Tenon Hospital A.P.-H.P., Paris (France)]. E-mail: emmanuel.touboul@tnn.aphp.fr; Lerouge, Delphine [Department of Radiation Oncology, Tenon Hospital A.P.-H.P., Paris (France); Grahek, Dany [Department of Nuclear Medicine, Tenon Hospital A.P.-H.P., Paris (France); Foulquier, Jean-Noel [Department of Radiation Oncology, Tenon Hospital A.P.-H.P., Paris (France); Petegnief, Yolande [Department of Nuclear Medicine, Tenon Hospital A.P.-H.P., Paris (France); Gres, Benoit [Department of Radiation Oncology, Tenon Hospital A.P.-H.P., Paris (France); El Balaa, Hanna [Department of Radiation Oncology, Tenon Hospital A.P.-H.P., Paris (France); Keraudy, Katia [Department of Radiation Oncology, Tenon Hospital A.P.-H.P., Paris (France); Kerrou, Kaldoun [Department of Nuclear Medicine, Tenon Hospital A.P.-H.P., Paris (France); Montravers, Francoise [Department of Nuclear Medicine, Tenon Hospital A.P.-H.P., Paris (France); Milleron, Bernard [Department of Respiratory Medicine, Tenon Hospital A.P.-H.P., Paris (France); Lebeau, Bernard [Department of Respiratory Medicine, Saint-Antoine Hospital A.P.-H.P., Paris (France) and Cancerest, Paris VI University, Paris (France); Talbot, Jean-Noel [Department of Nuclear Medicine, Tenon Hospital A.P.-H.P., Paris (France)

2005-12-01T23:59:59.000Z

29

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

Science Conference Proceedings (OSTI)

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.

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

30

A phantom for testing of 4D-CT for radiotherapy of small lesions  

SciTech Connect

Purpose: The use of time-resolved four-dimensional computed tomography (4D-CT) in radiotherapy requires strict quality assurance to ensure the accuracy of motion management protocols. The aim of this work was to design and test a phantom capable of large amplitude motion for use in 4D-CT, with particular interest in small lesions typical for stereotactic body radiotherapy. Methods: The phantom of 'see-saw' design is light weight, capable of including various sample materials and compatible with several surrogate marker signal acquisition systems. It is constructed of polymethylmethacrylate (Perspex) and its movement is controlled via a dc motor and drive wheel. It was tested using two CT scanners with different 4D acquisition methods: the Philips Brilliance Big Bore CT (helical scan, pressure belt) and a General Electric Discovery STE PET/CT (axial scan, infrared marker). Amplitudes ranging from 1.5 to 6.0 cm and frequencies of up to 40 cycles per minute were used to study the effect of motion on image quality. Maximum intensity projections (MIPs), as well as average intensity projections (AIPs) of moving objects were investigated and their quality dependence on the number of phase reconstruction bins assessed. Results: CT number discrepancies between moving and stationary objects were found to have no systematic dependence on amplitude, frequency, or specific interphase variability. MIP-delineated amplitudes of motion were found to match physical phantom amplitudes to within 2 mm for all motion scenarios tested. Objects undergoing large amplitude motions (>3.0 cm) were shown to cause artefacts in MIP and AIP projections when ten phase bins were assigned. This problem can be mitigated by increasing the number of phase bins in a 4D-CT scan. Conclusions: The phantom was found to be a suitable tool for evaluating the image quality of 4D-CT motion management technology, as well as providing a quality assurance tool for intercenter/intervendor testing of commercial 4D-CT systems. When imaging objects with large amplitudes, the completeness criterion described here indicates the number of phase bins required to prevent missing data in MIPs and AIPs. This is most relevant for small lesions undergoing large motions.

Dunn, L.; Kron, T.; Taylor, M. L.; Callahan, J.; Franich, R. D. [School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne 3000 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne 3000 (Australia) and Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne 3002 (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne 3000 (Australia); Physical Sciences, Peter MacCallum Cancer Centre, East Melbourne (Australia); School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne 3000 (Australia)

2012-09-15T23:59:59.000Z

31

Application of Computed Tomography to Microgravity Combustion  

Science Conference Proceedings (OSTI)

This paper describes applications of computed tomography (CT) to combustion phenomena under microgravity conditions. Infrared Thermography (IT) has been considered as a promising method for two-dimensional measurement of flames. We have applied IT to ... Keywords: computed tomography, diffusion flame, infrared thermography, microgravity combustion, spectroscopy

H. Sato; K. Itoh; M. Shimizu; S. Hayashi; Y. Fujimori; K. Maeno

1999-12-01T23:59:59.000Z

32

Hand-held optical fuel pin scanner  

DOE Patents (OSTI)

An optical scanner for indicia arranged in a focal plane perpendicular to an optical system including a rotatable dove prism. The dove prism transmits a rotating image to a stationary photodiode array.

Kirchner, Tommy L. (Richland, WA); Powers, Hurshal G. (Richland, WA)

1987-01-01T23:59:59.000Z

33

Hand-held optical fuel pin scanner  

DOE Patents (OSTI)

An optical scanner for indicia arranged in a focal plane perpendicular to an optical system including a rotatable dove prism. The dove prism transmits a rotating image to a stationary photodiode array.

Kirchner, T.L.; Powers, H.G.

1980-12-07T23:59:59.000Z

34

Multiple-energy Techniques in Industrial Computerized Tomography  

DOE R&D Accomplishments (OSTI)

Considerable effort is being applied to develop multiple-energy industrial CT techniques for materials characterization. Multiple-energy CT can provide reliable estimates of effective Z (Z{sub eff}), weight fraction, and rigorous calculations of absolute density, all at the spatial resolution of the scanner. Currently, a wide variety of techniques exist for CT scanners, but each has certain problems and limitations. Ultimately, the best multi-energy CT technique would combine the qualities of accuracy, reliability, and wide range of application, and would require the smallest number of additional measurements. We have developed techniques for calculating material properties of industrial objects that differ somewhat from currently used methods. In this paper, we present our methods for calculating Z{sub eff}, weight fraction, and density. We begin with the simplest case -- methods for multiple-energy CT using isotopic sources -- and proceed to multiple-energy work with x-ray machine sources. The methods discussed here are illustrated on CT scans of PBX-9502 high explosives, a lexan-aluminum phantom, and a cylinder of glass beads used in a preliminary study to determine if CT can resolve three phases: air, water, and a high-Z oil. In the CT project at LLNL, we have constructed several CT scanners of varying scanning geometries using {gamma}- and x-ray sources. In our research, we employed two of these scanners: pencil-beam CAT for CT data using isotopic sources and video-CAT equipped with an IRT micro-focal x-ray machine source.

Schneberk, D.; Martz, H.; Azevedo, S.

1990-08-01T23:59:59.000Z

35

Multiple-energy techniques in industrial computerized tomography  

SciTech Connect

Considerable effort is being applied to develop multiple-energy industrial CT techniques for materials characterization. Multiple-energy CT can provide reliable estimates of effective Z (Z{sub eff}), weight fraction, and rigorous calculations of absolute density, all at the spatial resolution of the scanner. Currently, a wide variety of techniques exist for CT scanners, but each has certain problems and limitations. Ultimately, the best multi-energy CT technique would combine the qualities of accuracy, reliability, and wide range of application, and would require the smallest number of additional measurements. We have developed techniques for calculating material properties of industrial objects that differ somewhat from currently used methods. In this paper, we present our methods for calculating Z{sub eff}, weight fraction, and density. We begin with the simplest case -- methods for multiple-energy CT using isotopic sources -- and proceed to multiple-energy work with x-ray machine sources. The methods discussed here are illustrated on CT scans of PBX-9502 high explosives, a lexan-aluminum phantom, and a cylinder of glass beads used in a preliminary study to determine if CT can resolve three phases: air, water, and a high-Z oil. In the CT project at LLNL, we have constructed several CT scanners of varying scanning geometries using {gamma}- and x-ray sources. In our research, we employed two of these scanners: pencil-beam CAT for CT data using isotopic sources and video-CAT equipped with an IRT micro-focal x-ray machine source.

Schneberk, D.; Martz, H.; Azevedo, S.

1990-08-01T23:59:59.000Z

36

LANSCE-R WIRE-SCANNER SYSTEM  

SciTech Connect

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.

Gruchalla, Michael E. [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

37

LANSCE Wire Scanner System Prototype: Switchyard Test  

Science Conference Proceedings (OSTI)

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.

Sedillo, James D [Los Alamos National Laboratory

2012-04-11T23:59:59.000Z

38

Supervised probabilistic segmentation of pulmonary nodules in CT scans  

Science Conference Proceedings (OSTI)

An automatic method for lung nodule segmentation from computed tomography (CT) data is presented that is different from previous work in several respects. Firstly, it is supervised; it learns how to obtain a reliable segmentation from examples in a training ...

Bram van Ginneken

2006-10-01T23:59:59.000Z

39

Segmentation of airway trees from multislice CT using fuzzy logic  

Science Conference Proceedings (OSTI)

The segmentation and reconstruction of the human airway tree from volumetric computed tomography (CT) images facilitates many clinical applications and physiological investigations. The main problem with standard automated region-growing segmentation ...

Tan Kok Liang; Toshiyuki Tanaka; Hidetoshi Nakamura; Toru Shirahata; Hiroaki Sugiura

2009-11-01T23:59:59.000Z

40

Design of a portable CAT scanner for utility pole inspection  

SciTech Connect

Work is under way at the University of Missouri, Columbia (UMC) to design, build, and test a portable computerized axial tomography (CAT) device for the nondestructive, field imaging of wooden utility poles. CAT is a well-established medical technology that has recently been applied to a number of industrial applications. Wooden utility poles are prone to rot and decay at ground level; current techniques to assess this loss of strength are relatively primitive, i.e., tapping the pole (hitting the pole with a hammer) or boring into the pole for samples and then testing inside the bore hole with an electrical pulse device. The accuracy in identifying poles needing replacement using these techniques is approx. 70%. Since the cost of replacing a pole ranges from hundreds to thousands of dollars, an accurate, nondestructive method is needed. CAT can accurately image a wooden utility pole (since the size, density, and atomic elements of a pole are similar to the human head to torso), as was confirmed by imaging poles using the UMC nuclear engineering EMI-1010 medical scanner. Detailed images have been produced showing the ring structure of the wood and voids due to rot or decay. Images approaching this quality have also been produced on living trees using semiportable systems by other researchers.

Miller, W.H.

1986-01-01T23:59:59.000Z

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41

Design of a DICOM image-based program for estimating patient exposure dose in computed tomography  

Science Conference Proceedings (OSTI)

During the past decade, there has been a notable worldwide increase in the number of computed tomographic (CT) examinations. Since the radiation exposure to the patient during CT examinations is relatively high, it is important to optimize the dose so ... Keywords: DICOM, computed tomography (CT), effective dose

Shuji Yamamoto; Tetsuya Horiuchi; Junko Sekiguchi; Shigeo Wada; Mitsuru Komizu; Takami Yamaguchi

2007-04-01T23:59:59.000Z

42

Positron Scanner for Locating Brain Tumors  

DOE R&D Accomplishments (OSTI)

A system is described that makes use of positron emitting isotopes for locating brain tumors. This system inherently provides more information about the distribution of radioactivity in the head in less time than existing scanners which use one or two detectors. A stationary circular array of 32 scintillation detectors scans a horizontal layer of the head from many directions simultaneously. The data, consisting of the number of counts in all possible coincidence pairs, are coded and stored in the memory of a Two-Dimensional Pulse-Height Analyzer. A unique method of displaying and interpreting the data is described that enables rapid approximate analysis of complex source distribution patterns. (auth)

Rankowitz, S.; Robertson, J. S.; Higinbotham, W. A.; Rosenblum, M. J.

1962-03-00T23:59:59.000Z

43

Virtual monochromatic imaging in dual-source dual-energy CT: Radiation dose and image quality  

Science Conference Proceedings (OSTI)

Purpose: To evaluate the image quality of virtual monochromatic images synthesized from dual-source dual-energy computed tomography (CT) in comparison with conventional polychromatic single-energy CT for the same radiation dose. Methods: In dual-energy CT, besides the material-specific information, one may also synthesize monochromatic images at different energies, which can be used for routine diagnosis similar to conventional polychromatic single-energy images. In this work, the authors assessed whether virtual monochromatic images generated from dual-source CT scanners had an image quality similar to that of polychromatic single-energy images for the same radiation dose. First, the authors provided a theoretical analysis of the optimal monochromatic energy for either the minimum noise level or the highest iodine contrast to noise ratio (CNR) for a given patient size and dose partitioning between the low- and high-energy scans. Second, the authors performed an experimental study on a dual-source CT scanner to evaluate the noise and iodine CNR in monochromatic images. A thoracic phantom with three sizes of attenuating rings was used to represent four adult sizes. For each phantom size, three dose partitionings between the low-energy (80 kV) and the high-energy (140 kV) scans were used in the dual-energy scan. Monochromatic images at eight energies (40 to 110 keV) were generated for each scan. Phantoms were also scanned at each of the four polychromatic single energy (80, 100, 120, and 140 kV) with the same radiation dose. Results: The optimal virtual monochromatic energy depends on several factors: phantom size, partitioning of the radiation dose between low- and high-energy scans, and the image quality metrics to be optimized. With the increase of phantom size, the optimal monochromatic energy increased. With the increased percentage of radiation dose on the low energy scan, the optimal monochromatic energy decreased. When maximizing the iodine CNR in monochromatic images, the optimal energy was lower than that when minimizing noise level. When the total radiation dose was equally distributed between low and high energy in dual-energy scans, for minimum noise, the optimal energies were 68, 71, 74, and 77 keV for small, medium, large, and extra-large (xlarge) phantoms, respectively; for maximum iodine CNR, the optimal energies were 66, 68, 70, 72 keV. With the optimal monochromatic energy, the noise level was similar to and the CNR was better than that in a single-energy scan at 120 kV for the same radiation dose. Compared to an 80 kV scan, however, the iodine CNR in monochromatic images was lower for the small, medium, and large phantoms. Conclusions: In dual-source dual-energy CT, optimal virtual monochromatic energy depends on patient size, dose partitioning, and the image quality metric optimized. With the optimal monochromatic energy, the noise level was similar to and the iodine CNR was better than that in 120 kV images for the same radiation dose. Compared to single-energy 80 kV images, the iodine CNR in virtual monochromatic images was lower for small to large phantom sizes.

Yu Lifeng; Christner, Jodie A.; Leng Shuai; Wang Jia; Fletcher, Joel G.; McCollough, Cynthia H. [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States)

2011-12-15T23:59:59.000Z

44

Kilovoltage Rotational External Beam Radiotherapy on a Breast Computed Tomography Platform: A Feasibility Study  

SciTech Connect

Purpose: To demonstrate the feasibility of a dedicated breast computed tomography (bCT) platform to deliver rotational kilovoltage (kV) external beam radiotherapy (RT) for partial breast irradiation, whole breast irradiation, and dose painting. Methods and Materials: Rotational kV-external beam RT using the geometry of a prototype bCT platform was evaluated using a Monte Carlo simulator. A point source emitting 178 keV photons (approximating a 320-kVp spectrum with 4-mm copper filtration) was rotated around a 14-cm voxelized polyethylene disk (0.1 cm tall) or cylinder (9 cm tall) to simulate primary and primary plus scattered photon interactions, respectively. Simulations were also performed using voxelized bCT patient images. Beam collimation was varied in the x-y plane (1-14 cm) and in the z-direction (0.1-10 cm). Dose painting for multiple foci, line, and ring distributions was demonstrated using multiple rotations with varying beam collimation. Simulations using the scanner's native hardware (120 kVp filtered by 0.2-mm copper) were validated experimentally. Results: As the x-y collimator was narrowed, the two-dimensional dose profiles shifted from a cupped profile with a high edge dose to an increasingly peaked central dose distribution with a sharp dose falloff. Using a 1-cm beam, the cylinder edge dose was <7% of the dose deposition at the cylinder center. Simulations using 120-kVp X-rays showed distributions similar to the experimental measurements. A homogeneous dose distribution (<2.5% dose fluctuation) with a 20% decrease in dose deposition at the cylinder edge (i.e., skin sparing) was demonstrated by weighted summation of four dose profiles using different collimation widths. Simulations using patient bCT images demonstrated the potential for treatment planning and image-guided RT. Conclusions: Rotational kV-external beam RT for partial breast irradiation, dose painting, and whole breast irradiation with skin sparing is feasible on a bCT platform with the potential for high-resolution image-guided RT.

Prionas, Nicolas D.; McKenney, Sarah E. [Department of Radiology, University of California, Davis, Medical Center, Sacramento, California (United States)] [Department of Radiology, University of California, Davis, Medical Center, Sacramento, California (United States); Stern, Robin L. [Department of Radiation Oncology, University of California, Davis, Medical Center, Sacramento, California (United States)] [Department of Radiation Oncology, University of California, Davis, Medical Center, Sacramento, California (United States); Boone, John M., E-mail: jmboone@ucdavis.edu [Department of Radiology, University of California, Davis, Medical Center, Sacramento, California (United States)

2012-10-01T23:59:59.000Z

45

Computerized axial tomography: technology and equipment. January, 1977-May, 1981 (Citations from the International Information Service for the Physics and Engineering Communities data base). Report for January 1977-May 1981  

SciTech Connect

This retrospective bibliography contains citations concerning many recent developments in the instrumentation, technology, and application of computerized axial tomography (CAT). Production model CAT scanners are compared and evaluated for noise, spatial resolution, axial position sensitivity, artefact and dose. Research and development on new scanners are considered. (Contains 71 citations fully indexed and including a title list.)

1981-05-01T23:59:59.000Z

46

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)

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 ...

Eastwick, Gary (Gary A.)

2010-01-01T23:59:59.000Z

47

Transient foam flow in porous media with CAT Scanner  

SciTech Connect

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.

Liu, Dianbin; Brigham, W.E.

1992-03-01T23:59:59.000Z

48

Positron Emission Tomography (PET) and Positron Scanning  

Office of Scientific and Technical Information (OSTI)

DOE R&D Accomplishments DOE R&D Accomplishments Search All Database Web Pages for Go The Basics Home About What's New FAQ Contact Us Laureates Nobel Laureates Fermi Laureates Nobel Physicists Nobel Chemists Medicine Nobels Explore Insights SC Stories Snapshots R&D Nuggets Database Search Browse Reports Database Help Finding Aids Site Map A - Z Index Menu Synopsis Blog Archive QR Code RSS Archive Tag Cloud Videos Widget XML Bookmark and Share Positron Emission Tomography (PET) and Positron Scanning Resources with Additional Information Positron Emission Tomography (PET) Scanner Courtesy Lawrence Berkeley National Laboratory 'Positron Emission Tomography ... [is a medical imaging technique that] can track chemical reactions in living tissues and merges chemistry with biological imaging. Its strength has been in studies of the brain where there has been significant progress in investigations of drug addiction, aging, mental illness, and neurogenic disorders. Positron Emission Tomography (PET) had its genesis in hot-atom chemical research supported by the Chemical Sciences Division of the Office of Basic Energy Sciences. Through this research it was learned, over many years, how to prepare short-lived positron emitters such as 18F whose half-life is 110 minutes. In 1975, the molecule [18F]fluorodeoxyglucose was successfully synthesized at Brookhaven National Laboratory (BNL) and set the stage for Positron Emission Tomography of the human brain.'

49

MicroComputed Tomography: Methodology and Applications  

Science Conference Proceedings (OSTI)

Due to the availability of commercial laboratory systems and the emergence of user facilities at synchrotron radiation sources, studies of microcomputed tomography or microCT have increased exponentially. MicroComputed Technology provides a complete introduction to the technology, describing how to use it effectively and understand its results. The first part of the book focuses on methodology, covering experimental methods, data analysis, and visualization approaches. The second part addresses various microCT applications, including porous solids, microstructural evolution, soft tissue studies, multimode studies, and indirect analyses. The author presents a sufficient amount of fundamental material so that those new to the field can develop a relative understanding of how to design their own microCT studies. One of the first full-length references dedicated to microCT, this book provides an accessible introduction to field, supplemented with application examples and color images.

(NWU)

2009-04-02T23:59:59.000Z

50

Low-Dose Spiral CT Scans for Early Lung Cancer Detection | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Low-Dose Spiral CT Scans for Early Lung Cancer Detection Low-Dose Spiral CT Scans for Early Lung Cancer Detection Low-Dose Spiral CT Scans for Early Lung Cancer Detection 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). A low-dose spiral chest CT differs from a full-dose conventional chest CT scan primarily in the amount of radiation emitted during CT scans. Chest CT, in general, requires less radiation exposure than other CT procedures because the air-filled tissues of the lungs are not as dense as the tissues of other organs (i.e., less x-ray radiation is needed to penetrate the lung). Radiation dose can be further reduced with lung cancer screening due to the

51

Evaluation of Turbine Blades Using Computed Tomography  

E-Print Network (OSTI)

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.

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

2006-01-01T23:59:59.000Z

52

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

SciTech Connect

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.

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

53

ECG-correlated image reconstruction from subsecond multi-slice spiral CT scans of the heart  

Science Conference Proceedings (OSTI)

Subsecond spiral computed tomography(CT) offers great potential for improving heartimaging. The new multi-row detector technology adds significantly to this potential. We therefore developed and validated dedicated cardiacreconstruction algorithms for imaging the heart with subsecond multi-slice spiral CT utilizing electrocardiogram (ECG) information. The single-slice cardiacz-interpolation algorithms 180°CI and 180°CD [Med. Phys. 25

Marc Kachelrieß; Stefan Ulzheimer; Willi A. Kalender

2000-01-01T23:59:59.000Z

54

Test of 3D CT reconstructions by EM + TV algorithm from undersampled data  

SciTech Connect

Computerized tomography (CT) plays an important role in medical imaging for diagnosis and therapy. However, CT imaging is connected with ionization radiation exposure of patients. Therefore, the dose reduction is an essential issue in CT. In 2011, the Expectation Maximization and Total Variation Based Model for CT Reconstruction (EM+TV) was proposed. This method can reconstruct a better image using less CT projections in comparison with the usual filtered back projection (FBP) technique. Thus, it could significantly reduce the overall dose of radiation in CT. This work reports the results of an independent numerical simulation for cone beam CT geometry with alternative virtual phantoms. As in the original report, the 3D CT images of 128 Multiplication-Sign 128 Multiplication-Sign 128 virtual phantoms were reconstructed. It was not possible to implement phantoms with lager dimensions because of the slowness of code execution even by the CORE i7 CPU.

Evseev, Ivan; Ahmann, Francielle; Silva, Hamilton P. da [Universidade Tecnologica Federal do Parana - UTFPR/FB, 85601-970, Caixa Postal 135, Francisco Beltrao - PR (Brazil); Schelin, Hugo R. [Universidade Tecnologica Federal do Parana-UTFPR/FB,85601-970,Caixa Postal 135,Francisco Beltrao-PR (Brazil) and Faculdades Pequeno Principe-FPP, Av. Iguacu, 333, Rebou (Brazil); Yevseyeva, Olga [Universidade Federal de Santa Catarina - UFSC/ARA, 88900-000, Rua Pedro Joao Pereira, 150, Ararangua - SC (Brazil); Klock, Margio C. L. [Universidade Federal do Parana - UFPR Litoral, 80230-901, Rua Jaguaraiva 512, Caioba, Matinhos - PR (Brazil)

2013-05-06T23:59:59.000Z

55

Allan Cormack, Computerized Axial Tomography (CAT), and Magnetic Resonance  

NLE Websites -- All DOE Office Websites (Extended Search)

Allan M. Cormack, Computerized Axial Tomography (CAT) Allan M. Cormack, Computerized Axial Tomography (CAT) and Magnetic Resonance Imaging (MRI) Resources with Additional Information magnetic resonance imaging system Computed axial tomography, commonly known as CAT scanning, was introduced in 1972. During a CAT scan, a large coil of x-ray tubes rotates around the patient's body, taking x-rays from all angles. A computer integrates all of these x-rays into a single, three-dimensional image on a television screen. The data can be saved on the computer. Allan M. Cormack, a high energy physicist at Tufts University, shared the 1979 Nobel Prize in Physiology and Medicine for his key work in developing the methods for CAT scanners. At the time of development, these methods were widely regarded as the most significant advance in medical radiography since the 1895 discovery of x-rays.

56

A comparison between amplitude sorting and phase-angle sorting using external respiratory measurement for 4D CT  

SciTech Connect

Respiratory motion can cause significant dose delivery errors in conformal radiation therapy for thoracic and upper abdominal tumors. Four-dimensional computed tomography (4D CT) has been proposed to provide the image data necessary to model tumor motion and consequently reduce these errors. The purpose of this work was to compare 4D CT reconstruction methods using amplitude sorting and phase angle sorting. A 16-slice CT scanner was operated in cine mode to acquire 25 scans consecutively at each couch position through the thorax. The patient underwent synchronized external respiratory measurements. The scans were sorted into 12 phases based, respectively, on the amplitude and direction (inhalation or exhalation) or on the phase angle (0-360 deg.) of the external respiratory signal. With the assumption that lung motion is largely proportional to the measured respiratory amplitude, the variation in amplitude corresponds to the variation in motion for each phase. A smaller variation in amplitude would associate with an improved reconstructed image. Air content, defined as the amount of air within the lungs, bronchi, and trachea in a 16-slice CT segment and used by our group as a surrogate for internal motion, was correlated to the respiratory amplitude and phase angle throughout the lungs. For the 35 patients who underwent quiet breathing, images (similar to those used for treatment planning) and animations (used to display respiratory motion) generated using amplitude sorting displayed fewer reconstruction artifacts than those generated using phase angle sorting. The variations in respiratory amplitude were significantly smaller (P<0.001) with amplitude sorting than those with phase angle sorting. The subdivision of the breathing cycle into more (finer) phases improved the consistency in respiratory amplitude for amplitude sorting, but not for phase angle sorting. For 33 of the 35 patients, the air content showed significantly improved (P<0.001) correlation with the respiratory amplitude than with the phase angle, suggesting a stronger relationship between internal motion and amplitude. Overall, amplitude sorting performed better than phase angle sorting for 33 of the 35 patients and equally well for two patients who were immobilized with a stereotactic body frame and an abdominal compression plate.

Lu Wei; Parikh, Parag J.; Hubenschmidt, James P.; Bradley, Jeffrey D.; Low, Daniel A. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States)

2006-08-15T23:59:59.000Z

57

Computed tomography guided localization of clinically occult breast carcinoma-the ''N'' skin guide  

SciTech Connect

Standard computed tomography (CT) can be used for the three-dimensional localization of clinically occult suspicious breast lesions whose exact position cannot be determined by standard mammographic views. A method is described that facilitates accurate preoperative needle localization using CT guidance, once the position of these lesions is defined.

Kopans, D.B.; Meyer, J.E.

1982-10-01T23:59:59.000Z

58

Lung nodule detection in low-dose and thin-slice computed tomography  

Science Conference Proceedings (OSTI)

A computer-aided detection (CAD) system for the identification of small pulmonary nodules in low-dose and thin-slice CT scans has been developed. The automated procedure for selecting the nodule candidates is mainly based on a filter enhancing spherical-shaped ... Keywords: Computer-aided detection (CAD), Image processing, Low-dose computed tomography (LDCT), Thin-slice CT

A. Retico; P. Delogu; M. E. Fantacci; I. Gori; A. Preite Martinez

2008-04-01T23:59:59.000Z

59

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

SciTech Connect

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.

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

60

Field implementation of geophysical diffraction tomography  

SciTech Connect

Geophysical diffraction tomography is a new technique that shows promise as a tool for quantitative subsurface (below-ground) imaging. The approach being used is based upon the filtered backpropagation algorithm, which is a mathematical extension of the reconstruction software used in conventional X-ray CAT scanners. The difference between this method and existing methods is that the new algorithm rigorously accounts for diffraction effects through an exact inversion of the wave equation. This refinement is necessary in that it admits the use of acoustic and long-wavelength electromagnetic waves, allowing tomography to be taken from the laboratory to the field. ORNL's effort in geophysical diffraction tomography involves reducing the filtered backpropagation algorithm to practice. This requires the design and construction of field instrumentation as well as the development of an improved algorithm. The original algorithm requires the imaged region to be illuminated by plane waves. This requirement simplifies the algorithm but complicates its field implementation in that plane waves are difficult to generate. Consequently, ORNL has been working to generalize the filtered backpropagation algorithm to allow a broader range of incoming wave fields which can more easily be realized in the field. The instrumentation aspects involve the selection of appropriate sonic sources and receivers along with the development of a state-of-art, portable, computer-controlled, multichannel data acquisition system. 5 references, 6 figures.

Witten, A.J.; Stevens, S.S.

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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61

A fuzzy segmentation method for Computed Tomography images  

Science Conference Proceedings (OSTI)

This paper describes a way of medical image segmentation using an appropriately defined fuzzy clustering method based on a fuzzy similarity relation. The considered relation is defined in terms of the Minkowski metric. A fuzzy similarity relation based ... Keywords: CT, computed tomography, data partitional clustering, fuzzy clustering, fuzzy segmentation, fuzzy similarity relations, image segmentation, medical imaging

Martin Tabakov

2007-04-01T23:59:59.000Z

62

Nonrigid registration-based coronary artery motion correction for cardiac computed tomography  

SciTech Connect

Purpose: X-ray computed tomography angiography (CTA) is the modality of choice to noninvasively monitor and diagnose heart disease with coronary artery health and stenosis detection being of particular interest. Reliable, clinically relevant coronary artery imaging mandates high spatiotemporal resolution. However, advances in intrinsic scanner spatial resolution (CT scanners are available which combine nearly 900 detector columns with focal spot oversampling) can be tempered by motion blurring, particularly in patients with unstable heartbeats. As a result, recently numerous methods have been devised to improve coronary CTA imaging. Solutions involving hardware, multisector algorithms, or {beta}-blockers are limited by cost, oversimplifying assumptions about cardiac motion, and populations showing contraindications to drugs, respectively. This work introduces an inexpensive algorithmic solution that retrospectively improves the temporal resolution of coronary CTA without significantly affecting spatial resolution. Methods: Given the goal of ruling out coronary stenosis, the method focuses on 'deblurring' the coronary arteries. The approach makes no assumptions about cardiac motion, can be used on exams acquired at high heart rates (even over 75 beats/min), and draws on a fast and accurate three-dimensional (3D) nonrigid bidirectional labeled point matching approach to estimate the trajectories of the coronary arteries during image acquisition. Motion compensation is achieved by employing a 3D warping of a series of partial reconstructions based on the estimated motion fields. Each of these partial reconstructions is created from data acquired over a short time interval. For brevity, the algorithm 'Subphasic Warp and Add' (SWA) reconstruction. Results: The performance of the new motion estimation-compensation approach was evaluated by a systematic observer study conducted using nine human cardiac CTA exams acquired over a range of average heart rates between 68 and 86 beats/min. Algorithm performance was based-lined against exams reconstructed using standard filtered-backprojection (FBP). The study was performed by three experienced reviewers using the American Heart Association's 15-segment model. All vessel segments were evaluated to quantify their viability to allow a clinical diagnosis before and after motion estimation-compensation using SWA. To the best of the authors' knowledge this is the first such observer study to show that an image processing-based software approach can improve the clinical diagnostic value of CTA for coronary artery evaluation. Conclusions: Results from the observer study show that the SWA method described here can dramatically reduce coronary artery motion and preserve real pathology, without affecting spatial resolution. In particular, the method successfully mitigated motion artifacts in 75% of all initially nondiagnostic coronary artery segments, and in over 45% of the cases this improvement was enough to make a previously nondiagnostic vessel segment clinically diagnostic.

Bhagalia, Roshni; Pack, Jed D.; Miller, James V.; Iatrou, Maria [GE Global Research, Niskayuna, New York 12309 (United States); GE Healthcare, Hoboken, New Jersey 07030 (United States)

2012-07-15T23:59:59.000Z

63

Determination of Internal Target Volume From a Single Positron Emission Tomography/Computed Tomography Scan in Lung Cancer  

SciTech Connect

Purpose: The use of four-dimensional computed tomography (4D-CT) to determine the tumor internal target volume (ITV) is usually characterized by high patient radiation exposure. The objective of this study was to propose and evaluate an approach that relies on a single static positron emission tomography (PET)/CT scan to determine the ITV, thereby eliminating the need for 4D-CT and thus reduce patient radiation dose. Methods and Materials: The proposed approach is based on the concept that the observed PET image is the result of a joint convolution of an ideal PET image (free from motion and partial volume effect) with a motion-blurring kernel (MBK) and partial volume effect. In this regard, the MBK and tumor ITV are then estimated from the deconvolution of this joint model. To test this technique, phantom and patient studies were performed using different sphere/tumor sizes and motion trajectories. In all studies, a 4D-CT and a PET/CT image of the sphere/tumor were acquired. The ITV from the proposed technique was then compared to the maximum intensity projection (MIP) volume of the 4D-CT images. A Dice coefficient of the two volumes was calculated to represent the similarity between the two ITVs. Results: The average ITVs of the proposed technique were 97.2% {+-} 0.3% and 81.0% {+-} 16.7% similar to the MIP volume in the phantom and patient studies, respectively. The average dice coefficients were 0.87 {+-} 0.05 and 0.73 {+-} 0.16, respectively, for the two studies. Conclusion: Using the proposed approach, a single static PET/CT scan has the potential to replace a 4D-CT to determine the tumor ITV. This approach has the added advantage of reducing patient radiation exposure and determining the tumor MBK compared to 4D-CT/MIP-CT.

Chang Guoping; Chang Tingting [Department of Electrical and Computer Engineering, Rice University, Houston, Texas (United States); Pan Tinsu [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Clark, John W. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas (United States); Mawlawi, Osama R., E-mail: OMawlawi@mdanderson.org [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2012-05-01T23:59:59.000Z

64

Spatial correlation of proton irradiation-induced activity and dose in polymer gel phantoms for PET/CT delivery verification studies  

Science Conference Proceedings (OSTI)

Purpose: This work demonstrates a novel application of BANG3-Pro2 polymer gel dosimeter as a dosimetric phantom able to accurately capture both dose and induced activity. Methods: BANG3-Pro2 dosimeters were irradiated with a clinical proton beam using an unmodulated beam and a spread-out Bragg peak (SOBP) modulation, the latter with a Lucite compensator to introduce a range offset in one quadrant of the circular field. The dosimeters were imaged in a nearby positron emission tomography/computed tomography (PET/CT) unit starting within 5 min of beam-off. Induced positron emission (PE) activity along the central axis of the beam was compared to analytical calculations. Dose distributions were read out using an optical CT scanner and were validated against ion chamber measurements and the treatment plan. The offset between the distal fall-off of dose and activity (50% level) was determined over the entire irradiated field. Lateral profiles of PE were correlated to measured dose for the unmodulated beam delivery. Results: Measured profiles of PE activity along the central beam axis were found to be within 10% of the predictions of analytical calculations. The depth-dose profiles agreed with the reference values (ion chamber or treatment plan) within 3%. The offset between the depth profiles of dose and activity for the unmodulated beam was 8.4 {+-} 1.4 mm. For the compensator-based SOBP delivery, the distribution of offsets throughout the field was found to be bimodal, with the mean of 8.9 {+-} 2.8 mm for the thinner region of the compensator and 4.3 {+-} 2.5 mm for the thicker region. For the pristine beam delivery, lateral profiles of dose and activity were found to exhibit fair spatial correlation throughout the beam range, with the mean 2D gamma index of 0.42 and 91% of the evaluated pixels passing the test. Conclusions: This work presents the first demonstration of simultaneous and accurate experimental measurement of three-dimensional distributions of dose and induced activity and lays the groundwork for further investigations using BANG3-Pro2 as a dosimetric phantom in PET/CT delivery verification studies.

Lopatiuk-Tirpak, Olena; Su Zhong; Li Zuofeng; Hsi Wen; Meeks, Sanford; Zeidan, Omar

2011-12-15T23:59:59.000Z

65

First Test Results of the New LANSCE Wire Scanner  

SciTech Connect

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.

Sedillo, James Daniel [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

66

Laser excited confocal microscope fluorescence scanner and method  

DOE Patents (OSTI)

A fluorescent scanner for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier including a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from said volume to provide a display of the separated sample.

Mathies, Richard A. (Contra Costa, CA); Peck, Konan (Contra Costa, CA)

1992-01-01T23:59:59.000Z

67

TRACKING CORTICAL SURFACE DEFORMATIONS BASED ON VESSEL STRUCTURE USING A LASER RANGE SCANNER  

E-Print Network (OSTI)

surface after deforma- tion. Also the scanner was modified by the attachment of 12 infrared light emitting diode (IRED) markers. This allowed us to track the scanner in physical-space and with the aid

Miga, Michael I.

68

Composite structure development decisions using X-ray CT measurements  

Science Conference Proceedings (OSTI)

X-ray computed tomography (CT) provides measurement data useful for making composite manufacturing development decisions. X-ray CT measurements of material characteristics are quantitative in terms of the dimensions, density, and composition. The CT data on internal conditions, such as consolidation, gaps, delaminations, cracks, porosity and detail placement can be applied to the refinement of production techniques for composite manufacture. The key item of interest is the effect of variations in pressure loading, temperature, mold shape, material surface preparation, and bond layer thickness on the resulting consolidation or bondline quality in new composite manufacturing processes. X-ray CT measurements of densification and defect presence as a function of technique parameters are of critical importance to processes such as resin transfer molding, injection molding, composite welding, composite layup and advanced bonding methods.

Bossi, R.H.; Georgeson, G.E. [Boeing Defense and Space Group, Seattle, WA (United States)

1995-10-01T23:59:59.000Z

69

Nuclear Medicine CT Angiography  

E-Print Network (OSTI)

Nuclear Medicine CT Angiography Stress Testing Rotation The Nuclear Medicine/CT angiography. Understand the indications for exercise treadmill testing and specific nuclear cardiology tests, safe use patient and learn the importance of physical and pharmacologic stress in nuclear cardiology 3. Interpret

Ford, James

70

Ultrafast three-dimensional x-ray computed tomography  

SciTech Connect

X-ray computed tomography (CT) is a well established visualization technique in medicine and nondestructive testing. However, since CT scanning requires sampling of radiographic projections from different viewing angles, common CT systems with mechanically moving parts are too slow for dynamic imaging, for instance of multiphase flows or live animals. Here, we introduce an ultrafast three-dimensional x-ray CT method based on electron beam scanning, which achieves volume rates of 500 s{sup -1}. Primary experiments revealed the capability of this method to recover the structure of phase boundaries in gas-solid and gas-liquid two-phase flows, which undergo three-dimensional structural changes in the millisecond scale.

Bieberle, Martina; Barthel, Frank; Hampel, Uwe [Institute of Safety Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Menz, Hans-Juergen; Mayer, Hans-Georg [Institute of Nuclear Technology and Energy Systems, University of Stuttgart, 70569 Stuttgart (Germany)

2011-01-17T23:59:59.000Z

71

Dynamic tomography with a priori information  

SciTech Connect

We present ''dynamic tomography'' algorithms that allow for the high-resolution, time-resolved imaging of dynamic (i.e., continuously time evolving) complex systems at existing x-ray micro-CT facilities. The behavior of complex systems is constrained by the underlying physics. By exploiting a priori knowledge of the geometry of the physical process being studied to allow the use of sophisticated iterative reconstruction techniques that incorporate constraints, we improve on current frame rates by at least an order of magnitude. This allows time-resolved imaging of previously intractable processes, such as two-phase fluid flow. We present reconstructions from experimental data collected at the Australian National University x-ray micro-CT facility.

Myers, Glenn R.; Kingston, Andrew M.; Varslot, Trond K.; Turner, Michael L.; Sheppard, Adrian P.

2011-07-10T23:59:59.000Z

72

Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development  

SciTech Connect

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.

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

73

Classification of breast computed tomography data  

Science Conference Proceedings (OSTI)

Differences in breast tissue composition are important determinants in assessing risk, identifying disease in images and following changes over time. This paper presents an algorithm for tissue classification that separates breast tissue into its three primary constituents of skin, fat and glandular tissue. We have designed and built a dedicated breast CT scanner. Fifty-five normal volunteers and patients with mammographically identified breast lesions were scanned. Breast CT voxel data were filtered using a 5 pt median filter and the image histogram was computed. A two compartment Gaussian fit of histogram data was used to provide an initial estimate of tissue compartments. After histogram analysis, data were input to region-growing algorithms and classified as to belonging to skin, fat or gland based on their value and architectural features. Once tissues were classified, a more detailed analysis of glandular tissue patterns and a more quantitative analysis of breast composition was made. Algorithm performance assessment demonstrated very good or excellent agreement between algorithm and radiologist observers in 97.7% of the segmented data. We observed that even in dense breasts the fraction of glandular tissue seldom exceeded 50%. For most individuals the composition is better characterized as being a 70% (fat)-30% (gland) composition than a 50% (fat)-50% (gland) composition.

Nelson, Thomas R.; Cervino, Laura I.; Boone, John M.; Lindfors, Karen K. [Department of Radiology, University of California, San Diego, La Jolla, California 92037-0610 (United States); University of California Davis Medical Center, 4860 Y Street, Ambulatory Care Center Suite 3100, Sacramento, California 95817 (United States)

2008-03-15T23:59:59.000Z

74

Uniqueness theorems in bioluminescence tomography Bioluminescence Tomography Laboratory and CT/Micro-CT Laboratory, Departments of Radiology,  

E-Print Network (OSTI)

2004; accepted for publication 7 May 2004; published 26 July 2004 Motivated by bioluminescent imaging research directions are also discussed. © 2004 American Association of Physicists in Medicine. DOI: 10.1118/1 uniqueness I. INTRODUCTION Small animals, particularly genetically engineered mice, are of increasing

Jiang, Ming

75

High contrast, CdTe portal scanner for radiation therapy  

Science Conference Proceedings (OSTI)

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.

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

76

Imaging atherosclerotic plaque inflammation with [18F]- fluorodeoxyglucose positron emission tomography  

E-Print Network (OSTI)

of tracer CI Confidence interval CO2 Carbon dioxide CRP C-reactive protein CT Computed tomography DPM Decays per minute eNOS Endothelial nitric oxide synthase EDTA Ethylene diamine tetra-acetic acid ETL Echo train... rabbit p Probability PBMC Peripheral blood mononuclear cells PBS Phosphate-buffered saline PDGF Platelet-derived growth factor PDW Proton density-weighted PET Positron emission tomography PK11195 1-(2-chlorophenyl...

Rudd, James H. F.

2003-10-07T23:59:59.000Z

77

Reconstruction of CT Images from Parsimonious Angular ...  

E-Print Network (OSTI)

internal human organs in a non-invasive manner. Any CT scan ...... Relative reconstruction error results for CT data without measurement error types of noisy CT ...

