Powered by Deep Web Technologies
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.


1

AUTOCORRECTING RECONSTRUCTION FOR FLEXIBLE CT SCANNERS Jeff Orchard  

E-Print Network [OSTI]

revolutionize the world of computed tomography (CT). Tiny x-ray emitters and detectors could be embedded scanners. Index Terms: computed tomography, image reconstruction, entropy, nanotechnology, autofocus 1. An automatic (data-driven) motion-correction method for SPECT (single photon emission computed tomog- raphy

Orchard, Jeffery J.

2

Compact conscious animal positron emission tomography scanner  

DOE Patents [OSTI]

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

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

2006-10-24T23:59:59.000Z

3

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

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

4

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.

5

Construction and Test of Low Cost X-Ray Tomography Scanner for Physical-Chemical Analysis and Nondestructive Inspections  

SciTech Connect (OSTI)

X-ray computed tomography (CT) refers to the cross-sectional imaging of an object measuring the transmitted radiation at different directions. In this work, we describe the development of a low cost micro-CT X-ray scanner that is being developed for nondestructive testing. This tomograph operates using a microfocus X-ray source and contains a silicon photodiode as detectors. The performance of the system, by its spatial resolution, has been estimated through its Modulation Transfer Function-MTF and the obtained value at 10% of MTF is 661 {mu}m. It was built as a general purpose nondestructive testing device.

Oliveira, Jose Martins Jr. de [Universidade de Sorocaba-UNISO, Campus Seminario, Caixa Postal 578, Av. Dr. Eugenio Salermo, 100, Centro, 18035-430, Sorocaba, SP (Brazil); Martins, Antonio Cesar Germano [Universidade Estadual Paulista Julio de Mesquita Filho-UNESP, GASI, Av. 3 de Marco, 511, Alto da Boa Vista, 18087-180, Sorocaba, SP (Brazil)

2009-06-03T23:59:59.000Z

6

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

E-Print Network [OSTI]

· . · , , , , . · , " , , . · , . , . : · . ·2-4 . ·2-3 -. ·) D,DMAIC, SPC, FMEA, Control Plan, Lean) 8(-. · -. ·. ·. NPI ·. · , , .' , ·" . " * . : ·) B.A ,(-. ·4-6. ·) QFD, CtQ breakdown, DfSS, SPC, AQP, FMEA, Control Plan.( ·Six Sigma GB

Pinsky, Ross

7

E-Print Network 3.0 - angiographic cone-beam ct Sample Search...  

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

Summary: medical multi-slicecone-beam CT scanners typically use equiangular projection data, our new formula may... : Computed tomography (CT), cone-beam geometry, Feldkamp-type...

8

A prototype fan-beam optical CT scanner for 3D dosimetry  

SciTech Connect (OSTI)

Purpose: The objective of this work is to introduce a prototype fan-beam optical computed tomography scanner for three-dimensional (3D) radiation dosimetry. Methods: Two techniques of fan-beam creation were evaluated: a helium-neon laser (HeNe, {lambda} = 543 nm) with line-generating lens, and a laser diode module (LDM, {lambda} = 635 nm) with line-creating head module. Two physical collimator designs were assessed: a single-slot collimator and a multihole collimator. Optimal collimator depth was determined by observing the signal of a single photodiode with varying collimator depths. A method of extending the dynamic range of the system is presented. Two sample types were used for evaluations: nondosimetric absorbent solutions and irradiated polymer gel dosimeters, each housed in 1 liter cylindrical plastic flasks. Imaging protocol investigations were performed to address ring artefacts and image noise. Two image artefact removal techniques were performed in sinogram space. Collimator efficacy was evaluated by imaging highly opaque samples of scatter-based and absorption-based solutions. A noise-based flask registration technique was developed. Two protocols for gel manufacture were examined. Results: The LDM proved advantageous over the HeNe laser due to its reduced noise. Also, the LDM uses a wavelength more suitable for the PRESAGE{sup TM} dosimeter. Collimator depth of 1.5 cm was found to be an optimal balance between scatter rejection, signal strength, and manufacture ease. The multihole collimator is capable of maintaining accurate scatter-rejection to high levels of opacity with scatter-based solutions (T < 0.015%). Imaging protocol investigations support the need for preirradiation and postirradiation scanning to reduce reflection-based ring artefacts and to accommodate flask imperfections and gel inhomogeneities. Artefact removal techniques in sinogram space eliminate streaking artefacts and reduce ring artefacts of up to {approx}40% in magnitude. The flask registration technique was shown to achieve submillimetre and subdegree placement accuracy. Dosimetry protocol investigations emphasize the need to allow gel dosimeters to cool gradually and to be scanned while at room temperature. Preliminary tests show that considerable noise reduction can be achieved with sinogram filtering and by binning image pixels into more clinically relevant grid sizes. Conclusions: This paper describes a new optical CT scanner for 3D radiation dosimetry. Tests demonstrate that it is capable of imaging both absorption-based and scatter-based samples of high opacities. Imaging protocol and gel dosimeter manufacture techniques have been adapted to produce optimal reconstruction results. These optimal results will require suitable filtering and binning techniques for noise reduction purposes.

Campbell, Warren G.; Rudko, D. A.; Braam, Nicolas A.; Jirasek, Andrew [University of Victoria, Victoria, British Columbia V8P 5C2 (Canada); Wells, Derek M. [British Columbia Cancer Agency, Vancouver Island Centre, Victoria, British Columbia V8R 6V5 (Canada)

2013-06-15T23:59:59.000Z

9

Conversion of the energy-subtracted CT number to electron density based on a single linear relationship: an experimental verification using a clinical dual-source CT scanner  

Science Journals Connector (OSTI)

In radiotherapy treatment planning, the conversion of the computed tomography (CT) number to electron density is one of the main processes that determine the accuracy of patient dose calculations. However, in general, the CT number and electron density of tissues cannot be interrelated using a simple one-to-one correspondence. This study aims to experimentally verify the clinical feasibility of an existing novel conversion method proposed by the author of this note, which converts the energy-subtracted CT number (?HU) to the relative electron density (?e) via a single linear relationship by using a dual-energy CT (DECT). The ?HU?econversion was performed using a clinical second-generation dual-source CT scanner operated in the dual-energy mode with tube potentials of 80kV and 140kV with and without an additional tin filter. The ?HU?ecalibration line was obtained from the DECT image acquisition for tissue substitutes in an electron density phantom. In addition, the effect of object size on ?HU?econversion was also experimentally investigated. The plot of the measured ?HU versus nominal ?evalues exhibited a single linear relationship over a wide ?erange from 0.00 (air) to 2.35 (aluminum). The ?HU?econversion performed with the tin filter yielded a lower dose and more reliable ?evalues that were less affected by the object-size variation when compared to the corresponding values obtained for the case without the tin filter.

Masayoshi Tsukihara; Yoshiyuki Noto; Takahide Hayakawa; Masatoshi Saito

2013-01-01T23:59:59.000Z

10

Positron Emission Tomography-Scanner at Children`s Hospital of Michigan at Detroit, Michigan  

SciTech Connect (OSTI)

The Department of Energy has prepared an environmental assessment (EA), DOE/EA-0795, to support the DOE decision to provide a grant of $7,953,600 to be used in support of a proposed Positron Emission Tomography Scanner at Children`s Hospital of Michigan at Detroit, Michigan. Based upon the analysis in the EA, DOE has determined that the proposed action is not a major Federal action significantly affected the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required and DOE is issuing this Finding of No Significant Impact (FONSI).

Not Available

1992-12-31T23:59:59.000Z

11

Computed Tomography (CT) Scanning For Petrophysical Applications  

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

12

Silicon photomultiplier choice for the scintillating fibre tracker in second generation proton computed tomography scanner  

SciTech Connect (OSTI)

Scintillating fibers are capable of charged particle tracking with high position resolution, as demonstrated by the central fiber tracker of the D0 experiment. The charged particles will deposit less energy in the polystyrene scintillating fibers as opposed to a typical silicon tracker of the same thickness, while SiPM's are highly efficient at detecting photons created by the passage of the charged particle through the fibers. The current prototype of the Proton Computed Tomography (pCT) tracker uses groups of three 0.5 mm green polystyrene based scintillating fibers connected to a single SiPM, while first generation prototype tracker used Silicon strip detectors. The results of R&D for the Scintillating Fiber Tracker (SFT) as part of the pCT detector are outlined, and the premise for the selection of SiPM is discussed.

Gearhart, A.; Johnson, E.; Medvedev, V.; /Northern Illinois U.; Ronzhin, A.; /Fermilab; Rykalin, V.; /Northern Illinois U.; Rubinov, P.; /Fermilab; Sleptcov, V.; /Unlisted, RU

2012-03-01T23:59:59.000Z

13

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

SciTech Connect (OSTI)

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

14

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

SciTech Connect (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

15

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

16

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

SciTech Connect (OSTI)

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

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

2014-02-15T23:59:59.000Z

17

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

18

NETL CT Imaging Facility  

SciTech Connect (OSTI)

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

None

2013-09-04T23:59:59.000Z

19

NETL CT Imaging Facility  

ScienceCinema (OSTI)

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

None

2014-05-21T23:59:59.000Z

20

Implications of CT noise and artifacts for quantitative {sup 99m}Tc SPECT/CT imaging  

SciTech Connect (OSTI)

Purpose: This paper evaluates the effects of computed tomography (CT) image noise and artifacts on quantitative single-photon emission computed-tomography (SPECT) imaging, with the aim of establishing an appropriate range of CT acquisition parameters for low-dose protocols with respect to accurate SPECT attenuation correction (AC). Methods: SPECT images of two geometric and one anthropomorphic phantom were reconstructed iteratively using CT scans acquired at a range of dose levels (CTDI{sub vol} = 0.4 to 46 mGy). Resultant SPECT image quality was evaluated by comparing mean signal, background noise, and artifacts to SPECT images reconstructed using the highest dose CT for AC. Noise injection was performed on linear-attenuation (?) maps to determine the CT noise threshold for accurate AC. Results: High levels of CT noise (? ? 200400 HU) resulted in low ?-maps noise (? ? 1%3%). Noise levels greater than ?10% in 140 keV ?-maps were required to produce visibly perceptible increases of ?15% in {sup 99m}Tc SPECT images. These noise levels would be achieved at low CT dose levels (CTDI{sub vol} = 4 ?Gy) that are over 2 orders of magnitude lower than the minimum dose for diagnostic CT scanners. CT noise could also lower (bias) the expected ? values. The relative error in reconstructed SPECT signal trended linearly with the relative shift in ?. SPECT signal was, on average, underestimated in regions corresponding with beam-hardening artifacts in CT images. Any process that has the potential to change the CT number of a region by ?100 HU (e.g., misregistration between CT images and SPECT images due to motion, the presence of contrast in CT images) could introduce errors in ?{sub 140} {sub keV} on the order of 10%, that in turn, could introduce errors on the order of ?10% into the reconstructed {sup 99m}Tc SPECT image. Conclusions: The impact of CT noise on SPECT noise was demonstrated to be negligible for clinically achievable CT parameters. Because CT dose levels that affect SPECT quantification is low (CTDI{sub vol} ? 4 ?Gy), the low dose limit for the CT exam as part of SPECT/CT will be guided by CT image quality requirements for anatomical localization and artifact reduction. A CT technique with higher kVp in combination with lower mAs is recommended when low-dose CT images are used for AC to minimize beam-hardening artifacts.

Hulme, K. W.; Kappadath, S. C., E-mail: skappadath@mdanderson.org [Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77030 (United States)

2014-04-15T23:59:59.000Z

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.


21

Trapping volumetric measurement by multidetector CT in chronic obstructive pulmonary disease: Effect of CT threshold  

SciTech Connect (OSTI)

Purpose: The purpose of this study was to evaluate the effect of various computed tomography (CT) thresholds on trapping volumetric measurements by multidetector CT in chronic obstructive pulmonary disease (COPD).Methods: Twenty-three COPD patients were scanned with a 64-slice CT scanner in both the inspiratory and expiratory phase. CT thresholds of ?950 Hu in inspiration and ?950 to ?890 Hu in expiration were used, after which trapping volumetric measurements were made using computer software. Trapping volume percentage (Vtrap%) under the different CT thresholds in the expiratory phase and below ?950 Hu in the inspiratory phase was compared and correlated with lung function.Results: Mean Vtrap% was similar under ?930 Hu in the expiratory phase and below ?950 Hu in the inspiratory phase, being 13.18 9.66 and 13.95 6.72 (both lungs), respectively; this difference was not significant (P= 0.240). Vtrap% under ?950 Hu in the inspiratory phase and below the ?950 to ?890 Hu threshold in the expiratory phase was moderately negatively correlated with the ratio of forced expiratory volume in one second to forced vital capacity and the measured value of forced expiratory volume in one second as a percentage of the predicted value.Conclusions: Trapping volumetric measurement with multidetector CT is a promising method for the quantification of COPD. It is important to know the effect of various CT thresholds on trapping volumetric measurements.

Wang, Xiaohua; Yuan, Huishu [Department of Radiology, Peking University Third Hospital, Beijing 100191 (China)] [Department of Radiology, Peking University Third Hospital, Beijing 100191 (China); Duan, Jianghui [Medical School, Peking University, Beijing 100191 (China)] [Medical School, Peking University, Beijing 100191 (China); Du, Yipeng; Shen, Ning; He, Bei [Department of Respiration Internal Medicine, Peking University Third Hospital, Beijing 100191 (China)] [Department of Respiration Internal Medicine, Peking University Third Hospital, Beijing 100191 (China)

2013-08-15T23:59:59.000Z

22

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

SciTech Connect (OSTI)

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

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

2014-04-15T23:59:59.000Z

23

Cone-beam Computed Tomography-guided Stereotactic Liver Punctures: A Phantom Study  

SciTech Connect (OSTI)

Purpose: Images from computed tomography (CT), combined with navigation systems, improve the outcomes of local thermal therapies that are dependent on accurate probe placement. Although the usage of CT is desired, its availability for time-consuming radiological interventions is limited. Alternatively, three-dimensional images from C-arm cone-beam CT (CBCT) can be used. The goal of this study was to evaluate the accuracy of navigated CBCT-guided needle punctures, controlled with CT scans. Methods: Five series of five navigated punctures were performed on a nonrigid phantom using a liver specific navigation system and CBCT volumetric dataset for planning and navigation. To mimic targets, five titanium screws were fixed to the phantom. Target positioning accuracy (TPE{sub CBCT}) was computed from control CT scans and divided into lateral and longitudinal components. Additionally, CBCT-CT guidance accuracy was deducted by performing CBCT-to-CT image coregistration and measuring TPE{sub CBCT-CT} from fused datasets. Image coregistration was evaluated using fiducial registration error (FRE{sub CBCT-CT}) and target registration error (TRE{sub CBCT-CT}). Results: Positioning accuracies in lateral directions pertaining to CBCT (TPE{sub CBCT} = 2.1 {+-} 1.0 mm) were found to be better to those achieved from previous study using CT (TPE{sub CT} = 2.3 {+-} 1.3 mm). Image coregistration error was 0.3 {+-} 0.1 mm, resulting in an average TRE of 2.1 {+-} 0.7 mm (N = 5 targets) and average Euclidean TPE{sub CBCT-CT} of 3.1 {+-} 1.3 mm. Conclusions: Stereotactic needle punctures might be planned and performed on volumetric CBCT images and controlled with multidetector CT with positioning accuracy higher or similar to those performed using CT scanners.

Toporek, Grzegorz, E-mail: grzegorz.toporek@artorg.unibe.ch; Wallach, Daphne, E-mail: daphne.wallach@artorg.unibe.ch; Weber, Stefan [ARTORG Center for Biomedical Engineering Research, University of Bern (Switzerland)] [ARTORG Center for Biomedical Engineering Research, University of Bern (Switzerland); Bale, Reto; Widmann, Gerlig [Innsbruck Medical University, Section of Microinvasive Therapy, Department of Radiology (Austria)] [Innsbruck Medical University, Section of Microinvasive Therapy, Department of Radiology (Austria)

2013-12-15T23:59:59.000Z

24

Interfractional Prostate Shifts: Review of 1870 Computed Tomography (CT) Scans Obtained During Image-Guided Radiotherapy Using CT-on-Rails for the Treatment of Prostate Cancer  

SciTech Connect (OSTI)

Purpose: To review 1870 CT scans of interfractional prostate shift obtained during image-guided radiotherapy. Methods and Materials: A total of 1870 pretreatment CT scans were acquired with CT-on-rails, and the corresponding shift data for 329 patients with prostate cancer were analyzed. Results: Of the 1870 scans reviewed, 44% required no setup adjustments in the anterior-posterior (AP) direction, 14% had shifts of 3-5 mm, 29% had shifts of 6-10 mm, and 13% had shifts of >10 mm. In the superior-inferior direction, 81% had no adjustments, 2% had shifts of 3-5 mm, 15% had shifts of 6-10 mm, and 2% had shifts of >10 mm. In the left-right direction, 65% had no adjustment, 13% had shifts of 3-5 mm, 17% had shifts of 6-10 mm, and 5% had shifts of >10 mm. Further analysis of the first 66 consecutive patients divided into three groups according to body mass index indicates that the shift in the AP direction for the overweight subgroup was statistically larger than those for the control and obese subgroups (p < 0.05). The interfractional shift in the lateral direction for the obese group (1 SD, 5.5 mm) was significantly larger than those for the overweight and control groups (4.1 and 2.9 mm, respectively) (p < 0.001). Conclusions: These data demonstrate that there is a significantly greater shift in the AP direction than in the lateral and superior-inferior directions for the entire patient group. Overweight and obese patient groups show a significant difference from the control group in terms of prostate shift.

Wong, James R. [Department of Radiation Oncology, Carol G. Simon Cancer Center, Morristown Memorial Hospital, Morristown, NJ (United States)], E-mail: james.wong@atlantichealth.org; Gao Zhanrong [Department of Radiation Oncology, Carol G. Simon Cancer Center, Morristown Memorial Hospital, Morristown, NJ (United States); Uematsu, Minoru [Department of Radiation Oncology, UAS Oncology Center, Kagoshima (Japan); Merrick, Scott; Machernis, Nolan P.; Chen, Timothy; Cheng, C.W. [Department of Radiation Oncology, The Carol G. Simon Cancer Center, Morristown Memorial Hospital, Morristown, NJ (United States)

2008-12-01T23:59:59.000Z

25

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

E-Print Network [OSTI]

-guided diagnosis and radiation therapy. For diagnosis, the fact that the patient dose committed by proton CT only render approximate stopping power estimates, limiting the power of proton radiation therapy radiation therapy is one of the most precise forms of image-guided cancer therapy since the sharp dose peak

California at Santa Cruz, University of

26

Biochip scanner device  

DOE Patents [OSTI]

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

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

2001-01-01T23:59:59.000Z

27

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

28

High throughput optical scanner  

DOE Patents [OSTI]

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

29

Investigation of water and CO2 (carbon dioxide) flooding using micro-CT (micro-computed tomography) images of Berea sandstone core using finite element simulations  

Science Journals Connector (OSTI)

The present study reports a numerical investigation of water and CO2 (carbon dioxide) flooding at the pore scale of a porous medium. We use high resolution micro-computed tomography (micro-CT) images of Berea sandstone core to obtain the pore geometry. The numerical solution used for the simulation was carried out by a finite element based software package. Level Set method is used to determine the position of the interface between two immiscible fluids when oil is displaced by water and CO2, respectively. The present formulation is validated against single-phase flow through the porous structure. It is found that, fluid flow inside the pore space takes place through preferential inlet and outlet pores. For two-phase flow, it is observed that continuous displacement of oil occurs during water flooding but CO2 is able to displace oil at certain locations in the pores. Also, the separation of flow front is observed in the case of CO2 flooding. A quantitative comparison of the results obtained in two types of flooding simulations suggests that water displaces a higher volume of oil than CO2 in the time period for which the simulations are performed.

Akshay C. Gunde; Bijoyendra Bera; Sushanta K. Mitra

2010-01-01T23:59:59.000Z

30

Positron Emission Tomography Physics, Instrumentation, Data Analysis  

E-Print Network [OSTI]

1 Positron Emission Tomography Physics, Instrumentation, Data Analysis Carl K. Hoh, MD Department fast computer Filtered Back Projection Iterative Reconstruction PET Image Reconstruction #12 PET Scanner Design · Smaller individual crystal size = better spatial resolution · Physical limit

Liu, Thomas T.

31

Radiation Exposure from CT Examinations in Japan  

Science Journals Connector (OSTI)

Computed tomography (CT) is the largest source of medical radiation exposure to the general population, and is ... assess the current situation of CT use in Japan, and to investigate variations in radiation expos...

Yoshito Tsushima; Ayako Taketomi-Takahashi; Hiroyuki Takei

2010-11-01T23:59:59.000Z

32

Reference dosimetry during diagnostic CT examination using XR-QA radiochromic film model  

SciTech Connect (OSTI)

Purpose: The authors applied 2D reference dosimetry protocol for dose measurements using XR-QA radiochromic film model during diagnostic computed tomography (CT) examinations carried out on patients and humanoid Rando phantom. Methods: Response of XR-QA model GAFCHROMIC film reference dosimetry system was calibrated in terms of Air-Kerma in air. Four most commonly used CT protocols were selected on their CT scanner (GE Lightspeed VCT 64), covering three anatomical sites (head, chest, and abdomen). For each protocol, 25 patients ongoing planned diagnostic CT examination were recruited. Surface dose was measured using four or eight film strips taped on patients' skin and on Rando phantom. Film pieces were scanned prior to and after irradiation using Epson Expression 10000XL document scanner. Optical reflectance of the unexposed film piece was subtracted from exposed one to obtain final net reflectance change, which is subsequently converted to dose using previously established calibration curves. Results: The authors' measurements show that body skin dose variation has a sinusoidal pattern along the scanning axis due to the helical movement of the x-ray tube, and a comb pattern for head dose measurements due to its axial movement. Results show that the mean skin dose at anterior position for patients is (51 {+-} 6) mGy, (29 {+-} 11) mGy, (45 {+-} 13) mGy and (38 {+-} 20) mGy for head, abdomen, angio Abdomen, and chest and abdomen protocol (UP position), respectively. The obtained experimental dose length products (DLP) show higher values than CT based DLP taken from the scanner console for body protocols, but lower values for the head protocol. Internal dose measurements inside the phantom's head indicate nonuniformity of dose distribution within scanned volume. Conclusions: In this work, the authors applied an Air-Kerma in air based radiochromic film reference dosimetry protocol for in vivo skin dose measurements. In this work, they employed green channel extracted from the scanned RGB image for dose measurements in the range from 0 to 200 mGy. Measured skin doses and corresponding DLPs were higher than DLPs provided by the CT scanner manufacturer as they were measured on patients' skin.

Boivin, Jonathan; Tomic, Nada; Fadlallah, Bassam; DeBlois, Francois; Devic, Slobodan [Institut de Genie Biomedical, Universite de Montreal, Montreal, Quebec H3C 3J7 (Canada); Medical Physics Unit, McGill University, Montral, Quebec H3G 1A4, Canada and Department of Radiation Oncology, SMBD Jewish General Hospital, McGill University, 3755 chemin de la Cote-Sainte-Catherine, Montreal, Quebec H3T 1E2 (Canada); Department of Biomedical Engineering, SMBD Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2 (Canada); Medical Physics Unit, McGill University, Montreal, Quebec H3G 1A4, Canada and Department of Radiation Oncology, SMBD Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2 (Canada)

2011-09-15T23:59:59.000Z

33

Improved proton computed tomography by dual modality image reconstruction  

SciTech Connect (OSTI)

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

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

2014-03-15T23:59:59.000Z

34

Dental CT: A New Diagnostic Tool in Dental Radiology Based on Double Spiral CT  

Science Journals Connector (OSTI)

In the beginning of 1990, dental computed tomography (CT) software program was developed which offers the possibility of reconstructing panoramic and transaxial images of the maxilla and the mandible from CT d...

U. Hirschfelder; H. Hirschfelder; J. Regn

1994-01-01T23:59:59.000Z

35

E-Print Network 3.0 - angiography computed tomography Sample...  

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

Solutions Computed Tomography (CTCAT) 3D volume is reconstructed... ) Computer Tomography (CT): Radon-Transformation reconstructs images from projection data-profiles ...

36

VACT: Visualization-Aware CT Reconstruction Ziyi Zheng and Klaus Mueller, Senior Member, IEEE  

E-Print Network [OSTI]

Abstract-- Computed tomography (CT) reconstruction methods are often unaware of the requirements Medical routine frequently utilizes 3D visualization tools for diagnosis. Computed tomography (CT between the raw projection data and their visualization via vol- ume rendering. Our framework can

Mueller, Klaus

37

Fusion of Immunoscintigraphy Single Photon Emission Computed Tomography (SPECT) with CT of the Chest in Patients with Non-Small Cell Lung Cancer  

Science Journals Connector (OSTI)

...the eighth patient, fusion demonstrated the absence...image registration or fusion of oefunctional studies...were acquired with dual energy windows to provide anatomic and landmark...the other. The 5761s FUSION OF CHEST SPECT AND CT...