78

Attenuation-based estimation of patient size for the purpose of size specific dose estimation in CT. Part II. Implementation on abdomen and thorax phantoms using cross sectional CT images and scanned projection radiograph images  

SciTech Connect

Purpose: To estimate attenuation using cross sectional CT images and scanned projection radiograph (SPR) images in a series of thorax and abdomen phantoms. Methods: Attenuation was quantified in terms of a water cylinder with cross sectional area of A{sub w} from both the CT and SPR images of abdomen and thorax phantoms, where A{sub w} is the area of a water cylinder that would absorb the same dose as the specified phantom. SPR and axial CT images were acquired using a dual-source CT scanner operated at 120 kV in single-source mode. To use the SPR image for estimating A{sub w}, the pixel values of a SPR image were calibrated to physical water attenuation using a series of water phantoms. A{sub w} and the corresponding diameter D{sub w} were calculated using the derived attenuation-based methods (from either CT or SPR image). A{sub w} was also calculated using only geometrical dimensions of the phantoms (anterior-posterior and lateral dimensions or cross sectional area). Results: For abdomen phantoms, the geometry-based and attenuation-based methods gave similar results for D{sub w}. Using only geometric parameters, an overestimation of D{sub w} ranging from 4.3% to 21.5% was found for thorax phantoms. Results for D{sub w} using the CT image and SPR based methods agreed with each other within 4% on average in both thorax and abdomen phantoms. Conclusions: Either the cross sectional CT or SPR images can be used to estimate patient attenuation in CT. Both are more accurate than use of only geometrical information for the task of quantifying patient attenuation. The SPR based method requires calibration of SPR pixel values to physical water attenuation and this calibration would be best performed by the scanner manufacturer.

Wang Jia; Christner, Jodie A.; Duan Xinhui; Leng Shuai; Yu Lifeng; McCollough, Cynthia H. [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States)

2012-11-15T23:59:59.000Z

79

Hysteresis Modeling and Inverse Feedforward Control of an AFM Piezoelectric Scanner Based on Nano Images  

E-Print Network (OSTI)

Hysteresis Modeling and Inverse Feedforward Control of an AFM Piezoelectric Scanner Based on Nano of micro/nano technology. As a critical part of AFM system, the piezoelectric scanner exists many defects in this paper possess a good performance for AFM nano imaging. Index Terms-- Hysteresis modeling, feedforward

Li, Yangmin

80

Spatial clearance verification using 3D laser range scanner and augmented reality  

Science Conference Proceedings (OSTI)

A spatial clearance verification system for supporting nuclear power plant dismantling work was developed and evaluated by a subjective evaluation. The system employs a three-dimensional laser range scanner to obtain threedimensional surface models of ... Keywords: augmented reality, decommissioning, laser range scanner, nuclear power plants, spatial clearance verification

Hirotake Ishii; Shuhei Aoyama; Yoshihito Ono; Weida Yan; Hiroshi Shimoda; Masanori Izumi

2011-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
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81

Scanner for integrated x-ray breast tomosynthesis and molecular breast imaging tomosynthesis  

Science Conference Proceedings (OSTI)

A dual modality tomosynthesis (DMT) breast scanner has been developed that combines x-ray breast tomosynthesis (XBT) and molecular breast imaging tomosynthesis (MBIT) on a common upright gantry to obtain co-registered structural and functional tomosynthesis ... Keywords: breast tomosynthesis, hybrid scanners, limited angle SPECT, molecular breast imaging, multimodality imaging

Mark B. Williams; Patricia G. Judy; Zongyi Gong; Audrey E. Graham; Stan Majewski; Spencer Gunn

2010-06-01T23:59:59.000Z

82

Rigid Prices: Evidence from U.S. Scanner Data ?  

E-Print Network (OSTI)

This paper uses over two years of weekly scanner data from two small US cities to characterize time and state dependence of grocers ’ pricing decisions. In these data, the probability of a nominal adjustment declines with the time since the last price change even after controlling for heterogeneity across store-product cells and replacing sale prices with regular prices. We also detect state dependence: The probability of a nominal adjustment is highest when a store’s price substantially differs from the average of other stores ’ prices. However, extreme prices typically reflect the selling store’s recent nominal adjustments rather than changes in other stores ’ prices. JEL Classification: E31, L16, L81.

unknown authors

2007-01-01T23:59:59.000Z

83

Portable Digital Radiography and Computed Tomography Manual  

SciTech Connect

This user manual describes the function and use of the portable digital radiography and computed tomography (DRCT) scanner. The manual gives a general overview of x-ray imaging systems along with a description of the DRCT system. An inventory of the all the system components, organized by shipping container, is also included. In addition, detailed, step-by-step procedures are provided for all of the exercises necessary for a novice user to successfully collect digital radiographs and tomographic images of an object, including instructions on system assembly and detector calibration and system alignment. There is also a short section covering the limited system care and maintenance needs. Descriptions of the included software packages, the DRCT Digital Imager used for system operation, and the DRCT Image Processing Interface used for image viewing and tomographic data reconstruction are given in the appendixes. The appendixes also include a cheat sheet for more experienced users, a listing of known system problems and how to mitigate them, and an inventory check-off sheet suitable for copying and including with the machine for shipment purposes.

Not Available

2007-11-01T23:59:59.000Z

84

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

SciTech Connect

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.

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

85

Range tomography: combining the practicality of boolean tomography with the resolution of analog tomography  

Science Conference Proceedings (OSTI)

The objective of early network tomography approaches was to produce a point estimate for the performance of each network link (Analog tomography). When it became clear that the previous approach is error-prone in practice, research shifted to Boolean ... Keywords: Network tomography, localization, performance metric

Sajjad Zarifzadeh; Madhwaraj Gowdagere; Constantine Dovrolis

2012-11-01T23:59:59.000Z

86

High Resolution Aircraft Scanner Mapping of Geothermal and Volcanic Areas  

DOE Green Energy (OSTI)

High spectral resolution GEOSCAN Mkll multispectral aircraft scanner imagery has been acquired, at 3-6 m spatial resolutions, over much of the Taupo Volcanic Zone as part of continuing investigations aimed at developing remote sensing techniques for exploring and mapping geothermal and volcanic areas. This study examined the 24-band: visible, near-IR (NIR), mid-IR (MIR) and thermal-IR (TIR) imagery acquired over Waiotapu geothermal area (3 m spatial resolution) and White Island volcano (6 m resolution). Results show that color composite images composed of visible and NIR wavelengths that correspond to color infrared (CIR) photographic wavelengths can be useful for distinguishing among bare ground, water and vegetation features and, in certain cases, for mapping various vegetation types. However, combinations which include an MIR band ({approx} 2.2 {micro}m) with either visible and NIR bands, or two NIR bands, are the most powerful for mapping vegetation types, water bodies, and bare and hydrothermally altered ground. Combinations incorporating a daytime TIR band with NIR and MIR bands are also valuable for locating anomalously hot features and distinguishing among different types of surface hydrothermal alteration.

Mongillo, M.A.; Cochrane, G.R.; Wood, C.P.; Shibata, Y.

1995-01-01T23:59:59.000Z

87

Wire Scanner Beam Profile Measurements for the LANSCE Facility  

SciTech Connect

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.

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

88

SLAC Scanner Processor: a FASTBUS module for data collection and processing  

SciTech Connect

A new, general purpose, programmable FASTBUS module, the SLAC Scanner Processor (SSP), is introduced. Both hardware and software elements of SSP operation are discussed. The role of the SSP within the upgraded Mark II Detector at SLAC is described.

Brafman, H.; Glanzman, T.; Lankford, A.J.; Olsen, J.; Paffrath, L.

1984-10-01T23:59:59.000Z

89

A multispectral scanner survey of the Rocky Flats Environmental Technology Site and surrounding area, Golden, Colorado  

SciTech Connect

Aerial multispectral scanner imagery was collected of the Rocky Flats Environmental Technology Site in Golden, Colorado, on June 3, 5, 6, and 7, 1994, using a Daedalus AADS1268 multispectral scanner and coincident aerial color and color infrared photography. Flight altitudes were 4,500 feet (1372 meters) above ground level to match prior 1989 survey data; 2,000 feet (609 meters) above ground level for sitewide vegetation mapping; and 1,000 feet (304 meters) above ground level for selected areas of special interest. A multispectral survey was initiated to improve the existing vegetation classification map, to identify seeps and springs, and to generate ARC/INFO Geographic Information System compatible coverages of the vegetation and wetlands for the entire site including the buffer zone. The multispectral scanner imagery and coincident aerial photography were analyzed for the detection, identification, and mapping of vegetation and wetlands. The multispectral scanner data were processed digitally while the color and color infrared photography were manually photo-interpreted to define vegetation and wetlands. Several standard image enhancement techniques were applied to the multispectral scanner data to assist image interpretation. A seep enhancement was applied and a color composite consisting of multispectral scanner channels 11, 7, and 5 (thermal infrared, mid-infrared, and red bands, respectively) proved most useful for detecting seeps, seep zones, and springs. The predawn thermal infrared data were also useful in identifying and locating seeps. The remote sensing data, mapped wetlands, and ancillary Geographic Information System compatible data sets were spatially analyzed for seeps.

Brewster, S.B. Jr.; Brickey, D.W.; Ross, S.L.; Shines, J.E.

1997-04-01T23:59:59.000Z

90

Experimental Adaptive Bayesian Tomography  

E-Print Network (OSTI)

We report an experimental realization of an adaptive quantum state tomography protocol. Our method takes advantage of a Bayesian approach to statistical inference and is naturally tailored for adaptive strategies. For pure states we observe close to 1/N scaling of infidelity with overall number of registered events, while best non-adaptive protocols allow for $1/\\sqrt{N}$ scaling only. Experiments are performed for polarization qubits, but the approach is readily adapted to any dimension.

Konstantin Kravtsov; Stanislav Straupe; Igor Radchenko; Neil Houlsby; Sergey Kulik

2013-03-07T23:59:59.000Z

91

Dosimetry of Y-90 Liquid Brachytherapy in a Dog with Osteosarcoma Using PET/CT  

E-Print Network (OSTI)

A novel Y-90 liquid brachytherapy strategy is currently being studied for the treatment of osteosarcoma using a preclinical translational model in dogs to assess its potential efficacy and toxicity. In this study, dosimetry calculations are performed for Y-90 liquid brachytherapy in a dog with osteosarcoma using the Geant4 Monte Carlo code. A total of 611.83 MBq Y-90 radiopharmaceutical is administered via direct injections, and the in vivo distribution of Y-90 is assessed using a time-of-flight (TOF) PET/CT scanner. A patient-specific geometry is built using anatomical data obtained from CT images. The material properties of tumor and surrounding tissues are calculated based on a CT number - electron density calibration. The Y-90 distribution is sampled in Geant4 from PET images using a collapsing 3-D rejection technique to determine the decay sites. Dose distributions in the tumor bed and surrounding tissues are calculated demonstrating significant heterogeneity with multiple hot spots at the injection sites. Dose volume histograms show about 33.9 percent of bone and tumor and 70.2 percent of bone marrow and trabecular bone receive a total dose over 200 Gy; about 3.2 percent of bone and tumor and 31.0 percent of bone marrow and trabecular bone receive a total dose of over 1000 Gy. Y-90 liquid brachytherapy has the potential to be used as an adjuvant therapy or for palliation purposes. Future work includes evaluation of pharmacokinetics of the Y-90 radiopharmaceutical, calibration of PET/CT scanners for the direct quantitative assessment of Y-90 activity concentration, and assessment of efficacy of the Y-90 liquid brachytherapy strategy.

Zhou, Jingjie

2011-05-01T23:59:59.000Z

92

Validation of mutual information-based registration of CT and bone SPECT images in dual-isotope studies  

Science Conference Proceedings (OSTI)

The registration of computed tomography (CT) and nuclear medicine (NM) images can substantially enhance patient diagnosis as it allows for the fusion of anatomical and functional information, as well as the attenuation correction of NM images. However, ... Keywords: Accuracy, Bone SPECT, Dual-isotope studies, Multi-modality registration, Multi-resolution, Mutual information, Precision, Qualitative evaluation, Quantitative validation, Reproducibility, Robustness, Sensitivity

Lisa Tang; Ghassan Hamarneh; Anna Celler

2008-11-01T23:59:59.000Z

93

Estimating the risk associated with computerized tomography doses  

SciTech Connect

The largest annual whole- body dose to the US population from man-made radiation is from medical sources. According to the BEIR report, the use of diagnostic x-rays by the medical profession has increased in recent years at an annual rate of 1 to 4%. Risk factors developed by the BEIR committee can be used to estimate the risk to the population due to the exposure incurred through medical radiography. In this paper, these risk factors are employed to obtain an estimate of risk due to radiation exposure from computerized tomography (CT).

Yalcintas, M.G.; Leggett, R.W.; Dunning, D.E.; Nalcioglu, O.

1979-01-01T23:59:59.000Z

94

A generic, geometric cocalibration method for a combined system of fluorescence molecular tomography and microcomputed tomography with arbitrarily shaped objects  

Science Conference Proceedings (OSTI)

Purpose: A combined system of fluorescence molecular tomography and microcomputed tomography (FMT and mCT) can provide molecular and anatomical information of small animals in a single study with intrinsically coregistered images. The anatomical information provided by the mCT subsystem is commonly used as a reference to locate the fluorophore distribution or as a priori structural information to improve the performance of FMT. Therefore, the transformation between the coordinate systems of the subsystem needs to be determined in advanced. Methods: A cocalibration method for the combined system of FMT and mCT is proposed. First, linear models are adopted to describe the galvano mirrors and the charge-coupled device (CCD) camera in the FMT subsystem. Second, the position and orientation of the galvano mirrors are determined with the input voltages of the galvano mirrors and the markers, whose positions are predetermined. The position, orientation and normalized pixel size of the CCD camera are obtained by analysing the projections of a point-like marker at different positions. Finally, the orientation and position of sources and the corresponding relationship between the detectors and their projections on the image plane are predicted. Because the positions of the markers are acquired with mCT, the registration of the FMT and mCT could be realized by direct image fusion. Results: The accuracy and consistency of this method in the presence of noise is evaluated by computer simulation. Next, a practical implementation for an experimental FMT and mCT system is carried out and validated. The maximum prediction error of the source positions on the surface of a cylindrical phantom is within 0.375 mm and that of the projections of a point-like marker is within 0.629 pixel. Finally, imaging experiments of the fluorophore distribution in a cylindrical phantom and a phantom with a complex shape demonstrate the feasibility of the proposed method. Conclusions: This method is universal in FMT and mCT, which could be performed with no restriction on the system geometry, calibration phantoms or imaging objects.

Fu Jianwei; Yang Xiaoquan; Wang Kan; Luo Qingming; Gong Hui [Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074 (China) and Key Laboratory of Biomedical Photonics of Ministry of Education, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074 (China); Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074 (China); Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074 (China) and Key Laboratory of Biomedical Photonics of Ministry of Education, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan 430074 (China)

2011-12-15T23:59:59.000Z

95

CT-Guided Percutaneous Fine-Needle Aspiration Biopsy of the Inferior Vena Cava Wall: A Posterior Coaxial Approach  

Science Conference Proceedings (OSTI)

A 72-year-old man was referred to our department with an incidentally diagnosed bronchogenic carcinoma of the right upper lobe. Positron emission tomography (PET) combined with computed tomography (PET-CT) revealed an unexpected hot spot in the ventral wall of the infrarenal segment of the inferior vena cava (IVC). Diagnostic biopsy of this lesion was performed under CT guidance with semiautomated 20G fine-needle aspiration (FNA) through a 19G coaxial needle. Cytology revealed few carcinoma cells, which led to the remarkable diagnosis of a distant metastasis to the IVC wall. Both the immediate postinterventional CT control and the further surveillance period of the patient were unremarkable; in particular, no signs of bleeding complications were detected. We conclude that coaxial FNA of an IVC wall lesion is technically feasible and may even help diagnose distant metastasis.

Kos, Sebastian, E-mail: skos@gmx.de; Bilecen, Deniz [University Hospital Basel, Institute of Radiology (Switzerland); Baumhoer, Daniel [University Hospital Basel, Institute of Pathology (Switzerland); Guillaume, Nicolas [University Hospital Basel, Institute of Nuclear Medicine (Switzerland); Jacob, Augustinus L. [University Hospital Basel, Institute of Radiology (Switzerland)

2010-02-15T23:59:59.000Z

96

Radiation-induced lung injury using a pig model: Evaluation by high-resolution computed tomography  

Science Conference Proceedings (OSTI)

To assess the early phase of radiation-induced lung injury using high-resolution computed tomography (CT) under experimental conditions and to perform precise CT-pathologic correlation. Five Yorkshire pigs received a single dose of 12.5 Gy to the right lower lung. Computed tomographic images were obtained at 2-week intervals. The animals were killed after follow-up periods of 4-16 weeks. The lungs were removed, inflated, fixed, dried, and sliced corresponding to the CT sections. Computed tomography, specimen radiography, and histologic findings were correlated. Various CT findings were observed during the first 16 weeks, including ground-glass opacity, discrete consolidation, patchy consolidation, thickened interlobular septum, and bronchovascular bundle. Ground-glass opacity was associated with thickened alveolar wall and scattered tiny fibrotic foci. Thickened interlobular septum and bronchovascular bundle were the results of fibrosis adjacent to these structures. Discrete consolidation correlated with intraalveolar edema with hemorrhage and infiltration of inflammatory cells. High-resolution CT correlated well with pathology of the lung due to radiation injury as verified by precise radiologic-pathologic correlation. 28 refs., 4 figs., 1 tab.

Takahashi, Masashi; Balazs, G.; Moskowitz, G.W.; Palestro, C.J.; Eacobacci, T.; Khan, A.; Herman, P.G. [Albert Einstein College of Medicine, New Hyde Park, NY (United States)

1995-02-01T23:59:59.000Z

97

Development of a dynamic flow imaging phantom for dynamic contrast-enhanced CT  

Science Conference Proceedings (OSTI)

Purpose: Dynamic contrast enhanced CT (DCE-CT) studies with modeling of blood flow and tissue perfusion are becoming more prevalent in the clinic, with advances in wide volume CT scanners allowing the imaging of an entire organ with sub-second image frequency and sub-millimeter accuracy. Wide-spread implementation of perfusion DCE-CT, however, is pending fundamental validation of the quantitative parameters that result from dynamic contrast imaging and perfusion modeling. Therefore, the goal of this work was to design and construct a novel dynamic flow imaging phantom capable of producing typical clinical time-attenuation curves (TACs) with the purpose of developing a framework for the quantification and validation of DCE-CT measurements and kinetic modeling under realistic flow conditions. Methods: The phantom is based on a simple two-compartment model and was printed using a 3D printer. Initial analysis of the phantom involved simple flow measurements and progressed to DCE-CT experiments in order to test the phantoms range and reproducibility. The phantom was then utilized to generate realistic input TACs. A phantom prediction model was developed to compute the input and output TACs based on a given set of five experimental (control) parameters: pump flow rate, injection pump flow rate, injection contrast concentration, and both control valve positions. The prediction model is then inversely applied to determine the control parameters necessary to generate a set of desired input and output TACs. A protocol was developed and performed using the phantom to investigate image noise, partial volume effects and CT number accuracy under realistic flow conditionsResults: This phantom and its surrounding flow system are capable of creating a wide range of physiologically relevant TACs, which are reproducible with minimal error between experiments ({sigma}/{mu} < 5% for all metrics investigated). The dynamic flow phantom was capable of producing input and output TACs using either step function based or typical clinical arterial input function (AIF) inputs. The measured TACs were in excellent agreement with predictions across all comparison metrics with goodness of fit (R{sup 2}) for the input function between 0.95 and 0.98, while the maximum enhancement differed by no more than 3.3%. The predicted output functions were similarly accurate producing R{sup 2} values between 0.92 and 0.99 and maximum enhancement to within 9.0%. The effect of ROI size on the arterial input function (AIF) was investigated in order to determine an operating range of ROI sizes which were minimally affected by noise for small dimensions and partial volume effects for large dimensions. It was possible to establish the measurement sensitivity of both the Toshiba (ROI radius range from 1.5 to 3.2 mm ''low dose'', 1.4 to 3.0 mm ''high dose'') and GE scanner (1.5 to 2.6 mm ''low dose'', 1.1 to 3.4 mm ''high dose''). This application of the phantom also provides the ability to evaluate the effect of the AIF error on kinetic model parameter predictions. Conclusions: The dynamic flow imaging phantom is capable of producing accurate and reproducible results which can be predicted and quantified. This results in a unique tool for perfusion DCE-CT validation under realistic flow conditions which can be applied not only to compare different CT scanners and imaging protocols but also to provide a ground truth across multimodality dynamic imaging given its MRI and PET compatibility.

Driscoll, B.; Keller, H.; Coolens, C. [Department of Radiation Physics, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada)

2011-08-15T23:59:59.000Z

98

Positron Emission Tomography (PET)  

DOE R&D Accomplishments (OSTI)

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.

Welch, M. J.

1990-01-00T23:59:59.000Z

99

CT NC0  

Office of Legacy Management (LM)

x-L* d! x-L* d! CT NC0 - i , ,. i, .' i :.:(e.!' ,A\~, L.,t, - (iI :i' , . y- 2 .L i ._ 1 c\ :- i;! Ii $ 4. Ci:lc:i.nnati. 39, t>:::i.f> (J&l3 q-1 -3 sui3 Jrn T3 FRCM .I iirz 1 ?j ~ 1.3 bL1 T:' IP !REFOI?T TC 5YC?CZCiC~ :EWllIFl;j",tsSS L' I"JIsIc:;. .:;xli3;. iCAN !fA(=;-fL,yg-j L' sc,, E. $.iCLX:i?, -iIJ,x:q()Is. ON hL4X 24 - 25 ) 1.9tic ;i. A. Quiglel;, A.3, 3, M. ChenauEt gpxrIvB OF TP.~ The purpose of t3is trip was tc observe a proposed method for the dchy- dratim of green salt md to determine that all health and safety measures were being xrried out, SurveiU.ance of this nature provided protection against excessi3z personnel exposure, insured compliance with ICC shipping regulaticns, tion of the equ'~ and determined when adequate decontamira-

100

Prospective-gated cardiac micro-CT imaging of free-breathing mice using carbon nanotube field emission x-ray  

Science Conference Proceedings (OSTI)

Purpose: Carbon nanotube (CNT) based field emission x-ray source technology has recently been investigated for diagnostic imaging applications because of its attractive characteristics including electronic programmability, fast switching, distributed source, and multiplexing. The purpose of this article is to demonstrate the potential of this technology for high-resolution prospective-gated cardiac micro-CT imaging. Methods: A dynamic cone-beam micro-CT scanner was constructed using a rotating gantry, a stationary mouse bed, a flat-panel detector, and a sealed CNT based microfocus x-ray source. The compact single-beam CNT x-ray source was operated at 50 KVp and 2 mA anode current with 100 {mu}mx100 {mu}m effective focal spot size. Using an intravenously administered iodinated blood-pool contrast agent, prospective cardiac and respiratory-gated micro-CT images of beating mouse hearts were obtained from ten anesthetized free-breathing mice in their natural position. Four-dimensional cardiac images were also obtained by gating the image acquisition to different phases in the cardiac cycle. Results: High-resolution CT images of beating mouse hearts were obtained at 15 ms temporal resolution and 6.2 lp/mm spatial resolution at 10% of system MTF. The images were reconstructed at 76 {mu}m isotropic voxel size. The data acquisition time for two cardiac phases was 44{+-}9 min. The CT values observed within the ventricles and the ventricle wall were 455{+-}49 and 120{+-}48 HU, respectively. The entrance dose for the acquisition of a single phase of the cardiac cycle was 0.10 Gy. Conclusions: A high-resolution dynamic micro-CT scanner was developed from a compact CNT microfocus x-ray source and its feasibility for prospective-gated cardiac micro-CT imaging of free-breathing mice under their natural position was demonstrated.

Cao Guohua; Burk, Laurel M.; Lee, Yueh Z.; Calderon-Colon, Xiomara; Sultana, Shabana; Lu Jianping; Zhou, Otto [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 and Department of Radiology, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States) and Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Curriculum in Applied Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States) and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

2010-10-15T23:59:59.000Z

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101

Motion Tracking Of A Handheld Scanner With An Infrared Vision System  

SciTech Connect

Handheld scanners are used in a large number of applications to inspect walls, floors, tanks, and other large structures. Measurements are made to characterize physical properties, uncover defects, detect evidence of tampering, quantify surface contamination, and so forth. Handheld scanning suffers from a number of drawbacks. The relationship between the data collected and scanned location is difficult or impossible to track. Humans using handheld scanners can unintentionally scan the same area multiple times or entirely overlook an area of interest. An automated scanner tracking system could improve upon current inspection practices with a handheld scanner in terms of efficiency, accuracy, and quality. The authors have developed a handheld scanner tracking system that will allow users to visualize previously scanned areas, highlight areas where important or unusual data are acquired, and store scanning location with acquired data. The scanned regions are saved in real time and projected back on the scanned area using a projector. The system currently utilizes the Smoothboard software, which has already been designed to interpret the location of a captured infrared source from a Wii Remote controller to create an interactive whiteboard. This software takes advantage of the Wii Remote’s ability to track the location of an infrared source, and when proper calibration of the Wii Remote orientation is complete, any surface can become a virtual whiteboard. In addition to recording and projecting scan pathways, the system developed by the authors can be used to make notes on the scanning process and project acquired data on top of the scanned area. This latter capability can be used to guide sample acquisition or demolition activities. This paper discusses development of the system and potential benefits to wall scanning with handheld scanners.

Seppi, Jeremy H.; Hatchell, Brian K.; McMakin, Douglas L.

2011-08-07T23:59:59.000Z

102

Patient-specific dose estimation for pediatric chest CT  

SciTech Connect

Current methods for organ and effective dose estimations in pediatric CT are largely patient generic. Physical phantoms and computer models have only been developed for standard/limited patient sizes at discrete ages (e.g., 0, 1, 5, 10, 15 years old) and do not reflect the variability of patient anatomy and body habitus within the same size/age group. In this investigation, full-body computer models of seven pediatric patients in the same size/protocol group (weight: 11.9-18.2 kg) were created based on the patients' actual multi-detector array CT (MDCT) data. Organs and structures in the scan coverage were individually segmented. Other organs and structures were created by morphing existing adult models (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. Organ and effective dose of these patients from a chest MDCT scan protocol (64 slice LightSpeed VCT scanner, 120 kVp, 70 or 75 mA, 0.4 s gantry rotation period, pitch of 1.375, 20 mm beam collimation, and small body scan field-of-view) was calculated using a Monte Carlo program previously developed and validated to simulate radiation transport in the same CT system. The seven patients had normalized effective dose of 3.7-5.3 mSv/100 mAs (coefficient of variation: 10.8%). Normalized lung dose and heart dose were 10.4-12.6 mGy/100 mAs and 11.2-13.3 mGy/100 mAs, respectively. Organ dose variations across the patients were generally small for large organs in the scan coverage (<7%), but large for small organs in the scan coverage (9%-18%) and for partially or indirectly exposed organs (11%-77%). Normalized effective dose correlated weakly with body weight (correlation coefficient: r=-0.80). Normalized lung dose and heart dose correlated strongly with mid-chest equivalent diameter (lung: r=-0.99, heart: r=-0.93); these strong correlation relationships can be used to estimate patient-specific organ dose for any other patient in the same size/protocol group who undergoes the chest scan. In summary, this work reported the first assessment of dose variations across pediatric CT patients in the same size/protocol group due to the variability of patient anatomy and body habitus and provided a previously unavailable method for patient-specific organ dose estimation, which will help in assessing patient risk and optimizing dose reduction strategies, including the development of scan protocols.

Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Frush, Donald P. [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Physics, Duke University, Durham, North Carolina 27710 (United States); and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Global Applied Science Laboratory, GE Healthcare, Waukesha, Wisconsin 53188 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 and Department of Radiology, Division of Pediatric Radiology, Duke University Medical Center, Durham North Carolina 27710 (United States)

2008-12-15T23:59:59.000Z

103

Category:Bridgeport, CT | Open Energy Information  

Open Energy Info (EERE)

Bridgeport, CT Bridgeport, CT Jump to: navigation, search Go Back to PV Economics By Location Media in category "Bridgeport, CT" The following 16 files are in this category, out of 16 total. SVFullServiceRestaurant Bridgeport CT Connecticut Light & Power Co.png SVFullServiceRestauran... 64 KB SVQuickServiceRestaurant Bridgeport CT Connecticut Light & Power Co.png SVQuickServiceRestaura... 63 KB SVHospital Bridgeport CT Connecticut Light & Power Co.png SVHospital Bridgeport ... 71 KB SVLargeHotel Bridgeport CT Connecticut Light & Power Co.png SVLargeHotel Bridgepor... 67 KB SVLargeOffice Bridgeport CT Connecticut Light & Power Co.png SVLargeOffice Bridgepo... 72 KB SVMediumOffice Bridgeport CT Connecticut Light & Power Co.png SVMediumOffice Bridgep...

104

Simulating Sonic Scanner responses in an interactive Web?based High Performance Computing environment  

Science Conference Proceedings (OSTI)

Sonic Scanner logging tool collects a wealth of data about the geological formation. The drawback of this is that we are now discovering new features on the acoustic logs that have never been observed before; only rigorous modeling can help properly interpret the data. Invariably

Valery Polyakov; Henri?Pierre Valero; Dzevat Omeragic; Raymond L. Kocian; Tarek M. Habashy; Jahir Pabon

2008-01-01T23:59:59.000Z

105

Ground Characterization of the Scanner for Radiation Budget (ScaRaB) Flight Model 1  

Science Conference Proceedings (OSTI)

The Scanner for Radiation Budget (ScaRaB) is a satellite-based radiometer for measurements of the planetary radiation budget. It was launched in January 1994 on a Russian METEOR-3 platform and provided excellent data from February 1994 to March ...

Johannes Mueller; Rolf Stuhlmann; Renate Becker; Ehrhard Raschke; Heiko Rinck; Peter Burkert; Jean-Louis Monge; Francis Sirou; Robert Kandel; Thierry Tremas; Leonid A. Pakhomov

1997-08-01T23:59:59.000Z

106

Effect of {sup 18}F-FDG PET/CT Imaging in Patients With Clinical Stage II and III Breast Cancer  

SciTech Connect

Purpose: To investigate the potential effect of using {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in the initial assessment of patients with clinical Stage II or III breast cancer. Methods and Materials: During 14 consecutive months, 39 patients (40 tumors) who presented with Stage II or III breast cancer on the basis of a routine extension assessment were prospectively included in this study. PET/CT was performed in addition to the initial assessment. Results: In 3 cases, PET/CT showed extra-axillary lymph node involvement that had not been demonstrated with conventional techniques. Two of these patients had hypermetabolic lymph nodes in the subpectoral and infraclavicular regions, and the third had a hypermetabolic internal mammary node. PET/CT showed distant uptake in 4 women. Of these 4 women, 1 had pleural involvement and 3 had bone metastasis. Overall, of the 39 women, the PET/CT results modified the initial stage in 7 (18%). The modified staging altered the treatment plan for 5 patients (13%). It led to radiotherapy in 4 patients (bone metastasis, pleural lesion, subpectoral lymph nodes, and internal mammary nodes) and excision of, and radiotherapy to, the infraclavicular lymph nodes in 1 patient. Conclusions: PET/CT can provide information on extra-axillary lymph node involvement and can uncover occult distant metastases in a significant percentage of patients. Therefore, initial PET/CT could enable better treatment planning for patients with Stage II and III breast cancer.

Groheux, David [Department of Nuclear Medicine, Breast Diseases Unit, Saint Louis Hospital, Paris (France)], E-mail: dgroheux@yahoo.fr; Moretti, Jean-Luc [Department of Nuclear Medicine, Breast Diseases Unit, Saint Louis Hospital, Paris (France); EAD Imagerie Moleculaire Diagnostique et Ciblage Therapeutique, IUH, University of Paris VII, Paris (France); Baillet, Georges [Department of Nuclear Medicine, Breast Diseases Unit, Saint Louis Hospital, Paris (France); Espie, Marc; Giacchetti, Sylvie [Department of Medical Oncology, Breast Diseases Unit, Saint Louis Hospital, Paris (France); Hindie, Elif [Department of Nuclear Medicine, Breast Diseases Unit, Saint Louis Hospital, Paris (France); EAD Imagerie Moleculaire Diagnostique et Ciblage Therapeutique, IUH, University of Paris VII, Paris (France); Hennequin, Christophe [EAD Imagerie Moleculaire Diagnostique et Ciblage Therapeutique, IUH, University of Paris VII, Paris (France); Department of Radiation Oncology, Breast Diseases Unit, Saint Louis Hospital, Paris (France); Vilcoq, Jacques-Robert [Department of Radiation Oncology, Hartmann Hospital, Neuilly sur Seine (France); Cuvier, Caroline [Department of Medical Oncology, Breast Diseases Unit, Saint Louis Hospital, Paris (France); Toubert, Marie-Elisabeth [Department of Nuclear Medicine, Breast Diseases Unit, Saint Louis Hospital, Paris (France); Filmont, Jean-Emmanuel [Department of Nuclear Medicine, Breast Diseases Unit, Saint Louis Hospital, Paris (France); EAD Imagerie Moleculaire Diagnostique et Ciblage Therapeutique, IUH, University of Paris VII, Paris (France); Sarandi, Farid [Department of Nuclear Medicine, Breast Diseases Unit, Saint Louis Hospital, Paris (France); Misset, Jean-Louis [Department of Medical Oncology, Breast Diseases Unit, Saint Louis Hospital, Paris (France)

2008-07-01T23:59:59.000Z

107

High Quality Image of Biomedical Object by X-ray Refraction Based Contrast Computed Tomography  

SciTech Connect

Recently we have developed a new Computed Tomography (CT) algorithm for refraction contrast that uses the optics of diffraction-enhanced imaging. We applied this new method to visualize soft tissue which is not visualized by the current absorption based contrast. The meaning of the contrast that appears in refraction-contrast X-ray CT images must be clarified from a biologic or anatomic point of view. It has been reported that the contrast is made with the specific gravity map with a range of approximately 10 {mu}arc sec. However, the relationship between the contrast and biologic or anatomic findings has not been investigated, to our knowledge. We compared refraction-contrast X-ray CT images with microscopic X-ray images, and we evaluated refractive indexes of pathologic lesions on phase-contrast X-ray CT images. We focused our attenuation of breast cancer and lung cancer as samples. X-ray refraction based Computed Tomography was appeared to be a pathological ability to depict the boundary between cancer nest and normal tissue, and inner structure of the disease.

Hashimoto, E. [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Maksimenko, A.; Hirano, K.; Hyodo, K. [Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Sugiyama, H. [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Shimao, D. [Department of Health Sciences, Ibaraki prefectural University of Health Sciences, 4669-2Ami, Ami, Inashiki, Ibaraki, 300-0394 (Japan); Nishino, Y.; Ishikawa, T. [RIKEN Harima Institute, 1-1-1 Kouto, Mikazuki, Sayo, Hyogo, 679-5148 (Japan); Yuasa, T. [Department of Bio-system Engineering, Faculty of Engineering Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510 (Japan); Ichihara, S. [Dept. of Path., Nagoya Med. Center, Nat. Hospital Organization, Naka-ku, Nagoya 460-0001 (Japan); Arai, Y. [Matsumoto Dental University, 1980 Hirooka, Shiojiri, Nagano (Japan); Ando, M. [Department of Photon-Science, School of Advanced Studies, Graduate University for Advanced Studies (GUAS), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Inst. of Sci. and Tech., Tokyo Univ. of Science, Yamasaki 2641, Noda, Chiba 278-8510 (Japan)

2007-01-19T23:59:59.000Z

108

Constructing Anatomically Accurate Face Models using Computed Tomography and Cyberware data  

E-Print Network (OSTI)

Facial animation and cranio-facial surgery simulation both stand to benefit from the development of anatomically accurate computer models of the human face. State-of-theart biomechanical models of the face have shown promise in animation, but they are inadequate for the purposes of cranio-facial surgery simulation. The goal of this thesis is to develop an improved facial model, using Cyberware data which captures the external structure and appearance of the face and head, as well as computed tomography (CT) data which captures the internal structure of facial soft and hard tissues. To this end, we develop algorithms to (1) register the CT and Cyberware datasets, (2) extract from the CT data a skull subsurface which serves as a foundation of the soft-tissue model, and (3) compute thic...

Faisal Zubair Qureshi

2000-01-01T23:59:59.000Z

109

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

Science Conference Proceedings (OSTI)

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).

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

110

Model Based HAADF STEM Tomography  

Science Conference Proceedings (OSTI)

P2-28: Characterization of Pores and Cracks in Underwater Welds by µCT and Digital Optical Microscopy · P3-01: 3D Visualisation of Crystallographic Pitting.

111

Patient-specific radiation dose and cancer risk estimation in CT: Part II. Application to patients  

SciTech Connect

Purpose: Current methods for estimating and reporting radiation dose from CT examinations are largely patient-generic; the body size and hence dose variation from patient to patient is not reflected. Furthermore, the current protocol designs rely on dose as a surrogate for the risk of cancer incidence, neglecting the strong dependence of risk on age and gender. The purpose of this study was to develop a method for estimating patient-specific radiation dose and cancer risk from CT examinations. Methods: The study included two patients (a 5-week-old female patient and a 12-year-old male patient), who underwent 64-slice CT examinations (LightSpeed VCT, GE Healthcare) of the chest, abdomen, and pelvis at our institution in 2006. For each patient, a nonuniform rational B-spine (NURBS) based full-body computer model was created based on the patient's clinical CT data. Large organs and structures inside the image volume were individually segmented and modeled. Other organs were created by transforming an existing adult male or female full-body computer model (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. A Monte Carlo program previously developed and validated for dose simulation on the LightSpeed VCT scanner was used to estimate patient-specific organ dose, from which effective dose and risks of cancer incidence were derived. Patient-specific organ dose and effective dose were compared with patient-generic CT dose quantities in current clinical use: the volume-weighted CT dose index (CTDI{sub vol}) and the effective dose derived from the dose-length product (DLP). Results: The effective dose for the CT examination of the newborn patient (5.7 mSv) was higher but comparable to that for the CT examination of the teenager patient (4.9 mSv) due to the size-based clinical CT protocols at our institution, which employ lower scan techniques for smaller patients. However, the overall risk of cancer incidence attributable to the CT examination was much higher for the newborn (2.4 in 1000) than for the teenager (0.7 in 1000). For the two pediatric-aged patients in our study, CTDI{sub vol} underestimated dose to large organs in the scan coverage by 30%-48%. The effective dose derived from DLP using published conversion coefficients differed from that calculated using patient-specific organ dose values by -57% to 13%, when the tissue weighting factors of ICRP 60 were used, and by -63% to 28%, when the tissue weighting factors of ICRP 103 were used. Conclusions: It is possible to estimate patient-specific radiation dose and cancer risk from CT examinations by combining a validated Monte Carlo program with patient-specific anatomical models that are derived from the patients' clinical CT data and supplemented by transformed models of reference adults. With the construction of a large library of patient-specific computer models encompassing patients of all ages and weight percentiles, dose and risk can be estimated for any patient prior to or after a CT examination. Such information may aid in decisions for image utilization and can further guide the design and optimization of CT technologies and scan protocols.

Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Toncheva, Greta; Yoshizumi, Terry T.; Frush, Donald P. [Medical Physics Graduate Program, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Medical Physics Graduate Program, Department of Physics, and Department of Biomedical Engineering, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Biomedical Engineering, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Duke Radiation Dosimetry Laboratory, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Duke Radiation Dosimetry Laboratory, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Division of Pediatric Radiology, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27710 (United States)

2011-01-15T23:59:59.000Z

112

Value of PET/CT and MR Lymphography in Treatment of Prostate Cancer Patients With Lymph Node Metastases  

Science Conference Proceedings (OSTI)

Purpose: To determine the clinical value of two novel molecular imaging techniques: {sup 11}C-choline positron emission tomography (PET)/computed tomography (CT) and ferumoxtran-10 enhanced magnetic resonance imaging (magnetic resonance lymphography [MRL]) for lymph node (LN) treatment in prostate cancer (PCa) patients. Therefore, we evaluated the ability of PET/CT and MRL to assess the number, size, and location of LN metastases in patients with primary or recurrent PCa. Methods and Materials: A total of 29 patients underwent MRL and PET/CT for LN evaluation. The MRL and PET/CT data were analyzed independently. The number, size, and location of the LN metastases were determined. The location was described as within or outside the standard clinical target volume for elective pelvic irradiation as defined by the Radiation Therapy Oncology Group. Subsequently, the results from MRL and PET/CT were compared. Results: Of the 738 LNs visible on MRL, 151 were positive in 23 of 29 patients. Of the 132 LNs visible on PET/CT, 34 were positive in 13 of 29 patients. MRL detected significantly more positive LNs (p < 0.001) in more patients than PET/CT (p = 0.002). The mean diameter of the detected suspicious LNs on MRL was significantly smaller than those detected by PET/CT, 4.9 mm and 8.4 mm, respectively (p < 0.0001). In 14 (61%) of 23 patients, suspicious LNs were found outside the clinical target volume with MRL and in 4 (31%) of 13 patients with PET/CT. Conclusion: In patients with PCa, both molecular imaging techniques, MRL and {sup 11}C-choline PET/CT, can detect LNs suspicious for metastasis, irrespective of the existing size and shape criteria for CT and conventional magnetic resonance imaging. On MRL and PET/CT, 61% and 31% of the suspicious LNs were located outside the conventional clinical target volume. Therefore, these techniques could help to individualize treatment selection and enable image-guided radiotherapy for patients with PCa LN metastases.

Fortuin, Ansje S., E-mail: A.Fortuin@rad.umcn.nl [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Deserno, Willem M.L.L.G. [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Meijer, Hanneke J.M. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Jager, Gerrit J. [Department of Radiology, Jeroen Bosch Hospital's, Hertogenbosch (Netherlands)] [Department of Radiology, Jeroen Bosch Hospital's, Hertogenbosch (Netherlands); Takahashi, Satoru; Debats, Oscar A. [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Reske, Sven N.; Schick, Christian [Department of Nuclear Medicine, University of Ulm, Ulm (Germany)] [Department of Nuclear Medicine, University of Ulm, Ulm (Germany); Krause, Bernd J. [Department of Nuclear Medicine, Technische Universitaet Muenchen, Muenchen (Germany)] [Department of Nuclear Medicine, Technische Universitaet Muenchen, Muenchen (Germany); Oort, Inge van; Witjes, Alfred J. [Department of Urology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Urology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Hoogeveen, Yvonne L. [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Lin, Emile N.J.Th. van [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Barentsz, Jelle O. [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)] [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)

2012-11-01T23:59:59.000Z

113

CT Investment Partners LLP | Open Energy Information  

Open Energy Info (EERE)

CT Investment Partners LLP Jump to: navigation, search Name CT Investment Partners LLP Place London, United Kingdom Zip WC2A 2AZ Sector Carbon Product Venture capital arm of the...