Sanjeev Katyal; Elissa Lipcon Kramer; Marilyn E. Noz; Dorothy McCauley; Abraham Chachoua; and Alan Steinfeld

1995-12-01T23:59:59.000Z

38

LimitedAngle Computed Tomography for Sandwich Structures using Data Fusion  

E-Print Network [OSTI]

1 Limited­Angle Computed Tomography for Sandwich Structures using Data Fusion Jeffrey E. Boyd and limited­angle computed­tomography (CT) are ill­posed problems, but where conventional CT has a small null. #12; 2 1. INTRODUCTION This paper presents a novel method for limited­angle computed tomography (CT

Boyd, Jeffrey E.

39

Computed Tomography software and standards  

SciTech Connect (OSTI)

This document establishes the software design, nomenclature, and conventions for industrial Computed Tomography (CT) used in the Nondestructive Evaluation Section at Lawrence Livermore National Laboratory. It is mainly a users guide to the technical use of the CT computer codes, but also presents a proposed standard for describing CT experiments and reconstructions. Each part of this document specifies different aspects of the CT software organization. A set of tables at the end describes the CT parameters of interest in our project. 4 refs., 6 figs., 1 tab.

Azevedo, S.G.; Martz, H.E.; Skeate, M.F.; Schneberk, D.J.; Roberson, G.P.

1990-02-20T23:59:59.000Z

40

Computed tomography:the details.  

SciTech Connect (OSTI)

Computed Tomography (CT) is a well established technique, particularly in medical imaging, but also applied in Synthetic Aperture Radar (SAR) imaging. Basic CT imaging via back-projection is treated in many texts, but often with insufficient detail to appreciate subtleties such as the role of non-uniform sampling densities. Herein are given some details often neglected in many texts.

Doerry, Armin Walter

2007-07-01T23:59:59.000Z

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.


41

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

SciTech Connect (OSTI)

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

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

2013-08-15T23:59:59.000Z

42

angiographic computed tomography: Topics by E-print Network  

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

the development and application of a 4-Dimensional Computed Tomography (4D CT) simulation program. The simulation is used to understand and quantify the sources of image...

43

Correction of CT artifacts and its influence on Monte Carlo dose calculations  

SciTech Connect (OSTI)

Computed tomography (CT) images of patients having metallic implants or dental fillings exhibit severe streaking artifacts. These artifacts may disallow tumor and organ delineation and compromise dose calculation outcomes in radiotherapy. We used a sinogram interpolation metal streaking artifact correction algorithm on several phantoms of exact-known compositions and on a prostate patient with two hip prostheses. We compared original CT images and artifact-corrected images of both. To evaluate the effect of the artifact correction on dose calculations, we performed Monte Carlo dose calculation in the EGSnrc/DOSXYZnrc code. For the phantoms, we performed calculations in the exact geometry, in the original CT geometry and in the artifact-corrected geometry for photon and electron beams. The maximum errors in 6 MV photon beam dose calculation were found to exceed 25% in original CT images when the standard DOSXYZnrc/CTCREATE calibration is used but less than 2% in artifact-corrected images when an extended calibration is used. The extended calibration includes an extra calibration point for a metal. The patient dose volume histograms of a hypothetical target irradiated by five 18 MV photon beams in a hypothetical treatment differ significantly in the original CT geometry and in the artifact-corrected geometry. This was found to be mostly due to miss-assignment of tissue voxels to air due to metal artifacts. We also developed a simple Monte Carlo model for a CT scanner and we simulated the contribution of scatter and beam hardening to metal streaking artifacts. We found that whereas beam hardening has a minor effect on metal artifacts, scatter is an important cause of these artifacts.

Bazalova, Magdalena; Beaulieu, Luc; Palefsky, Steven; Verhaegen, Frank [Medical Physics Department, McGill University, Montreal General Hospital, 1650 Cedar Avenue, Montreal, Quebec, H3G1A4 (Canada); Department de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec City, Quebec, G1K7P4 (Canada) and Department de Radio-Oncologie, Hotel Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec City, Quebec, G1R2J6 (Canada); Medical Physics Department, McGill University, Montreal General Hospital, 1650 Cedar Avenue, Montreal, Quebec, H3G1A4 (Canada)

2007-06-15T23:59:59.000Z

44

General Geometry CT Reconstruction Alexei Ramotar  

E-Print Network [OSTI]

, reconstruction, Filtered Back Projection Submitted to IPCV'06 Abstract We present an efficient and accurate acquired by a parallel-beam CT scanner. Once in that form, Filtered Back Projection can be used to perform technology that uses many small x-ray images to reconstruct a view of the internal structures of an object

Orchard, Jeffery J.

45

Measuring and segmentation in CT data using deformable Vclav Krajcek  

E-Print Network [OSTI]

tomography (CT). We take advantage of long-time research in the area of deformable models. We have developed Snakes, CT, Medical Segmentation, Volume Measurement. 1 INTRODUCTION Computed tomography is a common tool, that temperature of healthy body is about 36,5 C. Higher temperature means that body is fighting with an illness

Pelikan, Josef

46

X-Ray CT Image Reconstruction via Wavelet Frame Based Regularization and Radon Domain  

E-Print Network [OSTI]

to reconstruct high quality CT images from limited and noisy projection data. One of the common CT systems Bin Dong Jia Li Zuowei Shen December 22, 2011 Abstract X-ray computed tomography (CT) has been,8]. Numerical simulations and comparisons will be presented at the end. Keywords: Computed tomography, wavelet

Zakharov, Vladimir

47

Limited View Angle Iterative CT Reconstruction  

E-Print Network [OSTI]

;Some Prior Literature in Limited View Tomography CT with limited-angle data and few views IRR algorithm Iterative Reconstruction-Reprojection (IRR) : An Algorithm for Limited Data Cardiac- Computed-views and limited-angle data in divergent-beam CT by E. Y. Sidky, CM Kao, and X. Pan (2006) Few-View Projection

48

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

E-Print Network [OSTI]

tomographies (CT). Compared to simulated CT projection data, real measurements allowed less improvementsReduction of Metal Artifacts in Computed Tomographies for the Planning and Simulation of Radiation and numerical stability. 1. INTRODUCTION In radiation therapy, computed tomographies are used for patient

Zerfowski, Detlef

49

Combined PET/MRI scanner  

DOE Patents [OSTI]

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

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

2007-10-23T23:59:59.000Z

50

Clinical Application of In-Room Positron Emission Tomography for In Vivo Treatment Monitoring in Proton Radiation Therapy  

SciTech Connect (OSTI)

Purpose: The purpose of this study is to evaluate the potential of using in-room positron emission tomography (PET) for treatment verification in proton therapy and for deriving suitable PET scan times. Methods and Materials: Nine patients undergoing passive scattering proton therapy underwent scanning immediately after treatment with an in-room PET scanner. The scanner was positioned next to the treatment head after treatment. The Monte Carlo (MC) method was used to reproduce PET activities for each patient. To assess the proton beam range uncertainty, we designed a novel concept in which the measured PET activity surface distal to the target at the end of range was compared with MC predictions. The repositioning of patients for the PET scan took, on average, approximately 2 minutes. The PET images were reconstructed considering varying scan times to test the scan time dependency of the method. Results: The measured PET images show overall good spatial correlations with MC predictions. Some discrepancies could be attributed to uncertainties in the local elemental composition and biological washout. For 8 patients treated with a single field, the average range differences between PET measurements and computed tomography (CT) image-based MC results were <5 mm (<3 mm for 6 of 8 patients) and root-mean-square deviations were 4 to 11 mm with PET-CT image co-registration errors of approximately 2 mm. Our results also show that a short-length PET scan of 5 minutes can yield results similar to those of a 20-minute PET scan. Conclusions: Our first clinical trials in 9 patients using an in-room PET system demonstrated its potential for in vivo treatment monitoring in proton therapy. For a quantitative range prediction with arbitrary shape of target volume, we suggest using the distal PET activity surface.

Min, Chul Hee [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)] [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Zhu, Xuping [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States)] [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Winey, Brian A. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)] [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Grogg, Kira [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States)] [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Testa, Mauro [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)] [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); El Fakhri, Georges [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States)] [Center for Advanced Radiological Sciences, Nuclear Medicine and Molecular Imaging, Radiology Department, Massachusetts General Hospital, Boston, Massachusetts (United States); Bortfeld, Thomas R.; Paganetti, Harald [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)] [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States); Shih, Helen A., E-mail: hshih@partners.org [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (United States)

2013-05-01T23:59:59.000Z

51

Cone Beam Tomography using MPI on Heterogeneous Workstation Clusters  

E-Print Network [OSTI]

tomography is a computed tomography method which efficiently acquires projectional data through a single. Introduction Tomographic reconstruction from projections using computed tomography (CT) provides a noninvasive, the projectional data is projected back onto an image buffer with each de- tected ray backprojected in it

Chaudhary, Vipin

52

E-Print Network 3.0 - aided ct image Sample Search Results  

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

10 ARTICLE IN PRESS Computer-Aided Design ( ) Summary: a limited number of computed tomography (CT) images. The three-dimensional template geometry of a healthy... contour shown...

53

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

54

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

55

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

56

Explosive Detection in Aviation Applications Using CT  

SciTech Connect (OSTI)

CT scanners are deployed world-wide to detect explosives in checked and carry-on baggage. Though very similar to single- and dual-energy multi-slice CT scanners used today in medical imaging, some recently developed explosives detection scanners employ multiple sources and detector arrays to eliminate mechanical rotation of a gantry, photon counting detectors for spectral imaging, and limited number of views to reduce cost. For each bag scanned, the resulting reconstructed images are first processed by automated threat recognition algorithms to screen for explosives and other threats. Human operators review the images only when these automated algorithms report the presence of possible threats. The US Department of Homeland Security (DHS) has requirements for future scanners that include dealing with a larger number of threats, higher probability of detection, lower false alarm rates and lower operating costs. One tactic that DHS is pursuing to achieve these requirements is to augment the capabilities of the established security vendors with third-party algorithm developers. A third-party in this context refers to academics and companies other than the established vendors. DHS is particularly interested in exploring the model that has been used very successfully by the medical imaging industry, in which university researchers develop algorithms that are eventually deployed in commercial medical imaging equipment. The purpose of this paper is to discuss opportunities for third-parties to develop advanced reconstruction and threat detection algorithms.

Martz, H E; Crawford, C R

2011-02-15T23:59:59.000Z

57

Positron emission tomography wrist detector  

DOE Patents [OSTI]

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

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

2006-08-15T23:59:59.000Z

58

Development of a dynamic quality assurance testing protocol for multisite clinical trial DCE-CT accreditation  

SciTech Connect (OSTI)

Purpose: Credentialing can have an impact on whether or not a clinical trial produces useful quality data that is comparable between various institutions and scanners. With the recent increase of dynamic contrast enhanced-computed tomography (DCE-CT) usage as a companion biomarker in clinical trials, effective quality assurance, and control methods are required to ensure there is minimal deviation in the results between different scanners and protocols at various institutions. This paper attempts to address this problem by utilizing a dynamic flow imaging phantom to develop and evaluate a DCE-CT quality assurance (QA) protocol.Methods: A previously designed flow phantom, capable of producing predictable and reproducible time concentration curves from contrast injection was fully validated and then utilized to design a DCE-CT QA protocol. The QA protocol involved a set of quantitative metrics including injected and total mass error, as well as goodness of fit comparison to the known truth concentration curves. An additional region of interest (ROI) sensitivity analysis was also developed to provide additional details on intrascanner variability and determine appropriate ROI sizes for quantitative analysis. Both the QA protocol and ROI sensitivity analysis were utilized to test variations in DCE-CT results using different imaging parameters (tube voltage and current) as well as alternate reconstruction methods and imaging techniques. The developed QA protocol and ROI sensitivity analysis was then applied at three institutions that were part of clinical trial involving DCE-CT and results were compared.Results: The inherent specificity of robustness of the phantom was determined through calculation of the total intraday variability and determined to be less than 2.2 1.1% (total calculated output contrast mass error) with a goodness of fit (R{sup 2}) of greater than 0.99 0.0035 (n= 10). The DCE-CT QA protocol was capable of detecting significant deviations from the expected phantom result when scanning at low mAs and low kVp in terms of quantitative metrics (Injected Mass Error 15.4%), goodness of fit (R{sup 2}) of 0.91, and ROI sensitivity (increase in minimum input function ROI radius by 146 86%). These tests also confirmed that the ASIR reconstruction process was beneficial in reducing noise without substantially increasing partial volume effects and that vendor specific modes (e.g., axial shuttle) did not significantly affect the phantom results. The phantom and QA protocol were finally able to quickly (<90 min) and successfully validate the DCE-CT imaging protocol utilized at the three separate institutions of a multicenter clinical trial; thereby enhancing the confidence in the patient data collected.Conclusions: A DCE QA protocol was developed that, in combination with a dynamic multimodality flow phantom, allows the intrascanner variability to be separated from other sources of variability such as the impact of injection protocol and ROI selection. This provides a valuable resource that can be utilized at various clinical trial institutions to test conformance with imaging protocols and accuracy requirements as well as ensure that the scanners are performing as expected for dynamic scans.

Driscoll, B. [Department of Radiation Physics, Princess Margaret Cancer Center, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada)] [Department of Radiation Physics, Princess Margaret Cancer Center, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Keller, H. [Department of Radiation Physics, Princess Margaret Cancer Center, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, 150 College Street, Toronto, Ontario M5S 3E2 (Canada)] [Department of Radiation Physics, Princess Margaret Cancer Center, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, 150 College Street, Toronto, Ontario M5S 3E2 (Canada); Jaffray, D.; Coolens, C. [Department of Radiation Physics, Princess Margaret Cancer Center, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada) [Department of Radiation Physics, Princess Margaret Cancer Center, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Department of Radiation Oncology, University of Toronto, 150 College Street, Toronto, Ontario M5S 3E2 (Canada); Techna Institute, University Health Network, 124-100 College Street, Toronto, Ontario M5G 1L5 (Canada)

2013-08-15T23:59:59.000Z

59

Performance dependence of hybrid x-ray computed tomography/fluorescence molecular  

E-Print Network [OSTI]

Performance dependence of hybrid x-ray computed tomography/fluorescence molecular tomography imaging systems combining x-ray computed tomography (CT) and fluorescence tomography can im- prove Ntziachristos2 1 Department of Electrical and Computer Engineering, Northeastern University, 360 Huntington Ave

Miller, Eric

60

Accurate model-based high resolution cardiac image reconstruction in dual source CT  

Science Journals Connector (OSTI)

Cardiac imaging represents one of the most challenging imaging problems, requiring high spatial and temporal resolutions along with good tissue contrast. One of the newest clinical cardiac CT scanners incorporates two source-detector pairs in order to ... Keywords: cardiac, dual source CT, iterative method, model-based imaging

Synho Do; Sanghee Cho; W. Clem Karl; Mannudeep K. Kalra; Thomas J. Brady; Homer Pien

2009-06-01T23:59:59.000Z

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.


61

Locating the Eyes in CT Brain Scan Data Kostis Kaggelides, Peter J. Elliott  

E-Print Network [OSTI]

, a technique for locating the eyes in Computed Tomography brain scan data, is described. The objective and implemented an algorithm which automaticallyidenti es and locates the eyes in a Computed Tomography(CT) brainLocating the Eyes in CT Brain Scan Data Kostis Kaggelides, Peter J. Elliott IBM UK Scienti c Centre

Fisher, Bob

62

LANSCE Wire Scanner System Prototype: Switchyard Test  

SciTech Connect (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

63

Application of X-ray CT for investigating fluid flow and conformance control during CO2 injection in highly heterogeneous media  

E-Print Network [OSTI]

were performed using homogeneous and heterogeneous cores and a 4th generation X-Ray CT scanner was used to visualize heterogeneity and fluid flow in the core. Porosity and saturation measurements were made during the course of the experiment...

Chakravarthy, Deepak

2005-08-29T23:59:59.000Z

64

Miniature 'Wearable' PET Scanner Ready for Use  

ScienceCinema (OSTI)

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

Paul Vaska

2013-07-22T23:59:59.000Z

65

MagViz Bottled Liquid Scanner at Albuquerque International Sunport  

ScienceCinema (OSTI)

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

Surko, Stephen; Dennis, Steve; Espy, Michelle

2014-08-12T23:59:59.000Z

66

Potential of dual-energy subtraction for converting CT numbers to electron density based on a single linear relationship  

SciTech Connect (OSTI)

Purpose: The conversion of the computed tomography (CT) number to electron density is one of the main processes that determine the accuracy of patient dose calculations in radiotherapy treatment planning. However, the CT number and electron density of tissues cannot be generally interrelated via a simple one-to-one correspondence because the CT number depends on the effective atomic number as well as the electron density. The purpose of this study is to present a simple conversion from the energy-subtracted CT number ({Delta}HU) by means of dual-energy CT (DECT) to the relative electron density ({rho}{sub e}) via a single linear relationship. Methods: The {Delta}HU-{rho}{sub e} conversion method was demonstrated by performing analytical DECT image simulations that were intended to imitate a second-generation dual-source CT (DSCT) scanner with an additional tin filtration for the high-kV tube. The {Delta}HU-{rho}{sub e} calibration line was obtained from the image simulation with a 33 cm-diameter electron density calibration phantom equipped with 16 inserts including polytetrafluoroethylene, polyvinyl chloride, and aluminum; the elemental compositions of these three inserts were quite different to those of body tissues. The {Delta}HU-{rho}{sub e} conversion method was also applied to previously published experimental CT data, which were measured using two different CT scanners, to validate the clinical feasibility of the present approach. In addition, the effect of object size on {rho}{sub e}-calibrated images was investigated by image simulations using a 25 cm-diameter virtual phantom for two different filtrations: with and without the tin filter for the high-kV tube. Results: The simulated {Delta}HU-{rho}{sub e} plot exhibited a predictable linear relationship over a wide range of {rho}{sub e} from 0.00 (air) to 2.35 (aluminum). Resultant values of the coefficient of determination, slope, and intercept of the linear function fitted to the data were close to those of the ideal case. The maximum difference between the ideal and simulated {rho}{sub e} values was -0.7%. The satisfactory linearity of {Delta}HU-{rho}{sub e} was also confirmed from analyses of the experimental CT data. In the experimental cases, the maximum difference between the nominal and simulated {rho}{sub e} values was found to be 2.5% after two outliers were excluded. When compared with the case without the tin filter, the {Delta}HU-{rho}{sub e} conversion performed with the tin filter yielded a lower dose and more reliable {rho}{sub e} values that were less affected by the object-size variation. Conclusions: The {Delta}HU-{rho}{sub e} calibration line with a simple one-to-one correspondence would facilitate the construction of a well-calibrated {rho}{sub e} image from acquired dual-kV images, and currently, second generation DSCT may be a feasible modality for the clinical use of the {Delta}HU-{rho}{sub e} conversion method.

Saito, Masatoshi [Department of Radiological Technology, School of Health Sciences, Faculty of Medicine, Niigata University, Niigata 951-8518 (Japan)

2012-04-15T23:59:59.000Z

67

Raw Data Compression in Computed Tomography: Noise Shaping  

E-Print Network [OSTI]

Raw Data Compression in Computed Tomography: Noise Shaping Yao Xie (team member: Adam Wang) Project.1 Background X-ray computed tomography (CT) builds on the physical principles of radiography. It uses multiple ring that has a limited data transfer rate. Compression can be used to reduce the data rate through

Xie, Yao

68

Bayesian Image Reconstruction for Transmission Tomography Using Deterministic Annealing  

E-Print Network [OSTI]

and non-medical applications, however, the measured projection data are photon limited and the imaging;1 INTRODUCTION Transmission tomography is perhaps most familiar in its medical guise as CT (computed tomogra- phy procedure. Because of the relatively high dose in conventional CT, the measured projection data contain

Rangarajan, Anand

69

MRI-based Preplanning Using CT and MRI Data Fusion in Patients With Cervical Cancer Treated With 3D-based Brachytherapy: Feasibility and Accuracy Study  

SciTech Connect (OSTI)

Purpose: Magnetic resonance imaging (MRI)-assisted radiation treatment planning enables enhanced target contouring. The purpose of this study is to analyze the feasibility and accuracy of computed tomography (CT) and MRI data fusion for MRI-based treatment planning in an institution where an MRI scanner is not available in the radiotherapy department. Methods and Materials: The registration inaccuracy of applicators and soft tissue was assessed in 42 applications with CT/MRI data fusion. The absolute positional difference of the center of the applicators was measured in four different planes from the top of the tandem to the cervix. Any inaccuracy of registration of soft tissue in relation to the position of applicators was determined and dose-volume parameters for MRI preplans and for CT/MRI fusion plans with or without target and organs at risk (OAR) adaptation were evaluated. Results: We performed 6,132 measurements in 42 CT/MRI image fusions. Median absolute difference of the center of tandem on CT and MRI was 1.1 mm. Median distance between the center of the right ovoid on CT and MRI was 1.7 and 1.9 mm in the laterolateral and anteroposterior direction, respectively. Corresponding values for the left ovoid were 1.6 and 1.8 mm. Rotation of applicators was 3.1 Degree-Sign . Median absolute difference in position of applicators in relation to soft tissue was 1.93, 1.50, 1.05, and 0.84 mm in the respective transverse planes, and 1.17, 1.28, 1.27, and 1.17 mm in selected angular directions. The dosimetric parameters for organs at risk on CT/MRI fusion plans without OAR adaptation were significantly impaired whereas the target coverage was not influenced. Planning without target adaptation led to overdosing of the target volume, especially high-risk clinical target volume - D{sub 90} 88.2 vs. 83.1 (p < 0.05). Conclusions: MRI-based preplanning with consecutive CT/MRI data fusion can be safe and feasible, with an acceptable inaccuracy of soft tissue registration.

Dolezel, Martin, E-mail: dolezelm@email.cz [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic) [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); First Faculty of Medicine, Charles University, Prague (Czech Republic); Odrazka, Karel [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic) [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); First Faculty of Medicine, Charles University, Prague (Czech Republic); Zizka, Jan [Department of Radiology, Charles University Teaching Hospital, Hradec Kralove (Czech Republic)] [Department of Radiology, Charles University Teaching Hospital, Hradec Kralove (Czech Republic); Vanasek, Jaroslav; Kohlova, Tereza; Kroulik, Tomas [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)] [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); Spitzer, Dusan; Ryska, Pavel [Department of Radiology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)] [Department of Radiology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); Tichy, Michal; Kostal, Milan [Department of Gynaecology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)] [Department of Gynaecology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); Jalcova, Lubica [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)] [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)

2012-09-01T23:59:59.000Z

70

Neutron Tomography and Space  

E-Print Network [OSTI]

Kevin Shields, Optimization of neutron tomography for rapidNEUTRON TOMOGRAPHY AND SPACE Hal Egbert, Ronald Walker, R.industrial applications[1]. Neutron Computed Tomography was

Egbert, Hal; Walker, Ronald; Flocchini, R.

2007-01-01T23:59:59.000Z

71

Atom Probe Tomography | EMSL  

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

Atom Probe Tomography Atom Probe Tomography The LEAP 4000 XHR local electrode atom probe tomography instrument enabled the first-ever comprehensive and accurate 3-D chemical...

72

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

73

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

SciTech Connect (OSTI)

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

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

2012-09-15T23:59:59.000Z

74

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

75

Serial optical coherence scanner for brain imaging and mapping  

Science Journals Connector (OSTI)

The serial optical coherence scanner reconstructs macroscopic tissues at microscopic resolution using intrinsic optical contrasts. The anatomy, nerve fiber architectures and fiber...

Akkin, Taner; Wang, Hui

76

Pseudolocal tomography  

DOE Patents [OSTI]

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

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

1996-07-23T23:59:59.000Z

77

Pseudolocal tomography  

DOE Patents [OSTI]

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

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

1996-01-01T23:59:59.000Z

78

Doppler Tomography  

E-Print Network [OSTI]

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

T. R. Marsh

2000-11-01T23:59:59.000Z

79

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.'

80

Low-Dose Spiral CT Scans for Early Lung Cancer Detection  

Broader source: Energy.gov [DOE]

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

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.


81

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

Broader source: Energy.gov (indexed) [DOE]

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

82

X-ray MicroCT Training Presentation  

E-Print Network [OSTI]

X-ray MicroCT Training Presentation T. Fettah Kosar, PhD Center for Nanoscale Systems Harvard) Model: HMXST225 (max. 225 kV) #12;Overview 3 Introduction to X-ray imaging and Computed Tomography (CT) · What are X-rays and how do we generate and image them? · How do we magnify X-ray images and keep them

83

A geometric calibration method for cone beam CT systems  

SciTech Connect (OSTI)

Cone beam CT systems are being deployed in large numbers for small animal imaging, dental imaging, and other specialty applications. A new high-precision method for cone beam CT system calibration is presented in this paper. It uses multiple projection images acquired from rotating point-like objects (metal ball bearings) and the angle information generated from the rotating gantry system is also used. It is assumed that the whole system has a mechanically stable rotation center and that the detector does not have severe out-of-plane rotation (<2 deg.). Simple geometrical relationships between the orbital paths of individual BBs and five system parameters were derived. Computer simulations were employed to validate the accuracy of this method in the presence of noise. Equal or higher accuracy was achieved compared with previous methods. This method was implemented for the geometrical calibration of both a micro CT scanner and a breast CT scanner. The reconstructed tomographic images demonstrated that the proposed method is robust and easy to implement with high precision.

Yang, Kai; Kwan, Alexander L. C.; Miller, DeWitt F.; Boone, John M. [Department of Radiology, University of California, Davis Medical Center, 4701 X Street, Sacramento, California 95817 and Department of Biomedical Engineering, University of California, Davis, California 95616 (United States); Department of Radiology, University of California, Davis Medical Center, 4701 X Street, Sacramento, California 95817 (United States); Department of Radiology, University of California, Davis Medical Center, 4701 X Street, Sacramento, California 95817 and Department of Biomedical Engineering, University of California, Davis, California 95616 (United States)

2006-06-15T23:59:59.000Z

84

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

E-Print Network [OSTI]

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

Tan, Chew Lim

85

GPU IMPLEMENTATION OF A 3D BAYESIAN CT ALGORITHM AND ITS APPLICATION ON REAL FOAM RECONSTRUCTION  

E-Print Network [OSTI]

Tomography (CT) [1, 3]. The limits of these meth- ods appear when the number of projections is small, and as well as any iterative algebraic meth- ods is the computation time and especially for projection solve is to reconstruct the object f from the projection data g collected by a cone beam 3D CT. The link

Paris-Sud XI, Université de

86

Searching Effective Parameters for Low-Dose CT Reconstruction by Ant Colony Optimization  

E-Print Network [OSTI]

, Eric Papenhausen and Klaus Mueller Abstract-- Low-dose Computed Tomography (CT) has been gaining. To cope with the limited data collected at 30% of standard radiation, low-dose CT reconstruction algorithms generally require several iterations of forward projection, back-projection and regularization

Mueller, Klaus

87

Auto calibration of a cone-beam-CT  

SciTech Connect (OSTI)

Purpose: This paper introduces a novel autocalibration method for cone-beam-CTs (CBCT) or flat-panel CTs, assuming a perfect rotation. The method is based on ellipse-fitting. Autocalibration refers to accurate recovery of the geometric alignment of a CBCT device from projection images alone, without any manual measurements. Methods: The authors use test objects containing small arbitrarily positioned radio-opaque markers. No information regarding the relative positions of the markers is used. In practice, the authors use three to eight metal ball bearings (diameter of 1 mm), e.g., positioned roughly in a vertical line such that their projection image curves on the detector preferably form large ellipses over the circular orbit. From this ellipse-to-curve mapping and also from its inversion the authors derive an explicit formula. Nonlinear optimization based on this mapping enables them to determine the six relevant parameters of the system up to the device rotation angle, which is sufficient to define the geometry of a CBCT-machine assuming a perfect rotational movement. These parameters also include out-of-plane rotations. The authors evaluate their method by simulation based on data used in two similar approaches [L. Smekal, M. Kachelriess, S. E, and K. Wa, 'Geometric misalignment and calibration in cone-beam tomography,' Med. Phys. 31(12), 3242-3266 (2004); K. Yang, A. L. C. Kwan, D. F. Miller, and J. M. Boone, 'A geometric calibration method for cone beam CT systems,' Med. Phys. 33(6), 1695-1706 (2006)]. This allows a direct comparison of accuracy. Furthermore, the authors present real-world 3D reconstructions of a dry human spine segment and an electronic device. The reconstructions were computed from projections taken with a commercial dental CBCT device having two different focus-to-detector distances that were both calibrated with their method. The authors compare their reconstruction with a reconstruction computed by the manufacturer of the CBCT device to demonstrate the achievable spatial resolution of their calibration procedure. Results: Compared to the results published in the most closely related work [K. Yang, A. L. C. Kwan, D. F. Miller, and J. M. Boone, 'A geometric calibration method for cone beam CT systems,' Med. Phys. 33(6), 1695-1706 (2006)], the simulation proved the greater accuracy of their method, as well as a lower standard deviation of roughly 1 order of magnitude. When compared to another similar approach [L. Smekal, M. Kachelriess, S. E, and K. Wa, 'Geometric misalignment and calibration in cone-beam tomography,' Med. Phys. 31(12), 3242-3266 (2004)], their results were roughly of the same order of accuracy. Their analysis revealed that the method is capable of sufficiently calibrating out-of-plane angles in cases of larger cone angles when neglecting these angles negatively affects the reconstruction. Fine details in the 3D reconstruction of the spine segment and an electronic device indicate a high geometric calibration accuracy and the capability to produce state-of-the-art reconstructions. Conclusions: The method introduced here makes no requirements on the accuracy of the test object. In contrast to many previous autocalibration methods their approach also includes out-of-plane rotations of the detector. Although assuming a perfect rotation, the method seems to be sufficiently accurate for a commercial CBCT scanner. For devices which require higher dimensional geometry models, the method could be used as a initial calibration procedure.

Gross, Daniel; Heil, Ulrich; Schulze, Ralf; Schoemer, Elmar; Schwanecke, Ulrich [Department of Design, Computer Science and Media, RheinMain University of Applied Sciences, 65195 Wiesbaden, Germany and Institute of Computer Science, Johannes Gutenberg University Mainz, 55128 Mainz (Germany); Department of Oral Surgery (and Oral Radiology), University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz (Germany); Institute of Computer Science, Johannes Gutenberg University Mainz, 55128 Mainz (Germany); Department of Design, Computer Science and Media, RheinMain University of Applied Sciences, 65195 Wiesbaden (Germany)

2012-10-15T23:59:59.000Z

88

A computed tomography implementation of multiple-image radiography  

SciTech Connect (OSTI)

Conventional x-ray computed tomography (CT) produces a single volumetric image that represents the spatially variant linear x-ray attenuation coefficient of an object. However, in many situations, differences in the x-ray attenuation properties of soft tissues are very small and difficult to measure in conventional x-ray imaging. In this work, we investigate an analyzer-based imaging method, called computed tomography multiple-image radiography (CT-MIR), which is a tomographic implementation of the recently proposed multiple-image radiography method. The CT-MIR method reconstructs concurrently three physical properties of the object. In addition to x-ray attenuation, CT-MIR produces volumetric images that represent the refraction and ultrasmall-angle scattering properties of the object. These three images can provide a rich description of the object's physical properties that are revealed by the probing x-ray beam. An imaging model for CT-MIR that is based on the x-ray transform of the object properties is established. The CT-MIR method is demonstrated by use of experimental data acquired at a synchroton radiation imaging beamline, and is compared to the pre-existing diffraction-enhanced imaging CT method. We also investigate the merit of an iterative reconstruction method for use with future clinical implementations of CT-MIR, which we anticipate would be photon limited.

Brankov, Jovan G.; Wernick, Miles N.; Yang Yongyi; Li Jun; Muehleman, Carol; Zhong Zhong; Anastasio, Mark A. [Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 and Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Rush University Medical Center, Chicago, Illinois 60616 (United States); National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973 (United States); Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 (United States)

2006-02-15T23:59:59.000Z

89

Fast and High Accuracy Wire Scanner  

E-Print Network [OSTI]

Scanning of a high intensity particle beam imposes challenging requirements on a Wire Scanner system. It is expected to reach a scanning speed of 20 m.s-1 with a position accuracy of the order of 1 ?m. In addition a timing accuracy better than 1 millisecond is needed. The adopted solution consists of a fork holding a wire rotating by a maximum of 200. Fork, rotor and angular position sensor are mounted on the same axis and located in a chamber connected to the beam vacuum. The requirements imply the design of a system with extremely low vibration, vacuum compatibility, radiation and temperature tolerance. The adopted solution consists of a rotary brushless synchronous motor with the permanent magnet rotor installed inside of the vacuum chamber and the stator installed outside. The accurate position sensor will be mounted on the rotary shaft inside of the vacuum chamber, has to resist a bake-out temperature of 200C and ionizing radiation up to a dozen of kGy/year. A digital feedback controller allows maxi...

Koujili, M; Koopman, J; Ramos, D; Sapinski, M; De Freitas, J; Ait Amira, Y; Djerdir, A

2009-01-01T23:59:59.000Z

90

Waste Inspection Tomography (WIT)  

SciTech Connect (OSTI)

Waste Inspection Tomography (WIT) provides mobile semi-trailer mounted nondestructive examination (NDE) and assay (NDA) for nuclear waste drum characterization. WIT uses various computed tomography (CT) methods for both NDE and NDA of nuclear waste drums. Low level waste (LLW), transuranic (TRU), and mixed radioactive waste can be inspected and characterized without opening the drums. With externally transmitted x-ray NDE techniques, WIT has the ability to identify high density waste materials like heavy metals, define drum contents in two- and three-dimensional space, quantify free liquid volumes through density and x-ray attenuation coefficient discrimination, and measure drum wall thickness. With waste emitting gamma-ray NDA techniques, WIT can locate gamma emitting radioactive sources in two- and three-dimensional space, identify gamma emitting isotopic species, identify the external activity levels of emitting gamma-ray sources, correct for waste matrix attenuation, provide internal activity approximations, and provide the data needed for waste classification as LLW or TRU. The mobile feature of WIT allows inspection technologies to be brought to the nuclear waste drum storage site without the need to relocate drums for safe, rapid, and cost-effective characterization of regulated nuclear waste. The combination of these WIT characterization modalities provides the inspector with an unprecedented ability to non-invasively characterize the regulated contents of waste drums as large as 110 gallons, weighing up to 1,600 pounds. Any objects that fit within these size and weight restrictions can also be inspected on WIT, such as smaller waste bags and drums that are five and thirty-five gallons.

Bernardi, R.T.

1995-12-01T23:59:59.000Z

91

2-D TOMOGRAPHY FROM NOISY PROJECTIONS TAKEN AT UNKNOWN RANDOM DIRECTIONS  

E-Print Network [OSTI]

to the Fourier-projection slice theorem that relates the 1-D Fourier transform R(f) of the Radon transform2-D TOMOGRAPHY FROM NOISY PROJECTIONS TAKEN AT UNKNOWN RANDOM DIRECTIONS A. SINGER AND H.-T. WU Abstract. Computerized Tomography (CT) is a standard method for obtaining internal struc- ture of objects

Singer, Amit

92

1996 InternationalConference on Parallel Processing PARALLEL IMPLEMENTATION OF CONE BEAM TOMOGRAPHY  

E-Print Network [OSTI]

projections us- ing computed tomography (CT) is the noninvasive measure of structure from external as follows: A. Weight projection data B. Convolve weighted projection data Pe*(u,v) = P&L, U) * h(u) C1996 InternationalConference on Parallel Processing PARALLEL IMPLEMENTATION OF CONE BEAM TOMOGRAPHY

Chaudhary, Vipin

93

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 Level 2 proficiency in performing and interpreting cardiac nuclear imaging tests. Progression

Ford, James

94

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

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

95

A method for measuring joint kinematics designed for accurate registration of kinematic data to models constructed from CT data  

E-Print Network [OSTI]

A method for measuring three-dimensional kinematics that incorporates the direct cross-registration of experimental kinematics with anatomic geometry from Computed Tomography (CT) data has been developed. Plexiglas ...

Fischer, Kenneth J.; Manson, T. T.; Pfaeffle, H. J.; Tomaino, M. M.; Woo, S. L-Y

2001-03-01T23:59:59.000Z

96

3D Imaging with Holographic Tomography  

Science Journals Connector (OSTI)

There are two main types of tomography that enable the 3D internal structures of objects to be reconstructed from scattered data. The commonly known computerized tomography (CT) give good results in the x?ray wavelength range where the filtered back?projection theorem and Radon transform can be used. These techniques rely on the Fourier projection?slice theorem where rays are considered to propagate straight through the object. Another type of tomography called diffraction tomography applies in applications in optics and acoustics where diffraction and scattering effects must be taken into account. The latter proves to be a more difficult problem as light no longer travels straight through the sample. Holographic tomography is a popular way of performing diffraction tomography and there has been active experimental research on reconstructing complex refractive index data using this approach recently. However there are two distinct ways of doing tomography: either by rotation of the object or by rotation of the illumination while fixing the detector. The difference between these two setups is intuitive but needs to be quantified. From Fourier optics and information transformation point of view we use 3D transfer function analysis to quantitatively describe how spatial frequencies of the object are mapped to the Fourier domain. We first employ a paraxial treatment by calculating the Fourier transform of the defocused OTF. The shape of the calculated 3D CTF for tomography by scanning the illumination in one direction only takes on a form that we might call a peanut compared to the case of object rotation where a diablo is formed the peanut exhibiting significant differences and non?isotropy. In particular there is a line singularity along one transverse direction. Under high numerical aperture conditions the paraxial treatment is not accurate and so we make use of 3D analytical geometry to calculate the behaviour in the non?paraxial case. This time we obtain a similar peanut but without the line singularity.

Colin J. R. Sheppard; Shan Shan Kou

2010-01-01T23:59:59.000Z

97

A quality assurance framework for the fully automated and objective evaluation of image quality in cone-beam computed tomography  

SciTech Connect (OSTI)

Purpose: Thousands of cone-beam computed tomography (CBCT) scanners for vascular, maxillofacial, neurological, and body imaging are in clinical use today, but there is no consensus on uniform acceptance and constancy testing for image quality (IQ) and dose yet. The authors developed a quality assurance (QA) framework for fully automated and time-efficient performance evaluation of these systems. In addition, the dependence of objective Fourier-based IQ metrics on direction and position in 3D volumes was investigated for CBCT. Methods: The authors designed a dedicated QA phantom 10 cm in length consisting of five compartments, each with a diameter of 10 cm, and an optional extension ring 16 cm in diameter. A homogeneous section of water-equivalent material allows measuring CT value accuracy, image noise and uniformity, and multidimensional global and local noise power spectra (NPS). For the quantitative determination of 3D high-contrast spatial resolution, the modulation transfer function (MTF) of centrally and peripherally positioned aluminum spheres was computed from edge profiles. Additional in-plane and axial resolution patterns were used to assess resolution qualitatively. The characterization of low-contrast detectability as well as CT value linearity and artifact behavior was tested by utilizing sections with soft-tissue-equivalent and metallic inserts. For an automated QA procedure, a phantom detection algorithm was implemented. All tests used in the dedicated QA program were initially verified in simulation studies and experimentally confirmed on a clinical dental CBCT system. Results: The automated IQ evaluation of volume data sets of the dental CBCT system was achieved with the proposed phantom requiring only one scan for the determination of all desired parameters. Typically, less than 5 min were needed for phantom set-up, scanning, and data analysis. Quantitative evaluation of system performance over time by comparison to previous examinations was also verified. The maximum percentage interscan variation of repeated measurements was less than 4% and 1.7% on average for all investigated quality criteria. The NPS-based image noise differed by less than 5% from the conventional standard deviation approach and spatially selective 10% MTF values were well comparable to subjective results obtained with 3D resolution pattern. Determining only transverse spatial resolution and global noise behavior in the central field of measurement turned out to be insufficient. Conclusions: The proposed framework transfers QA routines employed in conventional CT in an advanced version to CBCT for fully automated and time-efficient evaluation of technical equipment. With the modular phantom design, a routine as well as an expert version for assessing IQ is provided. The QA program can be used for arbitrary CT units to evaluate 3D imaging characteristics automatically.

Steiding, Christian; Kolditz, Daniel; Kalender, Willi A., E-mail: willi.kalender@imp.uni-erlangen.de [Institute of Medical Physics, University of Erlangen-Nrnberg, Henkestrae 91, 91052 Erlangen, Germany and CT Imaging GmbH, 91052 Erlangen (Germany)

2014-03-15T23:59:59.000Z

98

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

SciTech Connect (OSTI)

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

99

AFIP-7 Tomography 2013 Status Report  

SciTech Connect (OSTI)

This project seeks to assess the geometric stability of the U-Mo monolithic fuel system by evaluating the radiation-induced changes in the AFIP-7 experiment device. Neutron radiography and computed tomography (CT) provide valuable information about the post-irradiation condition of the fuel specimen. Tomographic reconstructions of the AFIP-7 fuel element will be analyzed to assess the geometric condition of the element after irradiation and provide information regarding the condition of the fuel, including gross geometric defects, bowing, twist, plate buckling, cracks, and other defects. The INL, in collaboration with Oregon State University (OSU), Missouri University of Science and Technology (Missouri S&T), and Real Time Tomography, is developing advanced neutron detector systems and tomographic reconstruction techniques to evaluate the AFIP-7 fuel element. Neutron computed tomography using the current neutron radiography technique available at the Neutron Radiography reactor (NRAD) is impractical due to the long time and high cost to produce a set of images for tomographic reconstruction. Advanced neutron radiography systems such as the micro-channel plate (MCP) detector and neutron computed radiography (CR) may reduce the time and cost of acquiring images for neutron CT.

A.E. Craft; W.J. Williams; M.I.K. Abir; D.M. Wachs

2013-10-01T23:59:59.000Z

100

A COST EFFECTIVE MULTI-SPECTRAL SCANNER FOR NATURAL GAS DETECTION  

SciTech Connect (OSTI)

The objective of this project is to design, fabricate and field demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at En'Urga Inc. The multi-spectral scanner was also evaluated using a blind DoE study at RMOTC. The performance of the scanner was inconsistent during the blind DoE study. However, most of the leaks were outside the view of the multi-spectral scanner. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, a rugged prototype scanner will be developed and evaluated, both at En'Urga Inc. and any potential field sites.

Yudaya Sivathanu; Jongmook Lim; Vinoo Narayanan

2004-10-25T23:59:59.000Z

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.


101

Cone-beam mammo-computed tomography from data along two tilting arcs Hengyong Yu,b  

E-Print Network [OSTI]

Cone-beam mammo-computed tomography from data along two tilting arcs Kai Zeng,a Hengyong Yu . To address this problem, x-ray tomosynthesis and cone-beam computed tomography CT are two compelling from a limited num- ber of projections.4 Since its introduction in 1972, the area of tomosynthesis has

Virginia Tech

102

A Cost Effective Multi-Spectral Scanner for Natural Gas Detection  

SciTech Connect (OSTI)

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

Yudaya Sivathanu; Jongmook Lim; Vinoo Narayanan; Seonghyeon Park

2005-12-07T23:59:59.000Z

103

Patient preferences and acceptable risk for computed tomography in trauma  

Science Journals Connector (OSTI)

AbstractBackground Rising use of computed tomography (CT) to evaluate patients with trauma has increased both patient costs and risk of cancer from ionizing radiation, without demonstrable improvements in outcome. Patient-centred care mandates disclosure of the potential risks, costs and benefits of diagnostic testing whenever possible. Objective We sought to determine (1) patient preferences regarding emergency department (ED) real-time discussions of risks and costs of CT during their trauma evaluations; and (2) whether varying levels of odds of detection of life-threatening injury (LTI) were associated with changes in patient preferences for CT. Methods Excluding patients already receiving CT and patients with altered mental status, we surveyed adult, English-speaking patients at four Level I verified trauma centres. After informing subjects of cancer risks associated with chest CT, we used hypothetical scenarios with varying \\{LTIs\\} to assess patients preferences regarding CT. Results Of 941 patients enrolled, 50% were male and their mean age was 42 years. Most patients stated they would prefer to discuss CT radiation risks (73.5%, 95% CI [66.180.8]) and costs (53.2%, 95% CI [46.160.4]) with physicians. As the odds of detecting LTI decreased, preferences for receiving CT decreased accordingly: LTI 25% (desire 91.2%, 95% CI [89.493.1]), LTI 10% (desire 79.3%, 95% CI [76.781.9]), LTI 5% (desire 69.1%, 95% CI [66.172.1]) and LTI risks and costs of CT prior to receiving imaging. As the odds of detecting LTI decrease, fewer patients prefer to have CT; at an LTI threshold of 2%, approximately half of patients would prefer to forego CT. Adding out-of-pocket costs reduced this proportion to one-third of patients.

Robert M. Rodriguez; Tarann M. Henderson; Anne M. Ritchie; Mark I. Langdorf; Ali S. Raja; Eric Silverman; Joelle Schlang; Bryan Sloane; Clare E. Ronan; Craig L. Anderson; Brigitte M. Baumann

2014-01-01T23:59:59.000Z

104

Diffraction and coherence in breast ultrasound tomography: a study with a toroidal array  

SciTech Connect (OSTI)

Ultrasound is commonly used as an adjunct to mammography for diagnostic evaluation of suspicions arising from breast cancer screening. As an alternative to conventional sonography that uses hand-held transducers, toroidal array probes that encircle the breast immersed in a water bath have been investigated for ultrasound tomography. In this paper, two sets of experiments performed with a prototype ultrasound scanner on a phantom and a human breast in vivo are used to investigate the effects of diffraction and coherence in ultrasound tomography. Reconstructions obtained with transmission diffraction tomography (TDT) are compared with conventional reflection imaging and computerized ultrasound tomography showing a substantial improvement. The in vivo tests demonstrate that TDT can image the complex boundary of a cancer mass and suggest that it can reveal the anatomy of milk ducts and Cooper's ligaments.

Huang, Lianjie [Los Alamos National Laboratory; Simonetti, Francesco [IMPERIAL COLL.; Duric, Neb [KCI; Littrup, Peter [KCI

2008-01-01T23:59:59.000Z

105

A Detector for Proton Computed Tomography  

SciTech Connect (OSTI)

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

Blazey, G.; et al.,

2013-12-06T23:59:59.000Z

106

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

E-Print Network [OSTI]

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

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

2014-08-29T23:59:59.000Z

107

Turbocharging Quantum Tomography.  

SciTech Connect (OSTI)

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

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

2015-01-01T23:59:59.000Z

108

Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development  

SciTech Connect (OSTI)

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

109

CT Solar Loan  

Broader source: Energy.gov [DOE]

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

110

Modulated Luminescent Tomography  

E-Print Network [OSTI]

Two such techniques, X-ray luminescence computed tomography (XLCT), [9] and X-ray micro- ..... Optical-Thermal Response of Laser-Irradiated Tissue.

2014-09-10T23:59:59.000Z

111

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

SciTech Connect (OSTI)

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

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

2010-11-15T23:59:59.000Z

112

Scanner position sensor for an integrated laser/film rangefiner  

SciTech Connect (OSTI)

In an integrated laser/FLIR rangefinder a scanner position sensor comprising an LED of the array of LEDs of a forward looking infrared (FLIR) system, a reticle grating located at the image plane of LED optical path and a silicon detector positioned to receive the light passing through the reticle grating for producing a plurality of signals in response to light passing through each grating slot. One of the signals is selected for the synchronization logic for controlling the charging and firing of the laser. If there is no range return a second signal is selected for adjusting the position of the timing pulse.

Berdanier, B. N.

1985-09-24T23:59:59.000Z

113

Structural Investigation of Methane Hydrate Sediments by Microfocus X-ray Computed Tomography Technique under High-Pressure Conditions  

Science Journals Connector (OSTI)

The structure of natural gas hydrate sediments was observed by microfocus X-ray computed tomography (CT). A newly developed high-pressure vessel for the microfocus X-ray CT system was applied to observe the sediments at a temperature above 273 K and under high-pressure conditions. The obtained two-dimensional CT images clearly showed the spatial distribution of the free-gas pore, sand particles, water, and hydrates. These results demonstrated that microfocus X-ray CT can be effective for studying natural gas hydrate sediment samples.

Shigeki Jin; Jiro Nagao; Satoshi Takeya; Yusuke Jin; Junko Hayashi; Yasushi Kamata; Takao Ebinuma; Hideo Narita

2006-01-01T23:59:59.000Z

114

E-Print Network 3.0 - airborne laser scanner Sample Search Results  

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

Powered by Explorit Topic List Advanced Search Sample search results for: airborne laser scanner Page: << < 1 2 3 4 5 > >> 1 International Conference on Machine Control &...

115

E-Print Network 3.0 - active neutron scanner Sample Search Results  

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

Search Sample search results for: active neutron scanner Page: << < 1 2 3 4 5 > >> 1 The Neutron Scattering Society www.neutronscattering.org Summary: techniques; and service and...

116

Structure Analyses of Artificial Methane Hydrate Sediments by Microfocus X-ray Computed Tomography  

Science Journals Connector (OSTI)

The structure of natural gas hydrate sediments was characterized by microfocus X-ray computed tomography (CT). The obtained two-dimensional (2-D) and three-dimensional (3-D) images clearly showed the spatial distribution of the free-gas spaces, sand particles, and hydrates or ices. The estimated porosity from the X-ray CT data was consistent with the value that was obtained from the sample mass and volume. These results indicate that microfocus X-ray CT can be very useful for researching natural samples of hydrate sediments.

Shigeki Jin; Satoshi Takeya; Junko Hayashi; Jiro Nagao; Yasushi Kamata; Takao Ebinuma; Hideo Narita

2004-01-01T23:59:59.000Z

117

Tomography and reliable information  

Science Journals Connector (OSTI)

Principles of tomography are developed and applied to the problem of two-view interferometry on a tokamak plasma. It is shown that M equispaced views, or projections, of a...