114

Advanced characterization of physical properties of coals with different coal structures by nuclear magnetic resonance and X-ray computed tomography  

Science Conference Proceedings (OSTI)

In order to understand the correlation between coal structure and physical property of coal, samples with different coal structures were collected from the Late Permian period coal seams in the Laochang area, Yunnan Province, China. A set of experiments ... Keywords: Adsorption capacities, Coal structure, Nuclear magnetic resonance (NMR), Seepage capacities, X-ray computed tomography (X-CT)

Song Li; Dazhen Tang; Hao Xu; Zi Yang

2012-11-01T23:59:59.000Z

115

Resistivity Tomography | Open Energy Information  

Open Energy Info (EERE)

Resistivity Tomography Resistivity Tomography Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Resistivity Tomography Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Log Techniques Parent Exploration Technique: Resistivity Log Information Provided by Technique Lithology: Stratigraphic/Structural: Hydrological: Thermal: Cost Information Low-End Estimate (USD): 60.986,098 centUSD 0.061 kUSD 6.098e-5 MUSD 6.098e-8 TUSD / foot Median Estimate (USD): 76.227,622 centUSD 0.0762 kUSD 7.622e-5 MUSD 7.622e-8 TUSD / foot High-End Estimate (USD): 106.7110,671 centUSD 0.107 kUSD 1.0671e-4 MUSD 1.0671e-7 TUSD / foot Time Required Low-End Estimate: 1 days0.00274 years

116

Design and calibration method for microvision three-dimensional laser scanner  

Science Conference Proceedings (OSTI)

A microvision three-dimensional (3D) laser scanner with micron accuracy and the calibration method are presented in this article. The system is designed to measure and reconstruct the 3D shape of miniature objects. A new two-step calibration method is proposed to reduce measurement errors and improve the measurement precision. Repeated measurements show that the repeatability is better than ± 1 ? m . Moreover

Changku Sun; Bin Liu; Peng Wang

2009-01-01T23:59:59.000Z

117

LANSCE-R WIRE-SCANNER ANALOG FRONT-END ELECTRONICS  

SciTech Connect

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.

Gruchalla, Michael E. [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

118

Control system for the Spallation Neutron Source H{sup -} source test facility Allison scanner  

Science Conference Proceedings (OSTI)

Spallation Neutron Source is currently in progress of a multiyear plan to ramp ion beam power to the initial design power of 1.4 MW. Key to reaching this goal is understanding and improving the operation of the H{sup -} ion source. An Allison scanner was installed on the ion source in the test facility to support this improvement. This paper will discuss the hardware and the software control system of the installed Allison scanner. The hardware for the system consists of several parts. The heart of the system is the scanner head, complete with associated bias plates, slits, and signal detector. There are two analog controlled high voltage power supplies to bias the plates in the head, and a motor with associated controller to position the head in the beam. A multifunction data acquisition card reads the signals from the signal detector, as well as supplies the analog voltage control for the power supplies. To synchronize data acquisition with the source, the same timing signal that is used to trigger the source itself is used to trigger data acquisition. Finally, there is an industrial personal computer to control the rest of the hardware. Control software was developed using National Instruments LABVIEW, and consists of two parts: a data acquisition program to control the hardware and a stand alone application for offline user data analysis.

Long, C. D.; Stockli, M. P.; Gorlov, T. V.; Han, B.; Murray, S. N.; Pennisi, T. R. [Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)

2010-02-15T23:59:59.000Z

119

Control System for the SNS H- Source Test Stand Allison Scanner  

Science Conference Proceedings (OSTI)

SNS is currently in progress of a multi-year plan to ramp ion beam power to the initial design power of 1.4 MW. Key to reaching this goal is understanding and improving the operation of the H- ion source. An Allison scanner was installed on the ion source test stand to support this improvement. This paper will discuss the hardware and the software control system of the installed Allison scanner. The hardware for the system consists of several parts. The heart of the system is the scanner head, complete with associated bias plates, slits, and signal detector. There are two analog controlled high voltage power supplies to bias the plates in the head, and a motor with associated controller to position the head in the beam. A multifunction data acquisition card reads the signals from the signal detector, as well as supplying the analog voltage control for the power supplies. To synchronize data acquisition with the source, the same timing signal that is used to trigger the source itself is used to trigger data acquisition. Finally, there is an industrial PC to control the rest of the hardware. Control software was developed using National Instruments LabVIEW, and consists of two parts, a data acquisition program to control the hardware, and a stand alone application for offline user data analysis.

Long, Cary D [ORNL; Stockli, Martin P [ORNL; Gorlov, Timofey V [ORNL; Han, Baoxi [ORNL; Pennisi, Terry R [ORNL; Murray Jr, S N [ORNL

2010-01-01T23:59:59.000Z

120

Cranial computed tomography and real-time sonography in full-term neonates and infants  

Science Conference Proceedings (OSTI)

The results of cranial ultrasonography (US) and computed tomography (CT) were compared in 52 full-term neonates and young infants. The chief indications for examination included: increasing head size, dysmorphic features, myelomeningocele, inflammatory disease, and asphyxia. Disorders detected included hydrocephalus, parenchymal abnormalities, intracranial hemorrhage, extraparenchymal fluid collections, and vascular and other developmental malformations. CT and US essentially were equivalent in detecting hydrocephalus, moderate to large intraventricular hemorrhages or subdural collections, and large focal parenchymal lesions, although CT was somewhat better in determining the level and cause of obstruction in patients with hydrocephalus and characterizing parenchymal abnormalities. CT was more sensitive than ultrasound in detecting subarachnoid hemorrhage (100% vs. 0%), diffuse parenchymal abnormality (100% vs. 33%), and small intraventricular hemorrhages (100% vs. 0%) but these lesions often were not clinically significant. The results suggest that US should be used as the primary neuroradiological examination in term infants; CT probably should be reserved for further investigation after US in those patients with a history of hypoxia and progressive clinical deterioration.

Siegel, M.J.; Patel, J.; Gado, M.H.; Shackelford, G.D.

1983-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

First Results from the On-Orbit Calibrations of the Visible and Infrared Scanner for the Tropical Rainfall Measuring Mission  

Science Conference Proceedings (OSTI)

This work presents the first on-orbit calibration results using the Moon, the Sun, and cold deep space as inputs to the Visible and Infrared Scanner (VIRS) on board the Tropical Rainfall Measuring Mission (TRMM) satellite. The authors have ...

Cheng-Hsuan Lyu; William L. Barnes; Robert A. Barnes

2000-04-01T23:59:59.000Z

122

CT Offshore | Open Energy Information  

Open Energy Info (EERE)

CT Offshore CT Offshore Place Otterup, Denmark Zip 5450 Sector Wind energy Product Denmark-based consultancy which provides assistance for project management, damage assessment and stabilization as well as other activities related to wind farms and subsea maintenance. Coordinates 55.543228°, 10.40294° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":55.543228,"lon":10.40294,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

123

The 1981 ocean tomography experiment: Preliminary results  

Science Conference Proceedings (OSTI)

Preliminary results from a 1981 test ocean acoustic tomography experiment are presented. The system deployed in the southern North Atlantic

The Ocean Tomography Group; R. C. Spindel

1982-01-01T23:59:59.000Z

124

Geometric Tomography: A Limited-View Approach for Computed Tomography  

E-Print Network (OSTI)

- sitions is increasing to improve image quality which further increases patient radiation exposure as well of the internal organs of the body. As a result, CT is used routinely in the clinical arena to obtain three resulted in a substantial rise in population-radiation-dose [1], which may lead to an in- creased incidence

Corso, Jason J.

125

Siemens Corporate Technology CT | Open Energy Information  

Open Energy Info (EERE)

Name Siemens Corporate Technology (CT) Place Erlangan, Germany Sector Solar Product R&D lab for Siemens AG. Currently researching buckyballs and conductive plastic for solar...

126

CT Solar Loan | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

a pilot loan program, CT Solar Loan, to provide homeowners with 15-year loans for solar PV equipment. The loans are administered through Sungage. Interested residents must...

127

Assessment of the impact of the scanner-related factors on brain morphometry analysis with Brainvisa  

E-Print Network (OSTI)

performed using the same scanner. Only one volume was acquired at each scanning session. Data pre-processing Pre-processing of the 3D T1 images was carried out using the segmentation pipeline of Brainvisa (version 4.0) and included the following steps (also... recognition algorithms are shown for the 1.5 T group (left) and the 3 T group (right). Mean geodesic depth refers to the average geodesic depth across a given sulcal label (note that the depth a sulcus is usually non-uniform throughout its length and hence...

Shokouhi, Mahsa; Barnes, Anna; Suckling, John; Moorhead, Thomas WJ; Brennan, David; Job, Dominic; Lymer, Katherine; Dazzan, Paola; Reis Marques, Tiago; MacKay, Clare; McKie, Shane; Williams, Steven CR; Lawrie, Stephen M; Deakin, Bill; Williams, Steve R; Condon, Barrie

2011-12-21T23:59:59.000Z

128

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

SciTech Connect

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.

Sedillo, James Daniel [Los Alamos National Laboratory

2012-05-16T23:59:59.000Z

129

Earthquake Forecast via Neutrino Tomography  

E-Print Network (OSTI)

We discuss the possibility of forecasting earthquakes by means of (anti)neutrino tomography. Antineutrinos emitted from reactors are used as a probe. As the antineutrinos traverse through a region prone to earthquakes, observable variations in the matter effect on the antineutrino oscillation would provide a tomography of the vicinity of the region. In this preliminary work, we adopt a simplified model for the geometrical profile and matter density in a fault zone. We calculate the survival probability of electron antineutrinos for cases without and with an anomalous accumulation of electrons which can be considered as a clear signal of the coming earthquake, at the geological region with a fault zone, and find that the variation may reach as much as 3% for $\\bar \

Bin Wang; Ya-Zheng Chen; Xue-Qian Li

2010-01-17T23:59:59.000Z

130

Multicontrast x-ray computed tomography imaging using Talbot-Lau interferometry without phase stepping  

SciTech Connect

Purpose: The purpose of this work is to demonstrate that multicontrast computed tomography (CT) imaging can be performed using a Talbot-Lau interferometer without phase stepping, thus allowing for an acquisition scheme like that used for standard absorption CT. Methods: Rather than using phase stepping to extract refraction, small-angle scattering (SAS), and absorption signals, the two gratings of a Talbot-Lau interferometer were rotated slightly to generate a moire pattern on the detector. A Fourier analysis of the moire pattern was performed to obtain separate projection images of each of the three contrast signals, all from the same single-shot of x-ray exposure. After the signals were extracted from the detector data for all view angles, image reconstruction was performed to obtain absorption, refraction, and SAS CT images. A physical phantom was scanned to validate the proposed data acquisition method. The results were compared with a phantom scan using the standard phase stepping approach. Results: The reconstruction of each contrast mechanism produced the expected results. Signal levels and contrasts match those obtained using the phase stepping technique. Conclusions: Absorption, refraction, and SAS CT imaging can be achieved using the Talbot-Lau interferometer without the additional overhead of long scan time and phase stepping.

Bevins, Nicholas; Zambelli, Joseph; Li Ke; Qi Zhihua; Chen Guanghong [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) and Department of Radiology, University of Wisconsin-Madison, 600 Highland Avenue, Madison, Wisconsin 53792 (United States)

2012-01-15T23:59:59.000Z

131

Low-dose computed tomography image restoration using previous normal-dose scan  

Science Conference Proceedings (OSTI)

Purpose: In current computed tomography (CT) examinations, the associated x-ray radiation dose is of a significant concern to patients and operators. A simple and cost-effective means to perform the examinations is to lower the milliampere-seconds (mAs) or kVp parameter (or delivering less x-ray energy to the body) as low as reasonably achievable in data acquisition. However, lowering the mAs parameter will unavoidably increase data noise and the noise would propagate into the CT image if no adequate noise control is applied during image reconstruction. Since a normal-dose high diagnostic CT image scanned previously may be available in some clinical applications, such as CT perfusion imaging and CT angiography (CTA), this paper presents an innovative way to utilize the normal-dose scan as a priori information to induce signal restoration of the current low-dose CT image series. Methods: Unlike conventional local operations on neighboring image voxels, nonlocal means (NLM) algorithm utilizes the redundancy of information across the whole image. This paper adapts the NLM to utilize the redundancy of information in the previous normal-dose scan and further exploits ways to optimize the nonlocal weights for low-dose image restoration in the NLM framework. The resulting algorithm is called the previous normal-dose scan induced nonlocal means (ndiNLM). Because of the optimized nature of nonlocal weights calculation, the ndiNLM algorithm does not depend heavily on image registration between the current low-dose and the previous normal-dose CT scans. Furthermore, the smoothing parameter involved in the ndiNLM algorithm can be adaptively estimated based on the image noise relationship between the current low-dose and the previous normal-dose scanning protocols. Results: Qualitative and quantitative evaluations were carried out on a physical phantom as well as clinical abdominal and brain perfusion CT scans in terms of accuracy and resolution properties. The gain by the use of the previous normal-dose scan via the presented ndiNLM algorithm is noticeable as compared to a similar approach without using the previous normal-dose scan. Conclusions: For low-dose CT image restoration, the presented ndiNLM method is robust in preserving the spatial resolution and identifying the low-contrast structure. The authors can draw the conclusion that the presented ndiNLM algorithm may be useful for some clinical applications such as in perfusion imaging, radiotherapy, tumor surveillance, etc.

Ma, Jianhua; Huang, Jing; Feng, Qianjin; Zhang, Hua; Lu, Hongbing; Liang, Zhengrong; Chen, Wufan [Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China and Department of Radiology, State University of New York, Stony Brook, New York 11794 (United States); Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515 (China); Department of Biomedical Engineering, Fourth Military Medical University, Xi'An, Shanxi 710032 (China); Department of Radiology, State University of New York, Stony Brook, New York 11794 (United States); Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515 (China)

2011-10-15T23:59:59.000Z

132

CT Solar Loan | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

CT Solar Loan CT Solar Loan CT Solar Loan < Back Eligibility Multi-Family Residential Residential Savings Category Solar Buying & Making Electricity Program Info State Connecticut Program Type State Loan Program Provider Sungage, Inc. 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 through Sungage. Interested residents must apply online to be pre-qualified for the loan. Once the loan is in place, an approved installer files permits, order equipment, and installs the system on behalf of the resident. See the program web site for application materials. Source http://www.dsireusa.org/incentives/incentive.cfm?Incentive_Code=CT101F

133

Atom Probe Tomography and Transmission Electron Microscopy ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Atom probe tomography (APT) and analytical transmission .... of a Leaking Type 316 Socket Weld in a Boron Injection Tank Sampling Line.

134

Crosswell Seismic Tomography | Open Energy Information  

Open Energy Info (EERE)

2013 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for Crosswell Seismic Tomography Citation Schlumberger. Crosswell Seismic...

135

Prospects for Atomic-Scale Tomography  

Science Conference Proceedings (OSTI)

Abstract Scope, Atomic-scale tomography (AST) may be defined as any technique that ... Initial Age Hardening and Nanostructural Evolution in a Cu-Ni-P Alloy.

136

Imaging and sensing based on muon tomography  

SciTech Connect

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.

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

137

Radiation interactions for tomography. Revision 1  

SciTech Connect

There are new requirements emerging in the field of tomography: the need for spatial resolution in the micrometre range, atomic species specificity, and quantitative density discrimination.

Zolnay, A.S.

1985-05-20T23:59:59.000Z

138

Journal of Electronic Imaging 16(4), 043009 (Oct–Dec 2007) Scanner characterization for color measurement and diagnostics  

E-Print Network (OSTI)

Abstract. We propose a novel scanner characterization approach for applications requiring color measurement of hardcopy output in calibration, characterization, and diagnostics applications. The method is advantageous for common practical color printing systems that use more than the minimum of three colorants necessary for subtractive color reproduction; printing with cyan (C), magenta (M), yellow (Y), and black (K) is the most prevalent example we use in our description. The proposed method exploits the fact that for the scenarios in consideration, in addition to the scanner RGB values for a scanned patch, the CMYK control values used to print the patch are also available and can be exploited in characterization. An indexed family of 3D scanner characterizations is created, each characterization providing a mapping from scanner RGB to CIELAB for a fixed value of K, the latter constituting the index for the characterization. Combined together, the family of 3D characterizations provides a single 4D characterization that maps scanner RGB obtained from scanning a patch and the K control value used for printing the patch to a colorimetric CIELAB measurement for the patch. A significant improvement in the robustness of the method to variations in printing is obtained by modifying the K index to utilize the scanned output for a black-only patch printed with the corresponding K value instead of directly utilizing the control K value used at the printer. Results show that the proposed 4D scanner characterization technique can significantly outperform standard 3D approaches in the target applications. © 2007 SPIE and IS&T. ?DOI: 10.1117/1.2803833? 1

Bong-sun Lee; Raja Bala; Gaurav Sharma

2007-01-01T23:59:59.000Z

139

AAPM Task Group 108: PET and PET/CT Shielding Requirements  

SciTech Connect

The shielding of positron emission tomography (PET) and PET/CT (computed tomography) facilities presents special challenges. The 0.511 MeV annihilation photons associated with positron decay are much higher energy than other diagnostic radiations. As a result, barrier shielding may be required in floors and ceilings as well as adjacent walls. Since the patient becomes the radioactive source after the radiopharmaceutical has been administered, one has to consider the entire time that the subject remains in the clinic. In this report we present methods for estimating the shielding requirements for PET and PET/CT facilities. Information about the physical properties of the most commonly used clinical PET radionuclides is summarized, although the report primarily refers to fluorine-18. Typical PET imaging protocols are reviewed and exposure rates from patients are estimated including self-attenuation by body tissues and physical decay of the radionuclide. Examples of barrier calculations are presented for controlled and noncontrolled areas. Shielding for adjacent rooms with scintillation cameras is also discussed. Tables and graphs of estimated transmission factors for lead, steel, and concrete at 0.511 MeV are also included. Meeting the regulatory limits for uncontrolled areas can be an expensive proposition. Careful planning with the equipment vendor, facility architect, and a qualified medical physicist is necessary to produce a cost effective design while maintaining radiation safety standards.

Madsen, Mark T.; Anderson, Jon A.; Halama, James R. [Radiology, University of Iowa (United States)] (and others)

2006-01-15T23:59:59.000Z

140

NEUTRON IMAGING, RADIOGRAPHY AND TOMOGRAPHY.  

SciTech Connect

Neutrons are an invaluable probe in a wide range of scientific, medical and commercial endeavors. Many of these applications require the recording of an image of the neutron signal, either in one-dimension or in two-dimensions. We summarize the reactions of neutrons with the most important elements that are used for their detection. A description is then given of the major techniques used in neutron imaging, with emphasis on the detection media and position readout principle. Important characteristics such as position resolution, linearity, counting rate capability and sensitivity to gamma-background are discussed. Finally, the application of a subset of these instruments in radiology and tomography is described.

SMITH,G.C.

2002-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Northeast - NY NJ CT PA Area | Open Energy Information  

Open Energy Info (EERE)

Northeast - NY NJ CT PA Area Northeast - NY NJ CT PA Area (Redirected from New York Area - NY NJ CT PA) Jump to: navigation, search Contents 1 Clean Energy Clusters in the Northeast - NY NJ CT PA Area 1.1 Products and Services in the Northeast - NY NJ CT PA Area 1.2 Research and Development Institutions in the Northeast - NY NJ CT PA Area 1.3 Networking Organizations in the Northeast - NY NJ CT PA Area 1.4 Investors and Financial Organizations in the Northeast - NY NJ CT PA Area 1.5 Policy Organizations in the Northeast - NY NJ CT PA Area Clean Energy Clusters in the Northeast - NY NJ CT PA Area Products and Services in the Northeast - NY NJ CT PA Area Loading map... {"format":"googlemaps3","type":"ROADMAP","types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"limit":500,"offset":0,"link":"all","sort":[""],"order":[],"headers":"show","mainlabel":"","intro":"","outro":"","searchlabel":"\u2026

142

A Phase II Comparative Study of Gross Tumor Volume Definition With or Without PET/CT Fusion in Dosimetric Planning for Non-Small-Cell Lung Cancer (NSCLC): Primary Analysis of Radiation Therapy Oncology Group (RTOG) 0515  

SciTech Connect

Background: Radiation Therapy Oncology Group (RTOG) 0515 is a Phase II prospective trial designed to quantify the impact of positron emission tomography (PET)/computed tomography (CT) compared with CT alone on radiation treatment plans (RTPs) and to determine the rate of elective nodal failure for PET/CT-derived volumes. Methods: Each enrolled patient underwent definitive radiation therapy for non-small-cell lung cancer ({>=}60 Gy) and had two RTP datasets generated: gross tumor volume (GTV) derived with CT alone and with PET/CT. Patients received treatment using the PET/CT-derived plan. The primary end point, the impact of PET/CT fusion on treatment plans was measured by differences of the following variables for each patient: GTV, number of involved nodes, nodal station, mean lung dose (MLD), volume of lung exceeding 20 Gy (V20), and mean esophageal dose (MED). Regional failure rate was a secondary end point. The nonparametric Wilcoxon matched-pairs signed-ranks test was used with Bonferroni adjustment for an overall significance level of 0.05. Results: RTOG 0515 accrued 52 patients, 47 of whom are evaluable. The follow-up time for all patients is 12.9 months (2.7-22.2). Tumor staging was as follows: II = 6%; IIIA = 40%; and IIIB = 54%. The GTV was statistically significantly smaller for PET/CT-derived volumes (98.7 vs. 86.2 mL; p < 0.0001). MLDs for PET/CT plans were slightly lower (19 vs. 17.8 Gy; p = 0.06). There was no significant difference in the number of involved nodes (2.1 vs. 2.4), V20 (32% vs. 30.8%), or MED (28.7 vs. 27.1 Gy). Nodal contours were altered by PET/CT for 51% of patients. One patient (2%) has developed an elective nodal failure. Conclusions: PET/CT-derived tumor volumes were smaller than those derived by CT alone. PET/CT changed nodal GTV contours in 51% of patients. The elective nodal failure rate for GTVs derived by PET/CT is quite low, supporting the RTOG standard of limiting the target volume to the primary tumor and involved nodes.

Bradley, Jeffrey, E-mail: jbradley@wustl.edu [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO (United States); Bae, Kyounghwa [Department of Statistics, RTOG, Philadelphia, PA (United States); Choi, Noah [Massachusetts General Hospital, Boston, MA (United States); Forster, Ken [H. Lee Moffitt Cancer Center, Tampa, FL (United States); Siegel, Barry A. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO (United States); Brunetti, Jacqueline [Holy Name Medical Center, Teaneck, NJ (United States); Purdy, James [University of California at Davis, Davis, CA (United States); Faria, Sergio [McGill University, Montreal (Canada); Vu, Toni [Centre Hospitalier Universitaire de Montreal, Hospital Notre Dame, Montreal (Canada); Thorstad, Wade [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO (United States); Choy, Hak [University of Texas Southwestern, Dallas, TX (United States)

2012-01-01T23:59:59.000Z

143

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 RIS� DTU has started to build a newly designed laser-based lidar scanning facility for remote wind

144

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

E-Print Network (OSTI)

, and supporting structures for the fiber-optic lights. The stimulus generating programs writ- ten in ANSI C send the scanner bore. The supporting structures of fiber-optic lights are constructed according to the desired a fiber-optic based apparatus, where point-light stimuli were presented immediately adjacent Fig. 2

Sereno, Martin

145

CT based computerized identification and analysis of human airways: A review  

SciTech Connect

As one of the most prevalent chronic disorders, airway disease is a major cause of morbidity and mortality worldwide. In order to understand its underlying mechanisms and to enable assessment of therapeutic efficacy of a variety of possible interventions, noninvasive investigation of the airways in a large number of subjects is of great research interest. Due to its high resolution in temporal and spatial domains, computed tomography (CT) has been widely used in clinical practices for studying the normal and abnormal manifestations of lung diseases, albeit there is a need to clearly demonstrate the benefits in light of the cost and radiation dose associated with CT examinations performed for the purpose of airway analysis. Whereas a single CT examination consists of a large number of images, manually identifying airway morphological characteristics and computing features to enable thorough investigations of airway and other lung diseases is very time-consuming and susceptible to errors. Hence, automated and semiautomated computerized analysis of human airways is becoming an important research area in medical imaging. A number of computerized techniques have been developed to date for the analysis of lung airways. In this review, we present a summary of the primary methods developed for computerized analysis of human airways, including airway segmentation, airway labeling, and airway morphometry, as well as a number of computer-aided clinical applications, such as virtual bronchoscopy. Both successes and underlying limitations of these approaches are discussed, while highlighting areas that may require additional work.

Pu Jiantao; Gu Suicheng; Liu Shusen; Zhu Shaocheng; Wilson, David; Siegfried, Jill M.; Gur, David [Imaging Research Center, Department of Radiology, University of Pittsburgh, 3362 Fifth Avenue, Pittsburgh, Pennsylvania 15213 (United States); School of Computing, University of Utah, Salt Lake City, Utah 84112 (United States); Department of Radiology, Henan Provincial People's Hospital, Zhengzhou 450003 (China); Department of Medicine, University of Pittsburgh, 580 S. Aiken Avenue, Suite 400, Pittsburgh, Pennsylvania 15232 (United States); Department of Pharmacology and Chemical Biology, Hillman Cancer Center, Pittsburgh, Pennsylvania 15213 (United States); Imaging Research Center, Department of Radiology, University of Pittsburgh, 3362 Fifth Avenue, Pittsburgh, PA 15213 (United States)

2012-05-15T23:59:59.000Z

146

Detection sensitivity of x-ray CT imaging for NDE of green-state ceramics  

DOE Green Energy (OSTI)

Improved ceramic-processing methods that use pressure slip-casting and injection molding are being developed at Norton Advanced Ceramics, with a goal of producing reliable structural ceramics for advanced heat engines. Nondestructive evaluation (NDE) of ceramic parts at different stages of processing can provide useful diagnostic information to help improve processing techniques. For example, an evaluation of density gradients in as-cast green-body samples can be used to judge mold performance and make changes in mold design. Also, the ability to detect minute flaws (20 to 50 {mu}m), such as agglomerates, inclusions, and voids, in green-body, presintered, and densified parts is important in ensuring structural reliability of the final parts, because these flaws, above certain critical sizes, can lead to catastrophic failure. Three-dimensional microfocus X-ray computed tomography (CT) and nuclear magnetic resonance imaging (MRI) systems have been developed at Argonne National Laboratory (ANL) for application to quantitative NDE evaluation of ceramics. This paper evaluates the detection sensitivity of the ANL X-ray CT system when used to determine density gradients, inclusions, and voids in green-state Si{sub 3}N{sub 4} ceramics. A theoretical account of key system- and sample-related parameters affecting X-ray CT detection sensitivity is given, and results of experimental evaluation are presented. Density calibration phantoms and net-shape-formed tensile rods with seeded defects were used in the experimental evaluation of detection limits. 6 refs., 6 figs., 1 tab.

Gopalsami, N.; Rizo, P.; Ellingson, W.A. (Argonne National Lab., IL (United States)); Tracey, D.M. (Norton Co., Northboro, MA (United States). Advanced Ceramics Div.)

1991-01-01T23:59:59.000Z

147

Northeast - NY NJ CT PA Area | Open Energy Information  

Open Energy Info (EERE)

Northeast - NY NJ CT PA Area Northeast - NY NJ CT PA Area Jump to: navigation, search Contents 1 Clean Energy Clusters in the Northeast - NY NJ CT PA Area 1.1 Products and Services in the Northeast - NY NJ CT PA Area 1.2 Research and Development Institutions in the Northeast - NY NJ CT PA Area 1.3 Networking Organizations in the Northeast - NY NJ CT PA Area 1.4 Investors and Financial Organizations in the Northeast - NY NJ CT PA Area 1.5 Policy Organizations in the Northeast - NY NJ CT PA Area Clean Energy Clusters in the Northeast - NY NJ CT PA Area Products and Services in the Northeast - NY NJ CT PA Area Loading map... {"format":"googlemaps3","type":"ROADMAP","types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"limit":500,"offset":0,"link":"all","sort":[""],"order":[],"headers":"show","mainlabel":"","intro":"","outro":"","searchlabel":"\u2026

148

DOE - Office of Legacy Management -- American Brass Co - CT 01  

Office of Legacy Management (LM)

Brass Co - CT 01 Brass Co - CT 01 FUSRAP Considered Sites Site: American Brass Co (CT.01 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: Anaconda Company Brass Division CT.01-1 Location: 414 Meadow Street , Waterbury , Connecticut CT.01-1 Evaluation Year: 1986 CT.01-2 Site Operations: Limited work with copper clad uranium billets during the 1950s. CT.01-1 Site Disposition: Eliminated - Potential for contamination considered remote based upon the limited scope of activities at the site CT.01-2 Radioactive Materials Handled: Yes Primary Radioactive Materials Handled: Uranium CT.01-3 Radiological Survey(s): Yes - health and safety monitoring during operations only CT.01-3 Site Status: Eliminated from consideration under FUSRAP

149

DOE - Office of Legacy Management -- Fenn Machinery Co - CT 11  

Office of Legacy Management (LM)

Fenn Machinery Co - CT 11 Fenn Machinery Co - CT 11 FUSRAP Considered Sites Site: Fenn Machinery Co. (CT.11 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: New Britain , Connecticut CT.11-1 Evaluation Year: 1987 CT.11-1 Site Operations: Performed short-term tests on small quantities of uranium metal to explore potential for swaging, circa mid-1950 CT.11-1 CT.11-3 Site Disposition: Eliminated - Potential for contamination considered remote due to limited scope of activities and relatively small quantities of radioactive material used CT.11-1 Radioactive Materials Handled: Yes Primary Radioactive Materials Handled: Uranium CT.11-3 Radiological Survey(s): None Indicated Site Status: Eliminated from consideration under FUSRAP CT.11-2

150

Axial Tomography from Digitized Real Time Radiography  

DOE R&D Accomplishments (OSTI)

Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

Zolnay, A. S.; McDonald, W. M.; Doupont, P. A.; McKinney, R. L.; Lee, M. M.

1985-01-18T23:59:59.000Z

151

Axial tomography from digitized real time radiography  

SciTech Connect

Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

Zolnay, A.S.; McDonald, W.M.; Doupont, P.A.; McKinney, R.L.; Lee, M.M.

1985-01-18T23:59:59.000Z

152

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

SciTech Connect

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.

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

2010-07-01T23:59:59.000Z

153

Comparison of {sup 18}F-Fluorothymidine and {sup 18}F-Fluorodeoxyglucose PET/CT in Delineating Gross Tumor Volume by Optimal Threshold in Patients With Squamous Cell Carcinoma of Thoracic Esophagus  

SciTech Connect

Purpose: To determine the optimal method of using {sup 18}F-fluorothymidine (FLT) positron emission tomography (PET)/computed tomography (CT) simulation to delineate the gross tumor volume (GTV) in esophageal squamous cell carcinoma verified by pathologic examination and compare the results with those using {sup 18}F-fluorodeoxyglucose (FDG) PET/CT. Methods and Materials: A total of 22 patients were enrolled and underwent both FLT and FDG PET/CT. The GTVs with biologic information were delineated using seven different methods in FLT PET/CT and three different methods in FDG PET/CT. The results were compared with the pathologic gross tumor length, and the optimal threshold was obtained. Next, we compared the simulation plans using the optimal threshold of FLT and FDG PET/CT. The radiation dose was prescribed as 60 Gy in 30 fractions with a precise radiotherapy technique. Results: The mean +- standard deviation pathologic gross tumor length was 4.94 +- 2.21 cm. On FLT PET/CT, the length of the standardized uptake value 1.4 was 4.91 +- 2.43 cm. On FDG PET/CT, the length of the standardized uptake value 2.5 was 5.10 +- 2.18 cm, both of which seemed more approximate to the pathologic gross tumor length. The differences in the bilateral lung volume receiving >=20 Gy, heart volume receiving >=40 Gy, and the maximal dose received by spinal cord between FLT and FDG were not significant. However, the values for mean lung dose, bilateral lung volume receiving >=5, >=10, >=30, >=40, and >=50 Gy, mean heart dose, and heart volume receiving >=30 Gy using FLT PET/CT-based planning were significant lower than those using FDG PET/CT. Conclusion: A standardized uptake value cutoff of 1.4 on FLT PET/CT and one of 2.5 on FDG PET/CT provided the closest estimation of GTV length. Finally, FLT PET/CT-based treatment planning provided potential benefits to the lungs and heart.

Han Dali [Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, Shandong Province (China); Yu Jinming, E-mail: yujmwin@yahoo.c [Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, Shandong Province (China); Yu Yonghua; Zhang Guifang; Zhong Xiaojun; Lu Jie; Yin Yong [Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, Shandong Province (China); Fu Zheng [Department of Nuclear Medicine, Shandong Cancer Hospital and Institute, Jinan, Shandong Province (China); Mu Dianbin [Department of Pathology, Shandong Cancer Hospital and Institute, Jinan, Shandong Province (China); Zhang Baijiang [Department of Thoracic Surgery, Shandong Cancer Hospital and Institute, Jinan, Shandong Province (China); He Wei; Huo Zhijun; Liu Xijun; Kong Lei [Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, Shandong Province (China); Zhao Shuqiang [Department of Nuclear Medicine, Shandong Cancer Hospital and Institute, Jinan, Shandong Province (China); Sun Xiangyu [Department of Pathology, Shandong Cancer Hospital and Institute, Jinan, Shandong Province (China)

2010-03-15T23:59:59.000Z

154

Geometric classification of open-cell metal foams using X-ray micro-computed tomography  

Science Conference Proceedings (OSTI)

The geometry of foams has long been an area of interest, and a number of idealized geometric descriptions have been proposed. In order to acquire detailed, quantitative, geometric data for aluminum open-cell metal foams, X-ray {mu}CT is employed. The X-ray {mu}CT images are analyzed using specialized software, FoamView Registered-Sign , from which geometric information including strut length and pore shapes are extracted. The X-ray {mu}CT analysis allows comparison of the ideal geometric models to the actual geometric characteristics of the metal foam samples. The results reveal a high variability in ligament length, as well as features supporting the ideal geometry known as the Weaire-Phelan unit cell. The geometric findings provide information useful for improving current models of open-cell metal foam. Applications can range from predicting heat transfer or load failure to predicting liquid retention. Highlights: Black-Right-Pointing-Pointer Aluminum open-cell metal foams are geometrically classified Black-Right-Pointing-Pointer X-ray micro-computed tomography and specialized software are used to gather geometric data Black-Right-Pointing-Pointer The foams are shown to have a high variability in strut length Black-Right-Pointing-Pointer The Weaire-Phelan unit cell is shown to be a better representative of these foams.

Bock, Jessica, E-mail: bock6@illinois.edu; Jacobi, Anthony M., E-mail: a-jacobi@illinois.edu

2013-01-15T23:59:59.000Z

155

DOE - Office of Legacy Management -- Sperry Products Inc - CT 07  

NLE Websites -- All DOE Office Websites (Extended Search)

Sperry Products Inc - CT 07 Sperry Products Inc - CT 07 FUSRAP Considered Sites Site: SPERRY PRODUCTS, INC. (CT.07) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Danbury , Connecticut CT.07-1 Evaluation Year: 1994 CT.07-2 Site Operations: Performed tests involving non-destructive inspection techniques in the 1950s. CT.07-3 Site Disposition: Eliminated - Potential for contamination considered remote based on the limited scope of activities performed at the site CT.07-2 Radioactive Materials Handled: Yes Primary Radioactive Materials Handled: Uranium CT.07-3 Radiological Survey(s): No Site Status: Eliminated from consideration under FUSRAP Also see Documents Related to SPERRY PRODUCTS, INC. CT.07-1 - Sperry Products Letter; VanValkenburg to DeRenzis;

156

DOE - Office of Legacy Management -- American Cyanamid Co - CT 13  

NLE Websites -- All DOE Office Websites (Extended Search)

Cyanamid Co - CT 13 Cyanamid Co - CT 13 FUSRAP Considered Sites Site: American Cyanamid Co (CT.13 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Stamford , Connecticut CT.13-1 Evaluation Year: 1987 CT.13-1 Site Operations: Produced boron and possibly handled small amounts of refined radioactive source material circa 1940's. Also possibly performed research work on irradiated "J" slugs in 1952 and 1953. CT.13-1 CT.13-3 Site Disposition: Eliminated - Potential for contamination considered remote due to the limited scope of activities involving radioactive material performed at this site CT.13-2 Radioactive Materials Handled: Yes Primary Radioactive Materials Handled: Uranium CT.13-1 Radiological Survey(s): No

157

Buried Interface Analysis Using Atom Probe Tomography  

Science Conference Proceedings (OSTI)

Contributions of Atom Probe Tomography to the Understanding of Steels · Control of p-n ... Relationships in a Series of Co-Cr-Cu-Fe-Ni-Al High Entropy Alloys.

158

Atom Probe Tomography for Industrial Applications - Programmaster ...  

Science Conference Proceedings (OSTI)

Contributions of Atom Probe Tomography to the Understanding of Steels · Control of p-n ... Relationships in a Series of Co-Cr-Cu-Fe-Ni-Al High Entropy Alloys.

159

On proton CT reconstruction using MVCT-converted virtual proton projections  

Science Conference Proceedings (OSTI)

Purpose: To describe a novel methodology of converting megavoltage x-ray projections into virtual proton projections that are otherwise missing due to the proton range limit. These converted virtual proton projections can be used in the reconstruction of proton computed tomography (pCT). Methods: Relations exist between proton projections and multispectral megavoltage x-ray projections for human tissue. Based on these relations, these tissues can be categorized into: (a) adipose tissue; (b) nonadipose soft tissues; and (c) bone. These three tissue categories can be visibly identified on a regular megavoltage x-ray computed tomography (MVCT) image. With an MVCT image and its projection data available, the x-ray projections through heterogeneous anatomy can be converted to the corresponding proton projections using predetermined calibration curves for individual materials, aided by a coarse segmentation on the x-ray CT image. To show the feasibility of this approach, mathematical simulations were carried out. The converted proton projections, plotted on a proton sinogram, were compared to the simulated ground truth. Proton stopping power images were reconstructed using either the virtual proton projections only or a blend of physically available proton projections and virtual proton projections that make up for those missing due to the range limit. These images were compared to a reference image reconstructed from theoretically calculated proton projections. Results: The converted virtual projections had an uncertainty of {+-}0.8% compared to the calculated ground truth. Proton stopping power images reconstructed using a blend of converted virtual projections (48%) and physically available projections (52%) had an uncertainty of {+-}0.86% compared with that reconstructed from theoretically calculated projections. Reconstruction solely from converted virtual proton projections had an uncertainty of {+-}1.1% compared with that reconstructed from theoretical projections. If these images are used for treatment planning, the average proton range uncertainty is estimated to be less than 1.5% for an imaging dose in the milligray range. Conclusions: The proposed method can be used to convert x-ray projections into virtual proton projections. The converted proton projections can be blended with existing proton projections or can be used solely for pCT reconstruction, addressing the range limit problem of pCT using current therapeutic proton machines.

Wang Dongxu; Mackie, T. Rockwell; Tome, Wolfgang A. [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242 (United States); Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Morgridge Institute of Research, University of Wisconsin, Madison, Wisconsin 53715 (United States); Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Oncophysics Institute, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York 10461 (United States)

2012-06-15T23:59:59.000Z

160

Low-Energy Emittance Studies with the new Allison Emittance Scanner  

SciTech Connect

The new SNS Allison emittance scanner measures emittances of 65 kV ion beams over a range of +/- 116 mrad. Its versatile control system allows for time-dependent emittance measurements using an external trigger to synchronize with pulsed ion beam systems. After an adjustable initial delay, the system acquires an array of equally-delayed beam current measurements, each averaged over a certain time span, where all three time parameters are user selectable. The zero offset of the beam current measurements is determined by averaging a fraction of 1 ms shortly before the start of the ion beam pulse. This paper discusses the optimization of the angular range. In addition it presents the first results and reports an unresolved artefact. Data are presented on the time evolution of emittance ellipses during 0.8 ms long H- beam pulses emerging from the SNS test LEBT, which is important for loss considerations in the SNS accelerator. Additional data explore the emittance growth observed with increasing beam current and/or increasing RF-power.

Stockli, Martin P [ORNL; Blokland, Willem [ORNL; Gorlov, Timofey V [ORNL; Han, Baoxi [ORNL; Long, Cary D [ORNL; Pennisi, Terry R [ORNL; Assadi, Saeed [ORNL

2010-01-01T23:59:59.000Z

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161

Mechanical Design and Evaluation of the MP-11-Like Wire Scanner Prototype  

SciTech Connect

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.

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

162

Apparatus for positioning a sample in a computerized axial tomographic scanner  

SciTech Connect

An apparatus is described for positioning a sample in a radiation field of a computerized axial tomographic scanner (CAT) for scanning by the CAT, the apparatus comprising: a first support means positioned on a first side of the CAT having a first guide means; a first trolly means having means for engaging the first guide means; means for moving the first trolley means along the first guide means; a second support means positioned on a second side of the CAT, the second side being opposite the first side and the second support means having a second guide means; a second trolley means having means for engaging the second guide means; means for coupling the first trolley means to the second trolley means such that movement of the first trolley means causes similar movement of the second trolley means, the coupling means passing through the radiation field of the CAT; means attached to the coupling means for holding the sample; means for sensing the position of the sample holding means; and control means connected to the moving means and sensing means for controlling the positioning of the sample.

Vinegar, H.J.; Wellington, S.L.

1986-04-15T23:59:59.000Z

163

Recent results with a CdTe imaging portal scanner for radiation therapy  

SciTech Connect

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.

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

164

Mathematical Problems of Thermoacoustic Tomography  

E-Print Network (OSTI)

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 equation: one observes the data on a hyper-surface and reconstructs the initial perturbation. In this dissertation, we consider several mathematical problems of TAT. The first problem is the inversion formulas. We provide a family of closed form inversion formulas to reconstruct the initial perturbation from the observed data. The second problem is the range description. We present the range description of the spherical mean Radon transform, which is an important transform in TAT. The next problem is the stability analysis for TAT. We prove that the reconstruction of the initial perturbation from observed data is not H¨older stable if some observability condition is violated. The last problem is the speed determination. The question is whether the observed data uniquely determines the ultrasound speed and initial perturbation. We provide some initial results on this issue. They include the unique determination of the unknown constant speed, a weak local uniqueness, a characterization of the non-uniqueness, and a characterization of the kernel of the linearized operator.

Nguyen, Linh V.

2010-08-01T23:59:59.000Z

165

The Application of Monochromatic Energies to Investigate Multiphase Porous Media Systems using Synchrotron X-ray Tomography  

SciTech Connect

X-ray computed tomography (CT) is becoming a useful tool for nondestructive imaging of many geoenvironmental and geotechnical systems. Conventional X-ray CT systems typically utilize a polychromatic X-ray beam. While providing a high throughput of photons, the use of polychromatic energy can make quantifying material concentrations, densities or composition very difficult or impossible without appropriate standards. Synchrotron X-rays have an extremely small angular divergence, thus permitting spatial resolution that is only limited by the optical components of the system. In addition, the ability to tune to a monochromatic X-ray energy allows better phase contrast by reducing beam hardening and allowing for elemental discrimination. In this work we will show how monochromatic energy can be used to provide high-quality images allowing for phase separation several different porous media systems thus improving our ability to quantify a range of processes and phenomena.

Ham, Kyungmin; Willson, Clinton S. (LSU)

2006-01-31T23:59:59.000Z

166

CT imaging techniques for two-phase and three-phase in-situ saturation measurements  

SciTech Connect

The aim of this research is to use the SUPRI 3D steam injection laboratory model to establish a reliable method for 3-phase in-situ saturation measurements, and thereafter investigate the mechanism of steamflood at residual oil saturation. Demiral et al. designed and constructed a three dimensional laboratory model that can be used to measure temperature, pressure and heat loss data. The model is also designed so that its construction materials are not a limiting factor for CT scanning. We have used this model for our study. In this study, we saturated the model with mineral oil, and carried out waterflood until residual oil saturation. Steamflood was then carried out. A leak appeared at the bottom of the model. Despite this problem, the saturation results, obtained by using 2-phase and 3-phase saturation equations and obtained from the Cat scanner, were compared with the saturations obtained from material balance. The errors thus obtained were compared with those obtained by an error analysis carried out on the saturation equations. This report gives details of the experimental procedures, the data acquisition and data processing computer programs, and the analysis of a steamflood experiment carried out at residual oil saturation.