Howard, John

1988-01-01T23:59:59.000Z

118

CT volumetry of the skeletal tissues  

SciTech Connect (OSTI)

Computed tomography (CT) is an important and widely used modality in the diagnosis and treatment of various cancers. In the field of molecular radiotherapy, the use of spongiosa volume (combined tissues of the bone marrow and bone trabeculae) has been suggested as a means to improve the patient-specificity of bone marrow dose estimates. The noninvasive estimation of an organ volume comes with some degree of error or variation from the true organ volume. The present study explores the ability to obtain estimates of spongiosa volume or its surrogate via manual image segmentation. The variation among different segmentation raters was explored and found not to be statistically significant (p value >0.05). Accuracy was assessed by having several raters manually segment a polyvinyl chloride (PVC) pipe with known volumes. Segmentation of the outer region of the PVC pipe resulted in mean percent errors as great as 15% while segmentation of the pipe's inner region resulted in mean percent errors within {approx}5%. Differences between volumes estimated with the high-resolution CT data set (typical of ex vivo skeletal scans) and the low-resolution CT data set (typical of in vivo skeletal scans) were also explored using both patient CT images and a PVC pipe phantom. While a statistically significant difference (p value <0.002) between the high-resolution and low-resolution data sets was observed with excised femoral heads obtained following total hip arthroplasty, the mean difference between high-resolution and low-resolution data sets was found to be only 1.24 and 2.18 cm{sup 3} for spongiosa and cortical bone, respectively. With respect to differences observed with the PVC pipe, the variation between the high-resolution and low-resolution mean percent errors was a high as {approx}20% for the outer region volume estimates and only as high as {approx}6% for the inner region volume estimates. The findings from this study suggest that manual segmentation is a reasonably accurate and reliable means for the in vivo estimation of spongiosa volume. This work also provides a foundation for future studies where spongiosa volumes are estimated by various raters in more comprehensive CT data sets.

Brindle, James M.; Alexandre Trindade, A.; Pichardo, Jose C.; Myers, Scott L.; Shah, Amish P.; Bolch, Wesley E. [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, Florida 32611 (United States); Department of Statistics, University of Florida, Gainesville, Florida 32611 (United States); Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, Florida 32611 (United States); Department of Orthopaedics and Rehabilitation, University of Florida, Gainesville, Florida 32611 (United States); MD Anderson Cancer Center Orlando, Orlando, Florida 32806 (United States); Department of Nuclear and Radiological and Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2006-10-15T23:59:59.000Z

119

Multi-Scale Optical Coherence Tomography Imaging  

E-Print Network [OSTI]

Fourier domain optical coherence tomography and methods forspeed spectral-domain optical coherence tomography at 1.3umJ. G. (1991). Optical coherence tomography. Science, 254(

Oliveira, Michael

2014-01-01T23:59:59.000Z

120

Line-source based X-ray Tomography Deepak Bharkhada1,2  

E-Print Network [OSTI]

resolution is limited by the time necessary to acquire sufficient projection data over an angular range. #12 Science, Wake Forest University, Winston-Salem, NC 27109 Abstract: Current computed tomography (CT reconstruction technique (SART) algorithm for image reconstruction from projection data generated by an x

Plemmons, Robert J.

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

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

122

Impact of the number of registration points for replacement of three-dimensional computed tomography images in dental areas using three-dimensional light-scanned images of dental models  

Science Journals Connector (OSTI)

The aim of this study was to investigate the accuracy and reliability of registration methods for replacing dental areas of three-dimensional (3D) computed tomography (CT) images with 3D light-scanned dental i...

Young-Su Choi; Moon-Key Kim; Jae-Won Lee; Sang-Hoon Kang

2014-01-01T23:59:59.000Z

123

Portable Digital Radiography and Computed Tomography Manual  

SciTech Connect (OSTI)

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

124

Geometric Tomography: A Limited-View Approach for Computed Tomography  

E-Print Network [OSTI]

Geometric Tomography: A Limited-View Approach for Computed Tomography Peter B. Noël, Jinhui Xu Keywords Computed Tomography; Geometric Compressed Sensing; Topo- logical Peeling. ABSTRACT Computed to generate 3D data, denoted f, directly from projec- tions, denoted g. Thus, the projection relationship can

Corso, Jason J.

125

X-ray Computed Tomography of coal: Final report  

SciTech Connect (OSTI)

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

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

1986-12-01T23:59:59.000Z

126

Evaluation of the robustness of the preprocessing technique improving reversible compressibility of CT images: Tested on various CT examinations  

SciTech Connect (OSTI)

Purpose: To modify the preprocessing technique, which was previously proposed, improving compressibility of computed tomography (CT) images to cover the diversity of three dimensional configurations of different body parts and to evaluate the robustness of the technique in terms of segmentation correctness and increase in reversible compression ratio (CR) for various CT examinations.Methods: This study had institutional review board approval with waiver of informed patient consent. A preprocessing technique was previously proposed to improve the compressibility of CT images by replacing pixel values outside the body region with a constant value resulting in maximizing data redundancy. Since the technique was developed aiming at only chest CT images, the authors modified the segmentation method to cover the diversity of three dimensional configurations of different body parts. The modified version was evaluated as follows. In randomly selected 368 CT examinations (352 787 images), each image was preprocessed by using the modified preprocessing technique. Radiologists visually confirmed whether the segmented region covers the body region or not. The images with and without the preprocessing were reversibly compressed using Joint Photographic Experts Group (JPEG), JPEG2000 two-dimensional (2D), and JPEG2000 three-dimensional (3D) compressions. The percentage increase in CR per examination (CR{sub I}) was measured.Results: The rate of correct segmentation was 100.0% (95% CI: 99.9%, 100.0%) for all the examinations. The median of CR{sub I} were 26.1% (95% CI: 24.9%, 27.1%), 40.2% (38.5%, 41.1%), and 34.5% (32.7%, 36.2%) in JPEG, JPEG2000 2D, and JPEG2000 3D, respectively.Conclusions: In various CT examinations, the modified preprocessing technique can increase in the CR by 25% or more without concerning about degradation of diagnostic information.

Jeon, Chang Ho; Kim, Bohyoung; Gu, Bon Seung; Lee, Jong Min [Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707 (Korea, Republic of)] [Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707 (Korea, Republic of); Kim, Kil Joong [Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea and Department of Radiation Applied Life Science, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 110-799 (Korea, Republic of)] [Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea and Department of Radiation Applied Life Science, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul 110-799 (Korea, Republic of); Lee, Kyoung Ho [Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea and Institute of Radiation Medicine, Seoul National University Medical Research Center, and Clinical Research Institute, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744 (Korea, Republic of)] [Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707, South Korea and Institute of Radiation Medicine, Seoul National University Medical Research Center, and Clinical Research Institute, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744 (Korea, Republic of); Kim, Tae Ki [Medical Information Center, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707 (Korea, Republic of)] [Medical Information Center, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 300 Gumi-ro, Bundang-gu, Seongnam-si, Gyeonggi-do 463-707 (Korea, Republic of)

2013-10-15T23:59:59.000Z

127

Computed tomography of the thorax: a status report  

SciTech Connect (OSTI)

Computed tomography (CT) of the thorax shows early promise of important diagnostic advances. We believe that CT often provides information superior to that provided by standard roentgenographic techniques, is capable of significantly influencing patient management, and in selected instances, offers unique information not available by other methods. Computed tomography permits the imaging of mediastinal structures not possible with conventional roentgenographic methods and can diagnose with certainty benign mediastinal conditions such as pericardial cysts and focal or diffuse accumulations of fat. It is ideal for detecting pleural abnormalities and for displaying underlying parenchymal disease in patients with complex pleuroparenchymal shadows on conventional films. Pulmonary metastases unseen on the plain chest film can be detected with greater sensitivity than by any other method. Future applications of CT include the staging of mediastinal lymph nodes in bronchogenic carcinoma, the differentiation of benign from malignant solitary pulmonary nodules, and the detection of diffuse diseases involving the lung parenchyma before they are visible on conventional roentgenograms. Additional clinical experience and careful studies will determine CTs final role as a diagnostic aid for disorders of the thorax.

Pugatch, R.D.; Faling, L.J.

1981-11-01T23:59:59.000Z

128

Note: Design and development of an integrated three-dimensional scanner for atomic force microscopy  

SciTech Connect (OSTI)

A compact scanning head for the Atomic Force Microscope (AFM) greatly enhances the portability of AFM and facilitates easy integration with other tools. This paper reports the design and development of a three-dimensional (3D) scanner integrated into an AFM micro-probe. The scanner is realized by means of a novel design for the AFM probe along with a magnetic actuation system. The integrated scanner, the actuation system, and their associated mechanical mounts are fabricated and evaluated. The experimentally calibrated actuation ranges are shown to be over 1 ?m along all the three axes.

Rashmi, T.; Dharsana, G.; Sriramshankar, R.; Sri Muthu Mrinalini, R.; Jayanth, G. R. [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012 (India)] [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012 (India)

2013-11-15T23:59:59.000Z

129

Waste inspection tomography (WIT)  

SciTech Connect (OSTI)

The WIT program will provide an inspection system that offers the nuclear waste evaluator a unique combination of tools for regulatory-driven characterization of low-level waste (LLW), transuranic waste (TRU), and mixed waste drums. WIT provides nondestructive, noninvasive, and environmentally safe inspections using X-ray and gamma ray technologies, with reasonable cost and throughput. Two emission imaging techniques will be employed for characterizing materials in waste containers. The first of these is gamma emission tomography, commonly called single-photon emission computed tomography (SPECT). Rather than using an external radiation source, SPECT uses the emission of radioactive materials within the object of interest for imaging. In this case, emission from actual nuclear waste within a container will provide a three-dimensional image of the radioactive substances in the container. The second emission technique will use high-purity germanium detectors for gamma ray spectroscopy. This technique, called nondestructive assay (NDA), can identify the emitting isotopic species and strength. Work in emission tomography and assay of nuclear waste has been undertaken at Lawrence Livermore National Laboratory using a technique called Passive Tomography. Results from a process development unit are presented.

Bernardi, R.T.; Han, K.S.

1994-12-31T23:59:59.000Z

130

Model-based image reconstruction for dual-energy X-ray CT with fast KVP switching  

Science Journals Connector (OSTI)

The most recent generation of X-ray CT systems can collect dual energy (DE) sinograms by rapidly switching the X-ray tube voltage between two levels for alternate projection views. This reduces motion artifacts in DE imaging, but yields sinograms that ... Keywords: dualenergy X-ray computed tomography, model-based image reconstruction, penalized likelihood

Wonseok Huh; Jeffrey A. Fessler

2009-06-01T23:59:59.000Z

131

Multi-GPU parallelization of a 3D Bayesian CT algorithm and its application on real foam reconstruction with incomplete  

E-Print Network [OSTI]

Tomography (CT) [1,2]. The limits of these methods appear when the number of projections is small, and for example, the data set are not complete due to the limited acquistion time. In this specific context is the computation time and especially for projection and backprojection steps. In this study, first we show how we

Paris-Sud XI, Université de

132

E-Print Network 3.0 - assisted laser scanner Sample Search Results  

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

Powered by Explorit Topic List Advanced Search Sample search results for: assisted laser scanner Page: << < 1 2 3 4 5 > >> 1 Accuracy of 3D Scanning Technologies in a Face...

133

Trough-Focus OTF Based Optical Quality Testing of Whole Slide Scanners for Digital Pathology  

Science Journals Connector (OSTI)

We measure the through-focus OTF of whole slide scanners for optical quality testing and monitoring. Analysis of the OTF data gives a system level evaluation of astigmatism, field...

Shakeri, Mojtaba; Hulsken, Bas; van Vliet, Lucas; Stallinga, Sjoerd

134

Fast geometric transformation of scanner images for the operative tracking of surface currents in the ocean  

Science Journals Connector (OSTI)

A method for the fast transformation of initial images into preset map projections is suggested bases on the analysis of the NOAA satellite scanner images transmitted in the APT regime. The objective was to attai...

I. A. Goncharenko; V. A. Federyakov

1991-01-01T23:59:59.000Z

135

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

E-Print Network [OSTI]

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

Southern California, University of

136

Nary coded structured light-based range scanners using color invariants  

Science Journals Connector (OSTI)

We provide the images of the first set of our test objects in Fig.7.... These are: matte and shiny Atatrk, shiny teapot, shiny concave fish, shiny carafe, shiny...point clouds for each scanner separately next. ...

R?fat Benveniste; Cem nsalan

2014-06-01T23:59:59.000Z

137

Examination of viscous fingering using the Cat-Scanner  

E-Print Network [OSTI]

. 0052 0. 0050 a O e e 0. 0048 A 0. 0046 0. 0044 deviation 0. 0042 1 3 5 7 9 11 Scan number FIGURE 8- SCAN NUMBER VERSUS DEVIATION (TRIAL- I ) 34 0. 004 0. 002 I o. ooo -0. 002 I %. 004 CT-Avg -0. 006 1 5 7 Scan number 9 11... 0. 0048 0. 0046 DEVIATION 0. 0044 1 21 Scan Number 31 FIGURE 11-SCAN NUMBER VERSUS DEVIATION (TRIAL-2) 37 approximately constant value, From this study, it was concluded that a certain amount of time was necessary for the Cat...

D'Souza, Michael Anthony

2012-06-07T23:59:59.000Z

138

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

SciTech Connect (OSTI)

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

139

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

Science Journals Connector (OSTI)

Figure 7 Flow system used with GE X-ray CT scanner:? from left, air?water column, water pump, and cart containing flow meters. ... In Figure 24, the results of experimental holdup measurements on the column used for imaging are compared with SRP data from the hydraulic testing of Mellapak 250Y. ... The two-fluid model proved powerful in the prediction of the column hydraulics under various operational conditions such as atm. ...

Christian W. Green; John Farone; Julie K. Briley; R. Bruce Eldridge; Richard A. Ketcham; Ben Nightingale

2007-07-24T23:59:59.000Z

140

Evaluation of Biomaterials Using Micro-Computerized Tomography  

SciTech Connect (OSTI)

Micro-computed tomography or Micro-CT is a high resolution, non-invasive, x-ray scanning technique that allows precise three-dimensional imaging and quantification of micro-architectural and structural parameters of objects. Tomographic reconstruction is based on a cone-beam convolution-back-projection algorithm. Micro-architectural and structural parameters such as porosity, surface area to volume ratio, interconnectivity, pore size, wall thickness, anisotropy and cross-section area of biomaterials and bio-specimens such as trabecular bone, polymer scaffold, bio-ceramics and dental restorative were evaluated through imaging and computer aided manipulation of the object scan data sets.

Torris, A. T. Arun; Columbus, K. C. Soumya; Saaj, U. S.; Krishnan, Kalliyana V. [Dental Products Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala-695012 (India); Nair, Manitha B. [Transmission Electron Microscopy Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala-695012 (India)

2008-09-26T23:59:59.000Z

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

Neutron computed tomography  

E-Print Network [OSTI]

to make the Donner Algorithms run. TABLE OF CONTEliiTS CHAPTF. . R I NEI. TRON RADIOGRAPHY . I. 1 Background . I. 2 Theory . l. 3 Neutron Beam Characterization I. 4 Image Detectors . COMPI'TED TOMOGRAPHY . Il I Background . II. 2 Notation II. 3... data which is generated by rays traveling (and being attenuated) in straight lines. However in neutron radiography, what is measured is, to most extents, the levels of neutrons which are not attenuated. Neutrons are particles. They scatter...

Russell, Clifford Marlow

2012-06-07T23:59:59.000Z

142

Link between Tomography and Copula1 Doriano-Boris Pougaza, Ali Mohammad-Djafari, Jean-Francois Bercher2  

E-Print Network [OSTI]

in Computed To- mography (CT) is to reconstruct an image from its projections. In the bivariate case of Environmental Data [2, 3]. Recently, in17 Computational Biology, copulas were used for the reconstructionLink between Tomography and Copula1 Doriano-Boris Pougaza, Ali Mohammad-Djafari, Jean

Bercher, Jean-François

143

Enhanced local tomography  

DOE Patents [OSTI]

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

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

1996-01-01T23:59:59.000Z

144

Generalized local emission tomography  

DOE Patents [OSTI]

Emission tomography enables locations and values of internal isotope density distributions to be determined from radiation emitted from the whole object. In the method for locating the values of discontinuities, the intensities of radiation emitted from either the whole object or a region of the object containing the discontinuities are inputted to a local tomography function .function..sub..LAMBDA..sup.(.PHI.) to define the location S of the isotope density discontinuity. The asymptotic behavior of .function..sub..LAMBDA..sup.(.PHI.) is determined in a neighborhood of S, and the value for the discontinuity is estimated from the asymptotic behavior of .function..sub..LAMBDA..sup.(.PHI.) knowing pointwise values of the attenuation coefficient within the object. In the method for determining the location of the discontinuity, the intensities of radiation emitted from an object are inputted to a local tomography function .function..sub..LAMBDA..sup.(.PHI.) to define the location S of the density discontinuity and the location .GAMMA. of the attenuation coefficient discontinuity. Pointwise values of the attenuation coefficient within the object need not be known in this case.

Katsevich, Alexander J. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

145

Compact cold stage for micro-computerized tomography imaging of chilled or frozen samples  

SciTech Connect (OSTI)

High resolution X-ray microCT (computerized tomography) can be used to image a variety of objects, including temperature-sensitive materials. In cases where the sample must be chilled or frozen to maintain sample integrity, either the microCT machine itself must be placed in a refrigerated chamber, or a relatively expensive commercial cold stage must be purchased. We describe here the design and construction of a low-cost custom cold stage suitable for use in a microCT imaging system. Our device uses a boron nitride sample holder, two-stage Peltier cooler, fan-cooled heat sink, and electronic controller to maintain sample temperatures as low as ?25?C 0.2?C for the duration of a tomography acquisition. The design does not require modification to the microCT machine, and is easily installed and removed. Our custom cold stage represents a cost-effective solution for refrigerating CT samples for imaging, and is especially useful for shared equipment or machines unsuitable for cold room use.

Hullar, Ted; Anastasio, Cort, E-mail: canastasio@ucdavis.edu [Department of Land, Air, and Water Resources, University of California, Davis, California 95616 (United States)] [Department of Land, Air, and Water Resources, University of California, Davis, California 95616 (United States); Paige, David F. [Paige Instruments, Woodland, California 95776 (United States)] [Paige Instruments, Woodland, California 95776 (United States); Rowland, Douglas J. [Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California, Davis, California 95616 (United States)] [Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California, Davis, California 95616 (United States)

2014-04-15T23:59:59.000Z

146

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

SciTech Connect (OSTI)

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

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

2014-05-15T23:59:59.000Z

147

Effective dose estimation during conventional and CT urography  

Science Journals Connector (OSTI)

Abstract Intravenous urography (IVU) and CT urography (CTU) are efficient radiological examinations for the evaluation of the urinary system disorders. However patients are exposed to a significant radiation dose. The objectives of this study are to: (i) measure and compare patient radiation dose by computed tomography urography (CTU) and conventional intravenous urography (IVU) and (ii) evaluate organ equivalent dose and cancer risks from CTU and IVU imaging procedures. A total of 141 patients were investigated. A calibrated CT machine (Siemens-Somatom Emotion duo) was used for CTU, while a Shimadzu X ray machine was used for IVU. Thermoluminescence dosimeters (TLD-GR200A) were used to measure patients' entrance surface doses (ESD). \\{TLDs\\} were calibrated under reproducible reference conditions. Patients radiation dose values (DLP) for CTU were 17261mGycm, \\{CTDIvol\\} 4.752mGy and effective dose 2.581mSv. Patient cancer probabilities were estimated to be 1.4 per million per CTU examination. Patients \\{ESDs\\} values for IVU were 21.625mGy, effective dose 1.791mSv. CT involves a higher effective dose than IVU. In this study the radiation dose is considered low compared to previous studies. The effective dose from CTU procedures was 30% higher compared to IVU procedures. Wide dose variation between patient doses suggests that optimization is not fulfilled yet.

K. Alzimami; A. Sulieman; E. Omer; I.I. Suliman; K. Alsafi

2014-01-01T23:59:59.000Z

148

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-

149

Preventive maintenance system for the photomultiplier detector blocks of pet scanners  

DOE Patents [OSTI]

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

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

1995-01-24T23:59:59.000Z

150

Preventive maintenance system for the photomultiplier detector blocks of PET scanners  

DOE Patents [OSTI]

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

Levy, A.V.; Warner, D.

1995-01-24T23:59:59.000Z

151

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

152

Radial reflection diffraction tomography  

DOE Patents [OSTI]

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

Lehman, Sean K.

2012-12-18T23:59:59.000Z

153

High energy neutron Computed Tomography developed  

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

objects. May 9, 2014 Neutron tomography horizontal "slice" of a tungsten and polyethylene test object containing tungsten carbide BBs. Neutron tomography horizontal "slice"...

154

Prior-based artifact correction (PBAC) in computed tomography  

SciTech Connect (OSTI)

Purpose: Image quality in computed tomography (CT) often suffers from artifacts which may reduce the diagnostic value of the image. In many cases, these artifacts result from missing or corrupt regions in the projection data, e.g., in the case of metal, truncation, and limited angle artifacts. The authors propose a generalized correction method for different kinds of artifacts resulting from missing or corrupt data by making use of available prior knowledge to perform data completion. Methods: The proposed prior-based artifact correction (PBAC) method requires prior knowledge in form of a planning CT of the same patient or in form of a CT scan of a different patient showing the same body region. In both cases, the prior image is registered to the patient image using a deformable transformation. The registered prior is forward projected and data completion of the patient projections is performed using smooth sinogram inpainting. The obtained projection data are used to reconstruct the corrected image. Results: The authors investigate metal and truncation artifacts in patient data sets acquired with a clinical CT and limited angle artifacts in an anthropomorphic head phantom data set acquired with a gantry-based flat detector CT device. In all cases, the corrected images obtained by PBAC are nearly artifact-free. Compared to conventional correction methods, PBAC achieves better artifact suppression while preserving the patient-specific anatomy at the same time. Further, the authors show that prominent anatomical details in the prior image seem to have only minor impact on the correction result. Conclusions: The results show that PBAC has the potential to effectively correct for metal, truncation, and limited angle artifacts if adequate prior data are available. Since the proposed method makes use of a generalized algorithm, PBAC may also be applicable to other artifacts resulting from missing or corrupt data.

Heuer, Thorsten, E-mail: thorsten.heusser@dkfz-heidelberg.de; Brehm, Marcus [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)] [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Ritschl, Ludwig [Ziehm Imaging GmbH, Donaustrae 31, 90451 Nrnberg (Germany)] [Ziehm Imaging GmbH, Donaustrae 31, 90451 Nrnberg (Germany); Sawall, Stefan; Kachelrie, Marc [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Institute of Medical Physics, FriedrichAlexanderUniversity (FAU) of ErlangenNrnberg, Henkestrae 91, 91052 Erlangen (Germany)] [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Institute of Medical Physics, FriedrichAlexanderUniversity (FAU) of ErlangenNrnberg, Henkestrae 91, 91052 Erlangen (Germany)

2014-02-15T23:59:59.000Z

155

Electrical Impedance Tomography Liliana Borcea  

E-Print Network [OSTI]

Electrical Impedance Tomography Liliana Borcea #3; September 3, 2002 Abstract We review theoretical and numerical studies of the inverse problem of electrical impedance tomography which seeks the electrical conductivity and permittivity inside a body, given simul- taneous measurements of electrical currents

Borcea, Liliana

156

Computed tomography on small explosive parts  

SciTech Connect (OSTI)

We have investigated three small explosive parts for the Pantex Plant in Amarillo, Texas using computed tomography (CT). A medium resolution, fan beam system was used to test imaging capabilities for small holes drilled into one of the parts, and to identify any inhomogeneities, cracks, voids, and inclusions if present in the other two parts. This system provides volumetric imaging. Its information is qualitative in that is allows us to see interior features but it cannot provide quantitative attenuation data. A second part of the investigation was to perform effective atomic number computed tomography on the parts using energy dispersive spectroscopy methods. We wanted to experimentally identify the {open_quotes}average{close_quotes} chemical composition of the materials in the explosive and its shell and to detect any possible inhomogeneities in composition. A single beam, nuclear spectroscopy based system was used for this work. The radiation source was a silver anode x-ray tube. By measuring x-ray attenuation at specific energies (characteristic lines and narrow bands of continuum) we are able to quantitatively determine linear attenuation coefficients. By using ratios of such measurements, density cancels out and we effectively have ratios of mass attenuation coefficients. Through a look-up scheme of mass attenuation coefficients for different elements, we can determine the weighted average chemical composition, as averaged by x-ray attenuation. We call this averaged composition the effective atomic number ({open_quotes}Z{sub eff}{close_quotes}). We thereby obtain cross sectional images of a parameter related to the averaged chemistry of the object. Such images and the underlying data can reveal, for instance, segregation of explosive and binder.

Ryon, R.W.

1994-05-01T23:59:59.000Z

157

Improved fluorescence-enhanced optical imaging and tomography by enhanced excitation light rejection  

E-Print Network [OSTI]

) .................................................................88 xvi NOMENCLATURE Abbreviations 2-D Two-dimension 3-D Three-dimension ACR Amplitude ratio AOI Angle of incidence CCD Charge coupled device CT Computed tomography CW... molecular markers of disease at pico-molar to nano-molar concentrations. Light in the UV-visible range does not enable deep 7 penetration for fluorescence imaging mainly because of autofluorescence and a high level of endogenous absorbers...

Hwang, Kil Dong

2009-05-15T23:59:59.000Z

158

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...

159

3D objects visualization for remote interactive medical applications Johan Montagnat, Eduardo Davila, Isabelle E. Magnin  

E-Print Network [OSTI]

], such as Computed Tomography scanners (CT), Magnetic Resonance Imagers (MRI), Positon Emission To- mography scannersGrid project (EDG)1 although it is not limited to this architecture and it intends to provide a generic produced in health centers represent tremendous amounts of data spread over different places. Automatic

Paris-Sud XI, Université de

160

DOE - Office of Legacy Management -- Torrington Co - CT 09  

Office of Legacy Management (LM)

Alternate Name: Torrington Co. - Specialties Division CT.09-1 Location: Torrington , Connecticut CT.09-1 Evaluation Year: 1987 CT.09-1 Site Operations: Performed swaging...

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.


161

COMPARISON OF DSMS GENERATED FROM MINI UAV IMAGERY AND TERRESTRIAL LASER SCANNER IN A CULTURAL HERITAGE APPLICATION  

E-Print Network [OSTI]

COMPARISON OF DSMS GENERATED FROM MINI UAV IMAGERY AND TERRESTRIAL LASER SCANNER IN A CULTURAL was recorded using a terrestrial laser scanner (Riegl LMS-Z420i) and a mini UAV-system (Unmanned Aerial Vehicle targets was used. As a product of the laser data a regular raster grid with point spacing of 5 cm

162

Estimates of the image quality and the radiation dose for head and abdomen phantom image acquisition by using dual-energy CT  

Science Journals Connector (OSTI)

Using dual-energy computed tomography (CT) scans, we obtained ... data set by using low- and high-energy scans (usually 80 and 140 kV, ... and the abdomen examinations were performed using single-energy (120 kV) ...

Dae-Hong Kim; Hee-Joung Kim; Chang-Lae Lee

2012-04-01T23:59:59.000Z

163

High resolution cortical thickness measurement from clinical CT data G.M. Treece, A.H. Gee, P.M. Mayhew and K.E.S. Poole  

E-Print Network [OSTI]

) methods of assessing hip structure, most notably with multi-detector computed tomography, MDCT (Bouxsein and technically limited by thresholding errors caused by relatively low resolution data sets. Ideally, we wouldHigh resolution cortical thickness measurement from clinical CT data G.M. Treece, A.H. Gee, P

Drummond, Tom

164

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

SciTech Connect (OSTI)

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

165

Adaptive mean filtering for noise reduction in CT polymer gel dosimetry  

SciTech Connect (OSTI)

X-ray computed tomography (CT) as a method of extracting 3D dose information from irradiated polymer gel dosimeters is showing potential as a practical means to implement gel dosimetry in a radiation therapy clinic. However, the response of CT contrast to dose is weak and noise reduction is critical in order to achieve adequate dose resolutions with this method. Phantom design and CT imaging technique have both been shown to decrease image noise. In addition, image postprocessing using noise reduction filtering techniques have been proposed. This work evaluates in detail the use of the adaptive mean filter for reducing noise in CT gel dosimetry. Filter performance is systematically tested using both synthetic patterns mimicking a range of clinical dose distribution features as well as actual clinical dose distributions. Both low and high signal-to-noise ratio (SNR) situations are examined. For all cases, the effects of filter kernel size and the number of iterations are investigated. Results indicate that adaptive mean filtering is a highly effective tool for noise reduction CT gel dosimetry. The optimum filtering strategy depends on characteristics of the dose distributions and image noise level. For low noise images (SNR {approx}20), the filtered results are excellent and use of adaptive mean filtering is recommended as a standard processing tool. For high noise images (SNR {approx}5) adaptive mean filtering can also produce excellent results, but filtering must be approached with more caution as spatial and dose distortions of the original dose distribution can occur.

Hilts, Michelle; Jirasek, Andrew [Medical Physics, BC Cancer Agency-Vancouver Island Centre, Victoria, British Columbia, V8R6V5 (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, V8W2Y2 (Canada)

2008-01-15T23:59:59.000Z

166

Directions to scanner McCausland Center, Palmetto Health Richland Memorial Hospital  

E-Print Network [OSTI]

Directions to scanner McCausland Center, Palmetto Health Richland Memorial Hospital 6 Medical Park light) � Go through next light (Pedestrian crossing light) � Take next right into Heart Hospital and Outpatient surgery lot. Do not park in assigned doctor spaces. � Enter building on Heart Hospital Side (Left

Almor, Amit

167

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

SciTech Connect (OSTI)

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

Maloney, D.; Doggett, K.

1997-08-01T23:59:59.000Z

168

SEABED: Small molEcule activity scanner weB servicE baseD  

Science Journals Connector (OSTI)

......SEABED: Small molEcule activity scanner weB servicE baseD Carlos Fenollosa 1 2 Marcel...Alfonso Valencia Motivation: The SEABED web server integrates a variety of docking and...SEABED goes beyond the basic docking and QSAR web tools and implements extended functionalities......

Carlos Fenollosa; Marcel Otn; Pau Andrio; Jorge Corts; Modesto Orozco; J. Ramon Goi

2014-11-01T23:59:59.000Z

169

Ris DTU Dec.3 2009WindScanner.eu 1 Ris DTU, Technical University of Denmark  

E-Print Network [OSTI]

engulfing today's and tomorrows huge on and offshore wind turbines. - a brig less RI for renewable energy IWES (onshore sites, Alpha Ventus ­ FINO 1- 3 offshore) · Norway: SINTEF (offshore technology, floatingScanner.eu Envisioned new RI European Centre for Wind Energy Research in Atmospheric Turbulent Flow "The Wind

170

EXTENSION OF AN AUTOMATIC BUILDING EXTRACTION TECHNIQUE TO AIRBORNE LASER SCANNER DATA CONTAINING DAMAGED BUILDINGS  

E-Print Network [OSTI]

EXTENSION OF AN AUTOMATIC BUILDING EXTRACTION TECHNIQUE TO AIRBORNE LASER SCANNER DATA CONTAINING DAMAGED BUILDINGS F. Tarsha-Kurdi a , M. Rehor b , T. Landes a , P. Grussenmeyer a , H.-P. Bähr b-peter.baehr)@ipf.uni-karlsruhe.de KEY WORDS: Laser scanning, LIDAR, Point Cloud, DSM, Segmentation, Extraction, Building, Disaster

Paris-Sud XI, Université de

171

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

SciTech Connect (OSTI)

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

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

2012-11-01T23:59:59.000Z

172

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

SciTech Connect (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

173

Teleseismic transmission and reflection tomography  

E-Print Network [OSTI]

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

Burdick, Scott A. (Scott Anthony)

2014-01-01T23:59:59.000Z

174

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":""}]}

175

Drift-insensitive distributed calibration of probe microscope scanner in nanometer range: Real mode  

E-Print Network [OSTI]

A method is described intended for distributed calibration of a probe microscope scanner consisting in a search for a net of local calibration coefficients (LCCs) in the process of automatic measurement of a standard surface, whereby each point of the movement space of the scanner can be defined by a unique set of scale factors. Feature-oriented scanning (FOS) methodology is used to implement the distributed calibration, which permits to exclude in situ the negative influence of thermal drift, creep and hysteresis on the obtained results. The sensitivity of LCCs to errors in determination of position coordinates of surface features forming the local calibration structure (LCS) is eliminated by performing multiple repeated measurements followed by building regression surfaces. There are no principle restrictions on the number of repeated LCS measurements. Possessing the calibration database enables correcting in one procedure all the spatial distortions caused by nonlinearity, nonorthogonality and spurious cro...

Lapshin, Rostislav V

2015-01-01T23:59:59.000Z

176

Drift-insensitive distributed calibration of probe microscope scanner in nanometer range: Approach description  

E-Print Network [OSTI]

A method is described intended for distributed calibration of a probe microscope scanner consisting in a search for a net of local calibration coefficients (LCCs) in the process of automatic measurement of a standard surface, whereby each point of the movement space of the scanner can be defined by a unique set of scale factors. Feature-oriented scanning (FOS) methodology is used to implement the distributed calibration, which permits to exclude in situ the negative influence of thermal drift, creep and hysteresis on the obtained results. The sensitivity of LCCs to errors in determination of position coordinates of surface features forming the local calibration structure (LCS) is eliminated by performing multiple repeated measurements followed by building regression surfaces. There are no principle restrictions on the number of repeated LCS measurements. Possessing the calibration database enables correcting in one procedure all the spatial distortions caused by nonlinearity, nonorthogonality and spurious cro...

Lapshin, Rostislav V

2015-01-01T23:59:59.000Z

177

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

SciTech Connect (OSTI)

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

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

2013-12-15T23:59:59.000Z

178

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

E-Print Network [OSTI]

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

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

2013-05-23T23:59:59.000Z

179

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

180

TE Connectivity Finds Answers in Tomography  

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

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...

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.


181

MRI- Versus CT-Based Volume Delineation of Lumpectomy Cavity in Supine Position in Breast-Conserving Therapy: An Exploratory Study  

SciTech Connect (OSTI)

Purpose: To examine magnetic resonance imaging (MRI) and computed tomography (CT) for lumpectomy cavity (LC) volume delineation in supine radiotherapy treatment position and to assess the interobserver variability. Methods and Materials: A total of 15 breast cancer patients underwent a planning CT and directly afterward MRI in supine radiotherapy treatment position. Then, 4 observers (2 radiation oncologists and 2 radiologists) delineated the LC on the CT and MRI scans and assessed the cavity visualization score (CVS). The CVS, LC volume, conformity index (CI), mean shift of the center of mass (COM), with the standard deviation, were quantified for both CT and MRI. Results: The CVS showed that MRI and CT provide about equal optimal visibility of the LC. If the CVS was high, magnetic resonance imaging provided more detail of the interfaces of the LC seroma with the unaffected GBT. MRI also pictured in more detail the interfaces of axillary seromas (if present) with their surroundings and their relationship to the LC. Three observers delineated smaller, and one observer larger, LC volumes comparing the MRI- and CT-derived delineations. The mean {+-} standard deviation CI was 32% {+-} 25% for MRI and 52% {+-} 21% for CT. The mean {+-} standard deviation COM shift was 11 {+-} 10 mm (range 1-36) for MRI and 4 {+-} 3 mm (range 1-10) for CT. Conclusions: MRI does not add additional information to CT in cases in which the CVS is assessed as low. The conformity (CI) is lower for MRI than for CT, especially at a low CVS owing to greater COM shifts for MRI, probably caused by inadequate visibility of the surgical clips on magnetic resonance (MR) images. The COM shifts seriously dictate a decline in the CI more than the variability of the LC volumes does. In cases in which MRI provides additional information, MRI must be combined with the CT/surgical clip data.

Giezen, Marina, E-mail: marinagiezen@zonnet.nl [Radiotherapy Center West, Medical Center Haaglanden, The Hague (Netherlands); Kouwenhoven, Erik [Radiotherapy Center West, Medical Center Haaglanden, The Hague (Netherlands); Scholten, Astrid N. [Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands); Coerkamp, Emile G.; Heijenbrok, Mark [Department of Radiology, Medical Center Haaglanden, The Hague (Netherlands); Jansen, Wim P.A. [Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands); Mast, Mirjam E.; Petoukhova, Anna L. [Radiotherapy Center West, Medical Center Haaglanden, The Hague (Netherlands); Struikmans, Henk [Radiotherapy Center West, Medical Center Haaglanden, The Hague (Netherlands); Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands)

2012-03-15T23:59:59.000Z

182

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

Science Journals Connector (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 it is difficult to learn quickly how to run a modeling code set the parameters properly and be able to detect possible errors in the input. In addition complex modeling requires high power computing resources which are not always easily accessible the user. To address these problems we developed a multi?tier Web?based log modeling environment where the Sonic Scanner simulator is easily accessible from the common Web browser. The user builds the model in an intuitive AJAX?like interface and submits the simulation to a remote High Performance Cluster. The computed waveforms are played back in the browser using Scalable Vector Graphics in a variety of customizable displays. The Web application is easily available to any user with an Internet access. In addition a programmatically accessible Web service is available to application developers who desire to build their own interpretation applications using the Sonic Scanner simulator engine.

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

2008-01-01T23:59:59.000Z

183

Self-Guided Quantum Tomography  

Science Journals Connector (OSTI)

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

Christopher Ferrie

2014-11-07T23:59:59.000Z

184

Resolution enhancement of lung 4D-CT data using multiscale interphase iterative nonlocal means  

SciTech Connect (OSTI)

Purpose: Four-dimensional computer tomography (4D-CT) has been widely used in lung cancer radiotherapy due to its capability in providing important tumor motion information. However, the prolonged scanning duration required by 4D-CT causes considerable increase in radiation dose. To minimize the radiation-related health risk, radiation dose is often reduced at the expense of interslice spatial resolution. However, inadequate resolution in 4D-CT causes artifacts and increases uncertainty in tumor localization, which eventually results in extra damages of healthy tissues during radiotherapy. In this paper, the authors propose a novel postprocessing algorithm to enhance the resolution of lung 4D-CT data. Methods: The authors' premise is that anatomical information missing in one phase can be recovered from the complementary information embedded in other phases. The authors employ a patch-based mechanism to propagate information across phases for the reconstruction of intermediate slices in the longitudinal direction, where resolution is normally the lowest. Specifically, the structurally matching and spatially nearby patches are combined for reconstruction of each patch. For greater sensitivity to anatomical details, the authors employ a quad-tree technique to adaptively partition the image for more fine-grained refinement. The authors further devise an iterative strategy for significant enhancement of anatomical details. Results: The authors evaluated their algorithm using a publicly available lung data that consist of 10 4D-CT cases. The authors' algorithm gives very promising results with significantly enhanced image structures and much less artifacts. Quantitative analysis shows that the authors' algorithm increases peak signal-to-noise ratio by 3-4 dB and the structural similarity index by 3%-5% when compared with the standard interpolation-based algorithms. Conclusions: The authors have developed a new algorithm to improve the resolution of 4D-CT. It outperforms the conventional interpolation-based approaches by producing images with the markedly improved structural clarity and greatly reduced artifacts.

Zhang Yu [School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China and Department of Radiology and BRIC, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Yap, Pew-Thian; Wu Guorong [Department of Radiology and BRIC, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Feng Qianjin; Chen Wufan [School of Biomedical Engineering, Southern Medical University, Guangzhou 510515 (China); Lian Jun [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Shen Dinggang [Department of Radiology and BRIC, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Brain and Cognitive Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

2013-05-15T23:59:59.000Z

185

Cost-Effectiveness of CT Screening in the National Lung Screening Trial  

Science Journals Connector (OSTI)

Lung cancer is the leading cause of cancer-related deaths in the United States; however, until recently, no method of screening had been shown to reduce mortality from lung cancer. The National Lung Screening Trial (NLST) showed that screening with low-dose helical computed tomography (CT) of the... The screening of persons at risk for lung cancer may reduce lung-cancer mortality by 20%. Although cost-effectiveness estimates vary widely depending on assumptions, a careful analysis indicates that the cost is $81,000 per quality-adjusted life-year.

Black W.C.; Gareen I.F.; Soneji S.S.

2014-11-06T23:59:59.000Z

186

Discrete Tomography: A Neural Network Approach  

E-Print Network [OSTI]

Abstract Tomography tries to reconstruct an object from a number of projections in multiple directions quality reconstructions from a limited set of projections, while avoiding image artifacts that are often present in traditional approaches. 1 Introduction Tomography, or more especially computed tomography

Kosters, Walter

187

First pass cable artefact correction for cardiac C-arm CT imaging  

Science Journals Connector (OSTI)

Cardiac C-arm CT imaging delivers a tomographic region-of-interest reconstruction of the patient's heart during image guided catheter interventions. Due to the limited size of the flat detector a volume image is reconstructed, which is truncated in the cone-beam (along the patient axis) and the fan-beam (in the transaxial plane) direction. To practically address this local tomography problem correction methods, like projection extension, are available for first pass image reconstruction. For second pass correction methods, like metal artefact reduction, alternative correction schemes are required when the field of view is limited to a region-of-interest of the patient. In classical CT imaging metal artefacts are corrected by metal identification in a first volume reconstruction and generation of a corrected projection data set followed by a second reconstruction. This approach fails when the metal structures are located outside the reconstruction field of view. When a C-arm CT is performed during a cardiac intervention pacing leads and other cables are frequently positioned on the patients skin, which results in propagating streak artefacts in the reconstruction volume. A first pass approach to reduce this type of artefact is introduced and evaluated here. It makes use of the fact that the projected position of objects outside the reconstruction volume changes with the projection perspective. It is shown that projection based identification, tracking and removal of high contrast structures like cables, only detected in a subset of the projections, delivers a more consistent reconstruction volume with reduced artefact level. The method is quantitatively evaluated based on 50 simulations using cardiac CT data sets with variable cable positioning. These data sets are forward projected using a C-arm CT system geometry and generate artefacts comparable to those observed in clinical cardiac C-arm CT acquisitions. A C-arm CT simulation of every cardiac CT data set without cables served as a ground truth. The 3D root mean square deviation between the simulated data set with and without cables could be reduced for 96% of the simulated cases by an average of 37% (min ?9%, max 73%) when using the first pass correction method. In addition, image quality improvement is demonstrated for clinical whole heart C-arm CT data sets when the cable removal algorithm was applied.

C Haase; D Schfer; M Kim; S J Chen; J D Carroll; P Eshuis; O Dssel; M Grass

2014-01-01T23:59:59.000Z

188

A One-Step Cone-Beam CT-Enabled Planning-to-Treatment Model for Palliative Radiotherapy-From Development to Implementation  

SciTech Connect (OSTI)

Purpose: To develop a cone-beam computed tomography (CT)-enabled one-step simulation-to-treatment process for the treatment of bone metastases. Methods and Materials: A three-phase prospective study was conducted. Patients requiring palliative radiotherapy to the spine, mediastinum, or abdomen/pelvis suitable for treatment with simple beam geometry ({<=}2 beams) were accrued. Phase A established the accuracy of cone-beam CT images for the purpose of gross tumor target volume (GTV) definition. Phase B evaluated the feasibility of implementing the cone-beam CT-enabled planning process at the treatment unit. Phase C evaluated the online cone-beam CT-enabled process for the planning and treatment of patients requiring radiotherapy for bone metastases. Results: Eighty-four patients participated in this study. Phase A (n = 9) established the adequacy of cone-beam CT images for target definition. Phase B (n = 45) established the quality of treatment plans to be adequate for clinical implementation for bone metastases. When the process was applied clinically in bone metastases (Phase C), the degree of overlap between planning computed tomography (PCT) and cone-beam CT for GTV and between PCT and cone-beam CT for treatment field was 82% {+-} 11% and 97% {+-} 4%, respectively. The oncologist's decision to accept the plan under a time-pressured environment remained of high quality, with the cone-beam CT-generated treatment plan delivering at least 90% of the prescribed dose to 100% {+-} 0% of the cone-beam CT planning target volume (PTV). With the assumption that the PCT PTV is the gold-standard target, the cone-beam CT-generated treatment plan delivered at least 90% and at least 95% of dose to 98% {+-} 2% and 97% {+-} 5% of the PCT PTV, respectively. The mean time for the online planning and treatment process was 32.7 {+-} 4.0 minutes. Patient satisfaction was high, with a trend for superior satisfaction with the cone-beam CT-enabled process. Conclusions: The cone-beam CT-enabled palliative treatment process is feasible and is ready for clinical implementation for the treatment of bone metastases using simple beam geometry, providing a streamlined one-step process toward palliative radiotherapy.

Wong, Rebecca K.S., E-mail: rebecca.wong@rmp.uhn.on.ca [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Letourneau, Daniel; Varma, Anita [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada) [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Bissonnette, Jean Pierre; Fitzpatrick, David; Grabarz, Daniel; Elder, Christine [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada)] [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Martin, Melanie; Bezjak, Andrea [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada) [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Panzarella, Tony [Department of Biostatistics, Princess Margaret Hospital, Toronto, Ontario (Canada)] [Department of Biostatistics, Princess Margaret Hospital, Toronto, Ontario (Canada); Gospodarowicz, Mary [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada) [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Jaffray, David A. [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada) [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada)

2012-11-01T23:59:59.000Z

189

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

E-Print Network [OSTI]

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

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

2013-01-01T23:59:59.000Z

190

CT Solar Loan | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

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

191

DOE - Office of Legacy Management -- New England Lime Co - CT...  

Office of Legacy Management (LM)

consideration under FUSRAP Designated Name: Not Designated Alternate Name: NELCO (Magnesium Division) CT.10-1 Location: Canaan , Connecticut CT.10-2 Evaluation Year: 1987...

192

Lack of Correlation Between External Fiducial Positions and Internal Tumor Positions During Breath-Hold CT  

SciTech Connect (OSTI)

Purpose: For thoracic tumors, if four-dimensional computed tomography (4DCT) is unavailable, the internal margin can be estimated by use of breath-hold (BH) CT scans acquired at end inspiration (EI) and end expiration (EE). By use of external surrogates for tumor position, BH accuracy is estimated by minimizing the difference between respiratory extrema BH and mean equivalent-phase free breathing (FB) positions. We tested the assumption that an external surrogate for BH accuracy correlates with internal tumor positional accuracy during BH CT. Methods and Materials: In 16 lung cancer patients, 4DCT images, as well as BH CT images at EI and EE, were acquired. Absolute differences between BH and mean equivalent-phase (FB) positions were calculated for both external fiducials and gross tumor volume (GTV) centroids as metrics of external and internal BH accuracy, respectively, and the results were correlated. Results: At EI, the absolute difference between mean FB and BH fiducial displacement correlated poorly with the absolute difference between FB and BH GTV centroid positions on CT images (R{sup 2} = 0.11). Similarly, at EE, the absolute difference between mean FB and BH fiducial displacements correlated poorly with the absolute difference between FB and BH GTV centroid positions on CT images (R{sup 2} = 0.18). Conclusions: External surrogates for tumor position are not an accurate metric of BH accuracy for lung cancer patients. This implies that care should be taken when using such an approach because an incorrect internal margin could be generated.

Hunjan, Sandeep, E-mail: shunjan@mdanderson.or [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Starkschall, George; Prado, Karl; Dong Lei; Balter, Peter [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

2010-04-15T23:59:59.000Z

193

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

194

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

SciTech Connect (OSTI)

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

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

2014-02-24T23:59:59.000Z

195

Imaging and sensing based on muon tomography  

DOE Patents [OSTI]

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

196

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 (OSTI)

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

197

PET/CT for Radiotherapy Treatment Planning in Patients With Soft Tissue Sarcomas  

SciTech Connect (OSTI)

Purpose: To study the possibility of incorporating positron emission tomography/computed tomography (PET/CT) information into radiotherapy treatment planning in patients with high-grade soft tissue sarcomas (STS). Methods and Materials: We studied 17 patients treated with preoperative radiotherapy at our institution from 2005 to 2007. All patients had a high-grade STS and had had a staging PET/CT scan. For each patient, an MRI-based gross tumor volume (GTV), considered to be the contemporary standard for radiotherapy treatment planning, was outlined on a T1-gadolinium enhanced axial MRI (GTV{sub MRI}), and a second set of GTVs were outlined using different threshold values on PET images (GTV{sub PET}). PET-based target volumes were compared with the MRI-based GTV. Threshold values for target contouring were determined as a multiple (from 2 to 10 times) of the background soft tissue uptake values (B) sampled over healthy tissue. Results: PET-based GTVs contoured using a threshold value of 2 or 2.5 most closely resembled the GTV{sub MRI} volumes. Higher threshold values lead to PET volumes much smaller than the GTV{sub MRI}. The standard deviations between the average volumes of GTV{sub PET} and GTV{sub MRI} ratios for all thresholds were large, ranging from 36% for 2 xB up to 93% for 10 xB. Maximum uptake-to-background ratio correlated poorly with the maximum standardized uptake values. Conclusions: It is unlikely that PET/CT will make a significant contribution in GTV definition for radiotherapy treatment planning in patients with STS using threshold methods on PET images. Future studies will focus on molecular imaging and tumor physiology.

Karam, Irene [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Devic, Slobodan [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec (Canada); Hickeson, Marc [Department of Nuclear Medicine, McGill University Health Centre, Montreal, Quebec (Canada); Roberge, David [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Turcotte, Robert E. [Department of Orthopedic Surgery, McGill University Health Centre, Montreal, Quebec (Canada); Freeman, Carolyn R., E-mail: carolyn.freeman@muhc.mcgill.c [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada)

2009-11-01T23:59:59.000Z

198

The effect of CT scanner parameters and 3D volume rendering techniques on the accuracy of linear, angular, and volumetric measurements of the mandible  

E-Print Network [OSTI]

Professor ­ Department of Radiology Radiology Clinic- University of Wisconsin Hospital and Clinics Schimek of this study were presented at the American Society of Head and Neck Radiology's 45th annual meeting-3 and to develop clinical applications for dental4-5 and craniofacia

Vorperian, Houri K.