Sharma, B.C.; Brigham, W.E.; Castanier, L.M.

1997-06-01T23:59:59.000Z

167

DOE - Office of Legacy Management -- Wesleyan University - CT 12  

NLE Websites -- All DOE Office Websites (Extended Search)

Wesleyan University - CT 12 Wesleyan University - CT 12 FUSRAP Considered Sites Site: Wesleyan University (CT.12 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Middletown , Connecticut CT.12-1 Evaluation Year: 1995 CT.12-2 Site Operations: Spectrographic research on small quantities of uranium wire (several inches in length) in Physics Department circa late 1950. CT.12-1 Site Disposition: Eliminated - Potential for contamination considered remote due to the limited scope of activities performed CT.12-2 Radioactive Materials Handled: Yes Primary Radioactive Materials Handled: Uranium CT.12-1 Radiological Survey(s): No Site Status: Eliminated from consideration under FUSRAP Also see Documents Related to Wesleyan University

168

DOE - Office of Legacy Management -- New Canaan Site - CT 08  

Office of Legacy Management (LM)

Year: 1985 CT.08-2 Site Operations: None; Investigation of area prompted by public query; no site found in New Canaan. CT.08-1 Site Disposition: Eliminated - No AEC site...

169

TE Connectivity Finds Answers in Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

TE Connectivity Finds Answers in TE Connectivity Finds Answers in Tomography TE Connectivity Finds Answers in Tomography Print Thursday, 22 August 2013 10:50 TE Connectivity is a world leader in connectivity-the $13 billion global company designs and manufactures more than 500,000 different electronic connectivity products for the automotive, energy, industrial, broadband communications, consumer device, healthcare, aerospace, and defense industries. TE Connectivity has a long-standing commitment to innovation and engineering excellence. Their products help address challenges arising from companies' need for energy efficiency, always-on communications, and ever-increasing productivity. Recently, a team led by TE's senior manager of materials development, Dr. Jerzy Gazda (at left), has been investigating how ALS tomography capabilities can help the company develop more efficient connectors.

170

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

SciTech Connect

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.

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

171

Positron Computed Tomography: Current State, Clinical Results and Future Trends  

DOE R&D Accomplishments (OSTI)

An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends. (ACR)

Schelbert, H. R.; Phelps, M. E.; Kuhl, D. E.

1980-09-00T23:59:59.000Z

172

Reference-free ground truth metric for metal artifact evaluation in CT images  

SciTech Connect

Purpose: In computed tomography (CT), metal objects in the region of interest introduce data inconsistencies during acquisition. Reconstructing these data results in an image with star shaped artifacts induced by the metal inconsistencies. To enhance image quality, the influence of the metal objects can be reduced by different metal artifact reduction (MAR) strategies. For an adequate evaluation of new MAR approaches a ground truth reference data set is needed. In technical evaluations, where phantoms can be measured with and without metal inserts, ground truth data can easily be obtained by a second reference data acquisition. Obviously, this is not possible for clinical data. Here, an alternative evaluation method is presented without the need of an additionally acquired reference data set. Methods: The proposed metric is based on an inherent ground truth for metal artifacts as well as MAR methods comparison, where no reference information in terms of a second acquisition is needed. The method is based on the forward projection of a reconstructed image, which is compared to the actually measured projection data. Results: The new evaluation technique is performed on phantom and on clinical CT data with and without MAR. The metric results are then compared with methods using a reference data set as well as an expert-based classification. It is shown that the new approach is an adequate quantification technique for artifact strength in reconstructed metal or MAR CT images. Conclusions: The presented method works solely on the original projection data itself, which yields some advantages compared to distance measures in image domain using two data sets. Beside this, no parameters have to be manually chosen. The new metric is a useful evaluation alternative when no reference data are available.

Kratz, Baerbel; Ens, Svitlana; Mueller, Jan; Buzug, Thorsten M. [Institute of Medical Engineering, University of Luebeck, 23538 Luebeck (Germany)

2011-07-15T23:59:59.000Z

173

Positron Emission Tomography/Computed Tomography in the Staging and Treatment of Anal Cancer  

SciTech Connect

Purpose: This study was intended to determine the role of PET/CT in the staging of anal cancer as a supplement to three-dimensional transanal ultrasound (TAUS) and inguinal ultrasound (US). The impact of the PET/CT on the initial stage and treatment plan proposed by TAUS/US was assessed. Methods and Materials: Ninety-five (95) patients referred to our clinic between July 1, 2005, and December 31, 2009, were retrospectively reviewed. All patients had biopsy-proven primary squamous cell cancer of the anal canal. There were 65 females (68%) and 30 males (32%), and the median age was 58 years (range, 35-88 years). Six (6%) of the patients were HIV positive. All patients were staged with TAUS/US and PET/CT. Results: Twenty-eight (28) patients were diagnosed with suspicious perirectal node metastases. TAUS visualized 24 of these, whereas PET/CT detected 15. Suspicious inguinal nodes were visualized on either US or PET/CT in 41 patients. Seventeen (17) of these had confirmed malignant disease on biopsy, and 15 had confirmed benign disease. All 17 patients (100%) with malignant inguinal nodes were diagnosed by PET/CT, whereas US identified 16 (94%). Ten patients were diagnosed with suspicious inguinal nodes on PET/CT that had not been seen on US. One of these was malignant, three were benign, and six were not biopsied. PET/CT diagnosed eight metastatic sites, whereas TAUS/US diagnosed three. PET/CT discovered three of the five synchronous cancers seen in this study. PET/CT upstaged the disease in 14% of the cases and changed the treatment plan proposed by TAUS/US in 17%. Conclusion: PET/CT has great potential influence on the staging and treatment of anal cancer. TAUS is important in the staging of the primary tumor and N1-stage, whereas PET/CT seems necessary for the N2/3-stage, the M-stage and synchronous cancers.

Sveistrup, Joen, E-mail: joensveistrup@hotmail.com [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); Loft, Annika [PET and Cyclotron Unit, Department of Clinical Physiology and Nuclear Medicine, Centre of Diagnostic Investigations, Rigshospitalet, Copenhagen (Denmark); Berthelsen, Anne Kiil [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); PET and Cyclotron Unit, Department of Clinical Physiology and Nuclear Medicine, Centre of Diagnostic Investigations, Rigshospitalet, Copenhagen (Denmark); Henriksen, Birthe Merete; Nielsen, Michael Bachmann [Department of Radiology, Section of Ultrasound X4123, Rigshospitalet, Copenhagen (Denmark); Engelholm, Svend Aage [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark)

2012-05-01T23:59:59.000Z

174

Parallel implementation of stochastic inversion of seismic tomography data  

Science Conference Proceedings (OSTI)

In this paper parallel implementation of stochastic inversion of seismic tomography data was presented. Classical approach to travel time tomography assumes straight line of seismic rays between sources and receives points and isotropy of geological ... Keywords: inverse problem, master-slave paradigm, seismic anisotropy, seismic tomography

Maciej Dwornik; Anna Pi?ta

2011-09-01T23:59:59.000Z

175

Wireless Tomography, Part I: A Novel Approach to Remote Sensing  

E-Print Network (OSTI)

Wireless Tomography, Part I: A Novel Approach to Remote Sensing R. C. Qiu, M. C. Wicks, L. Li, Z. Browning.12@us.af.mil Abstract--Wireless tomography, a novel approach to remote sensing, is proposed--radio frequency tomography, remote sensing, cognitive radar, cognitive radio. I. INTRODUCTION The ever increasing

Qiu, Robert Caiming

176

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

E-Print Network (OSTI)

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. An accompanying data density image was created for each composite to indicate the degree of data coverage. Australian climatological data and 1000mb and 850mb monthly mean wind fields were used to interpret the dominant features in the composites. Because the primary source of the measured radiances in the Channel 4 data was thought to be suspended dust, it was theorized that the dominant aerosol features would be located downwind of regions with high dust storm activity. Elevated 670nm radiances were observed throughout 1979 within the portion of study region located between-I 5'S and the equator. However, the wind field data and rainfall climatology did not support dust transport to this region. Although biomass burning and biogenic hydrocarbon production were likely aerosol sources, the Channel 4 data suggested that they were not likely to be the primary source for the elevated radiances in the region. The low level wind fields and climatological data supported the feasibility of dust transport off the northwest coast of Australia over the Indian Ocean. The 1979 CZCS data indicated elevated 670nm radiances did occur in this region. However, the pattern of the signal suggested these radiances may not have been due to dust transport. The daily 670nm images indicated sun glint and faulty cloud-masking were probable sources for the observed radiances. The fallout of dust over New Zealand and mineral-rich deposits in sea floor sediments support the established theory of aeolian dust transport over the Tasman Sea. Elevated 670nm radiances were observed during the 1979 summer season, corroborating the existing empirical evidence. The seasonal climatology, dust storm activity, and wind field data further supported the theory of aeolian dust transport over the region during the summer months. Furthermore, due to fewer clouds and less sun glint, the potential problems with the CZCS algorithm were also thought to be reduced.

Giondomenica, Gregory Michael

1995-01-01T23:59:59.000Z

177

STANFORD GEOTHERMAL QUARTERLY REPORT  

E-Print Network (OSTI)

generator to the fluid and constant heat losses through the lines in the saturated zone. This allows us of the problems arise from the lack of the understanding of the mechanics and dynamics of this complex process tomography (CT) scanner, we visualized the process and determined the three- dimensional fluid distributions

Stanford University

178

MEASUREMENTS OF RELATIVE PERMEABILITY FOR STEAM-WATER FLOW IN POROUS MEDIA  

E-Print Network (OSTI)

MEASUREMENTS OF RELATIVE PERMEABILITY FOR STEAM-WATER FLOW IN POROUS MEDIA A REPORT SUBMITTED experimental efforts towards obtaining relative permeability for steam-water flow in a homogeneous porous computer tomography (CT) scanner. Steam fractional flow, crucial in evaluating relative permeabilities

Stanford University

179

Advanced Instrumentation for Positron Emission Tomography [PET  

DOE R&D Accomplishments (OSTI)

This paper summarizes the physical processes and medical science goals that underlay modern instrumentation design for Positron Emission Tomography. The paper discusses design factors such as detector material, crystalphototube coupling, shielding geometry, sampling motion, electronics design, time-of-flight, and the interrelationships with quantitative accuracy, spatial resolution, temporal resolution, maximum data rates, and cost.

Derenzo, S. E.; Budinger, T. F.

1985-04-00T23:59:59.000Z

180

Three-dimensional fluorescence lifetime tomography  

Science Conference Proceedings (OSTI)

Near-infrared fluorescence tomography using molecularly targeted lifetime-sensitive, fluorescent contrast agents have applications for early-stage cancer diagnostics. Yet, although the measurement of fluorescent lifetime imaging microscopy (FLIM) is extensively used in microscopy and spectroscopy applications, demonstration of fluorescence lifetime tomography for medical imaging is limited to two-dimensional studies. Herein, the feasibility of three-dimensional fluorescence-lifetime tomography on clinically relevant phantom volumes is established, using (i) a gain-modulated intensified charge coupled device (CCD) and modulated laser diode imaging system, (ii) two fluorescent contrast agents, e.g., Indocyanine green and 3-3'-Diethylthiatricarbocyanine iodide differing in their fluorescence lifetime by 0.62 ns, and (iii) a two stage approximate extended Kalman filter reconstruction algorithm. Fluorescence measurements of phase and amplitude were acquired on the phantom surface under different target to background fluorescence absorption (70:1, 100:1) and fluorescence lifetime (1:1, 2.1:1) contrasts at target depths of 1.4-2 cm. The Bayesian tomography algorithm was employed to obtain three-dimensional images of lifetime and absorption owing to the fluorophores.

Godavarty, Anuradha; Sevick-Muraca, Eva M.; Eppstein, Margaret J. [327 Votey Building, Department of Computer Science, University of Vermont, Burlington, Vermont 05405 (United States); 1011 Richardson Building, Photon Migration Laboratories, Texas A and M University, College Station, Texas 77843 (United States); 327 Votey Building, Department of Computer Science, University of Vermont, Burlington, Vermont 05405 (United States)

2005-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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181

Industrial tomography applied to reactor safety  

SciTech Connect

Work has begun which explores the use of Computed Axial Tomography (CAT), boundary detection, and internal surface reconstruction techniques in industrial nondestructive testing applications. This initial work is intended to inform the reader of the existence and interrelated nature of these techniques through the use of a realistic simulation of an industrial inspection problem.

Kruger, R.P.

1977-01-01T23:59:59.000Z

182

Progress in Cell Marking for Synchrotron X-ray Computed Tomography  

SciTech Connect

Recently there has been an increase in research activity into finding ways of marking cells in live animals for pre-clinical trials. Development of certain drugs and other therapies crucially depend on tracking particular cells or cell types in living systems. Therefore cell marking techniques are required which will enable longitudinal studies, where individuals can be examined several times over the course of a therapy or study. The benefits of being able to study both disease and therapy progression in individuals, rather than cohorts are clear. The need for high contrast 3-D imaging, without harming or altering the biological system requires a non-invasive yet penetrating imaging technique. The technique will also have to provide an appropriate spatial and contrast resolution. X-ray computed tomography offers rapid acquisition of 3-D images and is set to become one of the principal imaging techniques in this area. Work by our group over the last few years has shown that marking cells with gold nano-particles (GNP) is an effective means of visualising marked cells in-vivo using x-ray CT. Here we report the latest results from these studies. Synchrotron X-ray CT images of brain lesions in rats taken using the SYRMEP facility at the Elettra synchrotron in 2009 have been compared with histological examination of the tissues. Some deductions are drawn about the visibility of the gold loaded cells in both light microscopy and x-ray imaging.

Hall, Christopher [Monash Centre for Synchrotron Science, Monash University, Imaging and Medical Beam Line, Australian Synchrotron (Australia); Sturm, Erica [Department of Medical Imaging and Radiation Sciences, Monash University (Australia); Schultke, Elisabeth [Dept of Stereotactic Neurosurgery, Albert Ludwigs University of Freiburg (Germany); Arfelli, Fulvia; Astolfo, Alberto [Department of Physics, University of Trieste, Trieste (Italy); Menk, Ralf-Hendrik [Sincrotrone Trieste SCpA, Trieste (Italy); Juurlink, Bernhard H. J. [College of Medicine, Alfaisal University, Riyadh (Saudi Arabia)

2010-07-23T23:59:59.000Z

183

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

SciTech Connect

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.

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

2012-07-27T23:59:59.000Z

184

Radiation dose reduction to the breast in thoracic CT: Comparison of bismuth shielding, organ-based tube current modulation, and use of a globally decreased tube current  

SciTech Connect

Purpose: The purpose of this work was to evaluate dose performance and image quality in thoracic CT using three techniques to reduce dose to the breast: bismuth shielding, organ-based tube current modulation (TCM) and global tube current reduction. Methods: Semi-anthropomorphic thorax phantoms of four different sizes (15, 30, 35, and 40 cm lateral width) were used for dose measurement and image quality assessment. Four scans were performed on each phantom using 100 or 120 kV with a clinical CT scanner: (1) reference scan; (2) scan with bismuth breast shield of an appropriate thickness; (3) scan with organ-based TCM; and (4) scan with a global reduction in tube current chosen to match the dose reduction from bismuth shielding. Dose to the breast was measured with an ion chamber on the surface of the phantom. Image quality was evaluated by measuring the mean and standard deviation of CT numbers within the lung and heart regions. Results: Compared to the reference scan, dose to the breast region was decreased by about 21% for the 15-cm phantom with a pediatric (2-ply) shield and by about 37% for the 30, 35, and 40-cm phantoms with adult (4-ply) shields. Organ-based TCM decreased the dose by 12% for the 15-cm phantom, and 34-39% for the 30, 35, and 40-cm phantoms. Global lowering of the tube current reduced breast dose by 23% for the 15-cm phantom and 39% for the 30, 35, and 40-cm phantoms. In phantoms of all four sizes, image noise was increased in both the lung and heart regions with bismuth shielding. No significant increase in noise was observed with organ-based TCM. Decreasing tube current globally led to similar noise increases as bismuth shielding. Streak and beam hardening artifacts, and a resulting artifactual increase in CT numbers, were observed for scans with bismuth shields, but not for organ-based TCM or global tube current reduction. Conclusions: Organ-based TCM produces dose reduction to the breast similar to that achieved with bismuth shielding for both pediatric and adult phantoms. However, organ-based TCM does not affect image noise or CT number accuracy, both of which are adversely affected by bismuth shielding. Alternatively, globally decreasing the tube current can produce the same dose reduction to the breast as bismuth shielding, with a similar noise increase, yet without the streak artifacts and CT number errors caused by the bismuth shields. Moreover, globally decreasing the tube current reduces the dose to all tissues scanned, not simply to the breast.

Wang Jia; Duan Xinhui; Christner, Jodie A.; Leng Shuai; Yu Lifeng; McCollough, Cynthia H. [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States)

2011-11-15T23:59:59.000Z

185

CT-121_cover.p65  

NLE Websites -- All DOE Office Websites (Extended Search)

INNOVATIVE APPLICATIONS INNOVATIVE APPLICATIONS OF TECHNOLOGY FOR THE CT-121 FGD PROCESS PROJECT PERFORMANCE SUMMARY CLEAN COAL TECHNOLOGY DEMONSTRATION PROGRAM AUGUST 2002 SOUTHERN COMPANY SERVICES, INC. DOE/FE-0449 Disclaimer This report was prepared using publicly available information, including the Final Technical Report and other reports prepared pursuant to a cooperative agreement partially funded by the U.S. Department of Energy. Neither the United States Government nor any agency, employee, contractor, or representative thereof, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe upon privately

186

CT detection of occult pneumothorax in head trauma  

SciTech Connect

A prospective evaluation for occult pneumothorax was performed in 25 consecutive patients with serious head trauma by combining a limited chest CT examination with the emergency head CT examination. Of 21 pneuomothoraces present in 15 patients, 11 (52%) were found only by chest CT and were not identified clinically or by supine chest radiograph. Because of pending therapeutic measures, chest tubes were placed in nine of the 11 occult pneumothoraces, regardless of the volume. Chest CT proved itself as the most sensitive method for detection of occult pneumothorax, permitting early chest tube placement to prevent transition to a tension pneumothorax during subsequent mechanical ventilation or emergency surgery under general anesthesia.

Tocino, I.M.; Miller, M.H.; Frederick, P.R.; Bahr, A.L.; Thomas, F.

1984-11-01T23:59:59.000Z

187

Table CT1. Energy Consumption Estimates for Major Energy Sources ...  

U.S. Energy Information Administration (EIA)

R A D O. U.S. Energy Information Administration State Energy Data 2011: Consumption 89 Table CT6. Industrial Sector Energy Consumption Estimates, Selected Years, 1960 ...

188

Table CT1. Energy Consumption Estimates for Major Energy ...  

U.S. Energy Information Administration (EIA)

U.S. Energy Information Administration State Energy Data 2011: Consumption 365 Table CT2. Primary Energy Consumption Estimates, Selected Years, 1960-2011, North ...

189

Ground-based Microwave Cloud Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Microwave Cloud Tomography Microwave Cloud Tomography Experiment, SGP, May 15-June 15, 2009 Lead Scientist Dong Huang, BNL Co-Investigators Al Gasiewski, UC Boulder Maria Cadeddu, ANL Warren Wiscombe, BNL Radiation Processes Working Group March 30, 2009 multiple radiometers All good cloud radiation modelers should close their airplane window shades so as not to be corrupted by the spectacle of real 3D clouds. - Roger Davies In case you forget to do this, you see 3/30/2009 ARM RPWG 2 Effects of cloud structure on radiation 3/30/2009 ARM RPWG 3 Typical climate model - Cloud fraction & mean water content - Horizontally uniform clouds, no side radiation - Assumption on overlap Courtesy of Bernhard Mayer Cloud structure important to radiation - Cumulus (Benner & Evans 2001, Pincus et al. 2005), deep convection (DiGiuseppe &

190

Photon-number tomography and fidelity  

E-Print Network (OSTI)

The scheme of photon-number tomography is discussed in the framework of star-product quantization. The connection of dual quantization scheme and observables is reviewed. The quantizer and dequantizer operators and kernels of star product of tomograms in photon-number tomography scheme and its dual one are presented in explicit form. The fidelity and state purity are discussed in photon{number tomographic scheme, and the expressions for fidelity and purity are obtained in the form of integral of the product of two photon-number tomograms with integral kernel which is presented in explicit form. The properties of quantumness are discussed in terms of inequalities on state photon{number tomograms.

O. V. Man'ko

2012-12-23T23:59:59.000Z

191

A wavelet phase filter for emission tomography  

Science Conference Proceedings (OSTI)

The presence of a high level of noise is a characteristic in some tomographic imaging techniques such as positron emission tomography (PET). Wavelet methods can smooth out noise while preserving significant features of images. Mallat et al. proposed a wavelet based denoising scheme exploiting wavelet modulus maxima, but the scheme is sensitive to noise. In this study, the authors explore the properties of wavelet phase, with a focus on reconstruction of emission tomography images. Specifically, they show that the wavelet phase of regular Poisson noise under a Haar-type wavelet transform converges in distribution to a random variable uniformly distributed on [0, 2{pi}). They then propose three wavelet-phase-based denoising schemes which exploit this property: edge tracking, local phase variance thresholding, and scale phase variation thresholding. Some numerical results are also presented. The numerical experiments indicate that wavelet phase techniques show promise for wavelet based denoising methods.

Olsen, E.T.; Lin, B. [Illinois Inst. of Tech., Chicago, IL (United States). Dept. of Mathematics

1995-07-01T23:59:59.000Z

192

Piecewise structural diffusion defined on shape index for noise reduction in dual-energy CT images  

Science Conference Proceedings (OSTI)

The increasing radiation dose in dual-energy CT (DE-CT) scanning due to the double exposures at 80 kVp and 140 kVp is a major concern in the application of DE-CT. This paper presents a novel image-space denoising method, called piecewise structural ... Keywords: dual-energy CT, dual-energy CT colonography, noise reduction

Wenli Cai; June-Goo Lee; Da Zhang; Christina Piel; Hiroyuki Yoshida

2012-10-01T23:59:59.000Z

193

Improving scintillation crystals using muon tomography  

SciTech Connect

The cosmic ray muon scanning array provides information on NaI(T1) crystals using some 65,536 trajectories, each measuring the NaI(T1) response to high energy muons. With this information, it is possible to use established computer-aided-tomography techniques to deconvolute these integrated responses and produce a detailed picture of the detector's interior.

Dowell, D.H.; Fineman, B.J.; Sandorfi, A.M.

1987-01-01T23:59:59.000Z

194

CT reconstruction from limited projection angles  

SciTech Connect

When the available CT projection data are incomplete, there exists a null space in the space of possible reconstructions about which the data provide no information. Deterministic CT reconstructions are impotent in regard to this null space. Furthermore, it is shown that consistency conditions based on projection moments do not provide the missing projections. When the projection data consist of a set of parallel projections that do not encompass a complete 180/sup 0/ rotation, the null space corresponds to a missing sector in the Fourier transform of the original 2-D function. The long-range streak artifacts created by the missing sector can be reduced by attenuating the Fourier transform of the reconstruction smoothly to zero at the sector boundary. It is shown that the Fourier transform of a reconstruction obtained under a maximum entropy constraint is nearly zero in the missing sector. Hence, maximum entropy does not overcome the basic lack of information. It is suggested that some portion of the null space might be filled in by use of a priori knowledge of the type of image expected.

Hanson, K.M.

1982-01-01T23:59:59.000Z

195

The Effect of a Contrast Agent on Proton Beam Range in Radiotherapy Planning Using Computed Tomography for Patients With Locoregionally Advanced Lung Cancer  

SciTech Connect

Purpose: We evaluated the effect of a contrast agent (CA) on proton beam range in a treatment planning system (TPS) for patients with locoregionally advanced lung cancer. Methods and Materials: Two sets of computed tomography (CT) images (with and without CA) were obtained from 20 patients with lung cancer. Because the increase in Hounsfield unit ( Increment HU) value of the heart and great vessels due to the effect of CA is most prominent among thoracic structures, to evaluate the effect of CA on proton beam range in the TPS, we compared the calculated distal ranges in the plan with CA-enhanced CT with those with corrected CT, in which the HU values of the heart and great vessels in the CA-enhanced CT were replaced by average HU values obtained from the unenhanced CT. Results: The mean Increment HU value and the longest length of the heart and great vessels within the proton beam path in the field that passed through these structures were 189 {+-} 29 HU (range, 110-250 HU) and 7.1 {+-} 1.1 cm (range, 2.6-11.2 cm), respectively. The mean distal range error in the TPS because of the presence of CA was 1.0 {+-} 0.7 cm (range, 0.2-2.6 cm). Conclusion: If CA-enhanced CT images are used for radiotherapy planning using a proton beam for the treatment of lung cancer, our results suggest that the HU values of the heart and great vessels should be replaced by the average HU values of soft tissue to avoid discrepancies between planned and delivered doses.

Hwang, Ui-Jung; Shin, Dong Ho [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Kim, Tae Hyun, E-mail: k2onco@naver.com [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Moon, Sung Ho; Lim, Young Kyung; Jeong, Hojin; Rah, Jeong-Eun; Kim, Sang Soo; Kim, Joo-Young; Kim, Dae Yong; Park, Sung Yong; Cho, Kwan Ho [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of)

2011-11-15T23:59:59.000Z

196

Electronic cleansing in CT colonography: past, present, and future  

Science Conference Proceedings (OSTI)

Fecal tagging is a means of ‘marking' fecal residues (stool and fluid) in a colon by use of the oral administration of a positive contrast agent (barium or iodine) in CT Colonography (CTC). Electronic cleansing (EC) is an emerging technique for ... Keywords: CT colonography, bowel preparation, electronic cleansing, fecal tagging

Wenli Cai; Hiroyuki Yoshida

2010-09-01T23:59:59.000Z

197

Former Worker Program - Low-Dose Spiral CT Scans for Early Lung...  

NLE Websites -- All DOE Office Websites (Extended Search)

of radiation emitted during CT scans. Chest CT, in general, requires less radiation exposure than other CT procedures because the air-filled tissues of the lungs are not as dense...

198

Recent Advances in Atom Probe Tomography for Microstructural ...  

Science Conference Proceedings (OSTI)

In-situ Ultra Fast Micro-tomography for Material Characterization · In situ Characterization of Surfaces and Buried Interfaces Using Total Reflection Inelastic ...

199

The Application of Atom Probe Tomography to Oxide-Dispersion ...  

Science Conference Proceedings (OSTI)

Contributions of Atom Probe Tomography to the Understanding of Steels ... Investigation of the Microstructure-Property-Processing Relationships in a Series of ...

200

Time-dependent seismic tomography and its application to the...  

Open Energy Info (EERE)

changes in Earth structure are commonly determined using local earthquake tomography computer programs that invert multiple seismic-wave arrival time data sets separately and...

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Imaging and sensing based on muon tomography - Energy Innovation ...  

Subtraction techniques are described to enhance the processing of the muon tomography data. Skip to Content. ... Hydropower, Wave and Tidal; Industrial Technologies ...

202

Minimally invasive diagnostic imaging using high resolution Optical Coherence Tomography  

E-Print Network (OSTI)

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 ...

Herz, Paul Richard, 1972-

2004-01-01T23:59:59.000Z

203

MicroCT: Automated Analysis of CT Reconstructed Data of Home Made Explosive Materials Using the Matlab MicroCT Analysis GUI  

SciTech Connect

This Standard Operating Procedure (SOP) provides the specific procedural steps for analyzing reconstructed CT images obtained under the IDD Standard Operating Procedures for data acquisition [1] and MicroCT image reconstruction [2], per the IDD Quality Assurance Plan for MicroCT Scanning [3]. Although intended to apply primarily to MicroCT data acquired in the HEAFCAT Facility at LLNL, these procedures may also be applied to data acquired at Tyndall from the YXLON cabinet and at TSL from the HEXCAT system. This SOP also provides the procedural steps for preparing the tables and graphs to be used in the reporting of analytical results. This SOP applies to production work - for R and D there are two other semi-automated methods as given in [4, 5].

Seetho, I M; Brown, W D; Kallman, J S; Martz, H E; White, W T

2011-09-22T23:59:59.000Z

204

MicroCT: Semi-Automated Analysis of CT Reconstructed Data of Home Made Explosive Materials Using the Matlab MicroCT Analysis GUI  

SciTech Connect

This Standard Operating Procedure (SOP) provides the specific procedural steps for analyzing reconstructed CT images obtained under the IDD Standard Operating Procedures for data acquisition [1] and MicroCT image reconstruction [2], per the IDD Quality Assurance Plan for MicroCT Scanning [3]. Although intended to apply primarily to MicroCT data acquired in the HEAFCAT Facility at LLNL, these procedures may also be applied to data acquired at Tyndall from the YXLON cabinet and at TSL from the HEXCAT system. This SOP also provides the procedural steps for preparing the tables and graphs to be used in the reporting of analytical results. This SOP applies to R and D work - for production applications, use [4].

Seetho, I M; Brown, W D; Kallman, J S; Martz, H E; White, W T

2011-09-22T23:59:59.000Z

205

Novel ultrahigh resolution data acquisition and image reconstruction for multi-detector row CT  

Science Conference Proceedings (OSTI)

We present and evaluate a special ultrahigh resolution mode providing considerably enhanced spatial resolution both in the scan plane and in the z-axis direction for a routine medical multi-detector row computed tomography (CT) system. Data acquisition is performed by using a flying focal spot both in the scan plane and in the z-axis direction in combination with tantalum grids that are inserted in front of the multi-row detector to reduce the aperture of the detector elements both in-plane and in the z-axis direction. The dose utilization of the system for standard applications is not affected, since the grids are moved into place only when needed and are removed for standard scanning. By means of this technique, image slices with a nominal section width of 0.4 mm (measured full width at half maximum=0.45 mm) can be reconstructed in spiral mode on a CT system with a detector configuration of 32x0.6 mm. The measured 2% value of the in-plane modulation transfer function (MTF) is 20.4 lp/cm, the measured 2% value of the longitudinal (z axis) MTF is 21.5 lp/cm. In a resolution phantom with metal line pair test patterns, spatial resolution of 20 lp/cm can be demonstrated both in the scan plane and along the z axis. This corresponds to an object size of 0.25 mm that can be resolved. The new mode is intended for ultrahigh resolution bone imaging, in particular for wrists, joints, and inner ear studies, where a higher level of image noise due to the reduced aperture is an acceptable trade-off for the clinical benefit brought about by the improved spatial resolution.

Flohr, T. G.; Stierstorfer, K.; Suess, C.; Schmidt, B.; Primak, A. N.; McCollough, C. H. [Siemens Medical Solutions, Computed Tomography CTE PA Siemensstr. 1, 91301 Forchheim (Germany) and Department of Diagnostic Radiology, Eberhard-Karls-Universitaet Tuebingen (Germany); Siemens Medical Solutions, Computed Tomography CTE PA Siemensstr. 1, 91301 Forchheim (Germany); Mayo Clinic College of Medicine, Department of Radiology, Rochester, Minnesota (United States)

2007-05-15T23:59:59.000Z

206

CT Solar Loan | Open Energy Information  

Open Energy Info (EERE)

Solar Loan Solar Loan No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Summary Last modified on March 29, 2013. Financial Incentive Program Place Connecticut Name CT Solar Loan Incentive Type State Loan Program Applicable Sector Multi-Family Residential, Residential Eligible Technologies Photovoltaics Active Incentive Yes Implementing Sector State/Territory Energy Category Renewable Energy Incentive Programs Terms 15 years Program Administrator The Clean Energy Finance and Investment Authority Website http://www.energizect.com/residents/programs/ctsolarloan Last DSIRE Review 03/29/2013 References Database of State Incentives for Renewables and Efficiency[1] Summary The Clean Energy Finance and Investment Authority is offering a pilot loan

207

Microsoft Word - Ct121R1.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

Innovative Applications Innovative Applications of Technology for the CT-121 FGD Process A DOE Assessment DOE/NETL-2002/1177 September 2002 U.S. Department of Energy National Energy Technology Laboratory P.O. Box 880, 3610 Collins Ferry Road Morgantown, WV 26507-0880 P.O. Box 10940, 626 Cochrans Mill Road Pittsburgh, PA 15236-0940 West Third Street, Suite 1400 Tulsa, OK 74103-3519 website: www.netl.doe.gov 2 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents

208

CT113-53 Cape Wind Report_  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

M M Report of the Effect on Radar Performance of the Proposed Cape Wind Project and Advance Copy of USCG Findings and Mitigation U.S. Department of the Interior Minerals Management Service MMS Cape Wind Energy Project January 2009 Final EIS Appendix M Report of the Effect on Radar Performance of the Proposed Cape Wind Project and Advance Copy of USCG Findings and Mitigation Technology Service Corporation an employee-owned company 55 Corporate Drive 3rd Floor, Trumbull, Connecticut 06611 Phone: (203) 268-1249 Fax: (203) 452-0260 www.tsc.com Ref: TSC-CT113-53 Report of the Effect on Radar Performance of the Proposed Cape Wind Project Submitted to the United States Coast Guard December 16, 2008 USCG Order #HSCG24-08-F-16A248

209

NIST Standards for x-ray computed tomography  

Science Conference Proceedings (OSTI)

... a standard for lung CT imaging. Staff: ... Related programs and projects: Associated products: Beta-test versions of the density and length standards ...

2013-03-26T23:59:59.000Z

210

THE THERMAL SUNYAEV-ZEL'DOVICH TOMOGRAPHY  

Science Conference Proceedings (OSTI)

The thermal Sunyaev-Zel'dovich (tSZ) effect directly measures the thermal pressure of free electrons integrated along the line of sight and thus contains valuable information on the thermal history of the universe. However, the redshift information is entangled in the projection along the line of sight. This projection effect severely degrades the power of the tSZ effect to reconstruct the thermal history. We investigate the tSZ tomography technique to recover this otherwise lost redshift information by cross-correlating the tSZ effect with galaxies of known redshifts, or alternatively with matter distribution reconstructed from weak-lensing tomography. We investigate in detail the three-dimensional distribution of the gas thermal pressure and its relation with the matter distribution, through our adiabatic hydrodynamic simulation and the one with additional gastrophysics including radiative cooling, star formation, and supernova feedback. (1) We find a strong correlation between the gas pressure and matter distribution, with a typical cross-correlation coefficient r {approx}> 0.7 at k {approx}tight correlation will enable robust cross-correlation measurement between SZ surveys such as Planck, ACT, and SPT and lensing surveys such as DES and LSST, at {approx}>20{sigma}-100{sigma} level. (2) We propose a tomography technique to convert the measured cross-correlation into the contribution from gas in each redshift bin to the tSZ power spectrum. Uncertainties in gastrophysics may affect the reconstruction at {approx}2% level, due to the {approx}1% impact of gastrophysics on r found in our simulations. However, we find that the same gastrophysics affects the tSZ power spectrum at {approx}40% level, so it is robust to infer the gastrophysics from the reconstructed redshift-resolved contribution.

Shao Jiawei; Zhang Pengjie; Lin Weipeng; Jing Yipeng, E-mail: jwshao@shao.ac.cn [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Nandan Road 80, Shanghai 200030 (China)

2011-04-01T23:59:59.000Z

211

Predicting the fidelity of JPEG2000 compressed CT images using DICOM header information  

Science Conference Proceedings (OSTI)

Purpose: To propose multiple logistic regression (MLR) and artificial neural network (ANN) models constructed using digital imaging and communications in medicine (DICOM) header information in predicting the fidelity of Joint Photographic Experts Group (JPEG) 2000 compressed abdomen computed tomography (CT) images. Methods: Our institutional review board approved this study and waived informed patient consent. Using a JPEG2000 algorithm, 360 abdomen CT images were compressed reversibly (n = 48, as negative control) or irreversibly (n = 312) to one of different compression ratios (CRs) ranging from 4:1 to 10:1. Five radiologists independently determined whether the original and compressed images were distinguishable or indistinguishable. The 312 irreversibly compressed images were divided randomly into training (n = 156) and testing (n = 156) sets. The MLR and ANN models were constructed regarding the DICOM header information as independent variables and the pooled radiologists' responses as dependent variable. As independent variables, we selected the CR (DICOM tag number: 0028, 2112), effective tube current-time product (0018, 9332), section thickness (0018, 0050), and field of view (0018, 0090) among the DICOM tags. Using the training set, an optimal subset of independent variables was determined by backward stepwise selection in a four-fold cross-validation scheme. The MLR and ANN models were constructed with the determined independent variables using the training set. The models were then evaluated on the testing set by using receiver-operating-characteristic (ROC) analysis regarding the radiologists' pooled responses as the reference standard and by measuring Spearman rank correlation between the model prediction and the number of radiologists who rated the two images as distinguishable. Results: The CR and section thickness were determined as the optimal independent variables. The areas under the ROC curve for the MLR and ANN predictions were 0.91 (95% CI; 0.86, 0.95) and 0.92 (0.87, 0.96), respectively. The correlation coefficients of the MLR and ANN predictions with the number of radiologists who responded as distinguishable were 0.76 (0.69, 0.82, p < 0.001) and 0.78 (0.71, 0.83, p < 0.001), respectively. Conclusions: The MLR and ANN models constructed using the DICOM header information offer promise in predicting the fidelity of JPEG2000 compressed abdomen CT images.

Kim, Kil Joong; Kim, Bohyoung; Lee, Hyunna; Choi, Hosik; Jeon, Jong-June; Ahn, Jeong-Hwan; Lee, Kyoung Ho [Department of Radiation Applied Life Science, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul, 110-744 (Korea, Republic of); School of Computer Science and Engineering, Seoul National University, 599 Kwanak-Ro, Kwanak-Gu, Seoul, 151-742 (Korea, Republic of); Department of Informational Statistics, Hoseo University, 165, Sechul-ri, Baebang-myeon, Asan-si, Chungcheongnam-do, 336-795 (Korea, Republic of); Department of Statistics, Seoul National University, 599 Kwanak-Ro, Kwanak-Gu, Seoul, 151-742 (Korea, Republic of); Korean Intellectual Property Office, Government Complex-Daejeon, 139 Seonsa-ro, Seo-gu, Daejeon, 302-701 (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, Gyeonggi-do, 463-707 (Korea, Republic of)

2011-12-15T23:59:59.000Z

212

Error matrix in quantum process tomography  

E-Print Network (OSTI)

We discuss characterization of experimental quantum gates by the error matrix, which is similar to the standard process matrix $\\chi$ in the Pauli basis, except the desired unitary operation is factored out, by formally placing it either before or after the error process. The error matrix has only one large element, which is equal to the process fidelity, while other elements are small and indicate imperfections. The imaginary parts of the elements along the left column and/or top row directly indicate the unitary imperfection and can be used to find the needed correction. We discuss a relatively simple way to calculate the error matrix for a composition of quantum gates. Similarly, it is rather straightforward to find the first-order contribution to the error matrix due to the Lindblad-form decoherence. We also discuss a way to identify and subtract the tomography procedure errors due to imperfect state preparation and measurement. In appendices we consider several simple examples of the process tomography and also discuss an intuitive physical interpretation of the Lindblad-form decoherence.

Alexander N. Korotkov

2013-09-25T23:59:59.000Z

213

Dynamic Inversion for Hydrological Process Monitoring with Electrical Resistance Tomography Under Model Uncertainty  

E-Print Network (OSTI)

water content using electrical resistivity tomography, WaterJ. Nitao (1992), Electrical resistivity tomography of vadoseinverse model for electrical resistivity surveys and its

Lehikoinen, A.

2010-01-01T23:59:59.000Z

214

DOE - Office of Legacy Management -- Dorr Corp - CT 14  

Office of Legacy Management (LM)

to D. Arnold; Subject: Description of work and associated costs for tests; October 19, 1954 CT.14-2 - US NRC Letter; R. Bellamy to J. Russo; Subject: NRC Safety Inspection and...

215

Microsoft Word - CT for NETL Final rev4.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

Display 32 Fig. 25. Sensor Side of 64-Element Array 33 Fig. 26. Integral Surface Mount Support Electronics 33 Fig. 27. Screen Shot of 64-Element Display 34 Fig. 28. 16-Element CT...

216

Ultra-high resolution computed tomography imaging  

DOE Patents (OSTI)

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.

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

217

Positron emission tomography of the heart  

SciTech Connect

Positron emission computed tomography (PCT) represents an important new tool for the noninvasive evaluation and, more importantly, quantification of myocardial performance. Most currently available techniques permit assessment of only one aspect of cardiac function, i.e., myocardial perfusion by gamma scintillation camera imaging with Thallium-201 or left ventricular function by echocardiography or radionuclide angiocardiography. With PCT it may become possible to study all three major segments of myocardial performance, i.e., regional blood flow, mechanical function and, most importantly, myocardial metabolism. Each of these segments can either be evaluated separately or in combination. This report briefly describes the principles and technological advantages of the imaging device, reviews currently available radioactive tracers and how they can be employed for the assessment of flow, function and metabolism; and, lastly, discusses possible applications of PCT for the study of cardiac physiology or its potential role in the diagnosis of cardiac disease.

Schelbert, H.R.; Phelps, M.E.; Kuhl, D.E.

1979-01-01T23:59:59.000Z

218

Passive Network Tomography Using Bayesian Inference  

E-Print Network (OSTI)

this paper, we investigate the problem of identifying lossy links in the interior of the Internet by passively observing the end-to-end performance of existing traffic between a server and its clients. This is in contrast to the previous work on network tomography (e.g., [1]) that has been based on active probing. The key advantage of a passive approach is that it does not introduce wasteful traffic which might perturb the object of inference, i.e., the link loss rates. Moreover, our techniques depend only on knowing the number of lost and successful packets sent to each client rather than the exact loss sequence required by previous techniques such as [1]. While accuracy of link loss rate inference may consequently suffer, our techniques can still pinpoint the trouble spots in the network (e.g., highly lossy links)

Venkata N. Padmanabhan; Lili Qiu; Helen J. Wang

2002-01-01T23:59:59.000Z

219

DOE - Office of Legacy Management -- Olin Mathieson - CT 0-02  

Office of Legacy Management (LM)

Olin Mathieson - CT 0-02 Olin Mathieson - CT 0-02 FUSRAP Considered Sites Site: OLIN MATHIESON (CT.0-02 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: United Nuclear Corporation CT.0-02-1 Location: New Haven , Connecticut CT.0-02-1 Evaluation Year: 1987 CT.0-02-1 Site Operations: Began fabrication of nuclear reactor fuel elements for AEC circa late-1950s. Later became part of a group forming United Nuclear Corp. and were then licensed by AEC. Performed work for U.S. Navy and commercial applications. CT.0-02-1 Site Disposition: Eliminated - No Authority - AEC licensed CT.0-02-1 Radioactive Materials Handled: Yes CT.0-02-1 Primary Radioactive Materials Handled: Uranium CT.0-02-1 Radiological Survey(s): None Indicated

220

Permeability of laboratory-formed methane-hydrate-bearing sand: Measurements and observations using x-ray computed tomography  

SciTech Connect

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.