199

Dicentric chromosomes and -H2AX foci formation in lymphocytes of human blood samples exposed to a CT scanner: a direct comparison of dose response relationships  

Science Journals Connector (OSTI)

......laboratory using photon energies from 5.4 keV to...also enhance the frequency of dicentrics in...significantly increased frequencies of chromosomal fragments...dose. An early response to DNA-DSBs is...experiments with photon energies from 1.83 keV...at the electron storage ring BESSY II......

Sven Golfier; Gregor Jost; Hubertus Pietsch; Philipp Lengsfeld; Friederike Eckardt-Schupp; Ernst Schmid; Matthias Voth

2009-02-01T23:59:59.000Z

200

Image-guided radiotherapy for prostate cancer by CT-linear accelerator combination: Prostate movements and dosimetric considerations  

SciTech Connect (OSTI)

Purpose: Multiple studies have indicated that the prostate is not stationary and can move as much as 2 cm. Such prostate movements are problematic for intensity-modulated radiotherapy, with its associated tight margins and dose escalation. Because of these intrinsic daily uncertainties, a relative generous 'margin' is necessary to avoid marginal misses. Using the CT-linear accelerator combination in the treatment suite (Primatom, Siemens), we found that the daily intrinsic prostate movements can be easily corrected before each radiotherapy session. Dosimetric calculations were performed to evaluate the amount of discrepancy of dose to the target if no correction was done for prostate movement. Methods and materials: The Primatom consists of a Siemens Somatom CT scanner and a Siemens Primus linear accelerator installed in the same treatment suite and sharing a common table/couch. The patient is scanned by the CT scanner, which is movable on a pair of horizontal rails. During scanning, the couch does not move. The exact location of the prostate, seminal vesicles, and rectum are identified and localized. These positions are then compared with the planned positions. The daily movement of the prostate and rectum were corrected for and a new isocenter derived. The patient was treated immediately using the new isocenter. Results: Of the 108 patients with primary prostate cancer studied, 540 consecutive daily CT scans were performed during the last part of the cone down treatment. Of the 540 scans, 46% required no isocenter adjustments for the AP-PA direction, 54% required a shift of {>=}3 mm, 44% required a shift of >5 mm, and 15% required a shift of >10 mm. In the superoinferior direction, 27% required a shift of >3 mm, 25% required a shift of >5 mm, and 4% required a shift of >10 mm. In the right-left direction, 34% required a shift of >3 mm, 24% required a shift of >5 mm, and 5% required a shift of >10 mm. Dosimetric calculations for a typical case of prostate cancer using intensity-modulated radiotherapy with 5-mm margin coverage from the clinical target volume (prostate gland) was performed. With a posterior shift of 10 mm for the prostate, the dose coverage dropped from 95-107% to 71-100% coverage. Conclusion: We have described a technique that corrects for the daily prostate motion, allowing for extremely precise prostate cancer treatment. This technique has significant implications for dose escalation and for decreasing rectal complications in the treatment of prostate cancer.

Wong, James R. [Carol G. Simon Cancer Center, Morristown Memorial Hospital/Atlantic Health System, Morristown, NJ (United States); Department of Radiation Oncology, New York Presbyterian Hospital, Columbia University College of Physicians and Surgeons, New York, NY (United States); Grimm, Lisa [Carol G. Simon Cancer Center, Morristown Memorial Hospital/Atlantic Health System, Morristown, NJ (United States); Uematsu, Minoru [National Defense Medical College, Namiki, Tokorozawa (Japan); Oren, Reva [Carol G. Simon Cancer Center, Morristown Memorial Hospital/Atlantic Health System, Morristown, NJ (United States); Cheng, C.W. [Carol G. Simon Cancer Center, Morristown Memorial Hospital/Atlantic Health System, Morristown, NJ (United States); Merrick, Scott; Schiff, Peter [Department of Radiation Oncology, New York Presbyterian Hospital, Columbia University College of Physicians and Surgeons, New York, NY (United States)

2005-02-01T23:59:59.000Z

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.


201

Software-defined Radio based Wireless Tomography: Experimental Demonstration and  

E-Print Network [OSTI]

1 Software-defined Radio based Wireless Tomography: Experimental Demonstration and Verification presents an experimental demonstration of Software-Defined Radio (SDR) based wireless tomography us- ing follows our vision and previous theoretical study of wireless tomography which combines wireless

Qiu, Robert Caiming

202

Phenotyping transgenic embryonic murine hearts using optical coherence tomography  

E-Print Network [OSTI]

Phenotyping transgenic embryonic murine hearts using optical coherence tomography Michael W optical coherence tomography (OCT) to characterize the morphological phenotype of embryonic murine hearts the etiology of heart defects. Optical coherence tomography (OCT)6,7 measures coherently gated backreflected

203

Properties of Some Integral Transforms Arising in Tomography  

E-Print Network [OSTI]

This dissertation deals with several types of imaging: radio tomography, single scattering optical tomography, photoacoustic tomography, and Compton camera imaging. Each of these tomographic techniques leads to a Radon-type transform...

Moon, Sunghwan

2013-10-11T23:59:59.000Z

204

Comparison of Computed Tomography and Cineangiography in the Demonstration of Central Pulmonary Arteries in Cyanotic Congenital Heart Disease  

SciTech Connect (OSTI)

Purpose: To assess the diagnostic accuracy of contrast-enhanced computed tomography (CT) for central pulmonary artery pathology in patients with cyanotic congenital heart disease (CCHD) and right ventricular outflow obstruction. Methods: We compared contrast-enhanced CT and cine pulmonary arteriography in 24 patients with CCHD to assess central pulmonary arteries including the confluence. Both investigations were interpreted by a cardiac radiologist in a double-blinded manner at an interval of 3 weeks. Angiography was used as the gold standard for comparison. Results: The sensitivity for visualization of main pulmonary artery (MPA), right pulmonary artery (RPA), left pulmonary artery (LPA), and confluence on CT was 94%, 100%, 92.8%, and 92.8%, respectively. Diagnostic specificity for the same entities was 28.5%, 100%, 80%, and 50%, respectively. The positive predictive value for each was 76.2%, 100%, 94.1%, and 72.2%, respectively. The low specificity of CT in the evaluation of the MPA and the confluence is perhaps due to distorted right ventricular outflow anatomy in CCHD. Large aortopulmonary collaterals in this region were mistaken for the MPA in some patients with pulmonary atresia. Conclusion: CT is a useful, relatively noninvasive, imaging technique for the central pulmonary arteries in selected patients. It can supplement diagnostic information from angiography but cannot replace it. LPA demonstration on axial images alone is inadequate.

Taneja, Karuna; Sharma, Sanjiv [Department of Cardiovascular Radiology, C.T. Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110 029 (India); Kumar, Krishan [Department of Cardiology, C.T. Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110 029 (India); Rajani, Mira [Department of Cardiovascular Radiology, C.T. Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110 029 (India)

1996-03-15T23:59:59.000Z

205

Contribution of atom-probe tomography to a better understanding...  

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

atom-probe tomography to a better understanding of glass alteration mechanisms: application to a nuclear glass Contribution of atom-probe tomography to a better understanding of...

206

Resistivity Tomography At Crump's Hot Springs Area (DOE GTP)...  

Open Energy Info (EERE)

Tomography At Crump's Hot Springs Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Resistivity Tomography At Crump's Hot Springs...

207

Understanding Atom Probe Tomography of Oxide-Supported Metal...  

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

Atom Probe Tomography of Oxide-Supported Metal Nanoparticles by Correlation with Atomic Resolution Electron Understanding Atom Probe Tomography of Oxide-Supported Metal...

208

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

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

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

209

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

210

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

211

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

212

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

SciTech Connect (OSTI)

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

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

2012-11-01T23:59:59.000Z

213

Statistical inversion for medical x-ray tomography with few radiographs: II. Application to dental radiology  

Science Journals Connector (OSTI)

Diagnostic and operational tasks in dental radiology often require three-dimensional information that is difficult or impossible to see in a projection image. A CT-scan provides the dentist with comprehensive three-dimensional data. However, often CT-scan is impractical and, instead, only a few projection radiographs with sparsely distributed projection directions are available. Statistical (Bayesian) inversion is well-suited approach for reconstruction from such incomplete data. In statistical inversion, a priori information is used to compensate for the incomplete information of the data. The inverse problem is recast in the form of statistical inference from the posterior probability distribution that is based on statistical models of the projection data and the a priori information of the tissue. In this paper, a statistical model for three-dimensional imaging of dentomaxillofacial structures is proposed. Optimization and MCMC algorithms are implemented for the computation of posterior statistics. Results are given with in vitro projection data that were taken with a commercial intraoral x-ray sensor. Examples include limited-angle tomography and full-angle tomography with sparse projection data. Reconstructions with traditional tomographic reconstruction methods are given as reference for the assessment of the estimates that are based on the statistical model.

V Kolehmainen; S Siltanen; S Jrvenp; J P Kaipio; P Koistinen; M Lassas; J Pirttil; E Somersalo

2003-01-01T23:59:59.000Z

214

ALGEBRAIC ASPECTS OF EMISSION TOMOGRAPHY WITH ABSORPTION  

E-Print Network [OSTI]

ALGEBRAIC ASPECTS OF EMISSION TOMOGRAPHY WITH ABSORPTION L. Hajdu and R. Tijdeman Abstract of emission tomography with absorption, con- sider a ray (such as light or X-ray) transmitting through #1; e #22;x ; where #22; #21; 0 denotes the absorption coe?cient of the material, and x is the length

Tijdeman, Robert

215

Fast Globally Convergent Reconstruction in Emission Tomography  

E-Print Network [OSTI]

considerable speedup by using only a subset of the projection data per sub- iteration. However, OSEM1 Fast Globally Convergent Reconstruction in Emission Tomography Using COSEM, an Incremental EM globally convergent incremental EM algorithms for reconstruction in emission tomography, COSEM- ML

Rangarajan, Anand

216

Improving Electrical Resistivity Tomography for Characterization of  

E-Print Network [OSTI]

Improving Electrical Resistivity Tomography for Characterization of Non-point Source Contaminants runoff on Arizona's potable water. Electrical resistivity tomography (ERT) shows promise as a noninvasive on the environment. Urban and agricultural runoff are often associated with an increase in water electrical

Fay, Noah

217

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

E-Print Network [OSTI]

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

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

2014-08-07T23:59:59.000Z

218

A Neutron Based Scanner to Detect Explosives in Small, Sealed Containers  

SciTech Connect (OSTI)

A scanning system has been designed for portal protection applications, with the capability of detecting explosive materials after an initial scan of 30 seconds. The scanner operates using the principle of neutron induced return gamma-ray spectrometry. This system utilizes high purity germanium detectors, a neutron generator based on deuterium-tritium fusion and a unique neutron reflector and guide design. The neutron reflector amplifies the flux and alters the energy spectrum of neutrons produced by the generator. A depleted uranium reflector is shown to perform 7.3 times better than no reflector, and is found to perform 1.5 times better than a tungsten reflector using MCNP simulation. This improvement is due to neutron knockout and induced fission occurring in depleted uranium. The system is capable of detecting 300 g of explosives with 90% detection probability, which includes a 15% rescan rate after a 30 second initial scan.

Koltick, D.; Sword, E. [Physics Department, Purdue University 525 Northwestern Avenue, West Lafayette, IN 47907 (United States)

2009-03-10T23:59:59.000Z

219

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

SciTech Connect (OSTI)

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

220

TERRESTRIAL 3D-LASER SCANNER ZLS07 DEVELOPED AT ETH ZURICH: AN OVERVIEW OF ITS CONFIGURATION,  

E-Print Network [OSTI]

Utility Cavern ABSTRACT This paper introduces the terrestrial 3D-laser scanner ZLS07 which has been and the application of underground utility cavern acquisition for water and sewage engineering are presented. For utility cavern acquisitions, the ZLS07 is guided headfirst through a manhole into the utility cavern

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.


221

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

E-Print Network [OSTI]

Atlas-based attenuation correction for small animal PET/MRI scanners 1 Abhijit J. Chaudhari densities and not on electron densities. We propose a deformable mouse atlas-based registration method for AC in small animal PET/MRI. In this method, we first match the posture of the atlas to the posture

Leahy, Richard M.

222

PET Motion Compensation for Radiation Therapy Using a CT-Based Mid-Position Motion Model: Methodology and Clinical Evaluation  

SciTech Connect (OSTI)

Purpose: Four-dimensional positron emission tomography (4D PET) imaging of the thorax produces sharper images with reduced motion artifacts. Current radiation therapy planning systems, however, do not facilitate 4D plan optimization. When images are acquired in a 2-minute time slot, the signal-to-noise ratio of each 4D frame is low, compromising image quality. The purpose of this study was to implement and evaluate the construction of mid-position 3D PET scans, with motion compensated using a 4D computed tomography (CT)-derived motion model. Methods and Materials: All voxels of 4D PET were registered to the time-averaged position by using a motion model derived from the 4D CT frames. After the registration the scans were summed, resulting in a motion-compensated 3D mid-position PET scan. The method was tested with a phantom dataset as well as data from 27 lung cancer patients. Results: PET motion compensation using a CT-based motion model improved image quality of both phantoms and patients in terms of increased maximum SUV (SUV{sub max}) values and decreased apparent volumes. In homogenous phantom data, a strong relationship was found between the amplitude-to-diameter ratio and the effects of the method. In heterogeneous patient data, the effect correlated better with the motion amplitude. In case of large amplitudes, motion compensation may increase SUV{sub max} up to 25% and reduce the diameter of the 50% SUV{sub max} volume by 10%. Conclusions: 4D CT-based motion-compensated mid-position PET scans provide improved quantitative data in terms of uptake values and volumes at the time-averaged position, thereby facilitating more accurate radiation therapy treatment planning of pulmonary lesions.

Kruis, Matthijs F.; Kamer, Jeroen B. van de; Houweling, Antonetta C.; Sonke, Jan-Jakob; Belderbos, Jos S.A.; Herk, Marcel van, E-mail: m.v.herk@nki.nl

2013-10-01T23:59:59.000Z

223

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

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

224

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

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

225

Lorentz Force Electrical Impedance Tomography  

E-Print Network [OSTI]

This article describes a method called Lorentz Force Electrical Impedance Tomography. The electrical conductivity of biological tissues can be measured through their sonication in a magnetic field: the vibration of the tissues inside the field induces an electrical current by Lorentz force. This current, detected by electrodes placed around the sample, is proportional to the ultrasonic pressure, to the strength of the magnetic field and to the electrical conductivity gradient along the acoustic axis. By focusing at different places inside the sample, a map of the electrical conductivity gradient can be established. In this study experiments were conducted on a gelatin phantom and on a beef sample, successively placed in a 300 mT magnetic field and sonicated with an ultrasonic transducer focused at 21 cm emitting 500 kHz bursts. Although all interfaces are not visible, in this exploratory study a good correlation is observed between the electrical conductivity image and the ultrasonic image. This method offers...

Grasland-Mongrain, Pol; Chapelon, Jean-Yves; Lafon, Cyril

2014-01-01T23:59:59.000Z

226

Collimator-free photon tomography  

DOE Patents [OSTI]

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

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

1998-10-06T23:59:59.000Z

227

Collimator-free photon tomography  

DOE Patents [OSTI]

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

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

1998-10-06T23:59:59.000Z

228

Supercritical CO2 core flooding and imbibition in Berea sandstone CT imaging and numerical simulation  

Science Journals Connector (OSTI)

This paper reports a numerical simulation study of a full CO2 core flooding and imbibition cycle on a Berea sandstone core (measured 14.45cm long and 3.67cm in diameter). During the test, supercritical CO2 (at 10MPa and 40C) and CO2-saturated brine was injected into one end of the horizontal core and a X-ray CT scanner (with a resolution of 0.35mmנ0.35mm) was employed to monitor and record changes in the fluid saturations, which enabled 3D mapping of the saturation profiles throughout the core during the course of core flooding test. From the digital CT saturation data, mean saturation profiles along the core length were plotted with time. A 1D model of the core was constructed to simulate the core flooding test and attempt was made to history match core test results, particularly the evolution of the mean CO2 saturation profiles during CO2 injection. Curve-fitting of the centrifugal air-water capillary pressure data (drainage) for the Berea core showed that the core test data could be adequately described by the Van Genuchten equation. The matched set of parameters ( S l r , P 0 , m ) were 0.09, 20KPa, 0.425 respectively. In the absence of the relative permeability for the Berea core, it was decided to use the parameters obtained from matching the air-water capillary pressure data as a first approximation for the CO2-brine system in the model.

Ji-Quan Shi; Ziqiu Xue; Sevket Durucan

2011-01-01T23:59:59.000Z

229

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

230

Compressive deformation and yielding mechanisms in cellular Al alloys determined using X-ray tomography and surface strain mapping  

SciTech Connect (OSTI)

The mechanisms of compressive deformation that occur in closed cell Al alloys have been established. This has been achieved by using x-ray computed tomography (CT) and surface strain mapping to determine the deformation modes and the cell morphologies that control the onset of yielding. The deformation is found to localize in narrow bands having width of order of a cell diameter. Outside the bands, the material remains elastic. The cells within the bands that experience large permanent strains are primarily elliptical. A group of cells work collectively to allow large localized deformation. Size does not appear to be the initiator of the deformation bands. Equiaxed cells remain elastic. The implications for manufacturing materials with superior mechanical properties are discussed. Visualization of internal deformation of a closed cell Al alloy core, as part of a sandwich panel construction, is also possible using x-ray tomography. Preliminary results for a punch indentation test are presented.

Bart-Smith, H.; Bastawros, A.F.; Mumm, D.R.; Evans, A.G. [Harvard Univ., Cambridge, MA (United States). Div. of Engineering and Applied Sciences; Sypeck, D.J.; Wadley, H.N.G. [Univ. of Virginia, Charlottesville, VA (United States). School of Engineering and Applied Science

1998-12-31T23:59:59.000Z

231

New Method of Assessing Absolute Permeability of Natural Methane Hydrate Sediments by Microfocus X-ray Computed Tomography  

Science Journals Connector (OSTI)

The structure of natural-gas hydrate sediments was studied using a microfocus X-ray computed-tomography (CT) system. The free-gas spaces, sand particles, and hydrates or ices were identified from the obtained three-dimensional (3-D) images. We used CT data to analyze a continuous pore, which allows gas and water flow. The absolute permeability of sediment samples correlated well with horizontal-channel density in terms of direction. The grain-size distribution in sediment samples depended on the spread of flow channels. The average area and length of a channel evidently have little effect on absolute permeability. We determined that absolute permeability increased with the ratio of horizontal- to vertical-channel numbers. It was clear that the number ratio of the horizontal to vertical channels is a predominant factor that determines absolute permeability in similar porosity ranges. These results indicate that the pore network in sediments can be useful for assessing permeability.

Yusuke Jin; Junko Hayashi; Jiro Nagao; Kiyofumi Suzuki; Hideki Minagawa; Takao Ebinuma; Hideo Narita

2007-01-01T23:59:59.000Z

232

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

SciTech Connect (OSTI)

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

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

2014-02-15T23:59:59.000Z

233

Reduced Kilovoltage in Computed TomographyGuided Intervention in a Community Hospital: Effect on the Radiation Dose  

Science Journals Connector (OSTI)

AbstractPurpose The purpose of this study was to determine whether low-kilovoltage (80 or 100 kV) computed tomography (CT)-guided interventions performed in a community-based hospital are feasible and to compare radiation exposure incurred with conventional 120 kV potential. Materials and Methods Effective doses (ED) received by patients who underwent CT-guided intervention were analysed before and after a low-dose kilovoltage protocol was instituted in our department. We performed CT-guided procedures of 93 consecutive patients by using conventional 120-kV tube voltage (50 patients) and a low voltage of 80 or 100 kV for the remainder of this cohort. Automatic tube current modulation was enabled to obtain the best image quality. Procedure details were prospectively recorded and included examination site and type, slice width, tube voltage and current, dose length product, volume CT dose index, and size-specific dose estimate. Dose length product was converted to ED to account for radiosensitivity of specific organs. Statistical comparisons with test differences in the ED, volume CT dose index, size-specific dose estimate, and effective diameter (patient size) were made by using the Student t test. Results All but 6 of the procedures performed at 80 kV were successful, for a success rate of 86%. At lower voltages, the ED was significantly (P dose radiation technique by using 80 or 100 kV results in a high technical success rate for pelvic, chest, and abdomen CT-guided interventional procedures, although dramatically decreasing radiation exposure. There was no significant difference in effective diameter (patient size) between the conventional and the low-dose groups, which would suggest that dose reduction was indeed a result of kVp change and not patient size.

Saman Rezazadeh; Steven J. Co; Simon Bicknell

2014-01-01T23:59:59.000Z

234

Practical Characterization of Quantum Devices without Tomography  

Science Journals Connector (OSTI)

Quantum tomography is the main method used to assess the quality of quantum information processing devices. However, the amount of resources needed for quantum tomography is exponential in the device size. Part of the problem is that tomography generates much more information than is usually sought. Taking a more targeted approach, we develop schemes that enable (i) estimating the fidelity of an experiment to a theoretical ideal description, (ii) learning which description within a reduced subset best matches the experimental data. Both these approaches yield a significant reduction in resources compared to tomography. In particular, we demonstrate that fidelity can be estimated from a number of simple experiments that is independent of the system size, removing an important roadblock for the experimental study of larger quantum information processing units.

Marcus P. da Silva; Olivier Landon-Cardinal; David Poulin

2011-11-16T23:59:59.000Z

235

Phase-Conjugate Optical Coherence Tomography  

E-Print Network [OSTI]

We demonstrate a new type of optical coherence tomography using only classical resources to achieve results that are typically associated with quantum-enhanced metrology: factor-of-two axial resolution enhancement and ...

Shapiro, Jeffrey H.

236

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

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

237

Effect of magnetic reconnection on CT penetration into magnetized plasmas  

Science Journals Connector (OSTI)

To understand the fuelling process in a fusion device by a compact toroid (CT) injection method, three dimensional MHD numerical simulations, where a spheromak-like CT (SCT) is injected into...

Yoshio Suzuki; Takaya Hayashi; Yasuaki Kishimoto

2001-06-01T23:59:59.000Z

238

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

Office of Legacy Management (LM)

FUSRAP Designated Name: Not Designated Alternate Name: None Location: New Canaan , Connecticut CT.08-1 Evaluation Year: 1985 CT.08-2 Site Operations: None; Investigation of area...

239

Comparison of computed tomography dose reporting software  

Science Journals Connector (OSTI)

......and physics of radiation exposure(21...between the different software packages, and...awareness about adult radiation protection. Radiology...improvement program in CT safety for children...lightly: promoting radiation safety in pediatric interventional......

A. Abdullah; Z. Sun; N. Pongnapang; K.-H. Ng

2012-08-01T23:59:59.000Z

240

High-resolution imaging of microvasculature in human skin in-vivo with optical coherence tomography  

E-Print Network [OSTI]

using swept-source optical coherence tomography, Opt. Lett.J. G. Fujimoto, Optical coherence tomography, Science 254(volumes using optical coherence tomography, Opt. Lett. 22(

Liu, Gangjun; Jia, Wangcun; Sun, Victor; Choi, Bernard; Chen, Zhongping

2012-01-01T23:59:59.000Z

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.


241

Reference spectrum extraction and fixed-pattern noise removal in optical coherence tomography  

E-Print Network [OSTI]

OCIS codes: (110.4500) Optical coherence tomography; (170.4500) Optical coherence tomography; (100.2000) Digitalvs. time domain optical coherence tomography, Opt. Express

Moon, Sucbei; Lee, Sang-Won; Chen, Zhongping

2010-01-01T23:59:59.000Z

242

In vivo three-dimensional microelectromechanical endoscopic swept source optical coherence tomography  

E-Print Network [OSTI]

with endoscopic optical coherence tomography, Opt. Express,G. Fujimoto, "Optical coherence tomography," Science, 254,endoscope for optical coherence tomography,Opt. Lett. 21,

Su, Jianping; Zhang, Jun; Yu, Linfeng; Chen, Zhongping

2007-01-01T23:59:59.000Z

243

Dose calculation errors due to inaccurate representation of heterogeneity correction obtained from computerized tomography  

SciTech Connect (OSTI)

Computerized tomography (CT) is used routinely in evaluating radiation therapy isodose plans. With the introduction of 3D algorithms such as the voxel raytrace, which determines inhomogeneity corrections from actual CT Hounsfield numbers, caution must be used when evaluating isodose calculations. Artifacts from contrast media and dental work, radiopaque markers placed by the treatment planner, and changing bowel and rectal air patterns all have the potential to introduce error into the calculation due to inaccurate assessment of high or low density. Radiopaque makers such as x-spot BB's or solder wire are placed externally on the patient. Barium contrast media introduced at the time of simulation may be necessary to visualize specific anatomical structures on the CT images. While these localization and visualization tools may be necessary, it is important to understand the effects they may introduce in the planning process. Other problems encountered are patient specific and out of the control of the treatment planner. These include high- and low-density streaking caused by dental work, which produce computational errors due to overestimation, and small bowel and rectal air, the patterns of which change on a daily basis and may result in underestimation of structure density. It is important for each treatment planner to have an understanding of how this potentially tainted CT information may be applied in dose calculations and the possible effects they may have. At our institution, the voxel raytrace calculation is automatically forced any time couch angle is introduced. Errors in the calculation from the above mentioned situations may be introduced if a heterogeneity correction is applied. Examples of potential calculation errors and the magnitude of each will be discussed. The methods used to minimize these errors and the possible solutions will also be evaluated.

Williams, Greg; Tobler, Matthew; Gaffney, David; Moeller, John; Leavitt, Dennis

2002-12-31T23:59:59.000Z

244

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

SciTech Connect (OSTI)

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

245

Inter-slice bidirectional registration-based segmentation of the prostate gland in MR and CT image sequences  

SciTech Connect (OSTI)

Purpose: Accurate segmentation and volume estimation of the prostate gland in magnetic resonance (MR) and computed tomography (CT) images are necessary steps in diagnosis, treatment, and monitoring of prostate cancer. This paper presents an algorithm for the prostate gland volume estimation based on the semiautomated segmentation of individual slices in T2-weighted MR and CT image sequences. Methods: The proposedInter-Slice Bidirectional Registration-based Segmentation (iBRS) algorithm relies on interslice image registration of volume data to segment the prostate gland without the use of an anatomical atlas. It requires the user to mark only three slices in a given volume dataset, i.e., the first, middle, and last slices. Next, the proposed algorithm uses a registration algorithm to autosegment the remaining slices. We conducted comprehensive experiments to measure the performance of the proposed algorithm using three registration methods (i.e., rigid, affine, and nonrigid techniques). Results: The results with the proposed technique were compared with manual marking using prostate MR and CT images from 117 patients. Manual marking was performed by an expert user for all 117 patients. The median accuracies for individual slices measured using the Dice similarity coefficient (DSC) were 92% and 91% for MR and CT images, respectively. The iBRS algorithm was also evaluated regarding user variability, which confirmed that the algorithm was robust to interuser variability when marking the prostate gland. Conclusions: The proposed algorithm exploits the interslice data redundancy of the images in a volume dataset of MR and CT images and eliminates the need for an atlas, minimizing the computational cost while producing highly accurate results which are robust to interuser variability.

Khalvati, Farzad, E-mail: farzad.khalvati@uwaterloo.ca; Tizhoosh, Hamid R. [Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)] [Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Salmanpour, Aryan; Rahnamayan, Shahryar [Department of Engineering and Applied Science, University of Ontario Institute of Technology, Oshawa, Ontario L1H 7K4 (Canada)] [Department of Engineering and Applied Science, University of Ontario Institute of Technology, Oshawa, Ontario L1H 7K4 (Canada); Rodrigues, George [Department of Radiation Oncology, London Regional Cancer Program, London, Ontario N6C 2R6, Canada and Department of Epidemiology/Biostatistics, University of Western Ontario, London, Ontario N6A 3K7 (Canada)] [Department of Radiation Oncology, London Regional Cancer Program, London, Ontario N6C 2R6, Canada and Department of Epidemiology/Biostatistics, University of Western Ontario, London, Ontario N6A 3K7 (Canada)

2013-12-15T23:59:59.000Z

246

Experimental evaluation of actual delivered dose using mega-voltage cone-beam CT and direct point dose measurement  

SciTech Connect (OSTI)

Radiation therapy in patients is planned by using computed tomography (CT) images acquired before start of the treatment course. Here, tumor shrinkage or weight loss or both, which are common during the treatment course for patients with head-and-neck (H and N) cancer, causes unexpected differences from the plan, as well as dose uncertainty with the daily positional error of patients. For accurate clinical evaluation, it is essential to identify these anatomical changes and daily positional errors, as well as consequent dosimetric changes. To evaluate the actual delivered dose, the authors proposed direct dose measurement and dose calculation with mega-voltage cone-beam CT (MVCBCT). The purpose of the present study was to experimentally evaluate dose calculation by MVCBCT. Furthermore, actual delivered dose was evaluated directly with accurate phantom setup. Because MVCBCT has CT-number variation, even when the analyzed object has a uniform density, a specific and simple CT-number correction method was developed and applied for the H and N site of a RANDO phantom. Dose distributions were calculated with the corrected MVCBCT images of a cylindrical polymethyl methacrylate phantom. Treatment processes from planning to beam delivery were performed for the H and N site of the RANDO phantom. The image-guided radiation therapy procedure was utilized for the phantom setup to improve measurement reliability. The calculated dose in the RANDO phantom was compared to the measured dose obtained by metal-oxide-semiconductor field-effect transistor detectors. In the polymethyl methacrylate phantom, the calculated and measured doses agreed within about +3%. In the RANDO phantom, the dose difference was less than +5%. The calculated dose based on simulation-CT agreed with the measured dose within3%, even in the region with a high dose gradient. The actual delivered dose was successfully determined by dose calculation with MVCBCT, and the point dose measurement with the image-guided radiation therapy procedure.

Matsubara, Kana, E-mail: matsubara-kana@hs.tmu.ac.jp [Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa-ku Tokyo (Japan); Kohno, Ryosuke [National Cancer Center Hospital East, Chiba (Japan); National Cancer Center Research Institute, Chiba (Japan); Nishioka, Shie; Shibuya, Toshiyuki; Ariji, Takaki; Akimoto, Tetsuo [National Cancer Center Hospital East, Chiba (Japan); Saitoh, Hidetoshi [Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa-ku Tokyo (Japan)

2013-07-01T23:59:59.000Z

247

RADIATION EXPOSURE DURING PAEDIATRIC CT IN SUDAN: CT DOSE, ORGAN AND EFFECTIVE DOSES  

Science Journals Connector (OSTI)

......research-article Paper RADIATION EXPOSURE DURING PAEDIATRIC...Energy Commission, Radiation Safety Institute, PO Box 3001...assess the magnitude of radiation exposure during paediatric...CT-Expo 2.1 dosimetry software. Doses were evaluated......

I. I. Suliman; H. M. Khamis; T. H. Ombada; K. Alzimami; M. Alkhorayef; A. Sulieman

2014-11-01T23:59:59.000Z

248

Economical standard quantum process tomography  

E-Print Network [OSTI]

Recently, Bendersky \\emph{et al.} developed a method to complete the task of characterizing an arbitrary $\\chi$ matrix element in a scalable way, Phys. Rev. Lett. Vol. \\textbf{100}, 190403(2008), where an auxiliary system was needed. In present work, we shall show that the same task can also be completed within the scheme of standard quantum process tomography (SQPT) where there is no requirement for ancilla. Our method depends on two observations: With the elaborately chosen operators basis, the SQPT may have an economical form where a single run of experiment, in which we measure the expectation value of a chosen operator in the outport of the quantum channel with a known input, is sufficient to characterize a selected $\\chi$ matrix element; With the progress recently achieved in quantum entanglement detection, we also find that the number of the experimental settings to realize the experiment for the selected $\\chi$ matrix element does not exceed 2N for the N-qubits system. For practice, our scheme can be applied for the cases where the controlled two-body interaction is neither available nor desirable.

Xiaohua Wu; Ke Xu

2010-11-30T23:59:59.000Z

249

X-ray Scanner for ODP Leg 204: Drilling Gas Hydrates on Hydrate Ridge, Cascadia Continental Margin  

SciTech Connect (OSTI)

An x-ray scanner was designed and fabricated at Lawrence Berkeley National Laboratory to provide high speed acquisition of x-ray images of sediment cores collected on the Ocean Drilling Program (ODP) Leg 204: Drilling Gas Hydrates On Hydrate Ridge, Cascadia Continental Margin. This report discusses the design and fabrication of the instrument, detailing novel features that help reduce the weight and increase the portability of the instrument. Sample x-ray images are included. The x-ray scanner was transferred to scientific drilling vessel, the JOIDES Resolution, by the resupply ship Mauna Loa, out of Coos Bay, Oregon on July 25. ODP technicians were trained in the instruments operation. The availability of the x-ray scanner at the drilling site allows real-time imaging of cores containing methane hydrate immediately after retrieval. Thus, imaging experiments on cores can yield information on the distribution and quantity of methane hydrates. Performing these measurements at the location of core collection eliminates the need for high pressures or low temperature core handling while the cores are stored and transported to a remote imaging laboratory.

Freifeld, Barry; Kneafsey, Tim; Pruess, Jacob; Reiter, Paul; Tomutsa, Liviu

2002-08-08T23:59:59.000Z

250

Estimation of Rectal Dose Using Daily Megavoltage Cone-Beam Computed Tomography and Deformable Image Registration  

SciTech Connect (OSTI)

Purpose: The actual dose delivered to critical organs will differ from the simulated dose because of interfractional organ motion and deformation. Here, we developed a method to estimate the rectal dose in prostate intensity modulated radiation therapy with consideration to interfractional organ motion using daily megavoltage cone-beam computed tomography (MVCBCT). Methods and Materials: Under exemption status from our institutional review board, we retrospectively reviewed 231 series of MVCBCT of 8 patients with prostate cancer. On both planning CT (pCT) and MVCBCT images, the rectal contours were delineated and the CT value within the contours was replaced by the mean CT value within the pelvis, with the addition of 100 Hounsfield units. MVCBCT images were rigidly registered to pCT and then nonrigidly registered using B-Spline deformable image registration (DIR) with Velocity AI software. The concordance between the rectal contours on MVCBCT and pCT was evaluated using the Dice similarity coefficient (DSC). The dose distributions normalized for 1 fraction were also deformed and summed to estimate the actual total dose. Results: The DSC of all treatment fractions of 8 patients was improved from 0.750.04 (mean SD) to 0.90 0.02 by DIR. Six patients showed a decrease of the generalized equivalent uniform dose (gEUD) from total dose compared with treatment plans. Although the rectal volume of each treatment fraction did not show any correlation with the change in gEUD (R{sup 2}=0.180.13), the displacement of the center of gravity of rectal contours in the anterior-posterior (AP) direction showed an intermediate relationship (R{sup 2}=0.610.16). Conclusion: We developed a method for evaluation of rectal dose using DIR and MVCBCT images and showed the necessity of DIR for the evaluation of total dose. Displacement of the rectum in the AP direction showed a greater effect on the change in rectal dose compared with the rectal volume.

Akino, Yuichi, E-mail: akino@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Department of Radiology, Osaka University Hospital, Suita, Osaka (Japan); Yoshioka, Yasuo [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Fukuda, Shoichi [Department of Radiation Oncology, Osaka General Medical Center, Osaka (Japan); Maruoka, Shintaroh [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Takahashi, Yutaka [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Department of Radiation Oncology, University of Minnesota, Minneapolis, Minnesota (United States); Yagi, Masashi [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan); Mizuno, Hirokazu [Department of Radiology, Osaka University Hospital, Suita, Osaka (Japan); Isohashi, Fumiaki [Oncology Center, Osaka University Hospital, Suita, Osaka (Japan); Ogawa, Kazuhiko [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka (Japan)

2013-11-01T23:59:59.000Z

251

Introduction of heat map to fidelity assessment of compressed CT images  

SciTech Connect (OSTI)

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

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

2011-08-15T23:59:59.000Z

252

MRI and CT image indexing and retrieval using local mesh peak valley edge patterns  

Science Journals Connector (OSTI)

Abstract In this paper, a new pattern based feature, local mesh peak valley edge pattern (LMePVEP) is proposed for biomedical image indexing and retrieval. The standard LBP extracts the gray scale relationship between the center pixel and its surrounding neighbors in an image. Whereas the proposed method extracts the gray scale relationship among the neighbors for a given center pixel in an image. The relations among the neighbors are peak/valley edges which are obtained by performing the first-order derivative. The performance of the proposed method (LMePVEP) is tested by conducting two experiments on two benchmark biomedical databases. Further, it is mentioned that the databases used for experiments are OASIS?MRI database which is the magnetic resonance imaging (MRI) database and VIA/IELCAP-CT database which includes region of interest computer tomography (CT) images. The results after being investigated show a significant improvement in terms average retrieval precision (ARP) and average retrieval rate (ARR) as compared to LBP and LBP variant features.

Subrahmanyam Murala; Q.M. Jonathan Wu

2014-01-01T23:59:59.000Z

253

Comparative dosimetry of dental CBCT devices and 64-slice CT for oral and maxillofacial radiology  

Science Journals Connector (OSTI)

Objectives This study compares 2 measures of effective dose, E1990 and E2007, for 8 dentoalveolar and maxillofacial cone-beam computerized tomography (CBCT) units and a 64-slice multidetector CT (MDCT) unit. Study design Average tissue-absorbed dose, equivalent dose, and effective dose were calculated using thermoluminescent dosimeter chips in a radiation analog dosimetry phantom. Effective doses were derived using 1990 and the superseding 2007 International Commission on Radiological Protection (ICRP) recommendations. Results Large-field of view (FOV) CBCT E2007 ranged from 68 to 1,073 ?Sv. Medium-FOV CBCT E2007 ranged from 69 to 560 ?Sv, whereas a similar-FOV MDCT produced 860 ?Sv. The E2007 calculations were 23% to 224% greater than E1990. Conclusions The 2007 recommendations of the ICRP, which include salivary glands, extrathoracic region, and oral mucosa in the calculation of effective dose, result in an upward reassessment of fatal cancer risk from oral and maxillofacial radiographic examinations. Dental CBCT can be recommended as a dose-sparing technique in comparison with alternative medical CT scans for common oral and maxillofacial radiographic imaging tasks.

John B. Ludlow; Marija Ivanovic

2008-01-01T23:59:59.000Z

254

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

SciTech Connect (OSTI)

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

255

Thoracic target volume delineation using various maximum-intensity projection computed tomography image sets for radiotherapy treatment planning  

SciTech Connect (OSTI)

Purpose: Four-dimensional computed tomography (4D-CT) is commonly used to account for respiratory motion of target volumes in radiotherapy to the thorax. From the 4D-CT acquisition, a maximum-intensity projection (MIP) image set can be created and used to help define the tumor motion envelope or the internal gross tumor volume (iGTV). The purpose of this study was to quantify the differences in automatically contoured target volumes for usage in the delivery of stereotactic body radiation therapy using MIP data sets generated from one of the four methods: (1) 4D-CT phase-binned (PB) based on retrospective phase calculations, (2) 4D-CT phase-corrected phase-binned (PC-PB) based on motion extrema, (3) 4D-CT amplitude-binned (AB), and (4) cine CT built from all available images. Methods: MIP image data sets using each of the four methods were generated for a cohort of 28 patients who had prior thoracic 4D-CT scans that exhibited lung tumor motion of at least 1 cm. Each MIP image set was automatically contoured on commercial radiation treatment planning system. Margins were added to the iGTV to observe differences in the final simulated planning target volumes (PTVs). Results: For all patients, the iGTV measured on the MIP generated from the entire cine CT data set (iGTV{sub cine}) was the largest. Expressed as a percentage of iGTV{sub cine}, 4D-CT iGTV (all sorting methods) ranged from 83.8% to 99.1%, representing differences in the absolute volume ranging from 0.02 to 4.20 cm{sup 3}; the largest average and range of 4D-CT iGTV measurements was from the PC-PB data set. Expressed as a percentage of PTV{sub cine} (expansions applied to iGTV{sub cine}), the 4D-CT PTV ranged from 87.6% to 99.6%, representing differences in the absolute volume ranging from 0.08 to 7.42 cm{sup 3}. Regions of the measured respiratory waveform corresponding to a rapid change of phase or amplitude showed an increased susceptibility to the selection of identical images for adjacent bins. Duplicate image selection was most common in the AB implementation, followed by the PC-PB method. The authors also found that the image associated with the minimum amplitude measurement did not always correlate with the image that showed maximum tumor motion extent. Conclusions: The authors identified cases in which the MIP generated from a 4D-CT sorting process under-represented the iGTV by more than 10% or up to 4.2 cm{sup 3} when compared to the iGTV{sub cine}. They suggest utilization of a MIP generated from the full cine CT data set to ensure maximum inclusive tumor extent.

Zamora, David A.; Riegel, Adam C.; Sun Xiaojun; Balter, Peter; Starkschall, George; Mawlawi, Osama; Pan Tinsu [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

2010-11-15T23:59:59.000Z

256

PET/CT shielding design comparisons  

E-Print Network [OSTI]

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

Coker, Audra Lee

2007-09-17T23:59:59.000Z

257

TE Connectivity Finds Answers in Tomography  

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

258

Multilevel bioluminescence tomography based on radiative transfer equation  

E-Print Network [OSTI]

, "A fast forward solver of radiative transfer equation," Transport Theory and Statistical Physics 38Multilevel bioluminescence tomography based on radiative transfer equation Part 1: l1 approach for bioluminescence tomography based on radiative transfer equation with the emphasis on improving

Soatto, Stefano

259

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

260

Tomography and High-Resolution Electron Microscopy Study of Surfaces...  

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

Tomography and High-Resolution Electron Microscopy Study of Surfaces and Porosity in a Plate-Like ?-Al2O3. Tomography and High-Resolution Electron Microscopy Study of...

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

Integration and evaluation of a needle-positioning robot with volumetric microcomputed tomography image guidance for small animal stereotactic interventions  

SciTech Connect (OSTI)

Purpose: Preclinical research protocols often require insertion of needles to specific targets within small animal brains. To target biologically relevant locations in rodent brains more effectively, a robotic device has been developed that is capable of positioning a needle along oblique trajectories through a single burr hole in the skull under volumetric microcomputed tomography (micro-CT) guidance. Methods: An x-ray compatible stereotactic frame secures the head throughout the procedure using a bite bar, nose clamp, and ear bars. CT-to-robot registration enables structures identified in the image to be mapped to physical coordinates in the brain. Registration is accomplished by injecting a barium sulfate contrast agent as the robot withdraws the needle from predefined points in a phantom. Registration accuracy is affected by the robot-positioning error and is assessed by measuring the surface registration error for the fiducial and target needle tracks (FRE and TRE). This system was demonstrated in situ by injecting 200 {mu}m tungsten beads into rat brains along oblique trajectories through a single burr hole on the top of the skull under micro-CT image guidance. Postintervention micro-CT images of each skull were registered with preintervention high-field magnetic resonance images of the brain to infer the anatomical locations of the beads. Results: Registration using four fiducial needle tracks and one target track produced a FRE and a TRE of 96 and 210 {mu}m, respectively. Evaluation with tissue-mimicking gelatin phantoms showed that locations could be targeted with a mean error of 154{+-}113 {mu}m. Conclusions: The integration of a robotic needle-positioning device with volumetric micro-CT image guidance should increase the accuracy and reduce the invasiveness of stereotactic needle interventions in small animals.

Waspe, Adam C.; McErlain, David D.; Pitelka, Vasek; Holdsworth, David W.; Lacefield, James C.; Fenster, Aaron [Biomedical Engineering Graduate Program and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Department of Medical Biophysics and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Biomedical Engineering Graduate Program, Department of Medical Biophysics, Department of Medical Imaging, Department of Surgery, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Biomedical Engineering Graduate Program, Department of Electrical and Computer Engineering, Department of Medical Biophysics, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada); Biomedical Engineering Graduate Program, Department of Medical Biophysics, Department of Medical Imaging, and Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8 (Canada)

2010-04-15T23:59:59.000Z

262

Wavelength-dependent scattering in spectroscopic optical coherence tomography  

E-Print Network [OSTI]

Wavelength-dependent scattering in spectroscopic optical coherence tomography Chenyang Xu, P. Scott of light scattering spectroscopy (LSS) and the spatial localization of optical coherence tomography (OCT.4500) Optical coherence tomography; (290.0290) Scattering; (300.0300) Spectroscopy References and links 1. A

Bhargava, Rohit

263

Inverse scattering for rotationally scanned optical coherence tomography  

E-Print Network [OSTI]

Inverse scattering for rotationally scanned optical coherence tomography Daniel L. Marks, Tyler S May 16, 2006; posted May 26, 2006 (Doc. ID 67358) Optical coherence tomography of luminal structures coherence tomography1,2 (OCT), is determined in large part by the degree to which the images provide

Bhargava, Rohit

264

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

SciTech Connect (OSTI)

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

265

Investigation of self-sealing in high-strength and ultra-low-permeability concrete in water using micro-focus X-ray CT  

SciTech Connect (OSTI)

High-strength and ultra-low-permeability concrete (HSULPC) is thought to be useful as a radioactive waste package. Thus, a high confining ability is desirable. For cementitious materials, sealing of cracks may occur in water due to the precipitation of calcium compounds. This can affect the confining ability. In this study, the sealing of a crack in HSULPC in water was investigated using micro-focus X-ray computed tomography (CT). The sealing by precipitation occurred only around the end of the specimen. Sealed regions of the crack were identified using three-dimensional image registration and CT image subtraction of images obtained for the specimen before and after it was immersed in water to evaluate temporal changes of the sealing deposits in the crack. The sealing deposits increased as the HSULPC specimen was kept in water longer. It was concluded that cracks in HSULPC in water are sealed by precipitation.

Fukuda, Daisuke [Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)] [Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Nara, Yoshitaka, E-mail: nara.yoshitaka.2n@kyoto-u.ac.jp [Graduate School of Engineering, Kyoto University, Kyoto 611-8540 (Japan)] [Graduate School of Engineering, Kyoto University, Kyoto 611-8540 (Japan); Kobayashi, Yuya; Maruyama, Megumi; Koketsu, Mayuko [Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)] [Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Hayashi, Daisuke; Ogawa, Hideo [Taiheiyo Consultant Co., Ltd., Ohsaku, Sakura 285-8655 (Japan)] [Taiheiyo Consultant Co., Ltd., Ohsaku, Sakura 285-8655 (Japan); Kaneko, Katsuhiko [Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)] [Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)

2012-11-15T23:59:59.000Z

266

A Novel CBIR Approach to Differential Diagnosis of Liver Tumor on Computed Tomography Images  

Science Journals Connector (OSTI)

Liver tumor is one of the deadliest diseases which can be cured without much difficulty if diagnosed in early stages. Content based image retrieval (CBIR) constitutes an important tool in computer aided diagnosis (CAD) which improves the diagnostic decisions of the radiologist by retrieving similar pathology bearing images from the medical database. In order to assist the radiologist in diagnosis of liver cancer, this paper proposes a novel CBIR based approach for differential diagnosis of liver tumor on computed tomography (CT) images as benign or malign. First, tumor is characterized by extracting its shape features using Fourier descriptors and texture features using MPEG-7 Gabor filter and edge histogram descriptors. Next, the dimensionality of the feature vector is reduced by applying principal component analysis (PCA).Finally, similarity matching process is accelerated using cluster-based indexing. The proposed approach was tested on medical image database consisting of 764 CT images of liver tumor. The experimental results demonstrate that the proposed method can effectively and efficiently retrieve similar case images from the database in response to query image.

Megha.P. Arakeri; G. Ram Mohana Reddy

2012-01-01T23:59:59.000Z

267

Abstract --Advantages of proton computed tomography (pCT) have been recognized in the past. However, the quality of a pCT  

E-Print Network [OSTI]

estimation. A set of Monte Carlo simulations was carried out with the GEANT4 program, and reconstructed advantages in medical applications. First for diagnosis, its low-dose advantage might be utilized effectively are with the Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, CA 92354 USA. density

Mueller, Klaus

268

Reconstruction in tomography with diffracting sources  

E-Print Network [OSTI]

Homogeneous Model . . . . . . . . . . . . . . . . . . . 22 III LIMITED-VIEW THERMOACOUSTIC TOMOGRAPHY1 . . . 24 A. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . 24 1. Analysis of Singularities in Circular Radon Trans- form and Limited-view TAT... . . . . . . . . . . . . . . 26 a. Circular Radon Transform . . . . . . . . . . . . . 26 b. TAT . . . . . . . . . . . . . . . . . . . . . . . . . 27 c. Reconstruction Methods . . . . . . . . . . . . . . 30 2. Numerical Implementation . . . . . . . . . . . . . . . 35 viii CHAPTER...

Xu, Yuan

2005-02-17T23:59:59.000Z

269

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

270

Binary Tomography with Deblurring Stefan Weber1  

E-Print Network [OSTI]

two scenarios of limited-angle binary tomography with data distorted with an unknown convolution: Either the projec- tion data are taken from a blurred object, or the projection data them- selves the projection data before reconstruction (let us call them preprocessing) and then the reconstruction

Schnörr, Christoph

271

Experimental Investigation of Material Flows Within FSWs Using 3D Tomography  

SciTech Connect (OSTI)

There exists significant prior work using tracers or pre-placed hardened markers within friction stir welding (FSWing) to experimentally explore material flow within the FSW process. Our experiments replaced markers with a thin sheet of copper foil placed between the 6061 aluminum lap and butt joints that were then welded. The absorption characteristics of x-rays for copper and aluminum are significantly different allowing for non-destructive evaluation (NDE) methods such as x-ray computed tomography (CT) to be used to demonstrate the material movement within the weldment on a much larger scale than previously shown. 3D CT reconstruction of the copper components of the weldment allows for a unique view into the final turbulent state of the welding process as process parameters are varied. The x-ray CT data of a section of the weld region was collected using a cone-beam x-ray imaging system developed at the INL. Six-hundred projections were collected over 360-degrees using a 160-kVp Bremsstrahlung x-ray generator (25-micrometer focal spot) and amorphoussilicon x-ray detector. The region of the object that was imaged was about 3cm tall and 1.5cm x 1cm in cross section, and was imaged at a magnification of about 3.6x. The data were reconstructed on a 0.5x0.5x0.5 mm3 voxel grid. After reconstruction, the aluminum and copper could be easily discriminated using a gray level threshold allowing visualization of the copper components. Fractal analysis of the tomographic reconstructed material topology is investigated as a means to quantify macro level material flow based on process parameters. The results of multi-pass FSWs show increased refinement of the copper trace material. Implications of these techniques for quantifying process flow are discussed.