Kneafsey, T. J.; Seol, Y.; Gupta, A.; Tomutsa, L.

2010-09-15T23:59:59.000Z

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221

X-ray computed-tomography observations of water flow through anisotropic methane hydrate-bearing sand  

SciTech Connect

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.

Seol, Yongkoo; Kneafsey, Timothy J.

2009-06-01T23:59:59.000Z

222

Segmentation and quantification of materials with energy discriminating computed tomography: A phantom study  

Science Conference Proceedings (OSTI)

Purpose: To experimentally investigate whether a computed tomography (CT) system based on CdZnTe (CZT) detectors in conjunction with a least-squares parameter estimation technique can be used to decompose four different materials. Methods: The material decomposition process was divided into a segmentation task and a quantification task. A least-squares minimization algorithm was used to decompose materials with five measurements of the energy dependent linear attenuation coefficients. A small field-of-view energy discriminating CT system was built. The CT system consisted of an x-ray tube, a rotational stage, and an array of CZT detectors. The CZT array was composed of 64 pixels, each of which is 0.8x0.8x3 mm. Images were acquired at 80 kVp in fluoroscopic mode at 50 ms per frame. The detector resolved the x-ray spectrum into energy bins of 22-32, 33-39, 40-46, 47-56, and 57-80 keV. Four phantoms were constructed from polymethylmethacrylate (PMMA), polyethylene, polyoxymethylene, hydroxyapatite, and iodine. Three phantoms were composed of three materials with embedded hydroxyapatite (50, 150, 250, and 350 mg/ml) and iodine (4, 8, 12, and 16 mg/ml) contrast elements. One phantom was composed of four materials with embedded hydroxyapatite (150 and 350 mg/ml) and iodine (8 and 16 mg/ml). Calibrations consisted of PMMA phantoms with either hydroxyapatite (100, 200, 300, 400, and 500 mg/ml) or iodine (5, 15, 25, 35, and 45 mg/ml) embedded. Filtered backprojection and a ramp filter were used to reconstruct images from each energy bin. Material segmentation and quantification were performed and compared between different phantoms. Results: All phantoms were decomposed accurately, but some voxels in the base material regions were incorrectly identified. Average quantification errors of hydroxyapatite/iodine were 9.26/7.13%, 7.73/5.58%, and 12.93/8.23% for the three-material PMMA, polyethylene, and polyoxymethylene phantoms, respectively. The average errors for the four-material phantom were 15.62% and 2.76% for hydroxyapatite and iodine, respectively. Conclusions: The calibrated least-squares minimization technique of decomposition performed well in breast imaging tasks with an energy resolving detector. This method can provide material basis images containing concentrations of the relevant materials that can potentially be valuable in the diagnostic process.

Le, Huy Q.; Molloi, Sabee [Department of Radiological Sciences, University of California, Irvine, California 92697 (United States)

2011-01-15T23:59:59.000Z

223

Feasibility study for mega-electron-volt electron beam tomography  

SciTech Connect

Electron beam tomography is a promising imaging modality for the study of fast technical processes. But for many technical objects of interest x rays of several hundreds of keV energy are required to achieve sufficient material penetration. In this article we report on a feasibility study for fast electron beam computed tomography with a 1 MeV electron beam. The experimental setup comprises an electrostatic accelerator with beam optics, transmission target, and a single x-ray detector. We employed an inverse fan-beam tomography approach with radiographic projections being generated from the linearly moving x-ray source. Angular projections were obtained by rotating the object.

Hampel, U. [Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden (Germany); AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering, Technische Universitaet Dresden, 01062 Dresden (Germany); Baertling, Y.; Hoppe, D. [Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden (Germany); Kuksanov, N.; Fadeev, S.; Salimov, R. [Budker Institute of Nuclear Physics of Siberian Branch of Russian Academy of Science, Lavrentiev av. 11, Novosibirsk 630090 (Russian Federation)

2012-09-15T23:59:59.000Z

224

Implications of Respiratory Motion as Measured by Four-Dimensional Computed Tomography for Radiation Treatment Planning of Esophageal Cancer  

Science Conference Proceedings (OSTI)

Purpose: To evaluate the respiratory motion of primary esophageal cancers and pathologic celiac-region lymph nodes using time-resolved four-dimensional computed tomography (4D CT). Methods and Materials: Respiration-synchronized 4D CT scans were obtained to quantify the motion of primary tumors located in the proximal, mid-, or distal thoracic esophagus, as well as any involved celiac-region lymph nodes. Respiratory motion was measured in the superior-inferior (SI), anterior-posterior (AP), and left-right (LR) directions and was analyzed for correlation with anatomic location. Recommended margin expansions were determined for both primary and nodal targets. Results: Thirty patients underwent 4D CT scans at Massachusetts General Hospital for planned curative treatment of esophageal cancer. Measurements of respiratory tumor motion were obtained for 1 proximal, 4 mid-, and 25 distal esophageal tumors, as well as 12 involved celiac-region lymph nodes. The mean (SD) peak-to-peak displacements of all primary tumors in the SI, AP, and LR dimensions were 0.80 (0.45) cm, 0.28 (0.20) cm, and 0.22 (0.23) cm, respectively. Distal tumors were found to have significantly greater SI and AP motion than proximal or mid-esophageal tumors. The mean (SD) SI, AP, and LR peak-to-peak displacements of the celiac-region lymph nodes were 0.92 (0.56) cm, 0.46 (0.27) cm, and 0.19 (0.26) cm, respectively. Conclusions: Margins of 1.5 cm SI, 0.75 cm AP, and 0.75 cm LR would account for respiratory tumor motion of >95% of esophageal primary tumors in the dataset. All celiac-region lymph nodes would be adequately covered with SI, AP, and LR margins of 2.25 cm, 1.0 cm, and 0.75 cm, respectively.

Patel, Abhijit A.; Wolfgang, John A.; Niemierko, Andrzej; Hong, Theodore S.; Yock, Torunn [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Choi, Noah C. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States)], E-mail: nchoi@partners.org

2009-05-01T23:59:59.000Z

225

Further advancements for large area-detector based computed tomography system  

SciTech Connect

We present advancements made to a large area-detector based system for industrial x-ray computed tomography. Past performance improvements in data acquisition speeds were made by use of high-resolution large area, flat-panel amorphous-silicon (a-Si) detectors. The detectors have proven, over several years, to be a robust alternative to CCD-optics and image intensifier CT systems. These detectors also provide the advantage of area detection as compared with the single slice geometry of linear array systems. New advancements in this system include parallel processing of sinogram reconstructions, improved visualization software and migration to frame-rate a-Si detectors. Parallel processing provides significant speed improvements for data reconstruction, and is implemented for parallel-beam, fan-beam and Feldkamp cone-beam reconstruction algorithms. Reconstruction times are reduced by an order of magnitude by use of a cluster of ten or more equal-speed computers. Advancements in data visualization are made through interactive software, which allows interrogation of the full three-dimensional dataset. Inspection examples presented in this paper include an electromechanical device, a nonliving biological specimen and a press-cast plastic specimen. We also present a commonplace item for the benefit of the layperson.

Davis, A. W. (Anthony W.); Keating, S. C. (Scott C.); Claytor, T. N. (Thomas N.)

2001-01-01T23:59:59.000Z

226

Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators  

Open Energy Info (EERE)

Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin Details Activities (8) Areas (4) Regions (0) Abstract: Body and surface wave tomography are two of the primary methods for estimation of regional scale seismic velocity variations. Seismic velocity is affected by temperature and rock composition in complex ways, but when combined with geologic and structural maps, relative temperature can in some cases be estimated. We present preliminary tomographic models for compressional and shear-wave velocity using local and regional earthquakes recorded by Earthscope Transportable Array stations, network

227

Electrical capacitance volume tomography (ECVT) applied to bubbling fluid beds  

SciTech Connect

These presentation visuals illustrate the apparatus and method for applying Electrical Capacitance Volume Tomography (ECVT) to bubbling fluid beds to their solid fraction and bubble properties. Results are compared to estimated values.

Weber, J., Mei, J.

2012-01-01T23:59:59.000Z

228

Full-3D Waveform Tomography for Southern California | Argonne...  

NLE Websites -- All DOE Office Websites (Extended Search)

Submitted by mkaczmar on October 3, 2012 - 09:19 Authors: Lee, E., Chenm P., Jordan, T.H., Maechling, P.J., Denolle, M., Beroza, G.C. Our full-3D tomography (F3DT) uses...

229

Cerenkov luminescence tomography for in vivo radiopharmaceutical imaging  

Science Conference Proceedings (OSTI)

Cerenkov luminescence imaging (CLI) is a cost-effective molecular imaging tool for biomedical applications of radiotracers. The introduction of Cerenkov luminescence tomography (CLT) relative to planar CLI can be compared to the development of X-ray ...

Jianghong Zhong; Chenghu Qin; Xin Yang; Shuping Zhu; Xing Zhang; Jie Tian

2011-01-01T23:59:59.000Z

230

Satellite Remote Sensing by the Technique of Computed Tomography  

Science Conference Proceedings (OSTI)

Computed tomography is a medical diagnostic technique in which x-ray transmission measurements at numerous angles through the human body are processed by computer to produce cross-sectional pictures of the body. A modification of this technique, ...

Henry E. Fleming

1982-10-01T23:59:59.000Z

231

A Simulation Study of Satellite Emission Computed Tomography  

Science Conference Proceedings (OSTI)

Satellite emission computed tomography retrieves the temperature of the atmosphere from radiances observed at multiple viewing angles and frequencies. To the extent that it provides independent information, the use of multiple viewing angles ...

Ross N. Hoffman; Christopher Grassotti; Ronald G. Isaacs; Thomas J. Kleespies

1989-05-01T23:59:59.000Z

232

From quantum Bayesian inference to quantum tomography  

E-Print Network (OSTI)

We derive an expression for a density operator estimated via Bayesian quantum inference in the limit of an infinite number of measurements. This expression is derived under the assumption that the reconstructed system is in a pure state. In this case the estimation corresponds to an averaging over a generalized microcanonical ensemble of pure states satisfying a set of constraints imposed by the measured mean values of the observables under consideration. We show that via the ``purification'' ansatz, statistical mixtures can also be consistently reconstructed via the quantum Bayesian inference scheme. In this case the estimation corresponds to averaging over the generalized canonical ensemble of states satisfying the given constraints, and the reconstructed density operator maximizes the von Neumann entropy (i.e., this density operator is equal to the generalized canonical density operator which follows from the Jaynes principle of maximum entropy). We study in detail the reconstruction of the spin-1/2 density operator and discuss the logical connection between the three reconstruction schemes, i.e., (1) quantum Bayesian inference, (2) reconstruction via the Jaynes principle of maximum entropy, and (3) discrete quantum tomography.

R. Derka; V. Buzek; G. Adam; P. L. Knight

1997-01-23T23:59:59.000Z

233

A Compact Torus Fusion Reactor Utilizing a Continuously Generated Strings of CT's. The CT String Reactor, CTSR.  

Science Conference Proceedings (OSTI)

A fusion reactor is described in which a moving string of mutually repelling compact toruses (alternating helicity, unidirectional Btheta) is generated by repetitive injection using a magnetized coaxial gun driven by continuous gun current with alternating poloidal field. An injected CT relaxes to a minimum magnetic energy equilibrium, moves into a compression cone, and enters a conducting cylinder where the plasma is heated to fusion-producing temperature. The CT then passes into a blanketed region where fusion energy is produced and, on emergence from the fusion region, the CT undergoes controlled expansion in an exit cone where an alternating poloidal field opens the flux surfaces to directly recover the CT magnetic energy as current which is returned to the formation gun. The CT String Reactor (CTSTR) reactor satisfies all the necessary MHD stability requirements and is based on extrapolation of experimentally achieved formation, stability, and plasma confinement. It is supported by extensive 2D, MHD calculations. CTSTR employs minimal external fields supplied by normal conductors, and can produce high fusion power density with uniform wall loading. The geometric simplicity of CTSTR acts to minimize initial and maintenance costs, including periodic replacement of the reactor first wall.

Hartman, C W; Reisman, D B; McLean, H S; Thomas, J

2007-05-30T23:59:59.000Z

234

Nuclear fuel pin scanner  

DOE Patents (OSTI)

Systems and methods for inspection of nuclear fuel pins to determine fiss loading and uniformity. The system includes infeed mechanisms which stockpile, identify and install nuclear fuel pins into an irradiator. The irradiator provides extended activation times using an approximately cylindrical arrangement of numerous fuel pins. The fuel pins can be arranged in a magazine which is rotated about a longitudinal axis of rotation. A source of activating radiation is positioned equidistant from the fuel pins along the longitudinal axis of rotation. The source of activating radiation is preferably oscillated along the axis to uniformly activate the fuel pins. A detector is provided downstream of the irradiator. The detector uses a plurality of detector elements arranged in an axial array. Each detector element inspects a segment of the fuel pin. The activated fuel pin being inspected in the detector is oscillated repeatedly over a distance equal to the spacing between adjacent detector elements, thereby multiplying the effective time available for detecting radiation emissions from the activated fuel pin.

Bramblett, Richard L. (Friendswood, TX); Preskitt, Charles A. (La Jolla, CA)

1987-03-03T23:59:59.000Z

235

DOE - Office of Legacy Management -- Yale Heavy Ion Linear Accelerator - CT  

NLE Websites -- All DOE Office Websites (Extended Search)

Yale Heavy Ion Linear Accelerator - Yale Heavy Ion Linear Accelerator - CT 05 FUSRAP Considered Sites Site: Yale Heavy Ion Linear Accelerator (CT.05) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: New Haven , Connecticut CT.05-1 Evaluation Year: 1987 CT.05-3 Site Operations: Research and development with solvents. CT.05-1 Site Disposition: Eliminated - Potential for contamination remote based on limited amount of materials handled CT.05-3 Radioactive Materials Handled: Yes Primary Radioactive Materials Handled: Uranium, Radium CT.05-1 Radiological Survey(s): No Site Status: Eliminated from consideration under FUSRAP Also see Documents Related to Yale Heavy Ion Linear Accelerator CT.05-1 - MED Memorandum; To the Files, Thru Ruhoff, et. al.;

236

DOE - Office of Legacy Management -- Metals Selling Corp - CT 0-01  

Office of Legacy Management (LM)

Selling Corp - CT 0-01 Selling Corp - CT 0-01 FUSRAP Considered Sites Site: METALS SELLING CORP. (CT.0-01 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: Putnam , Connecticut CT.0-01-1 Evaluation Year: 1986 CT.0-01-1 Site Operations: Performed grinding of (non-radioactive) magnesium circa 1950 -1952 as a sub-contractor to Mallinckrodt Corp. CT.0-01-1 Site Disposition: Eliminated - No indication that radioactive materials were handled at this location CT.0-01-1 Radioactive Materials Handled: No Primary Radioactive Materials Handled: None Radiological Survey(s): No Site Status: Eliminated from consideration under FUSRAP Also see Documents Related to METALS SELLING CORP. CT.0-01-1 - DOE Memorandum/Checklist D. Levine to File; Subject -

237

Surface-Layer Fluxes Measured Using the CT2-Profile Method  

Science Conference Proceedings (OSTI)

The first experimental test of obtaining heat and momentum fluxes from measurements of the profile of the temperature structure parameter CT2 is performed. The parameter CT2 is obtained from resistance-wire thermometers as well as from optical-...

Reginald J. Hill; Gerard R. Ochs; James J. Wilson

1992-10-01T23:59:59.000Z

238

A New Approach in Metal Artifact Reduction for CT 3D Reconstruction  

Science Conference Proceedings (OSTI)

The 3D representation of CT scans is widely used in medical application such as virtual endoscopy, plastic reconstructive surgery, dental implant planning systems and more. Metallic objects present in CT studies cause strong artifacts like beam hardening ...

Valery Naranjo; Roberto Llorens; Patricia Paniagua; Mariano Alcañiz; Salvador Albalat

2009-06-01T23:59:59.000Z

239

Matter Matters: Unphysical Properties of the Rh = ct Universe  

E-Print Network (OSTI)

It is generally agreed that there is matter in the universe and, in this paper, we show that the existence of matter is extremely problematic for the proposed Rh = ct universe. Considering a dark energy component with an equation of state of w=-1/3, it is shown that the presence of matter destroys the strict expansion properties that define the evolution of Rh = ct cosmologies, distorting the observational properties that are touted as its success. We further examine whether an evolving dark energy component can save this form of cosmological expansion in the presence of matter by resulting in an expansion consistent with a mean value of = -1/3, finding that the presence of mass requires unphysical forms of the dark energy component in the early universe. We conclude that matter in the universe significantly limits the fundamental properties of the Rh = ct cosmology, and that novel, and unphysical, evolution of the matter component would be required to save it. Given this, Rh = ct cosmology is not simpler or...

Lewis, Geraint F

2013-01-01T23:59:59.000Z

240

Comparison of Tumor Volumes as Determined by Pathologic Examination and FDG-PET/CT Images of Non-Small-Cell Lung Cancer: A Pilot Study  

Science Conference Proceedings (OSTI)

Purpose: To determine the cut-off standardized uptake value (SUV) on {sup 18}F fluoro-2-deoxy-glucose (FDG) positron emission tomography/computed tomography (FDG-PET/CT) images that generates the best volumetric match to pathologic gross tumor volume (GTV{sub path}) for non-small-cell lung cancer (NSCLC). Methods and Materials: Fifteen patients with NSCLC who underwent FDG-PET/CT scans followed by lobectomy were enrolled. The surgical specimen was dissected into 5-7-mum sections at approximately 4-mm intervals and stained with hematoxylin and eosin. The tumor-containing area was outlined slice by slice and the GTV{sub path} determined by summing over all the slices, taking into account the interslice thickness and fixation-induced volume reduction. The gross tumor volume from the PET images, GTV{sub PET}, was determined as a function of cut-off SUV. The optimal threshold or optimal absolute SUV was defined as the value at which the GTV{sub PET} was the same as the GTV{sub path}. Results: The fixation process induced a volumetric reduction to 82% +- 10% (range, 62-100%) of the original. The maximal SUV was 10.1 +- 3.6 (range, 4.2-18.7). The optimal threshold and absolute SUV were 31% +- 11% and 3.0 +- 1.6, respectively. The optimal threshold was inversely correlated with GTV{sub path} and tumor diameter (p 0.05). Conclusion: This study evaluated the use of GTV{sub path} as a criterion for determining the optimal cut-off SUV for NSCLC target volume delineation. Confirmatory studies including more cases are being performed.

Yu Jinming, E-mail: jn7984729@public.jn.sd.c [Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan (China); Li Xinke [Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan (China); Xing Ligang [Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan (China); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Mu Dianbin [Department of Pathology, Shandong Cancer Hospital and Institute, Jinan (China); Fu Zheng [Department of Nuclear Medicine, Shandong Cancer Hospital and Institute, Jinan (China); Sun Xiaorong [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Nuclear Medicine, Shandong Cancer Hospital and Institute, Jinan (China); Sun Xiangyu [Department of Pathology, Shandong Cancer Hospital and Institute, Jinan (China); Yang Guoren [Department of Nuclear Medicine, Shandong Cancer Hospital and Institute, Jinan (China); Zhang Baijiang [Department of Thoracic Surgery, Shandong Cancer Hospital and Institute, Jinan (China); Sun Xindong [Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan (China); Ling, C. Clifton [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2009-12-01T23:59:59.000Z

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241

Characterization of adaptive statistical iterative reconstruction algorithm for dose reduction in CT: A pediatric oncology perspective  

Science Conference Proceedings (OSTI)

Purpose: This study demonstrates a means of implementing an adaptive statistical iterative reconstruction (ASiR Trade-Mark-Sign ) technique for dose reduction in computed tomography (CT) while maintaining similar noise levels in the reconstructed image. The effects of image quality and noise texture were assessed at all implementation levels of ASiR Trade-Mark-Sign . Empirically derived dose reduction limits were established for ASiR Trade-Mark-Sign for imaging of the trunk for a pediatric oncology population ranging from 1 yr old through adolescence/adulthood. Methods: Image quality was assessed using metrics established by the American College of Radiology (ACR) CT accreditation program. Each image quality metric was tested using the ACR CT phantom with 0%-100% ASiR Trade-Mark-Sign blended with filtered back projection (FBP) reconstructed images. Additionally, the noise power spectrum (NPS) was calculated for three common reconstruction filters of the trunk. The empirically derived limitations on ASiR Trade-Mark-Sign implementation for dose reduction were assessed using (1, 5, 10) yr old and adolescent/adult anthropomorphic phantoms. To assess dose reduction limits, the phantoms were scanned in increments of increased noise index (decrementing mA using automatic tube current modulation) balanced with ASiR Trade-Mark-Sign reconstruction to maintain noise equivalence of the 0% ASiR Trade-Mark-Sign image. Results: The ASiR Trade-Mark-Sign algorithm did not produce any unfavorable effects on image quality as assessed by ACR criteria. Conversely, low-contrast resolution was found to improve due to the reduction of noise in the reconstructed images. NPS calculations demonstrated that images with lower frequency noise had lower noise variance and coarser graininess at progressively higher percentages of ASiR Trade-Mark-Sign reconstruction; and in spite of the similar magnitudes of noise, the image reconstructed with 50% or more ASiR Trade-Mark-Sign presented a more smoothed appearance than the pre-ASiR Trade-Mark-Sign 100% FBP image. Finally, relative to non-ASiR Trade-Mark-Sign images with 100% of standard dose across the pediatric phantom age spectrum, similar noise levels were obtained in the images at a dose reduction of 48% with 40% ASIR Trade-Mark-Sign and a dose reduction of 82% with 100% ASIR Trade-Mark-Sign . Conclusions: The authors' work was conducted to identify the dose reduction limits of ASiR Trade-Mark-Sign for a pediatric oncology population using automatic tube current modulation. Improvements in noise levels from ASiR Trade-Mark-Sign reconstruction were adapted to provide lower radiation exposure (i.e., lower mA) instead of improved image quality. We have demonstrated for the image quality standards required at our institution, a maximum dose reduction of 82% can be achieved using 100% ASiR Trade-Mark-Sign ; however, to negate changes in the appearance of reconstructed images using ASiR Trade-Mark-Sign with a medium to low frequency noise preserving reconstruction filter (i.e., standard), 40% ASiR Trade-Mark-Sign was implemented in our clinic for 42%-48% dose reduction at all pediatric ages without a visually perceptible change in image quality or image noise.

Brady, S. L.; Yee, B. S.; Kaufman, R. A. [Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee 38105 (United States)

2012-09-15T23:59:59.000Z

242

Quantum process tomography of a single solid state qubit  

E-Print Network (OSTI)

We present an example of quantum process tomography performed on a single solid state qubit. The qubit used is two energy levels of the triplet state in the Nitrogen-Vacancy defect in Diamond. Quantum process tomography is applied to a qubit which has been allowed to decohere for three different time periods. In each case the process is found in terms of the $\\chi$ matrix representation and the affine map representation. The discrepancy between experimentally estimated process and the closest physically valid process is noted.

M. Howard; J. Twamley; C. Wittmann; T. Gaebel; F. Jelezko; J. Wrachtrup

2005-03-16T23:59:59.000Z

243

Quantum Process Tomography via L1-norm Minimization  

E-Print Network (OSTI)

For an initially well designed but imperfect quantum information system, the process matrix is almost sparse in an appropriate basis. Existing theory and associated computational methods (L1-norm minimization) for reconstructing sparse signals establish conditions under which the sparse signal can be perfectly reconstructed from a very limited number of measurements (resources). Although a direct extension to quantum process tomography of the L1-norm minimization theory has not yet emerged, the numerical examples presented here, which apply L1-norm minimization to quantum process tomography, show a significant reduction in resources to achieve a desired estimation accuracy over existing methods.

Robert L. Kosut

2008-12-23T23:59:59.000Z

244

Positron emission tomography in the evaluation of subdural hematomas  

SciTech Connect

Fifteen patients with 21 subdural effusions were investigated both with transmission computer assisted tomography (CAT) and positron emission tomography (PET). The tracer in the emission studies was /sup 68/Ga-EDTA. Twelve lesions were visualized both with CAT and PET. Five lesions that were negative or doubtful on CAT were visualized with PET, whereas four lesions negative or doubtful on PET were demonstrated by CAT. The two methods complement each other due to the fact that they are based on different mechanisms: CAT mainly on attenuation of the fluid collection. PET on isotope accumulation, particularly in the hematoma membranes.

Ericson, K.; Bergstroem, M.; Eriksson, L.

1980-12-01T23:59:59.000Z

245

Radiation dose reduction using a CdZnTe-based computed tomography system: Comparison to flat-panel detectors  

Science Conference Proceedings (OSTI)

Purpose: Although x-ray projection mammography has been very effective in early detection of breast cancer, its utility is reduced in the detection of small lesions that are occult or in dense breasts. One drawback is that the inherent superposition of parenchymal structures makes visualization of small lesions difficult. Breast computed tomography using flat-panel detectors has been developed to address this limitation by producing three-dimensional data while at the same time providing more comfort to the patients by eliminating breast compression. Flat panels are charge integrating detectors and therefore lack energy resolution capability. Recent advances in solid state semiconductor x-ray detector materials and associated electronics allow the investigation of x-ray imaging systems that use a photon counting and energy discriminating detector, which is the subject of this article. Methods: A small field-of-view computed tomography (CT) system that uses CdZnTe (CZT) photon counting detector was compared to one that uses a flat-panel detector for different imaging tasks in breast imaging. The benefits afforded by the CZT detector in the energy weighting modes were investigated. Two types of energy weighting methods were studied: Projection based and image based. Simulation and phantom studies were performed with a 2.5 cm polymethyl methacrylate (PMMA) cylinder filled with iodine and calcium contrast objects. Simulation was also performed on a 10 cm breast specimen. Results: The contrast-to-noise ratio improvements as compared to flat-panel detectors were 1.30 and 1.28 (projection based) and 1.35 and 1.25 (image based) for iodine over PMMA and hydroxylapatite over PMMA, respectively. Corresponding simulation values were 1.81 and 1.48 (projection based) and 1.85 and 1.48 (image based). Dose reductions using the CZT detector were 52.05% and 49.45% for iodine and hydroxyapatite imaging, respectively. Image-based weighting was also found to have the least beam hardening effect. Conclusions: The results showed that a CT system using an energy resolving detector reduces the dose to the patient while maintaining image quality for various breast imaging tasks.

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

2010-03-15T23:59:59.000Z

246

Design of Mega-Voltage X-ray Digital Radiography and Computed Tomography Performance Phantoms  

SciTech Connect

A number of fundamental scientific questions have arisen concerning the operation of high-energy DR and CT systems. Some of these questions include: (1) How deeply can such systems penetrate thickly shielded objects? (2) How well can such systems distinguish between dense and relatively high Z materials such as lead, tungsten and depleted uranium and lower Z materials such as steel, copper and tin? (3) How well will such systems operate for a uranium material which is an intermediate case between low density yellowcake and high density depleted uranium metal? These questions have led us to develop a set of phantoms to help answer these questions, but do not have any direct bearing on any smuggling concern. These new phantoms are designed to allow a systemic exploration of these questions by gradually varying their compositions and thicknesses. These phantoms are also good probes of the blurring behavior of radiography and tomography systems. These phantoms are composed of steel ({rho} assumed to be 7.8 g/cc), lead ({rho} assumed to be 11.4 g/cc), tungsten ({rho} assumed to be 19.25 g/cc), uranium oxide (UO{sub 3}) ({rho} assumed to be 4.6 g/cc), and depleted uranium (DU) ({rho} assumed to be 18.9 g/cc). There are five designed phantoms described in this report: (1) Cylindrical shells of Tungsten and Steel; (2) Depleted Uranium Inside Tungsten Hemi-cube Shells; (3) Nested Spherical Shells; (4) UO{sub 3} Cylinder; and (5) Shielded DU Sphere.

Aufderheide, M B; Martz, H E; Curtin, M

2009-06-22T23:59:59.000Z

247

Organ doses, effective doses, and risk indices in adult CT: Comparison of four types of reference phantoms across different examination protocols  

SciTech Connect

Purpose: Radiation exposure from computed tomography (CT) to the public has increased the concern among radiation protection professionals. Being able to accurately assess the radiation dose patients receive during CT procedures is a crucial step in the management of CT dose. Currently, various computational anthropomorphic phantoms are used to assess radiation dose by different research groups. It is desirable to better understand how the dose results are affected by different choices of phantoms. In this study, the authors assessed the uncertainties in CT dose and risk estimation associated with different types of computational phantoms for a selected group of representative CT protocols. Methods: Routinely used CT examinations were categorized into ten body and three neurological examination categories. Organ doses, effective doses, risk indices, and conversion coefficients to effective dose and risk index (k and q factors, respectively) were estimated for these examinations for a clinical CT system (LightSpeed VCT, GE Healthcare). Four methods were used, each employing a different type of reference phantoms. The first and second methods employed a Monte Carlo program previously developed and validated in our laboratory. In the first method, the reference male and female extended cardiac-torso (XCAT) phantoms were used, which were initially created from the Visible Human data and later adjusted to match organ masses defined in ICRP publication 89. In the second method, the reference male and female phantoms described in ICRP publication 110 were used, which were initially developed from tomographic data of two patients and later modified to match ICRP 89 organ masses. The third method employed a commercial dosimetry spreadsheet (ImPACT group, London, England) with its own hermaphrodite stylized phantom. In the fourth method, another widely used dosimetry spreadsheet (CT-Expo, Medizinische Hochschule, Hannover, Germany) was employed together with its associated male and female stylized phantoms. Results: For fully irradiated organs, average coefficients of variation (COV) ranged from 0.07 to 0.22 across the four male phantoms and from 0.06 to 0.18 across the four female phantoms; for partially irradiated organs, average COV ranged from 0.13 to 0.30 across the four male phantoms and from 0.15 to 0.30 across the four female phantoms. Doses to the testes, breasts, and esophagus showed large variations between phantoms. COV for gender-averaged effective dose and k factor ranged from 0.03 to 0.23 and from 0.06 to 0.30, respectively. COV for male risk index and q factor ranged from 0.06 to 0.30 and from 0.05 to 0.36, respectively; COV for female risk index and q factor ranged from 0.06 to 0.49 and from 0.07 to 0.54, respectively. Conclusions: Despite closely matched organ mass, total body weight, and height, large differences in organ dose exist due to variation in organ location, spatial distribution, and dose approximation method. Dose differences for fully irradiated radiosensitive organs were much smaller than those for partially irradiated organs. Weighted dosimetry quantities including effective dose, male risk indices, k factors, and male q factors agreed well across phantoms. The female risk indices and q factors varied considerably across phantoms.

Zhang Yakun; Li Xiang; Paul Segars, W.; Samei, Ehsan [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); Carl E. Ravin Advanced Imaging Laboratories, Duke University, Durham, North Carolina 27705 and Department of Radiology, 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) and Department of Radiology, 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) and Departments of Physics, Biomedical Engineering, and Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States)

2012-06-15T23:59:59.000Z

248

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

E-Print Network (OSTI)

pilot study suggested a lot of opportunities to reduce radiationradiation dose in CT scan while maintaining image quality. The pilot

Zhang, Di

2012-01-01T23:59:59.000Z

249

Statistical estimation of the quality of quantum-tomography protocols  

SciTech Connect

We present a complete methodology for testing the performances of quantum tomography protocols. The theory is validated by several numerical examples and by the comparison with experimental results achieved with various protocols for whole families of polarization states of qubits and ququarts including pure, mixed, entangled, and separable.

Bogdanov, Yu. I.; Bukeev, I. D. [Institute of Physics and Technology, Russian Academy of Sciences, 117218, Moscow (Russian Federation); Brida, G.; Genovese, M.; Shurupov, A. P. [INRIM, Strada delle Cacce 91 I-10135, Torino (Italy); Kravtsov, K. S. [Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow, 119991 (Russian Federation); Kulik, S. P.; Soloviev, A. A. [Faculty of Physics, Moscow State University, 119992, Moscow (Russian Federation); Moreva, E. V. [Moscow National Research Nuclear University ' ' MEPHI' ' , 115409, Moscow (Russian Federation)

2011-10-15T23:59:59.000Z

250

Experimental Cerenkov luminescence tomography of the mouse model with SPECT  

E-Print Network (OSTI)

Experimental Cerenkov luminescence tomography of the mouse model with SPECT imaging validation imaging resulting from Cerenkov radiation has become a motivating topic recently and will potentially open new avenues for the study of small animal imaging. Cerenkov-based optical imaging taken from living

Tian, Jie

251

Assessment of Summer RBOB Supply for NY & CT  

Gasoline and Diesel Fuel Update (EIA)

Update of Summer Reformulated Gasoline Supply Update of Summer Reformulated Gasoline Supply Assessment for New York and Connecticut May 5, 2004 In October 2003, EIA published a review of the status of the methyl tertiary butyl ether (MTBE) ban transition in New York (NY) and Connecticut (CT) 1 that noted significant uncertainties in gasoline supply for those States for the summer of 2004. To obtain updated information, EIA spoke to major suppliers to the two States over the past several months as the petroleum industry began the switch from winter- to summer-grade gasoline. As discussed on our earlier report, the NY and CT bans on MTBE mainly affect reformulated gasoline (RFG), which in recent years has been provided by domestic refineries on the East Coast (PADD 1) and imports. Our recent findings indicate that

252

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

SciTech Connect

The numerical simulator TOUGH+HYDRATE (T+H) was used to predict the transient pure methane hydrate (no sediment) dissociation data. X-ray computed tomography (CT) was used to visualize the methane hydrate formation and dissociation processes. A methane hydrate sample was formed from granular ice in a cylindrical vessel, and slow depressurization combined with thermal stimulation was applied to dissociate the hydrate sample. CT images showed that the water produced from the hydrate dissociation accumulated at the bottom of the vessel and increased the hydrate dissociation rate there. CT images were obtained during hydrate dissociation to confirm the radial dissociation of the hydrate sample. This radial dissociation process has implications for dissociation of hydrates in pipelines, suggesting lower dissociation times than for longitudinal dissociation. These observations were also confirmed by the numerical simulator predictions, which were in good agreement with the measured thermal data during hydrate dissociation. System pressure and sample temperature measured at the sample center followed the CH{sub 4} hydrate L{sub w}+H+V equilibrium line during hydrate dissociation. The predicted cumulative methane gas production was within 5% of the measured data. Thus, this study validated our simulation approach and assumptions, which include stationary pure methane hydrate-skeleton, equilibrium hydrate-dissociation and heat- and mass-transfer in predicting hydrate dissociation in the absence of sediments. It should be noted that the application of T+H for the pure methane hydrate system (no sediment) is outside the general applicability limits of T+H.

Gupta, A.; Moridis, G.J.; Kneafsey, T.J.; Sloan, Jr., E.D.

2009-08-15T23:59:59.000Z

253

An Approach for Preoperative Planning and Performance of MR-guided Interventions Demonstrated With a Manual Manipulator in a 1.5T MRI Scanner  

Science Conference Proceedings (OSTI)

Purpose: The aim of this work was to develop and test a general methodology for the planning and performance of robot-assisted, MR-guided interventions. This methodology also includes the employment of software tools with appropriately tailored routines to effectively exploit the capabilities of MRI and address the relevant spatial limitations. Methods: The described methodology consists of: (1) patient-customized feasibility study that focuses on the geometric limitations imposed by the gantry, the robotic hardware, and interventional tools, as well as the patient; (2) stereotactic preoperative planning for initial positioning of the manipulator and alignment of its end-effector with a selected target; and (3) real-time, intraoperative tool tracking and monitoring of the actual intervention execution. Testing was performed inside a standard 1.5T MRI scanner in which the MR-compatible manipulator is deployed to provide the required access. Results: A volunteer imaging study demonstrates the application of the feasibility stage. A phantom study on needle targeting is also presented, demonstrating the applicability and effectiveness of the proposed preoperative and intraoperative stages of the methodology. For this purpose, a manually actuated, MR-compatible robotic manipulation system was used to accurately acquire a prescribed target through alternative approaching paths. Conclusions: The methodology presented and experimentally examined allows the effective performance of MR-guided interventions. It is suitable for, but not restricted to, needle-targeting applications assisted by a robotic manipulation system, which can be deployed inside a cylindrical scanner to provide the required access to the patient facilitating real-time guidance and monitoring.

Seimenis, Ioannis [Medical Diagnostic Center 'Ayios Therissos' (Cyprus); Tsekos, Nikolaos V. [University of Huston, Medical Robotics Lab, Department of Computer Science (United States); Keroglou, Christoforos [University of Cyprus, Department of Electrical and Computer Engineering (Cyprus); Eracleous, Eleni [Medical Diagnostic Center 'Ayios Therissos' (Cyprus); Pitris, Constantinos [University of Cyprus, Department of Electrical and Computer Engineering (Cyprus); Christoforou, Eftychios G., E-mail: e.christoforou@ucy.ac.cy [University of Cyprus, KIOS Research Center (Cyprus)

2012-04-15T23:59:59.000Z

254

CT MEASUREMENTS OF TWO-PHASE FLOW IN FRACTURED POROUS MEDIA  

E-Print Network (OSTI)

between the blocks, and vii #12;a two-block system with no spacer. The blocks are sealed in epoxy so scanner. Preliminary results are presented from a water air experiment. These results suggest.5 inches thick. Permeability of the block was 27 Darcies and porosity was 45. The block was sealed

255

Resistivity Tomography At Silver Peak Area (DOE GTP) | Open Energy  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Resistivity Tomography At Silver Peak Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Single-Well and Cross-Well Resistivity At Silver Peak Area (DOE GTP) Exploration Activity Details Location Silver Peak Area Exploration Technique Single-Well and Cross-Well Resistivity Activity Date Usefulness not indicated DOE-funding Unknown References (1 January 2011) GTP ARRA Spreadsheet Retrieved from "http://en.openei.org/w/index.php?title=Resistivity_Tomography_At_Silver_Peak_Area_(DOE_GTP)&oldid=689883" Categories:

256

Discussion - Next Step for Fukushima Daiichi Muon Tomography  

Science Conference Proceedings (OSTI)

Specification of Fukushima Daiichi Muon Tomography (FMT): (1) 18-feet (5.5-m) drift tube, 2-inch (5-cm) diameter; (2) 108 tubes per layer; (3) Unit layer = 2 layer (detection efficiency: 0.96 x 0.96 = 92%); (4) 12 or 16 layer per module; (5) 16 layers allows momentum analysis at 30% level; (6) 2 module per super module (5.5 x 11 m{sup 2}); and (7) FMT = 2 super module. By deploying MMT next to a research reactor, we will be able to measure the impact of low level radiation fields on muon tomography and reconstruction processes. Radiation level during reactor operation is {approx}50 {micro}Sv/h which provides similar radiation environment of inside the FMT radiation shield at Fukushima Daiichi. We will implement coincidence algorithm on the FPGA board.

Miyadera, Haruo [Los Alamos National Laboratory

2012-08-13T23:59:59.000Z

257

Using electrical impedance tomography to map subsurface hydraulic conductivity  

DOE Patents (OSTI)

The use of Electrical Impedance Tomography (EIT) to map subsurface hydraulic conductivity. EIT can be used to map hydraulic conductivity in the subsurface where measurements of both amplitude and phase are made. Hydraulic conductivity depends on at least two parameters: porosity and a length scale parameter. Electrical Resistance Tomography (ERT) measures and maps electrical conductivity (which can be related to porosity) in three dimensions. By introducing phase measurements along with amplitude, the desired additional measurement of a pertinent length scale can be achieved. Hydraulic conductivity controls the ability to flush unwanted fluid contaminants from the surface. Thus inexpensive maps of hydraulic conductivity would improve planning strategies for subsequent remediation efforts. Fluid permeability is also of importance for oil field exploitation and thus detailed knowledge of fluid permeability distribution in three-dimension (3-D) would be a great boon to petroleum reservoir analysts.

Berryman, James G. (Danville, CA); Daily, William D. (Livermore, CA); Ramirez, Abelardo L. (Pleasanton, CA); Roberts, Jeffery J. (Livermore, CA)

2000-01-01T23:59:59.000Z

258

Dedicated breast CT: Fibroglandular volume measurements in a diagnostic population  

SciTech Connect

Purpose: To determine the mean and range of volumetric glandular fraction (VGF) of the breast in a diagnostic population using a high-resolution flat-panel cone-beam dedicated breast CT system. This information is important for Monte Carlo-based estimation of normalized glandular dose coefficients and for investigating the dependence of VGF on breast dimensions, race, and pathology. Methods: Image data from a clinical trial investigating the role of dedicated breast CT that enrolled 150 women were retrospectively analyzed to determine the VGF. The study was conducted in adherence to a protocol approved by the institutional human subjects review boards and written informed consent was obtained from all study participants. All participants in the study were assigned BI-RADS{sup Registered-Sign} 4 or 5 as per the American College of Radiology assessment categories after standard diagnostic work-up and underwent dedicated breast CT exam prior to biopsy. A Gaussian-kernel based fuzzy c-means algorithm was used to partition the breast CT images into adipose and fibroglandular tissue after segmenting the skin. Upon determination of the accuracy of the algorithm with a phantom, it was applied to 137 breast CT volumes from 136 women. VGF was determined for each breast and the mean and range were determined. Pathology results with classification as benign, malignant, and hyperplasia were available for 132 women, and were used to investigate if the distributions of VGF varied with pathology. Results: The algorithm was accurate to within {+-}1.9% in determining the volume of an irregular shaped phantom. The study mean ({+-} inter-breast SD) for the VGF was 0.172 {+-} 0.142 (range: 0.012-0.719). VGF was found to be negatively correlated with age, breast dimensions (chest-wall to nipple length, pectoralis to nipple length, and effective diameter at chest-wall), and total breast volume, and positively correlated with fibroglandular volume. Based on pathology, pairwise statistical analysis (Mann-Whitney test) indicated that at the 0.05 significance level, there was no significant difference in distributions of VGF without adjustment for age between malignant and nonmalignant breasts (p= 0.41). Pairwise comparisons of the distributions of VGF in increasing order of mammographic breast density indicated all comparisons were statistically significant (p < 0.002). Conclusions: This study used a different clinical prototype breast CT system than that in previous studies to image subjects from a different geographical region, and used a different algorithm for analysis of image data. The mean VGF estimated from this study is within the range reported in previous studies, indicating that the choice of 50% glandular weight fraction to represent an average breast for Monte Carlo-based estimation of normalized glandular dose coefficients in mammography needs revising. In the study, the distributions of VGF did not differ significantly with pathology.

Vedantham, Srinivasan; Shi Linxi; Karellas, Andrew; O'Connell, Avice M. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Department of Imaging Sciences, University of Rochester Medical Center, Rochester, New York 14642 (United States)

2012-12-15T23:59:59.000Z

259

Automated temporal tracking and segmentation of lymphoma on serial CT examinations  

Science Conference Proceedings (OSTI)

Purpose: It is challenging to reproducibly measure and compare cancer lesions on numerous follow-up studies; the process is time-consuming and error-prone. In this paper, we show a method to automatically and reproducibly identify and segment abnormal lymph nodes in serial computed tomography (CT) exams. Methods: Our method leverages initial identification of enlarged (abnormal) lymph nodes in the baseline scan. We then identify an approximate region for the node in the follow-up scans using nonrigid image registration. The baseline scan is also used to locate regions of normal, non-nodal tissue surrounding the lymph node and to map them onto the follow-up scans, in order to reduce the search space to locate the lymph node on the follow-up scans. Adaptive region-growing and clustering algorithms are then used to obtain the final contours for segmentation. We applied our method to 24 distinct enlarged lymph nodes at multiple time points from 14 patients. The scan at the earlier time point was used as the baseline scan to be used in evaluating the follow-up scan, resulting in 70 total test cases (e.g., a series of scans obtained at 4 time points results in 3 test cases). For each of the 70 cases, a ''reference standard'' was obtained by manual segmentation by a radiologist. Assessment according to response evaluation criteria in solid tumors (RECIST) using our method agreed with RECIST assessments made using the reference standard segmentations in all test cases, and by calculating node overlap ratio and Hausdorff distance between the computer and radiologist-generated contours. Results: Compared to the reference standard, our method made the correct RECIST assessment for all 70 cases. The average overlap ratio was 80.7 {+-} 9.7% s.d., and the average Hausdorff distance was 3.2 {+-} 1.8 mm s.d. The concordance correlation between automated and manual segmentations was 0.978 (95% confidence interval 0.962, 0.984). The 100% agreement in our sample between our method and the standard with regard to RECIST classification suggests that the true disagreement rate is no more than 6%. Conclusions: Our automated lymph node segmentation method achieves excellent overall segmentation performance and provides equivalent RECIST assessment. It potentially will be useful to streamline and improve cancer lesion measurement and tracking and to improve assessment of cancer treatment response.

Xu Jiajing; Greenspan, Hayit; Napel, Sandy; Rubin, Daniel L. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, 69978 (Israel); Department of Electrical Engineering, Stanford University, Stanford, California 94305 and Department of Radiology, Stanford University, Stanford, California 94305 (United States); Department of Radiology, Stanford University, Stanford, California 94305 (United States)

2011-11-15T23:59:59.000Z

260

The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI): A Completed Reference Database of Lung Nodules on CT Scans  

SciTech Connect

Purpose: The development of computer-aided diagnostic (CAD) methods for lung nodule detection, classification, and quantitative assessment can be facilitated through a well-characterized repository of computed tomography (CT) scans. The Lung Image Database Consortium (LIDC) and Image Database Resource Initiative (IDRI) completed such a database, establishing a publicly available reference for the medical imaging research community. Initiated by the National Cancer Institute (NCI), further advanced by the Foundation for the National Institutes of Health (FNIH), and accompanied by the Food and Drug Administration (FDA) through active participation, this public-private partnership demonstrates the success of a consortium founded on a consensus-based process. Methods: Seven academic centers and eight medical imaging companies collaborated to identify, address, and resolve challenging organizational, technical, and clinical issues to provide a solid foundation for a robust database. The LIDC/IDRI Database contains 1018 cases, each of which includes images from a clinical thoracic CT scan and an associated XML file that records the results of a two-phase image annotation process performed by four experienced thoracic radiologists. In the initial blinded-read phase, each radiologist independently reviewed each CT scan and marked lesions belonging to one of three categories (''nodule{>=}3 mm,''''nodule<3 mm,'' and ''non-nodule{>=}3 mm''). In the subsequent unblinded-read phase, each radiologist independently reviewed their own marks along with the anonymized marks of the three other radiologists to render a final opinion. The goal of this process was to identify as completely as possible all lung nodules in each CT scan without requiring forced consensus. Results: The Database contains 7371 lesions marked ''nodule'' by at least one radiologist. 2669 of these lesions were marked ''nodule{>=}3 mm'' by at least one radiologist, of which 928 (34.7%) received such marks from all four radiologists. These 2669 lesions include nodule outlines and subjective nodule characteristic ratings. Conclusions: The LIDC/IDRI Database is expected to provide an essential medical imaging research resource to spur CAD development, validation, and dissemination in clinical practice.

NONE

2011-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

LANL | TT | R&D 100 Awards | 2007 Summaries  

Muon tomography scanners will greatly increase border security against nuclear ... the fuel efficiency of commercial ... and hydrological cycle ;

262

Single electron quantum tomography in quantum Hall edge channels  

E-Print Network (OSTI)

We propose a quantum tomography protocol to measure single electron coherence in quantum Hall edge channels and therefore access for the first time the wave function of single electron excitations propagating in ballistic quantum conductors. Its implementation would open the way to quantitative studies of single electron decoherence and would provide a quantitative tool for analyzing single to few electron sources. We show how this protocol could be implemented using ultrahigh sensitivity noise measurement schemes.

Grenier, Charles; Bocquillon, Erwann; Parmentier, François D; Plaçais, Bernard; Berroir, Jean-Marc; Fève, Gwendal; Degiovanni, Pascal; 10.1088/1367-2630/13/9/093007

2011-01-01T23:59:59.000Z

263

Single electron quantum tomography in quantum Hall edge channels  

E-Print Network (OSTI)

We propose a quantum tomography protocol to measure single electron coherence in quantum Hall edge channels and therefore access for the first time the wave function of single electron excitations propagating in ballistic quantum conductors. Its implementation would open the way to quantitative studies of single electron decoherence and would provide a quantitative tool for analyzing single to few electron sources. We show how this protocol could be implemented using ultrahigh sensitivity noise measurement schemes.

Charles Grenier; Rémy Hervé; Erwann Bocquillon; François D. Parmentier; Bernard Plaçais; Jean-Marc Berroir; Gwendal Fève; Pascal Degiovanni

2010-10-11T23:59:59.000Z

264

MIEDER, WOLFGANG. Proverbs: A Handbook. Westport, CT: Greenwood, 2004. 304 pp.  

E-Print Network (OSTI)

selecta bibliografía, Proverbs: A Handbook interesado en unWOLFGANG. Proverbs: A Handbook. Westport, CT: Greenwood,libros de referencia de Handbooks" publicado en el nueva la

Lee, Alejandro

2005-01-01T23:59:59.000Z

265

10 A.M. CT TODAY: On-the Record Conference Call for Obama Administrati...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

White House Rural Economic Council Promotes Production of Next Generation Biofuels, Job Creation and Economic Opportunity WASHINGTON, Aug. 16, 2011 - Today at 10 a.m. CT (11...

266

Resolution and noise trade-off analysis for volumetric CT  

Science Conference Proceedings (OSTI)

Until recently, most studies addressing the trade-off between spatial resolution and quantum noise were performed in the context of single-slice CT. In this study, we extend the theoretical framework of previous works to volumetric CT and further extend it by taking into account the actual shapes of the preferred reconstruction kernels. In the experimental study, we also attempt to explore a three-dimensional approach for spatial resolution measurement, as opposed to the conventional two-dimensional approaches that were widely adopted in previously published studies. By scanning a finite-sized sphere phantom, the MTF was measured from the edge profile along the spherical surface. Cases of different resolutions (and noise levels) were generated by adjusting the reconstruction kernel. To reduce bias, the total photon fluxes were matched: 120 kVp, 200 mA, and 1 s per gantry rotation. All data sets were reconstructed using a modified FDK algorithm under the same condition: Scan field-of-view (SFOV)=10 cm, and slice thickness=0.625 mm. The theoretical analysis indicated that the variance of noise is proportional to >4th power of the spatial resolution. Our experimental results supported this conclusion by showing the relationship is 4.6th (helical) or 5th (axial) power.

Li Baojun; Avinash, Gopal B.; Hsieh, Jiang [Applied Science Laboratory, General Electric Healthcare, Waukesha, Wisconsin 53188 (United States)

2007-10-15T23:59:59.000Z

267

News in PML - Radiation and Biomolecular Physics  

Science Conference Proceedings (OSTI)

... Scanners. 06/05/13. CT Standards Save Time and Money. 01/18/13. Neutron Spin Filters. 12/21/12. CT calorimetry. 09/27/12. ...

2011-11-30T23:59:59.000Z

268

In-situ Three Dimensional (3D) X-Ray Synchrotron Tomography of ...  

Science Conference Proceedings (OSTI)

Local measurements of da/dN were possible with the 3D data sets obtained from tomography. In situ measurements of crack opening displacement (COD) were ...

269

Development of a seismic tomography system for use on a geotechnical centrifuge.  

E-Print Network (OSTI)

??[Truncated abstract] Seismic tomography has been extensively used in geophysics for different purposes such as geological mapping and prospecting for oil and gas. In geophysics,… (more)

Rammah, Khader Ibrahim

2008-01-01T23:59:59.000Z

270

Metal artifact reduction in dental CT images using polar mathematical morphology  

Science Conference Proceedings (OSTI)

Abstract: Most dental implant planning systems use a 3D representation of the CT scan of the patient under study as it provides a more intuitive view of the human jaw. The presence of metallic objects in human jaws, such as amalgam or gold fillings, ... Keywords: Artifact reduction, Dental CT, Polar morphology

Valery Naranjo; Roberto Lloréns; Mariano Alcañiz; Fernando López-Mir

2011-04-01T23:59:59.000Z

271

Five Years of Cyclotron Radioisotope Production Experiences at the First PET-CT in Venezuela  

Science Conference Proceedings (OSTI)

Five years operation of a compact cyclotron installed at PET-CT facility in Caracas, Venezuela is given. Production rate of {sup 18}F labeled FDG, operation and radiation monitoring experience are included. We conclude that {sup 18}FDG CT-PET is the most effective technique for patient diagnosis.

Colmenter, L.; Coelho, D.; Esteves, L. M.; Ruiz, N.; Morales, L.; Lugo, I. [Centro Diagnostico Docente, Las Mercedes, Caracas (Venezuela); Sajo-Bohus, L.; Liendo, J. A.; Greaves, E. D.; Barros, H. [Universidad Simon Bolivar, Seccion de Fisica Nuclear, Caracas (Venezuela); Castillo, J. [University of Applied Science of Aachen (Germany)

2007-10-26T23:59:59.000Z

272

AUTOMATIC HEART ISOLATION FOR CT CORONARY VISUALIZATION USING G. Funka-Lea1  

E-Print Network (OSTI)

AUTOMATIC HEART ISOLATION FOR CT CORONARY VISUALIZATION USING GRAPH-CUTS G. Funka-Lea1 , Y. Boykov3 isolate the outer surface of the entire heart in Computer Tomogra- phy (CT) cardiac scans. Isolating the entire heart allows the coronary vessels on the surface of the heart to be easily visu- alized despite

Boykov, Yuri

273

Understanding Cellulose Through Molecular Simulation and Electron Tomography  

SciTech Connect

High-resolution cellulose crystal structures have been determined from diffraction experiments using large diameter microfibrils as the sample material. However, cellulose microfibrils in plants are much smaller in diameter, and are more difficult to directly examine experimentally. Molecular dynamics simulation combined with quantum chemical calculations can help to elucidate the structure and dynamics of small diameter cellulose microfibrils. These simulation techniques also aid in the interpretation of electron tomography volumetric structural data from maize cell walls, where pretreatment with dilute acid or ammonia reveals microfibril geometry.

Matthews, J.

2013-01-01T23:59:59.000Z

274

Quantum process tomography of a controlled-NOT gate  

E-Print Network (OSTI)

We demonstrate complete characterization of a two-qubit entangling process - a linear optics controlled-NOT gate operating with coincident detection - by quantum process tomography. We use maximum-likelihood estimation to convert the experimental data into a physical process matrix. The process matrix allows accurate prediction of the operation of the gate for arbitrary input states, and calculation of gate performance measures such as the average gate fidelity, average purity and entangling capability of our gate, which are 0.90, 0.83 and 0.73, respectively.

J. L. O'Brien; G. J. Pryde; A. Gilchrist; D. F. V. James; N. K. Langford; T. C. Ralph; A. G. White

2004-02-23T23:59:59.000Z

275

Direct and Parallel Tomography of a Quantum Process  

E-Print Network (OSTI)

As the method to completely characterize quantum dynamical processes, quantum process tomography (QPT) is vitally important for quantum information processing and quantum control, where the faithfulness of quantum devices plays an essential role. Here via weak measurements, we present a new QPT scheme characterized by its directness and parallelism. Comparing with the existing schemes, our scheme needs a simpler state preparation and much fewer experimental setups. Furthermore, each parameter of the quantum process is directly determined from only five experimental values in our scheme, meaning that our scheme is robust against the accumulation of errors.

Yu-Xiang Zhang; Shengjun Wu; Zeng-Bing Chen

2013-09-23T23:59:59.000Z

276

Spatial emission tomography reconstruction using Pitman-Yor process  

SciTech Connect

In this paper, we address the problem of emission tomography spatial reconstruction in three dimensions following a Bayesian nonparametric approach. Our model makes use of a generalization of the Dirichlet process called Pitman-Yor process. The problem in this approach is to deal with the infinite representation of the distribution in the inference. So we propose an efficient Markov Chain Monte-Carlo sampling scheme which is able to generate samples from the posterior distribution of the activity distribution. An application to 3D-PET reconstruction is presented.

Fall, Mame Diarra; Mohammad-Djafari, Ali [L2S, Supelec, 3 rue Joliot-Curie, F-91192 Gif-sur-Yvette cedex (France); Barat, Eric [CEA-LIST, LPSS, CEA-Saclay, F-91191 Gif-sur-Yvette (France); Comtat, Claude [SHFJ, CEA/DSV/I2BM, F-91401 Orsay (France)

2009-12-08T23:59:59.000Z

277

Our Next Two Steps for Fukushima Daiichi Muon Tomography  

SciTech Connect

After the vast disasters caused by the great earthquake and tsunami in eastern Japan, we proposed applying our Muon Tomography (MT) technique to help and improve the emergency situation at Fukushima Daiichi using cosmic-ray muons. A reactor-tomography team was formed at LANL which was supported by the Laboratory as a response to a request by the former Japanese Prime Minister, Naoto Kan. Our goal is to help the Japanese people and support remediation of the reactors. At LANL, we have carried out a proof-of-principle technical demonstration and simulation studies that established the feasibility of MT to image a reactor core. This proposal covers the next two critical steps for Fukushima Daiichi Muon Imaging: (1) undertake case study mock-up experiments of Fukushima Daiichi, and (2) system optimization. We requested funding to the US and Japanese government to assess damage of reactors at Fukushima Daiichi. The two steps will bring our project to the 'ready-to-go' level.

Miyadera, Haruo [Los Alamos National Laboratory

2012-04-11T23:59:59.000Z

278

Temporal and spatial blood information estimation using Bayesian ICA in dynamic cerebral positron emission tomography  

Science Conference Proceedings (OSTI)

Positron emission tomography (PET) is a nuclear medicine technique that provides tomographic images of the distribution of positron-emitting radiopharmaceuticals. We have previously proposed a method for estimating an input blood curve based on a standard ... Keywords: Arterial blood sampling, Blood volume image, Ensemble learning, Independent component analysis, Positron emission tomography

Mika Naganawa; Yuichi Kimura; Kenji Ishii; Keiichi Oda; Kiichi Ishiwata

2007-09-01T23:59:59.000Z

279

WIND TOMOGRAPHY IN BINARY SYSTEMS O.Knill, R.Dgani and M.Vogel  

E-Print Network (OSTI)

WIND TOMOGRAPHY IN BINARY SYSTEMS O.Knill, R.Dgani and M.Vogel ETH-Zurich, CH-8092, Switzerland method is particularly suitable for determining the velocity laws of stellar winds. 1. WIND TOMOGRAPHY AND ABEL'S INTEGRAL Binary systems in which a compact, point-like radiation source shines through the wind

Knill, Oliver

280

All-optical quantitative framework for bioluminescence tomography with non-contact measurement  

Science Conference Proceedings (OSTI)

In this contribution, we present an all-optical quantitative framework for bioluminescence tomography with non-contact measurement. The framework is comprised of four indispensable steps: extraction of the geometrical structures of the subject, light ... Keywords: All-optical, bioluminescence tomography, non-contact, quantitative framework, surface extraction

Xue-Li Chen; Heng Zhao; Xiao-Chao Qu; Duo-Fang Chen; Xiao-Rui Wang; Ji-Min Liang

2012-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Whole-Body Cerenkov Luminescence Tomography with the Finite Element SP3 Method  

E-Print Network (OSTI)

Whole-Body Cerenkov Luminescence Tomography with the Finite Element SP3 Method JIANGHONG ZHONG, JIE Bai oversaw the review of this article. Abstract--Generation of an accurate Cerenkov luminescence-active approach toward whole-body Cerenkov luminescence tomography. The finite element framework employs

Tian, Jie

282

Microwave tomography for breast cancer detection on Cell broadband engine processors  

Science Conference Proceedings (OSTI)

Microwave tomography (MT) is a safe screening modality that can be used for breast cancer detection. The technique uses the dielectric property contrasts between different breast tissues at microwave frequencies to determine the existence of abnormalities. ... Keywords: Breast cancer detection, Cell BE processor, Finite-difference time-domain (FDTD), Microwave tomography (MT)

Meilian Xu; Parimala Thulasiraman; Sima Noghanian

2012-09-01T23:59:59.000Z

283

Using computerized tomography to determine ionospheric structures. Part 1, Notivation and basic approaches  

SciTech Connect

Properties of the ionosphere are reviewed along with its correlations with other geophysical phenomena and with applications of ionospheric studies to communication, navigation, and surveillance systems. Computer tomography is identified as a method to determine the detailed, three-dimensional distribution of electron density within the ionosphere. Several tomography methods are described, with a basic approach illustrated by an example. Limitations are identified.

Vittitoe, C.N.

1993-08-01T23:59:59.000Z

284

Temporal and spectral imaging with micro-CT  

Science Conference Proceedings (OSTI)

Purpose: Micro-CT is widely used for small animal imaging in preclinical studies of cardiopulmonary disease, but further development is needed to improve spatial resolution, temporal resolution, and material contrast. We present a technique for visualizing the changing distribution of iodine in the cardiac cycle with dual source micro-CT. Methods: The approach entails a retrospectively gated dual energy scan with optimized filters and voltages, and a series of computational operations to reconstruct the data. Projection interpolation and five-dimensional bilateral filtration (three spatial dimensions + time + energy) are used to reduce noise and artifacts associated with retrospective gating. We reconstruct separate volumes corresponding to different cardiac phases and apply a linear transformation to decompose these volumes into components representing concentrations of water and iodine. Since the resulting material images are still compromised by noise, we improve their quality in an iterative process that minimizes the discrepancy between the original acquired projections and the projections predicted by the reconstructed volumes. The values in the voxels of each of the reconstructed volumes represent the coefficients of linear combinations of basis functions over time and energy. We have implemented the reconstruction algorithm on a graphics processing unit (GPU) with CUDA. We tested the utility of the technique in simulations and applied the technique in an in vivo scan of a C57BL/6 mouse injected with blood pool contrast agent at a dose of 0.01 ml/g body weight. Postreconstruction, at each cardiac phase in the iodine images, we segmented the left ventricle and computed its volume. Using the maximum and minimum volumes in the left ventricle, we calculated the stroke volume, the ejection fraction, and the cardiac output. Results: Our proposed method produces five-dimensional volumetric images that distinguish different materials at different points in time, and can be used to segment regions containing iodinated blood and compute measures of cardiac function. Conclusions: We believe this combined spectral and temporal imaging technique will be useful for future studies of cardiopulmonary disease in small animals.

Johnston, Samuel M.; Johnson, G. Allan; Badea, Cristian T. [Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina 27710 (United States)

2012-08-15T23:59:59.000Z

285

Clinical cardiac positron emission tomography: State of the art  

SciTech Connect

Cardiac positron emission tomography (PET) has evolved rapidly from a relatively esoteric research tool into clinical applications providing unique, quantitative information on myocardial perfusion, metabolism, and cell membrane function and having a potentially significant impact on cardiovascular medicine. Although there are many different positron radionuclides for imaging diverse myocardial behavior, three radionuclides have reached accepted clinical utility. Cardiac PET using nitrogen-13-ammonia, rubidium-82, and fluoro-18-deoxyglucose has proved accurate and definitive in multiple university and private-practice sites for diagnosing and assessing severity and location of coronary artery disease in symptomatic or asymptomatic patients, for identifying injured but viable myocardium potentially salvageable by revascularization, and for ruling out clinically significant coronary artery stenosis with a high specificity in patients who might otherwise undergo coronary arteriography to document the absence of significant disease. 89 references.

Gould, K.L. (Division of Cardiology, University of Texas Health Science Center, Houston (United States))

1991-09-01T23:59:59.000Z

286

Functional Substitution Methods in Optimization for Bayesian Tomography  

E-Print Network (OSTI)

1 Bayesian tomographic reconstruction algorithms generally require the efficient optimization of a functional of many variables. In this setting as well as many other optimization tasks, functional substitution (FS) has been widely applied to simplify each step of the iterative process. The function to be minimized is replaced locally by an approximation having a more easily manipulated form, e.g. quadratic, but which maintains sufficient similarity to descend the true functional while computing only the substitute. In this paper, we provide two new applications of FS methods in iterative coordinate descent for Bayesian tomography. The first is a modification of our recently proposed coordinate descent algorithm with 1-D Newton-Raphson approximations to an alternative quadratic which allows convergence to be proven easily. In simulations we find essentially no difference in convergence speed between the two techniques. We also present a new algorithm which exploits the FS method to all...

Jun Zheng; Suhail Saquib; Ken Sauer; Charles Bouman

1997-01-01T23:59:59.000Z

287

Electrical resistance tomography from measurements inside a steel cased borehole  

DOE Patents (OSTI)

Electrical resistance tomography (ERT) produced from measurements taken inside a steel cased borehole. A tomographic inversion of electrical resistance measurements made within a steel casing was then made for the purpose of imaging the electrical resistivity distribution in the formation remotely from the borehole. The ERT method involves combining electrical resistance measurements made inside a steel casing of a borehole to determine the electrical resistivity in the formation adjacent to the borehole; and the inversion of electrical resistance measurements made from a borehole not cased with an electrically conducting casing to determine the electrical resistivity distribution remotely from a borehole. It has been demonstrated that by using these combined techniques, highly accurate current injection and voltage measurements, made at appropriate points within the casing, can be tomographically inverted to yield useful information outside the borehole casing.

Daily, William D. (Livermore, CA); Schenkel, Clifford (Walnut Creek, CA); Ramirez, Abelardo L. (Pleasanton, CA)

2000-01-01T23:59:59.000Z

288

American Ref-Fuel of SE CT Biomass Facility | Open Energy Information  

Open Energy Info (EERE)

American Ref-Fuel of SE CT Biomass Facility American Ref-Fuel of SE CT Biomass Facility Jump to: navigation, search Name American Ref-Fuel of SE CT Biomass Facility Facility American Ref-Fuel of SE CT Sector Biomass Facility Type Municipal Solid Waste Location New London County, Connecticut Coordinates 41.5185189°, -72.0468164° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.5185189,"lon":-72.0468164,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

289

10 A.M. CT TODAY: On-the Record Conference Call for Obama Administration to  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

A.M. CT TODAY: On-the Record Conference Call for Obama A.M. CT TODAY: On-the Record Conference Call for Obama Administration to Announce Major Initiative to Enhance America's Energy Security 10 A.M. CT TODAY: On-the Record Conference Call for Obama Administration to Announce Major Initiative to Enhance America's Energy Security August 16, 2011 - 9:52am Addthis White House Rural Economic Council Promotes Production of Next Generation Biofuels, Job Creation and Economic Opportunity WASHINGTON, Aug. 16, 2011 - Today at 10 a.m. CT (11 a.m. ET), the Obama Administration will advance a major initiative to produce next generation aviation and marine biofuels to power military and commercial transportation. The initiative responds to a directive from President Obama issued in March as part of his Blueprint for a Secure Energy Future, the

290

A Fossilized Opal A To Opal C-T Transformation On The Northeast Atlantic  

Open Energy Info (EERE)

Fossilized Opal A To Opal C-T Transformation On The Northeast Atlantic Fossilized Opal A To Opal C-T Transformation On The Northeast Atlantic Margin- Support For A Significantly Elevated Palaeogeothermal Gradient During The Neogene? Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Fossilized Opal A To Opal C-T Transformation On The Northeast Atlantic Margin- Support For A Significantly Elevated Palaeogeothermal Gradient During The Neogene? Details Activities (0) Areas (0) Regions (0) Abstract: Rock samples-collected from a recent deep-water exploration well drilled in the Faeroe-Shetland Channel, northwest of the UK-confirm that a distinctive high-amplitude seismic reflector that crosscuts the Upper Palaeogene and Neogene succession and covers an area of 10 000 km(2) is an example of a fossilized Opal A to Opal C/T (Cristobalite/Tridymite)

291

Positron Scanner for Brain Tumors  

DOE R&D Accomplishments (OSTI)

It was thought that if a multi-detector device could be developed, the scanning time would be greatly shortened, with such consequent advantages as being able to work with lower dose of radiation, to obtain serial determinations, and to work with shorter-lived isotopes.

Robertson, J. S.; Bozzo, S. R.

1964-10-09T23:59:59.000Z

292

Automated Electron Microscopy Film Scanner  

Renewable Energy; Environmental Technologies. ... film meets high performance specifications at higher electron energies while digital cameras do not; ...

293

Ranging Tests for Laser Scanners  

Science Conference Proceedings (OSTI)

... Group (683.01) provides special tests for instruments that measure distance using the passive reflectance of the target, ie, non-cooperative targets. ...

2011-10-28T23:59:59.000Z

294

Peak Tracking by Simultaneous Inversion: Toward a One-Step Acoustic Tomography Analysis  

Science Conference Proceedings (OSTI)

A number of geophysical observing techniques, including ocean acoustic tomography, obtain sequences of records of which the observed relative maxima (“peaks”) are used to infer properties of the system via inversions. Traditionally, these peaks ...

Uwe Send

1996-10-01T23:59:59.000Z

295

Advances in Optical Coherence Tomography and Microscopy for endoscopic applications and functional neuroimaging  

E-Print Network (OSTI)

Optical Coherence Tomography (OCT) is a developing medical imaging technology that generates micron resolution cross-sectional images of subsurface internal tissue structure in situ and in real time, without the need to ...

Aguirre, Aaron Dominic, 1977-

2008-01-01T23:59:59.000Z

296

Applications of Fourier Domain Mode Locked lasers for optical coherence tomography imaging  

E-Print Network (OSTI)

Optical coherence tomography (OCT) is a micrometer-resolution imaging technique that produces cross-sectional images of sample microstructure by measuring the amplitude and echo time delay of backscattered light. OCT imaging ...

Adler, Desmond Christopher, 1978-

2009-01-01T23:59:59.000Z

297

ARM - Field Campaign - Ground-based Cloud Tomography Experiment at SGP  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsGround-based Cloud Tomography Experiment at SGP govCampaignsGround-based Cloud Tomography Experiment at SGP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Ground-based Cloud Tomography Experiment at SGP 2009.05.26 - 2009.07.17 Lead Scientist : Dong Huang For data sets, see below. Description Knowledge of 3D cloud properties is pressingly needed in many research fields. One of the problems encountered when trying to represent 3D cloud fields in numerical models is that the existing techniques cannot provide necessary observations at the required spatial scale and resolution. We tested a new promising technique for measuring 3D cloud microphysical structure, called cloud microwave tomography, at the Southern Great Plains (SGP) site for one month in late April 2009. Five microwave scanning

298

Atom Probe Tomography Analysis of Solute Clustering in Al-Mg-Si ...  

Science Conference Proceedings (OSTI)

Contributions of Atom Probe Tomography to the Understanding of Steels · Control of p-n ... Relationships in a Series of Co-Cr-Cu-Fe-Ni-Al High Entropy Alloys.

299

One-Step Analysis of Nonlinear Traveltime Data in Ocean Acoustic Tomography  

Science Conference Proceedings (OSTI)

A new approach based on statistical estimation is proposed for the analysis of tomographic traveltime data in cases of significant nonlinear dependence of the traveltimes on the sound-speed variations. Traditional tomography schemes based on ...

E. K. Skarsoulis; U. Send

2000-02-01T23:59:59.000Z

300

A Planetary Wave Analysis Using the Acoustic and Conventional Arrays in the 1981 Ocean Tomography Experiment  

Science Conference Proceedings (OSTI)

Using the maximum likelihood estimation method, quasi-geostrophic wave solutions are fitted to the observations of the 1981 Ocean Acoustic Tomography Experiment. The experiment occupied a 300 km square area centered at 26°N, 70°W over a duration ...

Ching-Sang Chiu; Yves Desaubies

1987-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

NIBART: A New Interval Based Algebraic Reconstruction Technique for Error Quantification of Emission Tomography Images  

Science Conference Proceedings (OSTI)

This article presents a new algebraic method for reconstructing emission tomography images. This approach is mostly an interval extension of the conventional SIRT algorithm. One of the main characteristic of our approach is that the reconstructed activity ...

Olivier Strauss; Abdelkabir Lahrech; Agnès Rico; Denis Mariano-Goulart; Benoît Telle

2009-10-01T23:59:59.000Z

302

Non-linear inversion modeling for Ultrasound Computer Tomography: transition from soft to hard tissues imaging  

E-Print Network (OSTI)

Non-linear inversion modeling for Ultrasound Computer Tomography: transition from soft to hard, the tomographic procedure used is adapted to broadband data acquired in scattering configurations while, Iterative Approximation, Soft Tissues Imaging, Hard Tissues Imaging, Breast, Bones 1. INTRODUCTION

303

Evolution of upper mantle beneath East Asia and the Tibetan Plateau from P-wave tomography  

E-Print Network (OSTI)

The main objective of the research presented in this thesis is to improve our understanding for the evolution of the upper mantle beneath East Asia and the Tibetan Plateau through high resolution P-wave tomography. The ...

Li, Chang, Ph.D. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

304

Fuel Reliability Program: Assessment of Nuclear Fuel Pellets Using X-Ray Tomography  

Science Conference Proceedings (OSTI)

This EPRI technical report describes a feasibility study involving the application of X-ray tomography as an inspection technique to detect flaws on the surface of uranium pellets in nuclear fuel rods. The objective was to develop and evaluate a system for tomographic imaging of fuel pellets inside fuel rods that uses fast algorithms for analysis of each slice of the reconstructed image for detection of abnormalities in the pellet. The report describes the fundamentals of X-ray tomography and ...

2013-02-22T23:59:59.000Z

305

Predicting target vessel location on robot-assisted coronary artery bypass graft using CT to ultrasound registration  

SciTech Connect

Purpose: Although robot-assisted coronary artery bypass grafting (RA-CABG) has gained more acceptance worldwide, its success still depends on the surgeon's experience and expertise, and the conversion rate to full sternotomy is in the order of 15%-25%. One of the reasons for conversion is poor pre-operative planning, which is based solely on pre-operative computed tomography (CT) images. In this paper, the authors propose a technique to estimate the global peri-operative displacement of the heart and to predict the intra-operative target vessel location, validated via both an in vitro and a clinical study. Methods: As the peri-operative heart migration during RA-CABG has never been reported in the literatures, a simple in vitro validation study was conducted using a heart phantom. To mimic the clinical workflow, a pre-operative CT as well as peri-operative ultrasound images at three different stages in the procedure (Stage{sub 0}--following intubation; Stage{sub 1}--following lung deflation; and Stage{sub 2}--following thoracic insufflation) were acquired during the experiment. Following image acquisition, a rigid-body registration using iterative closest point algorithm with the robust estimator was employed to map the pre-operative stage to each of the peri-operative ones, to estimate the heart migration and predict the peri-operative target vessel location. Moreover, a clinical validation of this technique was conducted using offline patient data, where a Monte Carlo simulation was used to overcome the limitations arising due to the invisibility of the target vessel in the peri-operative ultrasound images. Results: For the in vitro study, the computed target registration error (TRE) at Stage{sub 0}, Stage{sub 1}, and Stage{sub 2} was 2.1, 3.3, and 2.6 mm, respectively. According to the offline clinical validation study, the maximum TRE at the left anterior descending (LAD) coronary artery was 4.1 mm at Stage{sub 0}, 5.1 mm at Stage{sub 1}, and 3.4 mm at Stage{sub 2}. Conclusions: The authors proposed a method to measure and validate peri-operative shifts of the heart during RA-CABG. In vitro and clinical validation studies were conducted and yielded a TRE in the order of 5 mm for all cases. As the desired clinical accuracy imposed by this procedure is on the order of one intercostal space (10-15 mm), our technique suits the clinical requirements. The authors therefore believe this technique has the potential to improve the pre-operative planning by updating peri-operative migration patterns of the heart and, consequently, will lead to reduced conversion to conventional open thoracic procedures.

Cho, Daniel S.; Linte, Cristian; Chen, Elvis C. S.; Bainbridge, Daniel; Wedlake, Chris; Moore, John; Barron, John; Patel, Rajni; Peters, Terry [Imaging Research Laboratories, Robarts Research Institute and Biomedical Engineering Graduate Program, University of Western Ontario, Ontario N6A 5K8 (Canada); Imaging Research Laboratories, Robarts Research Institute and Biomedical Imaging Resource, Mayo Clinic, Rochester, Minnesota 55905 (United States); Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, Ontario N6A 5K8 (Canada); Canadian Surgical Technologies and Advanced Robotics, London, Ontario N6A 5A5 (Canada); Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, Ontario N6A 5K8 (Canada); Department of Computer Science, University of Western Ontario, Ontario N6A 5B7 (Canada); Canadian Surgical Technologies and Advanced Robotics, London, Ontario N6A 5A5 (Canada); Imaging Research Laboratories, Robarts Research Institute, Biomedical Engineering Graduate Program, University of Western Ontario N6A 5K8 (Canada); and Canadian Surgical Technologies and Advanced Robotics, London, Ontario N6A 5A5 (Canada)

2012-03-15T23:59:59.000Z

306

Atom-probe Tomography and the Science of a New Class of High ...  

Science Conference Proceedings (OSTI)

P2-28: Characterization of Pores and Cracks in Underwater Welds by µCT and Digital Optical Microscopy · P3-01: 3D Visualisation of Crystallographic Pitting.

307

Parallelizable Bayesian Tomography Algorithms with Rapid, Guaranteed Convergence  

E-Print Network (OSTI)

Bayesian tomographic reconstruction algorithms generally require the efficient optimization of a functional of many variables. In this setting, as well as in many other optimization tasks, functional substitution (FS) has been widely applied to simplify each step of the iterative process. The function to be minimized is replaced locally by an approximation having a more easily manipulated form, e.g., quadratic, but which maintains sufficient similarity to descend the true functional while computing only the substitute. In this paper, we provide two new applications of FS methods in iterative coordinate descent for Bayesian tomography. The first is a modification of our coordinate descent algorithm with one-dimensional (1-D) Newton--Raphson approximations to an alternative quadratic which allows convergence to be proven easily. In simulations, we find essentially no difference in convergence speed between the two techniques. We also present a new algorithm which exploits the FS method to allow parallel updates of arbitrary sets of pixels using computations similar to iterative coordinate descent. The theoretical potential speed up of parallel implementations is nearly linear with the number of processors if communication costs are neglected.

Jun Zheng; Suhail S. Saquib; Ken Sauer; Charles A. Bouman

2000-01-01T23:59:59.000Z

308

Digital Radiography and Computed Tomography (DRCT) Product Improvement Plan (PIP)  

SciTech Connect

The Idaho National Laboratory (INL) has been developing and deploying x-ray inspection systems for chemical weapons containers for the past 12 years under the direction of the Project Manager for Non-Stockpile Chemical Materiel (PMNSCM). In FY-10 funding was provided to advance the capabilities of these systems through the DRCT (Digital Radiography and Computed Tomography) Product Improvement Plan (PIP), funded by the PMNSCM. The DRCT PIP identified three research tasks; end user study, detector evaluation and DRCT/PINS integration. Work commenced in February, 2010. Due to the late start and the schedule for field inspection of munitions at various sites, it was not possible to spend sufficient field time with operators to develop a complete end user study. We were able to interact with several operators, principally Mr. Mike Rowan who provided substantial useful input through several discussions and development of a set of field notes from the Pueblo, CO field mission. We will be pursuing ongoing interactions with field personnel as opportunities arise in FY-11.

Tim Roney; Bob Pink; Karen Wendt; Robert Seifert; Mike Smith

2010-12-01T23:59:59.000Z

309

Positron Emission Tomography Detector Development for Plant Biology  

Science Conference Proceedings (OSTI)

There are opportunities for the development of new tools to advance plant biology research through the use of radionuclides. Thomas Jefferson National Accelerator Facility, Duke University, West Virginia University and the University of Maryland are collaborating on the development of radionuclide imaging technologies to facilitate plant biology research. Biological research into optimizing plant productivity under various environmental constraints, biofuel and carbon sequestration research are areas that could potentially benefit from new imaging technologies. Using 11CO2 tracers, the investigators at Triangle University Nuclear Laboratory / Duke University Phytotron are currently researching the dynamical responses of plants to environmental changes forecasted from increasing greenhouse trace gases involved in global change. The biological research primary focus is to investigate the impact of elevated atmospheric CO2 and nutrients limitation on carbon and nitrogen dynamics in plants. We report here on preliminary results of 11CO2 plant imaging experiments involving barley plants using Jefferson Lab dual planar positron emission tomography detectors to image 11CO2 in live barley plants. New detector designs will be developed based on the preliminary studies reported here and further planned.

Weisenberger, A G; McKisson, J; Stolin, A; Zorn, C; Howell, C R; Crowell, A S; Reid, C D; Majewski, S

2010-01-01T23:59:59.000Z

310

Imaging algorithms for geophysical applications of impedance tomography  

SciTech Connect

The methods of impedance tomography may be employed to obtain images of subsurface electrical and conductivity variations. For practical reasons, voltages and currents are usually applied at locations on the ground surface or down a limited number of boreholes, but almost never over the entire surface of the region being investigated. The geophysical inversion process can be facilitated by constructing algorithms adopted to these particular geometries and to the lack of complete surface data. In this paper we assume that the fluctuations in conductivity are small compared to the background value. The imaging of these fluctuations is carried out exactly within the constraints imposed by the problem geometry. Several possible arrangements of injection and monitoring electrodes are considered. In two dimensions include: Cross-line geometry, current input along one line (borehole) and measurements along a separate parallel line. Single-line geometry, injection and monitoring using the same borehole. Surface reflection geometry, all input and measurement along the ground surface. Theoretical and practical limitations on the image quality produced by the algorithms are discussed. They are applied to several sets of simulated data, and the images produced are displayed and analyzed.

Witten, A.J. (Oak Ridge National Lab., TN (United States)); Molyneux, J.E. (Widener Univ., Dept. of Mechanical Engineering, Chester, PA (United States))

1992-06-02T23:59:59.000Z

311

Using electrical resistance tomography to map subsurface temperatures  

DOE Patents (OSTI)

A method is provided for measuring subsurface soil or rock temperatures remotely using electrical resistivity tomography (ERT). Electrical resistivity measurements are made using electrodes implanted in boreholes driven into the soil and/or at the ground surface. The measurements are repeated as some process changes the temperatures of the soil mass/rock mass. Tomographs of electrical resistivity are calculated based on the measurements using Poisson's equation. Changes in the soil/rock resistivity can be related to changes in soil/rock temperatures when: (1) the electrical conductivity of the fluid trapped in the soil's pore space is low, (2) the soil/rock has a high cation exchange capacity and (3) the temperature changes are sufficiently high. When these three conditions exist the resistivity changes observed in the ERT tomographs can be directly attributed to changes in soil/rock temperatures. This method provides a way of mapping temperature changes in subsurface soils remotely. Distances over which the ERT method can be used to monitor changes in soil temperature range from tens to hundreds of meters from the electrode locations.

Ramirez, Abelardo L. (Pleasanton, CA); Chesnut, Dwayne A. (San Francisco, CA); Daily, William D. (Livermore, CA)

1994-01-01T23:59:59.000Z

312

Using electrical resistance tomography to map subsurface temperatures  

DOE Patents (OSTI)

A method is provided for measuring subsurface soil or rock temperatures remotely using electrical resistivity tomography (ERT). Electrical resistivity measurements are made using electrodes implanted in boreholes driven into the soil and/or at the ground surface. The measurements are repeated as some process changes the temperatures of the soil mass/rock mass. Tomographs of electrical resistivity are calculated based on the measurements using Poisson's equation. Changes in the soil/rock resistivity can be related to changes in soil/rock temperatures when: (1) the electrical conductivity of the fluid trapped in the soil's pore space is low, (2) the soil/rock has a high cation exchange capacity and (3) the temperature changes are sufficiently high. When these three conditions exist the resistivity changes observed in the ERT tomographs can be directly attributed to changes in soil/rock temperatures. This method provides a way of mapping temperature changes in subsurface soils remotely. Distances over which the ERT method can be used to monitor changes in soil temperature range from tens to hundreds of meters from the electrode locations. 1 fig.

Ramirez, A.L.; Chesnut, D.A.; Daily, W.D.

1994-09-13T23:59:59.000Z

313

Electrical resistance tomography using steel cased boreholes as electrodes  

DOE Patents (OSTI)

An electrical resistance tomography method is described which uses steel cased boreholes as electrodes. The method enables mapping the electrical resistivity distribution in the subsurface from measurements of electrical potential caused by electrical currents injected into an array of electrodes in the subsurface. By use of current injection and potential measurement electrodes to generate data about the subsurface resistivity distribution, which data is then used in an inverse calculation, a model of the electrical resistivity distribution can be obtained. The inverse model may be constrained by independent data to better define an inverse solution. The method utilizes pairs of electrically conductive (steel) borehole casings as current injection electrodes and as potential measurement electrodes. The greater the number of steel cased boreholes in an array, the greater the amount of data is obtained. The steel cased boreholes may be utilized for either current injection or potential measurement electrodes. The subsurface model produced by this method can be 2 or 3 dimensional in resistivity depending on the detail desired in the calculated resistivity distribution and the amount of data to constrain the models. 2 figs.

Daily, W.D.; Ramirez, A.L.

1999-06-22T23:59:59.000Z

314

Electrical resistance tomography using steel cased boreholes as electrodes  

DOE Patents (OSTI)

An electrical resistance tomography method using steel cased boreholes as electrodes. The method enables mapping the electrical resistivity distribution in the subsurface from measurements of electrical potential caused by electrical currents injected into an array of electrodes in the subsurface. By use of current injection and potential measurement electrodes to generate data about the subsurface resistivity distribution, which data is then used in an inverse calculation, a model of the electrical resistivity distribution can be obtained. The inverse model may be constrained by independent data to better define an inverse solution. The method utilizes pairs of electrically conductive (steel) borehole casings as current injection electrodes and as potential measurement electrodes. The greater the number of steel cased boreholes in an array, the greater the amount of data is obtained. The steel cased boreholes may be utilized for either current injection or potential measurement electrodes. The subsurface model produced by this method can be 2 or 3 dimensional in resistivity depending on the detail desired in the calculated resistivity distribution and the amount of data to constain the models.

Daily, William D. (Livermore, CA); Ramirez, Abelardo L. (Pleasanton, CA)

1999-01-01T23:59:59.000Z

315

Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model  

SciTech Connect

Purpose: This research is designed to develop and evaluate a flat-panel detector-based dynamic cone beam CT system for dynamic angiography imaging, which is able to provide both dynamic functional information and dynamic anatomic information from one multirevolution cone beam CT scan. Methods: A dynamic cone beam CT scan acquired projections over four revolutions within a time window of 40 s after contrast agent injection through a femoral vein to cover the entire wash-in and wash-out phases. A dynamic cone beam CT reconstruction algorithm was utilized and a novel recovery method was developed to correct the time-enhancement curve of contrast flow. From the same data set, both projection-based subtraction and reconstruction-based subtraction approaches were utilized and compared to remove the background tissues and visualize the 3D vascular structure to provide the dynamic anatomic information. Results: Through computer simulations, the new recovery algorithm for dynamic time-enhancement curves was optimized and showed excellent accuracy to recover the actual contrast flow. Canine model experiments also indicated that the recovered time-enhancement curves from dynamic cone beam CT imaging agreed well with that of an IV-digital subtraction angiography (DSA) study. The dynamic vascular structures reconstructed using both projection-based subtraction and reconstruction-based subtraction were almost identical as the differences between them were comparable to the background noise level. At the enhancement peak, all the major carotid and cerebral arteries and the Circle of Willis could be clearly observed. Conclusions: The proposed dynamic cone beam CT approach can accurately recover the actual contrast flow, and dynamic anatomic imaging can be obtained with high isotropic 3D resolution. This approach is promising for diagnosis and treatment planning of vascular diseases and strokes.

Cai Weixing; Zhao Binghui; Conover, David; Liu Jiangkun; Ning Ruola [Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Radiology, Shanghai 6th People's Hospital, 600 Yishan Road, Xuhui, Shanghai (China); Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States) and Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States)

2012-01-15T23:59:59.000Z

316

Tomography of the Reionization Epoch with Multifrequency CMB Observations  

E-Print Network (OSTI)

We study the constraints that future multifrequency Cosmic Microwave Background (CMB) experiments will be able to set on the metal enrichment history of the Inter Galactic Medium at the epoch of reionisation. We forecast the signal to noise ratio for the detection of the signal introduced in the CMB by resonant scattering off metals at the end of the Dark Ages. We take into account systematics associated to inter-channel calibration, PSF reconstruction errors and innacurate foreground removal. We develop an algorithm to optimally extract the signal generated by metals during reionisation and to remove accurately the contamination due to the thermal Sunyaev-Zel'dovich effect. Although demanding levels of foreground characterisation and control of systematics are required, they are very distinct from those encountered in HI-21cm studies and CMB polarization, and this fact encourages the study of resonant scattering off metals as an alternative way of conducting tomography of the reionisation epoch. An ACT-like experiment with optimistic assumtions on systematic effects, and looking at clean regions of the sky, can detect changes of 3%-12% (95% c.l.) of the OIII abundance (with respect its solar value) in the redshift range $z\\in$ [12,22], for reionization redshift $z_{\\rm re}>10$. However, for $z_{\\rm re} solar value in the redshift range $z\\in$ [5.5,9], (95% c.l.). These constraints assume that inter-channel calibration is accurate down to one part in $10^{4}$, which constitutes the most critical technical requirement of this method, but still achievable with current technology.

Carlos Hernandez-Monteagudo; Licia Verde; Raul Jimenez

2006-04-14T23:59:59.000Z

317

In vivo breast sound-speed imaging with ultrasound tomography  

Science Conference Proceedings (OSTI)

We discuss a bent-ray ultrasound tomography algorithm with total-variation (TV) regularization. We have applied this algorithm to 61 in vivo breast datasets collected with our in-house clinical prototype for imaging sound-speed distributions in the breast. Our analysis showed that TV regularization could preserve sharper lesion edges than the classic Tikhonov regularization. Furthermore, the image quality of our TV bent-ray sound-speed tomograms was superior to that of the straight-ray counterparts for all types of breasts within BI-RADS density categories 1-4. For all four breast types from fatty to dense, the improvements for average sharpness (in the unit of (m{center_dot} s) {sup -1}) of lesion edges in our TV bent-ray tomograms are between 2.1 to 3.4 fold compared to the straight ray tomograms. Reconstructed sound-speed tomograms illustrated that our algorithm could successfully image fatty and glandular tissues within the breast. We calculated the mean sound-speed values for fatty tissue and breast parenchyma as 1422 {+-} 9 mls (mean{+-} SD) and1487 {+-} 21 mls, respectively. Based on 32 lesions in a cohort of 61 patients, we also found that the mean sound-speed for malignant breast lesions (1548{+-}17 mls) was higher, on average, than that of benign ones (1513{+-}27 mls) (one-sided p

Huang, Lianjie [Los Alamos National Laboratory; Li, Cuiping [KARMANOS CANCER INSTITUTE; Duric, Neb [KARMANOS CANCER INSTITUTE; Littrup, Peter [KARMONOS CANCER INSTITUTE

2009-01-01T23:59:59.000Z

318

THE ATTENUATED RADON TRANSFORM: APPLICATION TO SINGLE-PHOTON EMISSION COMPUTED TOMOGRAPHY IN THE PRESENCE OF A VARIABLE ATTENUATING MEDIUM  

E-Print Network (OSTI)

section imaging of radionuclide distributions in heart,the myocardium ivith radionuclides, Radiology, 125 (1977),attenuation correction in radionuclide computed tomography,

Gullberg, Grant T.

2013-01-01T23:59:59.000Z

319

Classification of the Colonic Polyps in CT-Colonography Using Region Covariance as Descriptor Features of Suspicious Regions  

Science Conference Proceedings (OSTI)

We present an algorithm to classify polyps in CT colonography images utilizing covariance matrices as object descriptors. Since these descriptors do not lie on a vector space, they cannot simply be fed to traditional machine learning tools such as support ... Keywords: CT colonography, Colonic polyp detection, Covariance descriptor

Niyazi Kilic; Olcay Kursun; Osman Nuri Ucan

2010-04-01T23:59:59.000Z

320

Concurrent segmentation of the prostate on MRI and CT via linked statistical shape models for radiotherapy planning  

Science Conference Proceedings (OSTI)

Purpose: Prostate gland segmentation is a critical step in prostate radiotherapy planning, where dose plans are typically formulated on CT. Pretreatment MRI is now beginning to be acquired at several medical centers. Delineation of the prostate on MRI is acknowledged as being significantly simpler to perform, compared to delineation on CT. In this work, the authors present a novel framework for building a linked statistical shape model (LSSM), a statistical shape model (SSM) that links the shape variation of a structure of interest (SOI) across multiple imaging modalities. This framework is particularly relevant in scenarios where accurate boundary delineations of the SOI on one of the modalities may not be readily available, or difficult to obtain, for training a SSM. In this work the authors apply the LSSM in the context of multimodal prostate segmentation for radiotherapy planning, where the prostate is concurrently segmented on MRI and CT. Methods: The framework comprises a number of logically connected steps. The first step utilizes multimodal registration of MRI and CT to map 2D boundary delineations of the prostate from MRI onto corresponding CT images, for a set of training studies. Hence, the scheme obviates the need for expert delineations of the gland on CT for explicitly constructing a SSM for prostate segmentation on CT. The delineations of the prostate gland on MRI and CT allows for 3D reconstruction of the prostate shape which facilitates the building of the LSSM. In order to perform concurrent prostate MRI and CT segmentation using the LSSM, the authors employ a region-based level set approach where the authors deform the evolving prostate boundary to simultaneously fit to MRI and CT images in which voxels are classified to be either part of the prostate or outside the prostate. The classification is facilitated by using a combination of MRI-CT probabilistic spatial atlases and a random forest classifier, driven by gradient and Haar features. Results: The authors acquire a total of 20 MRI-CT patient studies and use the leave-one-out strategy to train and evaluate four different LSSMs. First, a fusion-based LSSM (fLSSM) is built using expert ground truth delineations of the prostate on MRI alone, where the ground truth for the gland on CT is obtained via coregistration of the corresponding MRI and CT slices. The authors compare the fLSSM against another LSSM (xLSSM), where expert delineations of the gland on both MRI and CT are employed in the model building; xLSSM representing the idealized LSSM. The authors also compare the fLSSM against an exclusive CT-based SSM (ctSSM), built from expert delineations of the gland on CT alone. In addition, two LSSMs trained using trainee delineations (tLSSM) on CT are compared with the fLSSM. The results indicate that the xLSSM, tLSSMs, and the fLSSM perform equivalently, all of them out-performing the ctSSM. Conclusions: The fLSSM provides an accurate alternative to SSMs that require careful expert delineations of the SOI that may be difficult or laborious to obtain. Additionally, the fLSSM has the added benefit of providing concurrent segmentations of the SOI on multiple imaging modalities.

Chowdhury, Najeeb; Toth, Robert; Chappelow, Jonathan; Kim, Sung; Motwani, Sabin; Punekar, Salman; Lin Haibo; Both, Stefan; Vapiwala, Neha; Hahn, Stephen; Madabhushi, Anant

2012-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Positron Emission Tomography/Computed Tomography-Guided Intensity-Modulated Radiotherapy for Limited-Stage Small-Cell Lung Cancer  

Science Conference Proceedings (OSTI)

Purpose: Omitting elective nodal irradiation from planning target volumes does not compromise outcomes in patients with non-small-cell lung cancer, but whether the same is true for those with limited-stage small-cell lung cancer (LS-SCLC) is unknown. Therefore, in the present study, we sought to determine the clinical outcomes and the frequency of elective nodal failure in patients with LS-SCLC staged using positron emission tomography/computed tomography and treated with involved-field intensity-modulated radiotherapy. Methods and Materials: Between 2005 and 2008, 60 patients with LS-SCLC at our institution underwent disease staging using positron emission tomography/computed tomography before treatment using an intensity-modulated radiotherapy plan in which elective nodal irradiation was intentionally omitted from the planning target volume (mode and median dose, 45 Gy in 30 fractions; range, 40.5 Gy in 27 fractions to 63.8 Gy in 35 fractions). In most cases, concurrent platinum-based chemotherapy was administered. We retrospectively reviewed the clinical outcomes to determine the overall survival, relapse-free survival, and failure patterns. Elective nodal failure was defined as recurrence in initially uninvolved hilar, mediastinal, or supraclavicular nodes. Survival was assessed using the Kaplan-Meier method. Results: The median age of the study patients at diagnosis was 63 years (range, 39-86). The median follow-up duration was 21 months (range, 4-58) in all patients and 26 months (range, 4-58) in the survivors. The 2-year actuarial overall survival and relapse-free survival rate were 58% and 43%, respectively. Of the 30 patients with recurrence, 23 had metastatic disease and 7 had locoregional failure. We observed only one isolated elective nodal failure. Conclusions: To our knowledge, this is the first study to examine the outcomes in patients with LS-SCLC staged with positron emission tomography/computed tomography and treated with definitive intensity-modulated radiotherapy. In these patients, elective nodal irradiation can be safely omitted from the planning target volume for the purposes of dose escalation and toxicity reduction.

Shirvani, Shervin M.; Komaki, Ritsuko [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Heymach, John V.; Fossella, Frank V. [Department of Thoracic/Head and Neck Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Chang, Joe Y., E-mail: jychang@mdanderson.org [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

2012-01-01T23:59:59.000Z

322

A PET/CT directed, 3D ultrasound-guided biopsy system for prostate cancer  

Science Conference Proceedings (OSTI)

Prostate cancer affects 1 in 6 men in the USA. Systematic transrectal ultrasound (TRUS)-guided biopsy is the standard method for a definitive diagnosis of prostate cancer. However, this "blind" biopsy approach can miss at least 20% of prostate cancers. ... Keywords: 3D ultrasound imaging, PET/CT, image segmentation, imageguided biopsy, molecular imaging, nonrigid image registration, prostate cancer, wavelet transform

Baowei Fei; Viraj Master; Peter Nieh; Hamed Akbari; Xiaofeng Yang; Aaron Fenster; David Schuster

2011-09-01T23:59:59.000Z

323

Louisiana oyster CuLtCh ProjeCt General Project DescriPtion  

E-Print Network (OSTI)

secondary production. estiMateD cost The estimated cost to implement the Louisiana Oyster Cultch Project is $15,582,600. (Estimated costs for some of the projects were updated from those provided in the DERPLouisiana oyster CuLtCh ProjeCt General Project DescriPtion The Louisiana Oyster Cultch Project

324

Department of History, Yale University New Haven, CT 06520-8324  

E-Print Network (OSTI)

Dilemma': Making a Place for Historians in the Climate Change and Energy Debates," Environmental History History (undergraduate lecture) Energy in American History (undergraduate seminar) United States GlobalPaul Sabin Department of History, Yale University New Haven, CT 06520-8324 Telephone: (203) 436

325

Robust Segmentation and Anatomical Labeling of the Airway Tree from Thoracic CT Scans  

Science Conference Proceedings (OSTI)

A method for automatic extraction and labeling of the airway tree from thoracic CT scans is presented and extensively evaluated on 150 scans of clinical dose, low dose and ultra-low dose data, in inspiration and expiration from both relatively healthy ...

Bram Ginneken; Wouter Baggerman; Eva M. Rikxoort

2008-09-01T23:59:59.000Z

326

The noise power spectrum in CT with direct fan beam reconstruction  

Science Conference Proceedings (OSTI)

The noise power spectrum (NPS) is a useful metric for understanding the noise content in images. To examine some unique properties of the NPS of fan beam CT, the authors derived an analytical expression for the NPS of fan beam CT and validated it with computer simulations. The nonstationary noise behavior of fan beam CT was examined by analyzing local regions and the entire field-of-view (FOV). This was performed for cases with uniform as well as nonuniform noise across the detector cells and across views. The simulated NPS from the entire FOV and local regions showed good agreement with the analytically derived NPS. The analysis shows that whereas the NPS of a large FOV in parallel beam CT (using a ramp filter) is proportional to frequency, the NPS with direct fan beam FBP reconstruction shows a high frequency roll off. Even in small regions, the fan beam NPS can show a sharp transition (discontinuity) at high frequencies. These effects are due to the variable magnification and therefore are more pronounced as the fan angle increases. For cases with nonuniform noise, the NPS can show the directional dependence and additional effects.

Baek, Jongduk; Pelc, Norbert J. [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Department of Radiology, Stanford University, Stanford, California 94305 (United States); Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States) and Department of Bioengineering, Stanford University, Stanford, California 94305 (United States)

2010-05-15T23:59:59.000Z

327

CT-Guided Fiducial Placement for CyberKnife Stereotactic Radiosurgery: An Initial Experience  

Science Conference Proceedings (OSTI)

CyberKnife frameless image-guided radiosurgery has become a widely used system for parenchymal extracranial lesions. Gold fiducials are required for the planning and aiming of CyberKnife therapy. We report our initial experience and describe the technique of positioning tumor markers, under CT guidance. We conducted a retrospective review of 105 patients who were referred for CyberKnife stereotactic radiosurgery at Iatropolis CyberKnife Center in Athens. All patients underwent percutaneous fiducial placement via CT guidance. At the desired location, the 18-G needle was advanced into or near the tumor. Data collected included number and locations of fiducials placed and complications experienced to date. One hundred five patients underwent fiducial placement under CT guidance and a total number of 319 gold seeds were implanted. We experienced one episode of pneumothorax that required drainage, one mild pneumothorax, and three episodes of perifocal pulmonary hemorrhage. In conclusion, fiducial implantation under CT guidance appears to be a safe and efficient procedure, as long as it is performed by an experienced interventional radiologist.

Sotiropoulou, Evangelia ['Sotiria' General Hospital of Chest Diseases (Greece); Stathochristopoulou, Irene [Iatropolis CyberKnife Center (Greece); Stathopoulos, Konstantinos ['Sotiria' General Hospital of Chest Diseases (Greece); Verigos, Kosmas; Salvaras, Nikolaos [Iatropolis CyberKnife Center (Greece); Thanos, Loukas, E-mail: loutharad@yahoo.co ['Sotiria' General Hospital of Chest Diseases (Greece)

2010-06-15T23:59:59.000Z

328

Time-dependent seismic tomography and its application to the Coso  

Open Energy Info (EERE)

and its application to the Coso and its application to the Coso geothermal area, 1996-2006 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Time-dependent seismic tomography and its application to the Coso geothermal area, 1996-2006 Details Activities (1) Areas (1) Regions (0) Abstract: Measurements of temporal changes in Earth structure are commonly determined using local earthquake tomography computer programs that invert multiple seismic-wave arrival time data sets separately and assume that any differences in the structural results arise from real temporal variations. This assumption is dangerous because the results of repeated tomography experiments would differ even if the structure did not change, simply because of variation in the seismic ray distribution caused by the natural

329

Time-Dependent Seismic Tomography of the Coso Geothermal Area, 1996-2004 |  

Open Energy Info (EERE)

Dependent Seismic Tomography of the Coso Geothermal Area, 1996-2004 Dependent Seismic Tomography of the Coso Geothermal Area, 1996-2004 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Time-dependent seismic tomography of the Coso geothermal area, 1996-2004 Details Activities (1) Areas (1) Regions (0) Abstract: Local-earthquake tomographic images were calculated for each of the years 1996 - 2004 using arrival times from the U.S. Navy's permanent seismometer network at the Coso geothermal area, California. The results show irregular strengthening with time of the wave-speed ratio VP/VS at shallow depths. These changes result predominately from progressive relative increase in VS with respect to VP, and could result from processes associated with geothermal operations such as decrease in fluid pressure

330

Clinical evaluation of a commercial orthopedic metal artifact reduction tool for CT simulations in radiation therapy  

SciTech Connect

Purpose: Severe artifacts in kilovoltage-CT simulation images caused by large metallic implants can significantly degrade the conspicuity and apparent CT Hounsfield number of targets and anatomic structures, jeopardize the confidence of anatomical segmentation, and introduce inaccuracies into the radiation therapy treatment planning process. This study evaluated the performance of the first commercial orthopedic metal artifact reduction function (O-MAR) for radiation therapy, and investigated its clinical applications in treatment planning. Methods: Both phantom and clinical data were used for the evaluation. The CIRS electron density phantom with known physical (and electron) density plugs and removable titanium implants was scanned on a Philips Brilliance Big Bore 16-slice CT simulator. The CT Hounsfield numbers of density plugs on both uncorrected and O-MAR corrected images were compared. Treatment planning accuracy was evaluated by comparing simulated dose distributions computed using the true density images, uncorrected images, and O-MAR corrected images. Ten CT image sets of patients with large hip implants were processed with the O-MAR function and evaluated by two radiation oncologists using a five-point score for overall image quality, anatomical conspicuity, and CT Hounsfield number accuracy. By utilizing the same structure contours delineated from the O-MAR corrected images, clinical IMRT treatment plans for five patients were computed on the uncorrected and O-MAR corrected images, respectively, and compared. Results: Results of the phantom study indicated that CT Hounsfield number accuracy and noise were improved on the O-MAR corrected images, especially for images with bilateral metal implants. The {gamma} pass rates of the simulated dose distributions computed on the uncorrected and O-MAR corrected images referenced to those of the true densities were higher than 99.9% (even when using 1% and 3 mm distance-to-agreement criterion), suggesting that dose distributions were clinically identical. In all patient cases, radiation oncologists rated O-MAR corrected images as higher quality. Formerly obscured critical structures were able to be visualized. The overall image quality and the conspicuity in critical organs were significantly improved compared with the uncorrected images: overall quality score (1.35 vs 3.25, P= 0.0022); bladder (2.15 vs 3.7, P= 0.0023); prostate and seminal vesicles/vagina (1.3 vs 3.275, P= 0.0020); rectum (2.8 vs 3.9, P= 0.0021). The noise levels of the selected ROIs were reduced from 93.7 to 38.2 HU. On most cases (8/10), the average CT Hounsfield numbers of the prostate/vagina on the O-MAR corrected images were closer to the referenced value (41.2 HU, an average measured from patients without metal implants) than those on the uncorrected images. High {gamma} pass rates of the five IMRT dose distribution pairs indicated that the dose distributions were not significantly affected by the CT image improvements. Conclusions: Overall, this study indicated that the O-MAR function can remarkably reduce metal artifacts and improve both CT Hounsfield number accuracy and target and critical structure visualization. Although there was no significant impact of the O-MAR algorithm on the calculated dose distributions, we suggest that O-MAR corrected images are more suitable for the entire treatment planning process by offering better anatomical structure visualization, improving radiation oncologists' confidence in target delineation, and by avoiding subjective density overrides of artifact regions on uncorrected images.

Li Hua; Noel, Camille; Chen, Haijian; Harold Li, H.; Low, Daniel; Moore, Kevin; Klahr, Paul; Michalski, Jeff; Gay, Hiram A.; Thorstad, Wade; Mutic, Sasa [Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States); Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California 90095 (United States); Department of Radiation Oncology, University of California San Diego, San Diego, California 92093 (United States); Philips Healthcare System, Cleveland, Ohio 44143 (United States); Department of Radiation Oncology, Washington University, St. Louis, Missouri 63110 (United States)

2012-12-15T23:59:59.000Z

331

Fast synchrotron X-ray tomography study of the rod packing structures  

SciTech Connect

We present a fast synchrotron X-ray tomography study of the packing structures of rods under tapping. Utilizing the high flux of the X-rays generated from the third-generation synchrotron source, we can complete a tomography scan within several seconds, after which the three-dimensional (3D) packing structure can be obtained for the subsequent structural analysis. Due to the high-energy nature of the X-ray beam, special image processing steps including image phase-retrieval has been implemented. Overall, this study suggests the possibility of acquiring statistically significant static packing structures within a reasonable time scale using high-intensity X-ray sources.

Zhang Xiaodan; Xia Chengjie; Sun Haohua; Wang Yujie [Department of Physics, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240 (China)

2013-06-18T23:59:59.000Z

332

Simulation Study on the Characteristics of Carbon-Fiber-Reinforced Plastics in Electromagnetic Tomography Nondestructive Evaluation Systems  

Science Conference Proceedings (OSTI)

Simulations of carbon-fiber-reinforced plastics (CFRP) using the finite element method in electromagnetic tomography nondestructive evaluation systems are presented in this paper. Ansoft Maxwell 3D models describing the interaction of the sensors with ... Keywords: Carbon-fiber-reinforced plastics (CFRP), finite element, electromagnetic tomography (EMT), nondestructive evaluation (NDE), sensitivity matrix

Ze Liu; Yu Xu; Xiaofei Zhang; Yali Pei; Yiping Cheng; Wuliang Yin

2010-03-01T23:59:59.000Z

333

Comprehensive study of LASL Well C/T-2 Roosevelt Hot Springs KGRA, Utah, and applications to geothermal well logging  

DOE Green Energy (OSTI)

Utah State Geothermal Well 9-1 in the Roosevelt Hot Springs KGRA, Beaver County, Utah, has been donated by Phillips Petroleum Company for calibration and testing of well-logging equipment in the hot, corrosive, geothermal environment. It is the second Calibration/Test Well (C/T-2) in the Geothermal Log Interpretation Program. A study of cuttings and well logs from Well C/T-2 was completed. This synthesis and data presentation contains most of the subsurface geologic information needed to effect the total evaluation of geophysical logs acquired in this geothermal calibration/test well, C/T-2.

Glenn, W.E.; Hulen, J.B.; Nielson, D.L.

1981-02-01T23:59:59.000Z

334

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)

CT images showed that the water produced from the hydrateporous hydrate sample). Water produced from the dissociation

Gupta, A.

2010-01-01T23:59:59.000Z

335

Adaptive-window indicator kriging: A thresholding method for computed tomography images of porous media  

Science Conference Proceedings (OSTI)

Image segmentation is a crucial step in understanding the structure of porous materials, subsequent analyses being profoundly dependent upon segmentation accuracy. Computed tomography images of naturally occurring heterogeneous materials such as soils ... Keywords: Indicator kriging, Local segmentation, Microtomography, Soil, X-ray

A. N. Houston, W. Otten, P. C. Baveye, S. Hapca

2013-04-01T23:59:59.000Z

336

Open electrical impedance tomography file format: towards a first version Pascal Olivier Gaggero1  

E-Print Network (OSTI)

University, Ottawa, Canada pascal.gaggero@bfh.ch Retrieving and analyzing historical electrical impedanceOpen electrical impedance tomography file format: towards a first version Pascal Olivier Gaggero1 acquired at a different frame rate than the EIT data stream The "eit" folder stores XML

Adler, Andy

337

Analysis of hydraulic tomography using temporal moments of drawdown recovery data  

E-Print Network (OSTI)

and Tian-Chyi J. Yeh Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona are discussed subsequently. Citation: Zhu, J., and T.-C. J. Yeh (2006), Analysis of hydraulic tomography using temporal moments of drawdown recovery data, Water Resour. Res., 42, W02403, doi:10.1029/2005WR004309. 1

Daniels, Jeffrey J.

338

GPS tomography in the polar cap: comparison with ionosondes and in situ spacecraft data  

Science Conference Proceedings (OSTI)

Tomographic 4D reconstructions of ionospheric anomalies appearing in the high-latitude polar cap region are compared with plasma density measurements by digital ionosonde located near the north magnetic pole at Eureka station and with in situ plasma ... Keywords: GPS tomography, Geomagnetic storms, Ionosphere

Dimitry Pokhotelov; P. T. Jayachandran; Cathryn N. Mitchell; John W. Macdougall; Michael H. Denton

2011-01-01T23:59:59.000Z

339

Time-lapse electrical resistivity tomography applied to cave sustainability (Barbados) and groundwater exploration (Saint Lucia)  

E-Print Network (OSTI)

In this work we apply the method of two-dimensional time-lapse electrical resistivity tomography (2D time-lapse ERT) for two different problems. In the first problem, we monitor the structural stability of the roof of the ...

Agramakova, Yulia

2011-01-01T23:59:59.000Z

340

Multi-resolution system for artifact removal and edge enhancement in computerized tomography images  

Science Conference Proceedings (OSTI)

The aim of image enhancement means adopting some technical method, which includes algorithm, to stand out the interested characteristics of the image and to restrain some useless characteristics of the image. The image, which has been improved, can satisfy ... Keywords: Edge enhancement, Industrial CT images, Multi-resolution techniques

S. Arivazhagan; S. Deivalakshmi; K. Kannan; B. N. Gajbhiye; C. Muralidhar; Sijo N. Lukose; M. P. Subramanian

2007-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
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341

A survey of prostate segmentation methodologies in ultrasound, magnetic resonance and computed tomography images  

Science Conference Proceedings (OSTI)

Prostate segmentation is a challenging task, and the challenges significantly differ from one imaging modality to another. Low contrast, speckle, micro-calcifications and imaging artifacts like shadow poses serious challenges to accurate prostate segmentation ... Keywords: CT images, MR images, Prostate gland segmentation methods, TRUS images

Soumya Ghose; Arnau Oliver; Robert Martí; Xavier Lladó; Joan C. Vilanova; Jordi Freixenet; Jhimli Mitra; DéSiré Sidibé; Fabrice Meriaudeau

2012-10-01T23:59:59.000Z

342

x???íN*A**? ZDK(mP?óIH äz *à?âCT"Hh?x*4* *??C*? ...  

Science Conference Proceedings (OSTI)

x???íN*A**? ZDK(mP?óIH?äz?*à?âCT"Hh?x*4*?*??C*???;G@ PBJ·}???è¥????IÇUu?¢?ñ??`o?1ƒ\\?*N????x

2011-03-02T23:59:59.000Z

343

Fossil Energy Today - First Quarter, 2012 | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

In This Issue.... CT Scanners Give Energy Researchers a Core Understanding of Marcellus Shale Large-Scale CO2 Injection Begins SPR Completes Drawdown of 30 Million Barrels...

344

NETL: Onsite Research  

NLE Websites -- All DOE Office Websites (Extended Search)

technique also has been shown effective in enhancing oil recovery and displacing coal bed methane. The CT Scanner Laboratory provides imaging data that can be used for computer...

345

Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography  

E-Print Network (OSTI)

method, Water Resources Research 36 (8), 2095-2105 Yeh, T. -determine the water saturation. However, Yeh at al. , 2000Yeh (2005), Characterization of aquifer heterogeneity using transient hydraulic tomography, Water

Brauchler, R.

2012-01-01T23:59:59.000Z

346

Simultaneous maximum-likelihood reconstruction for x-ray grating based phase-contrast tomography avoiding intermediate phase retrieval  

E-Print Network (OSTI)

Phase-wrapping artifacts, statistical image noise and the need for a minimum amount of phase steps per projection limit the practicability of x-ray grating based phase-contrast tomography, when using filtered back projection reconstruction. For conventional x-ray computed tomography, the use of statistical iterative reconstruction algorithms has successfully reduced artifacts and statistical issues. In this work, an iterative reconstruction method for grating based phase-contrast tomography is presented. The method avoids the intermediate retrieval of absorption, differential phase and dark field projections. It directly reconstructs tomographic cross sections from phase stepping projections by the use of a forward projecting imaging model and an appropriate likelihood function. The likelihood function is then maximized with an iterative algorithm. The presented method is tested with tomographic data obtained through a wave field simulation of grating based phase-contrast tomography. The reconstruction result...

Ritter, André; Durst, Jürgen; Gödel, Karl; Haas, Wilhelm; Michel, Thilo; Rieger, Jens; Weber, Thomas; Wucherer, Lukas; Anton, Gisela

2013-01-01T23:59:59.000Z

347

Preprocessing of backprojection images in the McClellan Nuclear Radiation Center tomography system  

DOE Green Energy (OSTI)

Neutron tomography is being investigated as a nondestructive technique for quantitative assessment of low atomic mass impurity concentration in metals. Neutrons maximize the sensitivity given their higher cross sections for low Z isotopes while tomography provides the three dimensional density information. The specific application is the detection of Hydrogen down to 200 ppm weight in aircraft engine compressor blades. A number of preprocessing corrections have been implemented for the backprojection images in order to achieve the detection requirements for a testing rate of three blades per hour. Among the procedures are corrections for neutron scattering and beam hardening. With these procedures the artifacts in tomographic reconstructions are shown to be less than the signal for 100 ppm hydrogen in titanium alloy samples.

Gibbons, M. R., LLNL

1998-02-19T23:59:59.000Z

348

Quantum process tomography and Linblad estimation of a solid state qubit  

E-Print Network (OSTI)

We present an example of quantum process tomography (QPT) performed on a single solid state qubit. The qubit used is two energy levels of the triplet state in the Nitrogen-Vacancy defect in Diamond. Quantum process tomography is applied to a qubit which has been allowed to decohere for three different time periods. In each case the process is found in terms of the chi matrix representation and the affine map representation. The discrepancy between experimentally estimated process and the closest physically valid process is noted. The results of QPT performed after three different decoherence times are used to find the error generators, or Lindblad operators, for the system, using the technique introduced by Boulant et al. [N. Boulant, T.F. Havel, M.A. Pravia and D.G. Cory, Phys. Rev. A 67, 042322 (2003)].

M. Howard; J. Twamley; C. Wittmann; T. Gaebel; F. Jelezko; J. Wrachtrup

2006-01-25T23:59:59.000Z

349

Neutron Computed Tomography of Freeze/thaw Phenomena in Polymer Electrolyte Fuel Cells  

DOE Green Energy (OSTI)

This report summarizes the final year's progress of the three-year NEER program. The overall objectives of this program were to 1) design and construct a sophisticated hight-resolution neutron computed tomography (NCT) facility, 2) develop novel and sophisticated liquid water and ice quantification analysis software for computed tomography, and 3) apply the advanced software and NCT capability to study liquid and ice distribution in polymer electrolyte fuel cells (PEFCs) under cold-start conditions. These objectives have been accomplished by the research team, enabling a new capability for advanced 3D image quantification with neutron imaging for fuel cell and other applications. The NCT water quantification methodology and software will greatly add to the capabilities of the neutron imaging community, and the quantified liquid water and ice distribution provided by its application to PEFCs will enhance understanding and guide design in the fuel cell community.

Matthew M. Mech; Jack Brenizer; Kenan Unlu; A.K. Heller

2008-12-12T23:59:59.000Z

350

Global convergence of diluted iterations in maximum-likelihood quantum tomography  

E-Print Network (OSTI)

In this paper we present an inexact stepsize selection for the Diluted R\\rho R algorithm, used to obtain the maximum likelihood estimate to the density matrix in quantum state tomography. We give a new interpretation for the diluted R\\rho R iterations that allows us to prove the global convergence under weaker assumptions. Thus, we propose a new algorithm which is globally convergent and suitable for practical implementation.

D. S. Gonçalves; M. A. Gomes-Ruggiero; C. Lavor

2013-06-13T23:59:59.000Z

351

A simple setup for neutron tomography at the Portuguese Nuclear Research Reactor  

E-Print Network (OSTI)

A simple setup for neutron radiography and tomography was recently installed at the Portuguese Research Reactor. The objective of this work was to determine the operational characteristics of the installed setup, namely the irradiation time to obtain the best dynamic range for individual images and the spatial resolution. The performance of the equipment was demonstrated by imaging a fragment of a 17th century decorative tile.

M. A. Stanojev Pereira; J. G. Marques; R. Pugliesi

2012-05-15T23:59:59.000Z

352

Simulation and preliminary performance characteristics of a computed tomography device for industrial applications  

SciTech Connect

A computed tomography system designed to function in an industrial environment is being constructed. The modular design maintains the flexibility necessary in an environment where source strength and energy, as well as detector type, could change with each application. The static nature of industrial objects also allow economies of design not possible where dynamic objects are to be analyzed. Simulation of the device has been completed and expected image qualities obtained.

Kruger, R.P.; Cannon, T.M.; Lundy, A.S.; Morris, R.A.

1978-01-01T23:59:59.000Z

353

Detection and Imaging of High-Z Materials with a Muon Tomography Station Using GEM Detectors  

E-Print Network (OSTI)

Muon tomography based on the measurement of multiple scattering of atmospheric cosmic ray muons is a promising technique for detecting and imaging heavily shielded high-Z nuclear materials such as enriched uranium. This technique could complement standard radiation detection portals currently deployed at international borders and ports, which are not very sensitive to heavily shielded nuclear materials. We image small targets in 3D using $2\\times 2 \\times 2$ mm^3 voxels with a minimal muon tomography station prototype that tracks muons with Gas Electron Multiplier (GEM) detectors read out in 2D with x-y microstrips of 400 micron pitch. With preliminary electronics, the GEM detectors achieve a spatial resolution of 130 microns in both dimensions. With the next GEM-based prototype station we plan to probe an active volume of ~27 liters. We present first results on reading out all 1536 microstrips of a $30 \\times 30$ cm^2 GEM detector for the next muon tomography prototype with final frontend electronics and DAQ...

Gnanvo, K; Bittner, W; Costa, F; Grasso, L; Hohlmann, M; Locke, J B; Martoiu, S; Muller, H; Staib, M; Tarazona, A; Toledo, J

2010-01-01T23:59:59.000Z

354

Robust inverse scattering full waveform seismic tomography for imaging complex structure  

SciTech Connect

Seismic tomography becomes important tool recently for imaging complex subsurface. It is well known that imaging complex rich fault zone is difficult. In this paper, The application of time domain inverse scattering wave tomography to image the complex fault zone would be shown on this paper, especially an efficient time domain inverse scattering tomography and their run in cluster parallel computer which has been developed. This algorithm is purely based on scattering theory through solving Lippmann Schwienger integral by using Born's approximation. In this paper, it is shown the robustness of this algorithm especially in avoiding the inversion trapped in local minimum to reach global minimum. A large data are solved by windowing and blocking technique of memory as well as computation. Parameter of windowing computation is based on shot gather's aperture. This windowing technique reduces memory as well as computation significantly. This parallel algorithm is done by means cluster system of 120 processors from 20 nodes of AMD Phenom II. Benchmarking of this algorithm is done by means Marmoussi model which can be representative of complex rich fault area. It is shown that the proposed method can image clearly the rich fault and complex zone in Marmoussi model even though the initial model is quite far from the true model. Therefore, this method can be as one of solution to image the very complex mode.

Nurhandoko, Bagus Endar B.; Sukmana, Indriani; Wibowo, Satryo; Deny, Agus; Kurniadi, Rizal; Widowati, Sri; Mubarok, Syahrul; Susilowati; Kaswandhi [Wave Inversion and Subsurface Fluid Imaging Research (WISFIR) Lab., Complex System Research Division, Physics Department, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung. and Rock Fluid Imaging Lab., Rock Physics and Cluster C (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung (Indonesia); Physics Department of Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung, Indonesia and Institut Teknologi Telkom, Bandung (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung (Indonesia)

2012-06-20T23:59:59.000Z

355

CT calorimetry  

Science Conference Proceedings (OSTI)

... reactions can alter the temperature in various ways, producing a ... The four black items at right below the centimeter rule are ... That way, the immediate ...

2013-01-03T23:59:59.000Z

356

Improving best-phase image quality in cardiac CT by motion correction with MAM optimization  

SciTech Connect

Purpose: Research in image reconstruction for cardiac CT aims at using motion correction algorithms to improve the image quality of the coronary arteries. The key to those algorithms is motion estimation, which is currently based on 3-D/3-D registration to align the structures of interest in images acquired in multiple heart phases. The need for an extended scan data range covering several heart phases is critical in terms of radiation dose to the patient and limits the clinical potential of the method. Furthermore, literature reports only slight quality improvements of the motion corrected images when compared to the most quiet phase (best-phase) that was actually used for motion estimation. In this paper a motion estimation algorithm is proposed which does not require an extended scan range but works with a short scan data interval, and which markedly improves the best-phase image quality. Methods: Motion estimation is based on the definition of motion artifact metrics (MAM) to quantify motion artifacts in a 3-D reconstructed image volume. The authors use two different MAMs, entropy, and positivity. By adjusting the motion field parameters, the MAM of the resulting motion-compensated reconstruction is optimized using a gradient descent procedure. In this way motion artifacts are minimized. For a fast and practical implementation, only analytical methods are used for motion estimation and compensation. Both the MAM-optimization and a 3-D/3-D registration-based motion estimation algorithm were investigated by means of a computer-simulated vessel with a cardiac motion profile. Image quality was evaluated using normalized cross-correlation (NCC) with the ground truth template and root-mean-square deviation (RMSD). Four coronary CT angiography patient cases were reconstructed to evaluate the clinical performance of the proposed method. Results: For the MAM-approach, the best-phase image quality could be improved for all investigated heart phases, with a maximum improvement of the NCC value by 100% and of the RMSD value by 81%. The corresponding maximum improvements for the registration-based approach were 20% and 40%. In phases with very rapid motion the registration-based algorithm obtained better image quality, while the image quality of the MAM algorithm was superior in phases with less motion. The image quality improvement of the MAM optimization was visually confirmed for the different clinical cases. Conclusions: The proposed method allows a software-based best-phase image quality improvement in coronary CT angiography. A short scan data interval at the target heart phase is sufficient, no additional scan data in other cardiac phases are required. The algorithm is therefore directly applicable to any standard cardiac CT acquisition protocol.

Rohkohl, Christopher; Bruder, Herbert; Stierstorfer, Karl [Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Flohr, Thomas [Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Institute of Diagnostic Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)

2013-03-15T23:59:59.000Z

357

Detective quantum efficiency of CT reconstruction: the detection of small objects  

SciTech Connect

The loss of detection sensitivity incurred by any stage of image processing may normally be characterized by the frequency dependence of the detective quantum efficiency (DQE) of that stage of processing, provided the image is represented in continuous coordinates. However, limitations to the DQE concept arise when discretely sampled projection data are used to obtain discretely sampled computed tomographic (CT) reconstructions. The source of these limitations is the aliasing produced by the discrete sampling which mixes contributions from various frequencies. An associated problem is that the signal-to-noise ratio (SNR) for the detection of an object can depend upon the position of the object relative to the discrete reconstruction pixels. The effective SNR for discrete images must take into account this variation. While there may be no loss in the detection SNR for reconstructions in continuous coordinates (DQE = 100%), a reduction in the SNR will result from aliasing for discrete reconstructions. A simple one-dimensional model elucidates the characteristics of discrete CT reconstruction.

Hanson, K.M.

1979-01-01T23:59:59.000Z

358

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)

of a breathing cycle. Thus the radiation exposure during the data acquisition is at least 10 times higher than. This will result in unacceptable radiation to the patient. Lower the radiation exposure will sacrifice the imageInternational Conference on Fully 3D Reconstruction in Radiology and Nuclear Medicine, Linau

359

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

360

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

362

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

363

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Wednesday, 24 February 2010 00:00 Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

364

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Imaging Antifungal Drug Molecules in Action using Soft X-Ray Tomography Print Humankind has benefitted from a long and productive relationship with yeast. For example, fermentation by yeast is an essential step in the production of bread, beer, wine, and even biofuels. However, not all yeast are beneficial. One strain of yeast, Candida albicans, grows unnoticed on most peoples' skin and in the intestines. In response to certain environmental conditions, C. albicans can switch to a pathogenic phenotype that causes infection. Yeast infections are commonplace, and in otherwise healthy individuals are usually treatable with over-the-counter medications; however, individuals with weakened immune systems can have very serious systemic consequences from a yeast infection. Treating systemic yeast infections is becoming increasingly difficult due to the growing number of yeast strains that have developed resistance to existing antimicrobial drugs. Consequently, there is a pressing need to develop new types of drugs capable of circumventing yeast drug-resistance mechanisms. To this end Stanford, University of California, San Francisco and LBNL researchers have used soft x-ray tomography to image the 3-D structure of both benign and infectious C. albicans yeast. They then imaged this yeast when treated with peptoids, a class of molecules that mimic the peptides our immune system uses as the first line of defense against microbial attack. Unlike conventional antimicrobials, microbes have yet to develop resistance mechanisms against peptides or peptoids, making them appealing candidates for pharmaceutical development.

365

New Cyclotron Targetry to Enhance F-18 clinical Position Emission Tomography  

SciTech Connect

This project proposes to develop cyclotron targets that produce F-18 for clinical Positron Emission Tomography (PET) at significantly higher rates than that available from current targetry. This production rate of 18F is directly proportional to the beam current. Higher beam currents would result in increased 18F production but would be accompanied by higher heat loads to the target. The beam power available in most commercial cyclotrons exceeds the heat removal capacity of current target technology by a factor of two to four, significantly limiting the production rate of Fluorine-18.

J. Michael Doster

2008-12-19T23:59:59.000Z

366

Minimum tomography of two entangled qutrits using local measurements of one-qutrit SIC-POVM  

E-Print Network (OSTI)

An experimental demonstration of two-qutrit state tomography via one-qutrit symmetric informationally complete positive operator-valued measure (SIC-POVM) is presented. A two-qutrit state is encoded in the transversal paths of a spontaneous parametric down-converted photon pair. A spatial light modulator allows to implement the necessary 81 POVM elements to reconstruct the state. The quality of the reconstruction is evaluated by comparing independent measurements with the predicted results calculated with the reconstructed state. Entanglement in the system is calculated via negativity and generalized robustness from the two-qutrit reconstructed density operator.

W. M. Pimenta; B. Marques; T. O. Maciel; R. O. Vianna; A. Delgado; C. Saavedra; S. Pádua

2013-12-04T23:59:59.000Z

367

Detection of foreign body using fast thermoacoustic tomography with a multielement linear transducer array  

SciTech Connect

Current imaging modalities face challenges in clinical applications due to limitations in resolution or contrast. Microwave-induced thermoacoustic imaging may provide a complementary modality for medical imaging, particularly for detecting foreign objects due to their different absorption of electromagnetic radiation at specific frequencies. A thermoacoustic tomography system with a multielement linear transducer array was developed and used to detect foreign objects in tissue. Radiography and thermoacoustic images of objects with different electromagnetic properties, including glass, sand, and iron, were compared. The authors' results demonstrate that thermoacoustic imaging has the potential to become a fast method for surgical localization of occult foreign objects.

Nie Liming; Xing Da; Yang Diwu; Zeng Lvming; Zhou Quan [MOE Key Laboratory of Laser Life Science, South China Normal University, Guangzhou 510631 (China) and Institute of Laser Life Science, South China Normal University, Guangzhou 510631 (China)

2007-04-23T23:59:59.000Z

368

Tomography of a High-Purity Narrowband Photon From a Transient Atomic Collective Excitation  

E-Print Network (OSTI)

We demonstrate the efficient heralded generation of high purity narrow-bandwidth single photons from a transient collective spin excitation in a hot atomic vapour cell. Employing optical homodyne tomography, we fully reconstruct the density matrix of the generated photon and observe a Wigner function reaching the zero value without correcting for any inefficiencies. The narrow bandwidth of the photon produced is accompanied by a high generation rate yielding a high spectral brightness. The source is therefore compatible with atomic-based quantum memories as well as other applications in light-atom interfacing. This work paves the way to preparing and measuring arbitrary superposition states of collective atomic excitations.

MacRae, A; Lvovsky, A I

2011-01-01T23:59:59.000Z

369

Three-dimensional visualization of forming Hepatitis C virus-like particles by electron-tomography  

Science Conference Proceedings (OSTI)

Hepatitis C virus infects almost 170 million people per year but its assembly pathway, architecture and the structures of its envelope proteins are poorly understood. Using electron tomography of plastic-embedded sections of insect cells, we have visualized the morphogenesis of recombinant Hepatitis C virus-like particles. Our data provide a three-dimensional sketch of viral assembly at the endoplasmic reticulum showing different budding stages and contiguity of buds. This latter phenomenon could play an important role during the assembly of wt-HCV and explain the size-heterogeneity of its particles.

Badia-Martinez, Daniel; Peralta, Bibiana [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain)] [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); Andres, German; Guerra, Milagros [Electron Microscopy Unit, Centro de Biologia Molecular Severo Ochoa, CSIC-UAM, Campus Cantoblanco, 28049 Madrid (Spain)] [Electron Microscopy Unit, Centro de Biologia Molecular Severo Ochoa, CSIC-UAM, Campus Cantoblanco, 28049 Madrid (Spain); Gil-Carton, David [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain)] [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); Abrescia, Nicola G.A., E-mail: nabrescia@cicbiogune.es [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)

2012-09-01T23:59:59.000Z

370

Computer-assisted tomography for the observation of oil displacement in porous media  

SciTech Connect

Computer-assisted tomography (CAT) is used to obtain cross-sectional images of Berea sandstone cores during oil displacement experiments. Local oil saturation averaged over an area of about 0.03X0.03 in. (0.8X0.8 mm) square is computed as a function of spatial position and time. A series of CAT scan images displaying the time evolution of the fluid distribution at one cross section are shown to illustrate the formation of viscous fingers.

Wang, S.Y.; Ayral, S.; Gryte, C.C.

1984-02-01T23:59:59.000Z

371

Optimization of neutron tomography for rapid hydrogen concentration inspection of metal castings  

DOE Green Energy (OSTI)

Hydrogen embrittlement describes a group of phenomena leading to the degradation of metal alloy properties. The hydrogen concentration in the alloy can be used as an indicator for the onset of embrittlement. A neutron tomography system has been optimized to perform nondestructive detection of hydrogen concentration in titanium aircraft engine compressor blades. Preprocessing of back projection images and postprocessing of tomographic reconstructions are used to achieve hydrogen concentration sensitivity below 200 ppm weight. This paper emphasizes the postprocessing techniques which allow automated reporting of hydrogen concentration.

Gibbons, M. R., LLNL

1998-02-03T23:59:59.000Z

372

High-resolution retinal imaging using adaptive optics and Fourier-domain optical coherence tomography  

DOE Patents (OSTI)

This invention permits retinal images to be acquired at high speed and with unprecedented resolution in three dimensions (4.times.4.times.6 .mu.m). The instrument achieves high lateral resolution by using adaptive optics to correct optical aberrations of the human eye in real time. High axial resolution and high speed are made possible by the use of Fourier-domain optical coherence tomography. Using this system, we have demonstrated the ability to image microscopic blood vessels and the cone photoreceptor mosaic.

Olivier, Scot S. (Livermore, CA); Werner, John S. (Davis, CA); Zawadzki, Robert J. (Sacramento, CA); Laut, Sophie P. (Pasedena, CA); Jones, Steven M. (Livermore, CA)

2010-09-07T23:59:59.000Z

373

Segmenting CT prostate images using population and patient-specific statistics for radiotherapy  

SciTech Connect

Purpose: In the segmentation of sequential treatment-time CT prostate images acquired in image-guided radiotherapy, accurately capturing the intrapatient variation of the patient under therapy is more important than capturing interpatient variation. However, using the traditional deformable-model-based segmentation methods, it is difficult to capture intrapatient variation when the number of samples from the same patient is limited. This article presents a new deformable model, designed specifically for segmenting sequential CT images of the prostate, which leverages both population and patient-specific statistics to accurately capture the intrapatient variation of the patient under therapy. Methods: The novelty of the proposed method is twofold: First, a weighted combination of gradient and probability distribution function (PDF) features is used to build the appearance model to guide model deformation. The strengths of each feature type are emphasized by dynamically adjusting the weight between the profile-based gradient features and the local-region-based PDF features during the optimization process. An additional novel aspect of the gradient-based features is that, to alleviate the effect of feature inconsistency in the regions of gas and bone adjacent to the prostate, the optimal profile length at each landmark is calculated by statistically investigating the intensity profile in the training set. The resulting gradient-PDF combined feature produces more accurate and robust segmentations than general gradient features. Second, an online learning mechanism is used to build shape and appearance statistics for accurately capturing intrapatient variation. Results: The performance of the proposed method was evaluated on 306 images of the 24 patients. Compared to traditional gradient features, the proposed gradient-PDF combination features brought 5.2% increment in the success ratio of segmentation (from 94.1% to 99.3%). To evaluate the effectiveness of online learning mechanism, the authors carried out a comparison between partial online update strategy and full online update strategy. Using the full online update strategy, the mean DSC was improved from 86.6% to 89.3% with 2.8% gain. On the basis of full online update strategy, the manual modification before online update strategy was introduced and tested, the best performance was obtained; here, the mean DSC and the mean ASD achieved 92.4% and 1.47 mm, respectively. Conclusions: The proposed prostate segmentation method provided accurate and robust segmentation results for CT images even under the situation where the samples of patient under radiotherapy were limited. A conclusion that the proposed method is suitable for clinical application can be drawn.

Feng, Qianjin; Foskey, Mark; Chen Wufan; Shen Dinggang [Biomedical Engineering College, South Medical University, Guangzhou (China) and Department of Radiology, University of North Carolina, Chapel Hill, North Carolina 27510 (United States); Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Biomedical Engineering College, South Medical University, Guangzhou 510510 (China); Department of Radiology, University of North Carolina, Chapel Hill, North Carolina 27510 (United States)

2010-08-15T23:59:59.000Z

374

NIST Manuscript Publication Search  

Science Conference Proceedings (OSTI)

... Author(s): Chiara F. Ferraris; Edward J. Garboczi; ... tomography (CT) and the relationship between X-ray CT, Brunauer-Emmett-Teller surface area ...

2013-01-14T23:59:59.000Z

375

Micro-CT for the quantification of 3D voids within damaged structures  

SciTech Connect

Micro X-ray Computed Tomography (MXCT) is widely used in the materials community to examine the internal structure of materials for voids and cracks due to damage or casting, or other defects. Most research in this area focuses on the qualitative aspect of the image, simply answering; Are there voids present? Here we present an ongoing study of the quantified incipient spall voids in Cu with different grain sizes, using a gas gun with various velocities. Data analysis packages for MXCT are just now becoming able to dimensionally measure and produce statistics on the voids-present. In order to make the size of the features in the 3D image quantifiable, the question, how many radiographs are required to render the object dimensionally accurate in 3D, must be answered. A series of data sets has been coUected, varying the number of radiographs collected in order to determine the appropriate number required.

Patterson, Brian M [Los Alamos National Laboratory; Hamilton, Christopher E [Los Alamos National Laboratory; Cerreta, Ellen K [Los Alamos National Laboratory; Dennis - Koller, Darcie [Los Alamos National Laboratory; Bronkhorst, C. A. [Los Alamos National Laboratory; Hansen, B. L. [Los Alamos National Laboratory

2011-01-26T23:59:59.000Z

376

Accuracy of volume measurement using 3D ultrasound and development of CT-3D US image fusion algorithm for prostate cancer radiotherapy  

Science Conference Proceedings (OSTI)

Purpose: To evaluate the accuracy of measuring volumes using three-dimensional ultrasound (3D US), and to verify the feasibility of the replacement of CT-MR fusion images with CT-3D US in radiotherapy treatment planning. Methods: Phantoms, consisting of water, contrast agent, and agarose, were manufactured. The volume was measured using 3D US, CT, and MR devices. A CT-3D US and MR-3D US image fusion software was developed using the Insight Toolkit library in order to acquire three-dimensional fusion images. The quality of the image fusion was evaluated using metric value and fusion images. Results: Volume measurement, using 3D US, shows a 2.8 {+-} 1.5% error, 4.4 {+-} 3.0% error for CT, and 3.1 {+-} 2.0% error for MR. The results imply that volume measurement using the 3D US devices has a similar accuracy level to that of CT and MR. Three-dimensional image fusion of CT-3D US and MR-3D US was successfully performed using phantom images. Moreover, MR-3D US image fusion was performed using human bladder images. Conclusions: 3D US could be used in the volume measurement of human bladders and prostates. CT-3D US image fusion could be used in monitoring the target position in each fraction of external beam radiation therapy. Moreover, the feasibility of replacing the CT-MR image fusion to the CT-3D US in radiotherapy treatment planning was verified.

Baek, Jihye; Huh, Jangyoung; Hyun An, So; Oh, Yoonjin [Department of Medical Sciences, Ewha Womans University, Seoul 158-710 (Korea, Republic of); Kim, Myungsoo; Kim, DongYoung; Chung, Kwangzoo; Cho, Sungho; Lee, Rena [Department of Radiation Oncology, School of Medicine, Ewha Womans University, Seoul 158-710 (Korea, Republic of)

2013-02-15T23:59:59.000Z

377

DOE Challenge Home Case Study, Preferred Builders, Old Greenwhich, CT, Custom  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Preferred Preferred Builders, Inc. Old Greenwich, CT BUILDING TECHNOLOGIES OFFICE DOE Challenge Home builders are in the top 1% of builders in the country meeting the extraordinary levels of excellence and quality specifi ed by the U.S. Department of Energy. Every DOE Challenge Home starts with ENERGY STAR for Homes Version 3 for an energy-effi cient home built on a solid foundation of building science research. Then, even more advanced technologies are designed in for a home that goes above and beyond current code to give you the superior quality construction, HVAC, appliances, indoor air quality, safety, durability, comfort, and solar-ready components along with ultra-low or no utility bills. This provides homeowners with a quality home that will last for generations to come.

378

DOE Challenge Home Case Study, BPC Green Builders, Custom Home, New Fairfield, CT  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

BPC Green BPC Green Builders New Fairfi eld, CT BUILDING TECHNOLOGIES OFFICE DOE Challenge Home builders are in the top 1% of builders in the country meeting the extraordinary levels of excellence and quality specifi ed by the U.S. Department of Energy. Every DOE Challenge Home starts with ENERGY STAR for Homes Version 3 for an energy-effi cient home built on a solid foundation of building science research. Then, even more advanced technologies are designed in for a home that goes above and beyond current code to give you the superior quality construction, HVAC, appliances, indoor air quality, safety, durability, comfort, and solar-ready components along with ultra-low or no utility bills. This provides homeowners with a quality home that will last for generations to come.

379

Multi-organ segmentation from multi-phase abdominal CT via 4D graphs using enhancement, shape and location optimization  

Science Conference Proceedings (OSTI)

The interpretation of medical images benefits from anatomical and physiological priors to optimize computer-aided diagnosis (CAD) applications. Diagnosis also relies on the comprehensive analysis of multiple organs and quantitative measures of soft tissue. ... Keywords: 4D graph, enhancement, multi-phase CT, segmentation, shape

Marius George Linguraru; John A. Pura; Ananda S. Chowdhury; Ronald M. Summers

2010-09-01T23:59:59.000Z

380

Circle plus partial helical scan scheme for a flat panel detector-based cone beam breast X-ray CT  

Science Conference Proceedings (OSTI)

Flat panel detector-based cone beam breast CT (CBBCT) can provide 3D image of the scanned breast with 3D isotropic spatial resolution, overcoming the disadvantage of the structure superimposition associated with X-ray projection mammography. It is very ...

Dong Yang; Ruola Ning; Weixing Cai

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tomography ct scanners" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

NJ WY AK AL CA AR CO CT DE FL GA HI ID KS IL IN IA IA KY LA  

Gasoline and Diesel Fuel Update (EIA)

176, "Annual Report of Natural and Supplemental Gas Supply and Disposition." NJ WY AK AL CA AR CO CT DE FL GA HI ID KS IL IN IA IA KY LA ME MI MA MD MN MS MT MO NE ND OH NV NM NY...

382

Quantification of tc-99m sestamibi distribution in normal breast tissue using dedicated breast SPECT-CT  

Science Conference Proceedings (OSTI)

The use of Tc-99m-Sestamibi in molecular breast imaging is common due to its preferential uptake in malignant tissue. However, quantification of the baseline uptake in normal, healthy breast tissue is not possible using planar-imaging devices. Using ... Keywords: CT, SPECT, breast cancer, breast imaging, quantification, sestamibi

Steve D. Mann; Kristy L. Perez; Emily K. E. McCracken; Jainil P. Shah; Kingshuk R. Choudhury; Terence Z. Wong; Martin P. Tornai

2012-07-01T23:59:59.000Z

383

Hagit P. Affek Yale University, Dept. of Geology & Geophysics, 210 Whitney Ave. New Haven, CT 06520-8109  

E-Print Network (OSTI)

and Geophysics. · Caltech, Pasadena, CA. 2003-2007. Posdoc in Isotope geochemistry. Department of GeologicalHagit P. Affek Yale University, Dept. of Geology & Geophysics, 210 Whitney Ave. New Haven, CT 06520 Plants: Physiological Role and Isotopic Composition. Adviser: Dan Yakir. Professional experience · Yale

384

Detecting Radiation-Induced Injury Using Rapid 3D Variogram Analysis of CT Images of Rat Lungs  

SciTech Connect

A new heterogeneity analysis approach to discern radiation-induced lung damage was tested on CT images of irradiated rats. The method, combining octree decomposition with variogram analysis, demonstrated a significant correlation with radiation exposure levels, whereas conventional measurements and pulmonary function tests did not. The results suggest the new approach may be highly sensitive for assessing even subtle radiation-induced changes

Jacob, Rick E.; Murphy, Mark K.; Creim, Jeffrey A.; Carson, James P.

2013-10-01T23:59:59.000Z

385

Automatic tracking of implanted fiducial markers in cone beam CT projection images  

SciTech Connect

Purpose: This paper describes a novel method for simultaneous intrafraction tracking of multiple fiducial markers. Although the proposed method is generic and can be adopted for a number of applications including fluoroscopy based patient position monitoring and gated radiotherapy, the tracking results presented in this paper are specific to tracking fiducial markers in a sequence of cone beam CT projection images. Methods: The proposed method is accurate and robust thanks to utilizing the mean shift and random sampling principles, respectively. The performance of the proposed method was evaluated with qualitative and quantitative methods, using data from two pancreatic and one prostate cancer patients and a moving phantom. The ground truth, for quantitative evaluation, was calculated based on manual tracking preformed by three observers. Results: The average dispersion of marker position error calculated from the tracking results for pancreas data (six markers tracked over 640 frames, 3840 marker identifications) was 0.25 mm (at iscoenter), compared with an average dispersion for the manual ground truth estimated at 0.22 mm. For prostate data (three markers tracked over 366 frames, 1098 marker identifications), the average error was 0.34 mm. The estimated tracking error in the pancreas data was < 1 mm (2 pixels) in 97.6% of cases where nearby image clutter was detected and in 100.0% of cases with no nearby image clutter. Conclusions: The proposed method has accuracy comparable to that of manual tracking and, in combination with the proposed batch postprocessing, superior robustness. Marker tracking in cone beam CT (CBCT) projections is useful for a variety of purposes, such as providing data for assessment of intrafraction motion, target tracking during rotational treatment delivery, motion correction of CBCT, and phase sorting for 4D CBCT.

Marchant, T. E.; Skalski, A.; Matuszewski, B. J. [Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester M20 4BX, United Kingdom and Manchester Academic Health Science Centre, University of Manchester, Manchester M20 4BX (United Kingdom); AGH University of Science and Technology, al. A. Mickiewicza 30, Krakow 30-059 (Poland); School of Computing, Engineering and Physical Sciences, University of Central Lancashire, Preston PR1 2HE (United Kingdom)

2012-03-15T23:59:59.000Z

386

Adaptive planning using megavoltage fan-beam CT for radiation therapy with testicular shielding  

Science Conference Proceedings (OSTI)

This study highlights the use of adaptive planning to accommodate testicular shielding in helical tomotherapy for malignancies of the proximal thigh. Two cases of young men with large soft tissue sarcomas of the proximal thigh are presented. After multidisciplinary evaluation, preoperative radiation therapy was recommended. Both patients were referred for sperm banking and lead shields were used to minimize testicular dose during radiation therapy. To minimize imaging artifacts, kilovoltage CT (kVCT) treatment planning was conducted without shielding. Generous hypothetical contours were generated on each 'planning scan' to estimate the location of the lead shield and generate a directionally blocked helical tomotherapy plan. To ensure the accuracy of each plan, megavoltage fan-beam CT (MVCT) scans were obtained at the first treatment and adaptive planning was performed to account for lead shield placement. Two important regions of interest in these cases were femurs and femoral heads. During adaptive planning for the first patient, it was observed that the virtual lead shield contour on kVCT planning images was significantly larger than the actual lead shield used for treatment. However, for the second patient, it was noted that the size of the virtual lead shield contoured on the kVCT image was significantly smaller than the actual shield size. Thus, new adaptive plans based on MVCT images were generated and used for treatment. The planning target volume was underdosed up to 2% and had higher maximum doses without adaptive planning. In conclusion, the treatment of the upper thigh, particularly in young men, presents several clinical challenges, including preservation of gonadal function. In such circumstances, adaptive planning using MVCT can ensure accurate dose delivery even in the presence of high-density testicular shields.

Yadav, Poonam [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); School of Advance Sciences, Vellore Institue of Technology University, Vellore, Tamil Nadu (India); Kozak, Kevin [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Tolakanahalli, Ranjini [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); Ramasubramanian, V. [School of Advance Sciences, Vellore Institue of Technology University, Vellore, Tamil Nadu (India); Paliwal, Bhudatt R. [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); University of Wisconsin, Riverview Cancer Centre, Wisconsin Rapids, WI (United States); Welsh, James S. [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, Madison, WI (United States); Rong, Yi, E-mail: rong@humonc.wisc.edu [Department of Human Oncology, University of Wisconsin, Madison, Madison, WI (United States); University of Wisconsin, Riverview Cancer Centre, Wisconsin Rapids, WI (United States)

2012-07-01T23:59:59.000Z

387

Using seismic tomography to characterize fracture systems induced by hydraulic fracturing  

DOE Green Energy (OSTI)

Microearthquakes induced by hydraulic fracturing have been studied by many investigators to characterize fracture systems created by the fracturing process and to better understand the locations of energy resources in the earth`s subsurface. The pattern of the locations often contains a great deal of information about the fracture system stimulated during the hydraulic fracturing. Seismic tomography has found applications in many areas for characterizing the subsurface of the earth. It is well known that fractures in rock influence both the P and S velocities of the rock. The influence of the fractures is a function of the geometry of the fractures, the apertures and number of fractures, and the presence of fluids in the fractures. In addition, the temporal evolution of the created fracture system can be inferred from the temporal changes in seismic velocity and the pattern of microearthquake locations. Seismic tomography has been used to infer the spatial location of a fracture system in a reservoir that was created by hydraulic fracturing.

Fehler, M.; Rutledge, J.

1995-01-01T23:59:59.000Z

388

Three-dimensional characterization of near-field transducers by electron tomography  

SciTech Connect

Transmission electron microscopy (TEM) was employed to study the structure of near-field transducers (NFT) for applications in heat-assisted magnetic recording (HAMR) heads. The overall shape of NFTs that had passed or failed an optical test was similar, as determined by scanning transmission electron microscopy tomography. However, the absence of a well-defined peg and the presence of a flat top on the 'FAIL' NFT disk induced poor thermal heat transfer from the NFT to the phase change medium and resulted in the optical test failure. The thermal heating around the NFT led to Ta diffusion from the adjacent tantala core and to the presence of Ta-rich particles in the alumina matrix in the plane of the NFT. - Highlights: Black-Right-Pointing-Pointer Very site specific TEM specimen prepared by dual-beam SEM/FIB system. Black-Right-Pointing-Pointer Near field transducer characterization by STEM tomography. Black-Right-Pointing-Pointer Elemental analysis in 2D by STEM-EDX.

Liu, Yuzi, E-mail: yuziliu@anl.gov [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States) [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Center for Nanoscale Materials, Argonne National Laboratory, Argonne IL, 60439 (United States); Schreiber, Daniel K. [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States) [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Petford-Long, Amanda K. [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States) [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Center for Nanoscale Materials, Argonne National Laboratory, Argonne IL, 60439 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 (United States); Gao, Kai-Zhong [Head and Media R and D, Seagate Technology, Bloomington, MN 55435 (United States)] [Head and Media R and D, Seagate Technology, Bloomington, MN 55435 (United States)

2012-10-15T23:59:59.000Z

389

Enhanced x-ray imaging for a thin film cochlear implant with metal artefacts using phase retrieval tomography  

SciTech Connect

Phase retrieval tomography has been successfully used to enhance imaging in systems that exhibit poor absorption contrast. However, when highly absorbing regions are present in a sample, so-called metal artefacts can appear in the tomographic reconstruction. We demonstrate that straightforward approaches for metal artefact reconstruction, developed in absorption contrast tomography, can be applied when using phase retrieval. Using a prototype thin film cochlear implant that has high and low absorption components made from iridium (or platinum) and plastic, respectively, we show that segmentation of the various components is possible and hence measurement of the electrode geometry and relative location to other regions of interest can be achieved.

Arhatari, B. D. [Department of Physics, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Coherent X-ray Science, Melbourne (Australia); Harris, A. R.; Paolini, A. G. [School of Psychological Science, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Electromaterials Science, Melbourne (Australia); Peele, A. G. [Department of Physics, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Coherent X-ray Science, Melbourne (Australia); Australian Synchrotron, Victoria 3168 (Australia)

2012-06-01T23:59:59.000Z

390

Electron holographic tomography for mapping the three-dimensional distribution of electrostatic potential in III-V semiconductor nanowires  

Science Conference Proceedings (OSTI)

Electron holographic tomography (EHT), the combination of off-axis electron holography with electron tomography, is a technique, which can be applied to the quantitative 3-dimensional (3D) mapping of electrostatic potential at the nanoscale. Here, we show the results obtained in the EHT investigation of GaAs and GaAs-AlGaAs core-shell nanowires grown by Au-catalysed metalorganic vapor phase epitaxy. The unique ability of EHT of disentangling the materials mean inner potential (MIP) from the specimen projected thickness allows reconstruction of the nanowire 3D morphology and inner compositional structure as well as the measurement of the MIP.

Wolf, D.; Lichte, H. [Triebenberg Laboratory, Institute of Structure Physics, Technische Universitaet Dresden, D-01062 Dresden (Germany); Pozzi, G. [Department of Physics, Universita di Bologna, Viale B. Pichat 6/2, I-40127 Bologna (Italy); Prete, P. [IMM-CNR, Lecce Research Unit, S.P. 6 Lecce-Monteroni, I-73100 Lecce (Italy); Lovergine, N. [Dipartimento di Ingegneria dell'Innovazione, Universita del Salento, S.P. 6 Lecce-Monteroni, I-73100 Lecce (Italy)

2011-06-27T23:59:59.000Z

391

Web Application Scanner Focus Group - SAMATE  

Science Conference Proceedings (OSTI)

... Ory Segal, IBM; Lee Sommer, NIH; Pravir Chandra, Cigital; Han Thai, NIST. Retrieved from "http://samate.nist.gov/index.php ...

2013-05-22T23:59:59.000Z

392

X-ray tomography of preserved samples from The Geysers scientific corehole  

DOE Green Energy (OSTI)

Approximately 800 ft. of continuous core was recovered from borehole SB-15 D (on unit 15, near the site of the abandoned Geysers Resort) during a recently completed drilling operation funded by the USDOE. Sections of this core were collected at 50 ft intervals for subsequent examination as drilling proceeded. Five foot sections were not removed at the drill site, but were sealed in the innermost sleeve of a triple tube coring system to minimize drying and disturbance of the core. All cores remained sealed and were radiographed within 72 hours of drilling: the five foot core from near 1400 ft. was scanned within 18 hours of drilling. A third generation x-ray scanner, which uses high energy radiation to penetrate the aluminum sleeve and 3.5 inch cores, was used to make preliminary radiographs and to collect multiple views of the sample as the core is rotated in front of the beam. True three dimensional tomographs are then reconstructed from the data. At present, the images have a spatial resolution of approximately 140 micrometers and can resolve contrast differences of 0.2%. The tomographs clearly show differences in lithology with depth in the reservoir. Partially filled fractures, vein selvage and vuggy porosity are all evident in parts of the core. A principle goal of the imaging effort is to help determine the fluid content of the reservoir. Important questions to investigate include water loss during core recovery, infiltration of drilling fluid, and the heterogeneous distribution of pore fluid. Images show that radial gradients in x-ray attenuation commonly occur in jacketed cores. Regions of excess attenuation extend about halfway into the 3.5 in. core, and are probably caused by mud invasion induced by capillarity of the small scale porosity of the graywacke matrix. X-ray measurements will be coordinated with other independent measurements of fluid content underway in separate studies, particularly NMR spectroscopy of frozen ''pressure core'', and compressional velocity and electrical resistivity measurements.

Bonner, B.P.; Roberts, J.J.; Schneberk, D.J.; Marsh, A.; Ruddle, C.; Updike, E.

1995-01-26T23:59:59.000Z

393

3-D Electrical Resistivity Tomography for Cliff Stability Assessment at Pointe du Hoc in Normandy, France  

E-Print Network (OSTI)

Pointe du Hoc overlooking the English Channel in Normandy, France was host to one of the most important military engagements of World War II. While the site is a valuable historic cultural resource, it is vulnerable to cliff collapses that already have endangered the observation post and Rudder?s command post. The observation post has been closed to visitors for some time due to safety concerns. Geophysical techniques have been used increasingly in recent years for slope stability investigation purposes. The objective of this study is to apply advanced 3?D resistivity tomography toward a detailed site stability assessment with special attention to the two at-risk buildings. 3?D resistivity tomography datasets at Pointe du Hoc in the presence of extreme topography and dense cultural clutter have been successfully acquired, inverted, and interpreted. The cliff stability in the areas around the two at?risk buildings has been analyzed. A hazard assessment scheme has been designed in which regions of high resistivity are interpreted as zones of open, dry fractures with a moderate mass movement potential. Regions of low resistivity are zones of wet, clay?filled fractures with a high mass movement potential. The observation post tomography results indicate that the highest mass movement hazard appears to be associated with the marine caverns at the base of the cliff that are positioned at the point of strongest wave attack. These caverns likely occupy the future site of development of a sea arch which will definitely threaten the observation post building. A high probability of a soil wedge failure is on the east?facing cliff edge close to the observation post that could damage or destroy the building. The mass movement potential at the Rudder?s command post area is low to moderate. The greatest risk is associated with soil wedge failures at the top of the cliffs. The resistivity geophysical data add great value to the natural geohazard assessment at Pointe du Hoc and constitute an integral component of an interdisciplinary approach to the problem of cultural resource preservation at the site. Geophysics is a non?invasive and relatively inexpensive technology that provides unique constraints which are unobtainable using traditional engineering geology methods for site characterization. However, the technology is difficult to master and the inherent limitations must be carefully understood to ensure a reliable geotechnical interpretation.

Udphuay, Suwimon

2008-12-01T23:59:59.000Z

394

Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography  

SciTech Connect

In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.

Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M.

2012-01-10T23:59:59.000Z

395

arXiv:astro-ph/0208093v327Nov2002 Dark Energy and Matter Evolution from Lensing Tomography  

E-Print Network (OSTI)

arXiv:astro-ph/0208093v327Nov2002 Dark Energy and Matter Evolution from Lensing Tomography Wayne Hu on the growth function of structure and the evolution of the dark energy density. We examine this potential tests for the existence of multiple dark matter components or a dark energy component

Hu, Wayne

396

Storage of Pressuirzed Carbon Dioxide in Coal Observed Using X-Ray Tomography  

NLE Websites -- All DOE Office Websites (Extended Search)

OF PRESSURIZED CARBON DIOXIDE IN COAL OBSERVED USING X-RAY OF PRESSURIZED CARBON DIOXIDE IN COAL OBSERVED USING X-RAY TOMOGRAPHY Jonathan P. Mathews (jpm10@psu.edu; 814 863 6213) Ozgen Karacan, (karacan@pnge.psu.edu; 814 865 9570) Phillip Halleck (phil@pnge.psu.edu; 814 863 1701) Gareth D. Mitchell (n8h@psu.edu; 814 863 6543) Abraham Grader (grader@pnge.psu.edu; 814 863 5813) The Energy Institute & Department of Energy & GeoEnvironmental Engineering 151 Holser Building, The Pennsylvania State University University Park, PA 16802 Introduction The sequestration of CO 2 in coal seams has been proposed as a mitigation strategy for climate change. To maximize sorption potential it is essential that the heterogeneity of the coal seam be represented in the computational models used to predict the complex flow and sorption within

397

Pre- and post-selected quantum states: density matrices, tomography, and Kraus operators  

E-Print Network (OSTI)

We present a general formalism for charecterizing 2-time quantum states, describing pre- and post-selected quantum systems. The most general 2-time state is characterized by a `density vector' that is independent of measurements performed between the preparation and post-selection. We provide a method for performing tomography of an unknown 2-time density vector. This procedure, which cannot be implemented by weak or projective measurements, brings new insight to the fundamental role played by Kraus operators in quantum measurements. Finally, after showing that general states and measurements are isomorphic, we show that any measurement on a 2-time state can be mapped to a measurement on a preselected bipartite state.

Ralph Silva; Yelena Guryanova; Nicolas Brunner; Noah Linden; Anthony J. Short; Sandu Popescu

2013-08-09T23:59:59.000Z

398

Demonstration of Emitted-Neutron Computed Tomography to Quantify Nuclear Materials  

Science Conference Proceedings (OSTI)

In this document, we report demonstration of emitted-neutron computed tomography using fast fission neutrons to infer the geometry of sources of special nuclear material (SNM). The imaging system employed in the demonstration is based on a newly constructed array of pixelated neutron detectors that are suitable for arrangement in a close-packed imaging array and whose active volume consists of liquid scintillator EJ-309 which allows neutron-gamma discrimination via pulse shape to enable essentially pure fast-neutron imaging. The system is capable of high quality fast-neutron imaging where tomographic reconstruction of slices through an object resolves neutron sources similar in dimension to a fuel pellet, or about 1 cm. During measurements of Pu MOX fuel rodlet arrays in soup cans at the INL ZPPR facility, the position of a partial defect of a single rodlet containing Pu replaced by one containing depleted uranium (DU) was detected.

Hausladen, Paul [ORNL; Blackston, Matthew A [ORNL; Newby, Robert Jason [ORNL

2011-09-01T23:59:59.000Z

399

Monitoring Carbon Dioxide Sequestration Using Electrical Resistance Tomography (ERT): Sensitivity Studies  

NLE Websites -- All DOE Office Websites (Extended Search)

Monitoring Carbon Dioxide Sequestration Using Electrical Resistance Monitoring Carbon Dioxide Sequestration Using Electrical Resistance Tomography (ERT): Sensitivity Studies Robin L. Newmark (newmark@llnl.gov, 925-423-3644) Abelardo L. Ramirez (ramirez3@llnl.gov; 925-422-6909) William D. Daily (daily1@llnl.gov; 925-422-8623) Lawrence Livermore National Laboratory P.O. Box 808 Livermore, Ca. 94550 Abstract If geologic formations are used to sequester carbon dioxide (CO 2 ), monitoring the CO 2 injection will be required to confirm the performance of the reservoir system, assess leaks and flow paths, and understand the geophysical and geochemical interactions between the CO 2 and the geologic minerals and fluids. Electrical methods are well suited for monitoring processes involving fluids, as electrical properties are sensitive to the

400

Time-dependent seismic tomography of the Coso geothermal area, 1996-2004 |  

Open Energy Info (EERE)

of the Coso geothermal area, 1996-2004 of the Coso geothermal area, 1996-2004 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Time-dependent seismic tomography of the Coso geothermal area, 1996-2004 Details Activities (1) Areas (1) Regions (0) Abstract: Local-earthquake tomographic images were calculated for each of the years 1996 - 2004 using arrival times from the U.S. Navy's permanent seismometer network at the Coso geothermal area, California. The results show irregular strengthening with time of the wave-speed ratio VP/VS at shallow depths. These changes result predominately from progressive relative increase in VS with respect to VP, and could result from processes associated with geothermal operations such as decrease in fluid pressure and the drying of argillaceous minerals such as illite.

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401

Coherent exciton dynamics in supramolecular light-harvesting nanotubes revealed by ultrafast quantum process tomography  

E-Print Network (OSTI)

Long-lived exciton coherences have been recently observed in photosynthetic complexes via ultrafast spectroscopy, opening exciting possibilities for the study and design of coherent exciton transport. Yet, ambiguity in the spectroscopic signals has led to arguments for interpreting them in terms of the exciton dynamics, demanding more stringent tests. We propose a novel strategy, Quantum Process Tomography (QPT) for ultrafast spectroscopy, to reconstruct the evolving quantum state of excitons in double-walled supramolecular light-harvesting nanotubes at room temperature. The protocol calls for eight transient grating experiments with varied pulse spectra. Our analysis reveals unidirectional energy transfer from the outer to the inner wall excitons, absence of nonsecular processes, and an unexpected coherence between those two states lasting about 150 femtoseconds, indicating weak electronic coupling between the walls. Our work constitutes the first experimental QPT in a 'warm' and complex system, and provides an elegant scheme to maximize information from ultrafast spectroscopy experiments.

Joel Yuen-Zhou; Dylan H. Arias; Dorthe M. Eisele; Colby P. Steiner; Jacob J. Krich; Moungi Bawendi; Keith A. Nelson; Alán Aspuru-Guzik

2013-08-19T23:59:59.000Z

402

Atomic Scale Characterization of Compound Semiconductors using Atom Probe Tomography: Preprint  

DOE Green Energy (OSTI)

Internal interfaces are critical in determining the performance of III-V multijunction solar cells. Studying these interfaces with atomic resolution using a combination of transmission electron microscopy (TEM), atom probe tomography (APT), and density functional calculations enables a more fundamental understanding of carrier dynamics in photovoltaic (PV) device structures. To achieve full atomic scale spatial and chemical resolution, data acquisition parameters in laser pulsed APT must be carefully studied to eliminate surface diffusion. Atom probe data with minimized group V ion clustering and expected stoichiometry can be achieved by adjusting laser pulse power, pulse repetition rate, and specimen preparation parameters such that heat flow away from the evaporating surface is maximized. Applying these improved analysis conditions to III-V based PV gives an atomic scale understanding of compositional and dopant profiles across interfaces and tunnel junctions and the initial stages of alloy clustering and dopant accumulation. Details on APT experimental methods and future in-situ instrumentation developments are illustrated.

Gorman, B. P.; Guthrey, H.; Norman, A. G.; Al-Jassim, M.; Lawrence, D.; Prosa, T.

2011-07-01T23:59:59.000Z

403

Carbon nanotube based microfocus field emission x-ray source for microcomputed tomography  

Science Conference Proceedings (OSTI)

Microcomputed tomography is now widely used for in vivo small animal imaging for cancer studies. Achieving high imaging quality of live objects requires the x-ray source to have both high spatial and temporal resolutions. Preliminary studies have shown that carbon nanotube (CNT) based field emission x-ray source has significant intrinsic advantages over the conventional thermionic x-ray tube including better temporal resolution and programmability. Here we report the design and characterization of a CNT based field emission x-ray source that also affords a high spatial resolution. The device uses modified asymmetric Einzel lenses for electron focusing and an elliptical shaped CNT cathode patterned by photolithography. Stable and small isotropic x-ray focal spot sizes were obtained.

Liu Zejian; Yang Guang; Lee, Yueh Z.; Bordelon, David; Lu Jianping; Zhou, Otto [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); School of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Curriculum in Applied and Materials Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 and Curriculum in Applied and Materials Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

2006-09-04T23:59:59.000Z

404

Semiconductor detectors for medical tomography with high-energy heavy ions  

SciTech Connect

High-energy heavy ion beams are in use at the Lawrence Berkeley Laboratory for cancer therapy. In order to take full advantage of the very favorable depth-dose characteristics of those beams, it is necessary to determine the stopping characteristics of the ions in the complex media of a human with greater accuracy than obtainable with x-ray CAT scanning. Initial measurements with an array of Si dE/dx position sensitive detectors and a windowless thin planar Ge detector used in a side entry mode show the potential for fabricating an instrument for high accuracy on-line CAT scanning using the same ions to be used for therapy. It is estimated that one tomography can be obtained with a dose of 0.72 Rad-gm.

Llacer, J.; Haller, E.E.; Hansen, W.L.; Walton, J.T.; Batho, E.K.

1980-11-01T23:59:59.000Z

405

Comparison of radionuclide scans with computer-assisted tomography in diagnosis of intracranial disease  

SciTech Connect

Radionuclide brain scans were compared with computer-assisted tomography (CAT) for the diagnosis of intracranial disorders in 297 patients. The diagnosis was confirmed in 281 patients who formed the population for the study. The radionuclide scan was false positive for 12 patients (3.9 percent) and false negative for eight (2.6 percent). The CAT was false positive for three patients (1 percent) and false negative for one (0.3 percent). In the 133 patients in whom both tests were negative, no evidence of central nervous system pathology has been found during the 6 to 18 month follow-up. Brain tumors and intracerebral hemorrhage are more readily detectable with CAT.

Clifford, J.R.; Connolly, E.S.; Voorhies, R.M.

1976-12-01T23:59:59.000Z

406

Computed axial tomography (CAT) contribution for dosimetry and treatment evaluation in lung cancer  

SciTech Connect

The use of computed axial tomography (CAT) scans in postoperative patients with lung cancer was studied to evaluate its contribution in dosimetry and to study the late effects of irradiation. Comparisons were made between the treatment planning generated from CAT scan data and that obtained from two orthogonal radiographs. Both methods offered a good approximation but with orthogonal radiographs possible mediastinal and lung shift could not be seen and the dose delivered to the spinal cord was overestimated. A control CAT scan performed 6 to 18 months after treatment showed a lung fibrosis that was strictly correlated with the treatment planning and related with doses and volume treated. CAT scans allowed more accurate treatment planning.

Van Houtte, P.; Piron, A.; Lustman-Marechal, J.; Osteaux, M.; Henry, J.

1980-08-01T23:59:59.000Z

407

Investigation of plasma-doped fin structure and characterization of dopants by atom probe tomography  

Science Conference Proceedings (OSTI)

As and P dopants in a plasma-doped Si-based fin structure were analyzed using atom probe tomography. The distributions and concentrations of As and P atoms in various regions of the fin structure and the oxidation levels for different dopants were determined. Most dopants were segregated at the fin boundary, and the As and P concentrations exceeded 9 Multiplication-Sign 10{sup 20} atoms/cm{sup 3} and 2 Multiplication-Sign 10{sup 20} atoms/cm{sup 3}, respectively. The atomic oxygen and SiO{sub 2} concentrations depended on the dopant type. The larger and heavier As dopant severely damaged the surface of the fin structure and could cause more severe oxidation.

Kim, B. H.; Park, S. M. [Department of Materials Science and Engineering, POSTECH, Pohang (Korea, Republic of); Park, S. W.; Park, Y. B.; Kim, H. J. [Research and Development Division, SK Hynix, 2091, Gyeongchung-daero, Bubal-eub, Ichon-si, Gyeonggi-do (Korea, Republic of); Park, C. G. [Department of Materials Science and Engineering, POSTECH, Pohang (Korea, Republic of); National Center for Nanomaterials Technology (NCNT), Pohang 790-784 (Korea, Republic of)

2012-11-19T23:59:59.000Z

408

Influence of Process Induced Defects  

Science Conference Proceedings (OSTI)

Symposium, Advanced Materials, Processes and Applications for Additive ... Process induced defects were characterized by computer tomography (CT), ...

409

Computing traveltime and amplitude sensitivity kernels in finite-frequency tomography  

Science Conference Proceedings (OSTI)

The efficient computation of finite-frequency traveltime and amplitude sensitivity kernels for velocity and attenuation perturbations in global seismic tomography poses problems both of numerical precision and of validity of the paraxial approximation used. We investigate these aspects, using a local model parameterization in the form of a tetrahedral grid with linear interpolation in between grid nodes. The matrix coefficients of the linear inverse problem involve a volume integral of the product of the finite-frequency kernel with the basis functions that represent the linear interpolation. We use local and global tests as well as analytical expressions to test the numerical precision of the frequency and spatial quadrature. There is a trade-off between narrowing the bandpass filter and quadrature accuracy and efficiency. Using a minimum step size of 10 km for S waves and 30 km for SS waves, relative errors in the quadrature are of the order of 1% for direct waves such as S, and a few percent for SS waves, which are below data uncertainties in delay time or amplitude anomaly observations in global seismology. Larger errors may occur wherever the sensitivity extends over a large volume and the paraxial approximation breaks down at large distance from the ray. This is especially noticeable for minimax phases such as SS waves with periods >20 s, when kernels become hyperbolic near the reflection point and appreciable sensitivity extends over thousands of km. Errors becomes intolerable at epicentral distance near the antipode when sensitivity extends over all azimuths in the mantle. Effects of such errors may become noticeable at epicentral distances > 140{sup o}. We conclude that the paraxial approximation offers an efficient method for computing the matrix system for finite-frequency inversions in global tomography, though care should be taken near reflection points, and alternative methods are needed to compute sensitivity near the antipode.

Tian Yue [Department of Geosciences, Guyot Hall, Princeton University, NJ 08544 (United States)], E-mail: ytian@princeton.edu; Montelli, Raffaella [ExxonMobil Upstream Research Company, P.O. Box 22189, GW03-940A, Houston, TX 77252-2189 (United States); Nolet, Guust; Dahlen, F.A. [Department of Geosciences, Guyot Hall, Princeton University, NJ 08544 (United States)