Charles R. Tolle; Timothy A. White; Karen S. Miller; Denis E. Clark; Herschel B. Smartt

2008-06-01T23:59:59.000Z

272

Spatial variation of void ratio and shear band thickness in sand using X-ray computed tomography  

SciTech Connect (OSTI)

A detailed study of spatial variation of void ratio and shear band thickness measurements is presented in this paper. A prismatic sand specimen that initially measured 57{center_dot}4 mm wide x 120{center_dot}5 mm long x 182{center_dot}1 mm high was sheared under plane-strain (biaxial) loading conditions. The specimen was prepared at a relative density of 79% using F-75 Ottawa sand. X-ray computed tomography was used to scan the specimen before shearing and after the onset of the shear band. The specimen failed through a single shear band with an inclination angle of 65{center_dot}6{sup o} measured from the direction of the minor principal stress. Computer algorithms were developed to calibrate CT images and quantify void ratio (e) variation within the specimen. CT data analysis revealed cross-sectional spatial variation in void ratio where density is higher in regions close to the edges of the specimen due to membrane effects and confining pressure with no significant variation in void ratio in the axial direction (top to bottom) before shearing. The shear band was easily identified from the CT images, and analysis of void ratio showed a noticeable jump in void ratio profile across the shear band. A detailed statistical summary of the thickness of the shear band and variation of void ratio across the shear band is presented and discussed.

Alshibli, K.A.; Hasan, A. (LSU)

2008-05-01T23:59:59.000Z

273

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

Office of Legacy Management (LM)

Site Operations: Conducted heat treatment tests of source material using depleted uranium in an enclosed calciner CT.14-2 Site Disposition: Eliminated - No Authority - AEC...

274

CT-121_cover.p65  

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

275

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 (OSTI)

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

276

Trends of CT Utilization in North America Over the Last Decade  

Science Journals Connector (OSTI)

Given the improvements in technology and usefulness of CT for diagnosis and therapeutic-planning, the growth in CT utilization is not surprising. Current estimates are that more than 85 million CT scans are pe...

Lauren M. B. Burke; Richard C. Semelka; Rebecca Smith-Bindman

2014-11-01T23:59:59.000Z

277

Ground-based Microwave Cloud Tomography  

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

278

Radiation Protection in Newer Medical Imaging Technologies: PET/CT  

Science Journals Connector (OSTI)

......58 timely. Safety Report Series...challenging topic of Radiation Exposure of...of various software packages is...and age. To Safety Report Series...CT dosimetry software site impactscan...its June 2006 software version fade...Management of Radiation Dose in CT...Section 5 of Safety Report Series......

Dawn Banghart

2009-07-01T23:59:59.000Z

279

CT Poison Control Center 2014 Video Contest Rules  

E-Print Network [OSTI]

entry form (found on posioncontrol.uchc.edu) b. Include a link to your video from your You Tube account and community partners. Judges will consider: length of video, appropriate format, accuracy of information poison center means to you, value of the CT Poison Control Center · Programming your phone with the CT

Kim, Duck O.

280

On recent claims concerning the Rh=ct Universe  

Science Journals Connector (OSTI)

......density rho. One-on-one comparative tests between R h-=-ct and lambdaCDM have...corollary (see also Weinberg 1972). To test whether in fact the EOS p-=-rho/3...carried out an extensive suite of comparative tests using lambdaCDM and R h-=-ct, together......

Fulvio Melia

2015-01-01T23:59:59.000Z

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.


281

Efficient and facile delivery of gold nanoparticles in vivo using dissolvable microneedles for contrast-enhanced optical coherence tomography  

E-Print Network [OSTI]

J. G. Fujimoto, Optical coherence tomography, Science 254(and imaging using optical coherence tomography, Nat. Med.J. G. Fujimoto, Optical coherence tomography for optical

Kim, Chang Soo; Ahn, Yeh-Chan; Wilder-Smith, Petra; Oh, Seajin; Chen, Zhongping; Kwon, Young Jik

2010-01-01T23:59:59.000Z

282

Spectral-domain optical coherence tomography of conjunctival mucosa-associated lymphoid tissue lymphoma with presumed choroidal involvement  

E-Print Network [OSTI]

lymphoid tissue . MALT . Optical coherence tomography . OCTdo not include ocular coherence tomography (OCT). We presentSpectral-domain optical coherence tomography of conjunctival

Williams, Basil K.; Tsui, Irena; McCannel, Tara A.

2010-01-01T23:59:59.000Z

283

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

SciTech Connect (OSTI)

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

284

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

SciTech Connect (OSTI)

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

285

Contouring Variability of the Penile Bulb on CT Images: Quantitative Assessment Using a Generalized Concordance Index  

SciTech Connect (OSTI)

Purpose: Within a multicenter study (DUE-01) focused on the search of predictors of erectile dysfunction and urinary toxicity after radiotherapy for prostate cancer, a dummy run exercise on penile bulb (PB) contouring on computed tomography (CT) images was carried out. The aim of this study was to quantitatively assess interobserver contouring variability by the application of the generalized DICE index. Methods and Materials: Fifteen physicians from different Institutes drew the PB on CT images of 10 patients. The spread of DICE values was used to objectively select those observers who significantly disagreed with the others. The analyses were performed with a dedicated module in the VODCA software package. Results: DICE values were found to significantly change among observers and patients. The mean DICE value was 0.67, ranging between 0.43 and 0.80. The statistics of DICE coefficients identified 4 of 15 observers who systematically showed a value below the average (p value range, 0.013 - 0.059): Mean DICE values were 0.62 for the 4 'bad' observers compared to 0.69 of the 11 'good' observers. For all bad observers, the main cause of the disagreement was identified. Average DICE values were significantly worse from the average in 2 of 10 patients (0.60 vs. 0.70, p < 0.05) because of the limited visibility of the PB. Excluding the bad observers and the 'bad' patients,' the mean DICE value increased from 0.67 to 0.70; interobserver variability, expressed in terms of standard deviation of DICE spread, was also reduced. Conclusions: The obtained values of DICE around 0.7 shows an acceptable agreement, considered the small dimension of the PB. Additional strategies to improve this agreement are under consideration and include an additional tutorial of the so-called bad observers with a recontouring procedure, or the recontouring by a single observer of the PB for all patients included in the DUE-01 study.

Carillo, Viviana [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Cozzarini, Cesare [Department of Radiotherapy, San Raffaele Scientific Institute, Milano (Italy)] [Department of Radiotherapy, San Raffaele Scientific Institute, Milano (Italy); Perna, Lucia; Calandra, Mauro [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Gianolini, Stefano [Medical Software Solutions GmbH, Hagendorn (Switzerland)] [Medical Software Solutions GmbH, Hagendorn (Switzerland); Rancati, Tiziana [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy)] [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy); Spinelli, Antonello Enrico [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy); Vavassori, Vittorio [Department of Radiotherapy, Cliniche Gavazzeni Humanitas, Bergamo (Italy)] [Department of Radiotherapy, Cliniche Gavazzeni Humanitas, Bergamo (Italy); Villa, Sergio [Department of Radiotherapy 1, IRCCS National Institute of Cancer, Milano (Italy)] [Department of Radiotherapy 1, IRCCS National Institute of Cancer, Milano (Italy); Valdagni, Riccardo [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy) [Prostate Cancer Program, IRCCS National Institute of Cancer, Milano (Italy); Department of Radiotherapy 1, IRCCS National Institute of Cancer, Milano (Italy); Fiorino, Claudio, E-mail: fiorino.claudio@hsr.it [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)] [Department of Medical Physics, San Raffaele Scientific Institute, Milano (Italy)

2012-11-01T23:59:59.000Z

286

Best fit refractive index of matching liquid for 3D NIPAM gel dosimeters using optical CT  

Science Journals Connector (OSTI)

Abstract The accuracy of an optical computed tomography (CT)-based dosimeter is significantly affected by the refractive index (RI) of the matching liquid. Mismatched RI induces reflection and refraction as the laser beam passes through the gel phantom. Moreover, the unwanted light rays collected by the photodetector produce image artifacts after image reconstruction from the collected data. To obtain the best image quality, this study investigates the best-fit RI of the matching liquid for a 3D NIPAM gel dosimeter. The three recipes of NIPAM polymer gel used in this study consisted of 5% gelatin, 5% NIPAM and 3% N,N'-methylene bisacrylamide, which were combined with three compositions (5, 10, and 20mM) of Tetrakis (hydroxymethyl) phosphonium chloride. Results were evaluated using a quantitative evaluation method of the gamma evaluation technique. Results showed that the best-fit RI for the non-irradiated NIPAM gel ranges from 1.340 to 1.346 for various NIPAM recipes with sensitivities ranging from 0.0113 to 0.0227. The greatest pass rate of 88.00% is achieved using best-fit RI=1.346 of the matching liquid. The adoption of mismatching RI decreases the gamma pass rate by 2.63% to 16.75% for all three recipes of NIPAM gel dosimeters. In addition, the maximum average deviation is less than 0.1% for the red and transparent matching liquids. Thus, the color of the matching liquid does not affect the measurement accuracy of the NIPAM gel dosimeter, as measured by optical CT.

Chin-Hsing Chen; Jay Wu; Bor-Tsung Hsieh; De-Shiou Chen; Tzu-Hwei Wang; Sou-Hsin Chien; Yuan-Jen Chang

2014-01-01T23:59:59.000Z

287

Reducing metal artifacts in cone-beam CT images by preprocessing projection data  

SciTech Connect (OSTI)

Purpose: Computed tomography (CT) streak artifacts caused by metallic implants remain a challenge for the automatic processing of image data. The impact of metal artifacts in the soft-tissue region is magnified in cone-beam CT (CBCT), because the soft-tissue contrast is usually lower in CBCT images. The goal of this study was to develop an effective offline processing technique to minimize the effect. Methods and Materials: The geometry calibration cue of the CBCT system was used to track the position of the metal object in projection views. The three-dimensional (3D) representation of the object can be established from only two user-selected viewing angles. The position of the shadowed region in other views can be tracked by projecting the 3D coordinates of the object. Automatic image segmentation was used followed by a Laplacian diffusion method to replace the pixels inside the metal object with the boundary pixels. The modified projection data were then used to reconstruct a new CBCT image. The procedure was tested in phantoms, prostate cancer patients with implanted gold markers and metal prosthesis, and a head-and-neck patient with dental amalgam in the teeth. Results: Both phantom and patient studies demonstrated that the procedure was able to minimize the metal artifacts. Soft-tissue visibility was improved near or away from the metal object. The processing time was 1-2 s per projection. Conclusion: We have implemented an effective metal artifact-suppressing algorithm to improve the quality of CBCT images.

Zhang Yongbin [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Zhang Lifei [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Zhu, X. Ronald [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Lee, Andrew K. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Chambers, Mark [Department of Dental Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Dong Lei [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)]. E-mail: ldong@mdanderson.org

2007-03-01T23:59:59.000Z

288

Pediatric CT scan usage in Japan: results of a hospital survey  

Science Journals Connector (OSTI)

CT radiation dose settings are adjusted for children based on guidelines issued by the Japan Radiological Society, with few limitations. CT...

Nader Ghotbi; Akira Ohtsuru; Yoji Ogawa; Mariko Morishita

2006-10-01T23:59:59.000Z

289

Microsoft Word - Ct121R1.doc  

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

290

CT113-53 Cape Wind Report_  

Broader source: Energy.gov (indexed) [DOE]

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

291

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

292

A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability  

SciTech Connect (OSTI)

We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d{sub 31} coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices.

Wang, Qi; Wang, Junting; Lu, Qingyou, E-mail: qxl@ustc.edu.cn [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China) [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China); Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Hou, Yubin [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China)] [High Magnetic Field Laboratory, Chinese Academy of Sciences and University of Science and Technology of China, Hefei, Anhui 230026 (China)

2013-11-15T23:59:59.000Z

293

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

Open Energy Info (EERE)

to the Coso geothermal area, 1996-2006 Abstract Measurements of temporal changes in Earth structure are commonly determined using local earthquake tomography computer programs...

294

Emerging trends in cone-beam computed tomography utilization.  

E-Print Network [OSTI]

?? Utilization of cone-beam computed tomography (CBCT) provides precise and interactive images, which facilitate the diagnosis of dental disease and guided therapy. As with any (more)

Boyle, Elizabeth M.

2010-01-01T23:59:59.000Z

295

White-Etching Crack Failure Overview, Tomography Analysis, and...  

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

White-Etching Crack Failure Overview, Tomography Analysis, and Test Development Presented by Aaron Greco of Argonne National Laboratory at the Wind Turbine Tribology Seminar 2014....

296

Three-Dimensional Thermal Tomography Advances Cancer Treatment...  

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

Three-Dimensional Thermal Tomography Advances Cancer Treatment Technology available for licensing: A 3D technique to detect early skin changes due to radiation treatment in breast...

297

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

SciTech Connect (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

298

A hybrid approach for rapid, accurate, and direct kilovoltage radiation dose calculations in CT voxel space  

SciTech Connect (OSTI)

Purpose: To develop and validate a fast and accurate method that uses computed tomography (CT) voxel data to estimate absorbed radiation dose at a point of interest (POI) or series of POIs from a kilovoltage (kV) imaging procedure. Methods: The authors developed an approach that computes absorbed radiation dose at a POI by numerically evaluating the linear Boltzmann transport equation (LBTE) using a combination of deterministic and Monte Carlo (MC) techniques. This hybrid approach accounts for material heterogeneity with a level of accuracy comparable to the general MC algorithms. Also, the dose at a POI is computed within seconds using the Intel Core i7 CPU 920 2.67 GHz quad core architecture, and the calculations are performed using CT voxel data, making it flexible and feasible for clinical applications. To validate the method, the authors constructed and acquired a CT scan of a heterogeneous block phantom consisting of a succession of slab densities: Tissue (1.29 cm), bone (2.42 cm), lung (4.84 cm), bone (1.37 cm), and tissue (4.84 cm). Using the hybrid transport method, the authors computed the absorbed doses at a set of points along the central axis and x direction of the phantom for an isotropic 125 kVp photon spectral point source located along the central axis 92.7 cm above the phantom surface. The accuracy of the results was compared to those computed with MCNP, which was cross-validated with EGSnrc, and served as the benchmark for validation. Results: The error in the depth dose ranged from -1.45% to +1.39% with a mean and standard deviation of -0.12% and 0.66%, respectively. The error in the x profile ranged from -1.3% to +0.9%, with standard deviations of -0.3% and 0.5%, respectively. The number of photons required to achieve these results was 1x10{sup 6}. Conclusions: The voxel-based hybrid method evaluates the LBTE rapidly and accurately to estimate the absorbed x-ray dose at any POI or series of POIs from a kV imaging procedure.

Kouznetsov, Alexei; Tambasco, Mauro [Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Department of Physics and Astronomy and Department of Oncology, University of Calgary and Tom Baker Cancer Centre, 1331-29 Street NW Calgary, Alberta T2N 4N2 (Canada)

2011-03-15T23:59:59.000Z

299

Tumor Tracking Method Based on a Deformable 4D CT Breathing Motion Model Driven by an External Surface Surrogate  

SciTech Connect (OSTI)

Purpose: To develop a tumor tracking method based on a surrogate-driven motion model, which provides noninvasive dynamic localization of extracranial targets for the compensation of respiration-induced intrafraction motion in high-precision radiation therapy. Methods and Materials: The proposed approach is based on a patient-specific breathing motion model, derived a priori from 4-dimensional planning computed tomography (CT) images. Model parameters (respiratory baseline, amplitude, and phase) are retrieved and updated at each treatment fraction according to in-room radiography acquisition and optical surface imaging. The baseline parameter is adapted to the interfraction variations obtained from the daily cone beam (CB) CT scan. The respiratory amplitude and phase are extracted from an external breathing surrogate, estimated from the displacement of the patient thoracoabdominal surface, acquired with a noninvasive surface imaging device. The developed method was tested on a database of 7 lung cancer patients, including the synchronized information on internal and external respiratory motion during a CBCT scan. Results: About 30 seconds of simultaneous acquisition of CBCT and optical surface images were analyzed for each patient. The tumor trajectories identified in CBCT projections were used as reference and compared with the target trajectories estimated from surface displacement with the a priori motion model. The resulting absolute differences between the reference and estimated tumor motion along the 2 image dimensions ranged between 0.7 and 2.4 mm; the measured phase shifts did not exceed 7% of the breathing cycle length. Conclusions: We investigated a tumor tracking method that integrates breathing motion information provided by the 4-dimensional planning CT with surface imaging at the time of treatment, representing an alternative approach to point-based externalinternal correlation models. Although an in-room radiograph-based assessment of the reliability of the motion model is envisaged, the developed technique does not involve the estimation and continuous update of correlation parameters, thus requiring a less intense use of invasive imaging.

Fassi, Aurora, E-mail: aurora.fassi@mail.polimi.it [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Schaerer, Jol; Fernandes, Mathieu [CREATIS, CNRS UMR 5220, INSERM U1044, Universit Lyon 1, INSA-Lyon, Villeurbanne (France); Department of Radiotherapy, Centre Lon Brard, Lyon (France); Riboldi, Marco [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy); Sarrut, David [CREATIS, CNRS UMR 5220, INSERM U1044, Universit Lyon 1, INSA-Lyon, Villeurbanne (France); Department of Radiotherapy, Centre Lon Brard, Lyon (France); Baroni, Guido [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy)

2014-01-01T23:59:59.000Z

300

Screening of mixed surfactant systems: Phase behavior studies and CT imaging of surfactant-enhanced oil recovery experiments  

SciTech Connect (OSTI)

A systematic chemical screening study was conducted on selected anionic-nonionic and nonionic-nonionic systems. The objective of the study was to evaluate and determine combinations of these surfactants that would exhibit favorable phase behavior and solubilization capacity. The effects of different parameters including (a) salinity, (b) temperature, (c) alkane carbon number, (c) hydrophilic/lipophilic balance (HLB) of nonionic component, and (d) type of surfactant on the behavior of the overall chemical system were evaluated. The current work was conducted using a series of ethoxylated nonionic surfactants in combinations of several anionic systems with various hydrocarbons. Efforts to correlate the behavior of these mixed systems led to the development of several models for the chemical systems tested. The models were used to compare the different systems and provided some guidelines for formulating them to account for variations in salinity, oil hydrocarbon number, and temperature. The models were also evaluated to determine conformance with the results from experimental measurements. The models provided good agreement with experimental results. X-ray computed tomography (CT) was used to study fluid distributions during chemical enhanced oil recovery experiments. CT-monitored corefloods were conducted to examine the effect of changing surfactant slug size injection on oil bank formation and propagation. Reducing surfactant slug size resulted in lower total oil production. Oil recovery results, however, did not correlate with slug size for the low-concentration, alkaline, mixed surfactant system used in these tests. The CT measurements showed that polymer mobility control and core features also affected the overall oil recovery results.

Llave, F.M.; Gall, B.L.; Lorenz, P.B.; Cook, I.M.; Scott, L.J.

1993-11-01T23:59:59.000Z

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

TH?D?201C?08: Multi?Modal MRI SPECT and CT Imaging of Theranostic Nanoplatforms  

Science Journals Connector (OSTI)

Purpose: The development of non?invasive imaging techniques for the assessment of cancer treatment is rapidly becoming highly important. Magnetic Cationic Liposomes (MCL) that carry a cargo of anti?cancer drugs and magnetic nanoparticles that will selectively target primary and metastatic cancertumorsdeliver drugs to them and visualize their effects through magnetic resonance imaging(MRI)single photon emission computed tomography(SPECT) and fluorescence spectroscopy. The aim of the present study is to evaluate MCL as a versatile theranostic nanoplatform for enhanced drug deliveryimaging and monitoring of cancer treatment. Materials and Method: Poly?ethyleneglycol (PEG) coated cationic liposomes are loaded with superparamagnetic iron oxide nanoparticles (SPIONS) and tagged with the radioisotope Indium?111. MCL was administered to SCID mouse with metastatic (B16?F10) melanoma grown in the right flank. Pre?injection and post?injection MR and SPECT/CT images were used to assess response to magnetic targeting effects and tumor and organ distribution. Results:Tumor signal intensities in T2 weighted images decreased an average of 205% and T2* values decreased and average of 147ms in the absence of magnetic targeting. This compares to an average signal decrease of 5712% and a decrease in T2* relaxation times of 278ms with the aid of external magnet showing up to 2?fold greater accumulation by magnetic targeting. SPECT/CT images showed the localization and distribution of MCL in the tumor.Conclusion: MR SPECT/CT and biodistribution analyses clearly show the efficacy of MCL as MRI contrast agents prove the use of magnetic guidance and demonstrate the potential of MCL as agents for imaging guidance and therapeutic delivery.

F Reynoso; E Gultepe; A Jhaveri; P Kulkarni; B Gershman; C Ferris; R Campbell; M Harisinghani; S Sridhar

2010-01-01T23:59:59.000Z

302

Survey of clinical doses from computed tomography examinations in the Canadian province of Manitoba  

Science Journals Connector (OSTI)

......scanners were computed. The Kruskal-Wallis test was used to compare the...scanners were calculated. The Kruskal-Wallis test was used to compare dose...all protocols considered. The Kruskal-Wallis test resulted in p 0.0001 for......

Idris A. Elbakri; Iain D. C. Kirkpatrick

2013-12-01T23:59:59.000Z

303

Direct Sampling Method for Diffusive Optical Tomography  

E-Print Network [OSTI]

In this work, we are concerned with the diffusive optical tomography (DOT) problem in the case when only one or two pairs of Cauchy data is available. We propose a simple and efficient direct sampling method (DSM) to locate inhomogeneities inside a homogeneous background and solve the DOT problem in both full and limited aperture cases. This new method is easy to implement and less expensive computationally. Numerical experiments demonstrate its effectiveness and robustness against noise in the data. This provides a new promising numerical strategy for the DOT problem.

Yat Tin Chow; Kazufumi Ito; Keji Liu; Jun Zou

2014-10-06T23:59:59.000Z

304

Double common-path interferometer for flexible optical probe of optical coherence tomography  

E-Print Network [OSTI]

J. Fujimoto, Optical coherence tomography, Science 254(D. E. N. Davies, Optical coherence-domain reflectometry: afiber common-path optical coherence tomography: sensitivity

Park, Jae Seok; Chen, Zhongping; Jeong, Myung Yung; Kim, Chang-Seok

2012-01-01T23:59:59.000Z

305

High-speed upper-airway imaging using full-range optical coherence tomography  

E-Print Network [OSTI]

Huang et al. , Optical coherence tomography, Science 254(endoscopic long-range optical coherence tomogra- phy, Opt.tracking with optical coherence tomography: proof-of-

Jing, Joseph; Zhang, Jun; Loy, Anthony Chin; Wong, Brian F.; Chen, Zhongping

2012-01-01T23:59:59.000Z

306

XEDS STEM Tomography For 3D Chemical CharacterizationOf Nanoscale...  

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

XEDS STEM Tomography For 3D Chemical CharacterizationOf Nanoscale Particles. XEDS STEM Tomography For 3D Chemical CharacterizationOf Nanoscale Particles. Abstract: We present a...

307

E-Print Network 3.0 - artery computed tomography Sample Search...  

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

computed tomography Search Powered by Explorit Topic List Advanced Search Sample search results for: artery computed tomography Page: << < 1 2 3 4 5 > >> 1 Abstract Computed...

308

The Role of Computed Tomography in the Management of the Neck After Chemoradiotherapy in Patients With Head-and-Neck Cancer  

SciTech Connect (OSTI)

Purpose: The aim of this study was to describe the outcome in patients with head-and neck-squamous cell carcinoma (HNSCC) followed up without neck dissection (ND) after concomitant chemoradiotherapy (CRT) based on computed tomography (CT) response. The second objective was to establish CT characteristics that can predict which patients can safely avoid ND. Methods and Materials: Between 1998 and 2007, 369 patients with node-positive HNSCC were treated with primary CRT at our institution. After a clinical and a radiologic evaluation based on CT done 6 to 8 weeks after CRT, patients were labeled with a complete neck response (CR) or with a partial neck response (PR). Results: The median follow-up was 44 months. The number of patients presenting with N3, N2, or N1 disease were 54 (15%), 268 (72%), and 47 (13%), respectively. After CRT, 263 (71%) patients reached a CR, and 253 of them did not undergo ND. Ninety-six patients reached a PR and underwent ND. Of those, 34 (35%) had residual disease on pathologic evaluation. A regression of the diameter of {>=}80% and a residual largest diameter of 15 mm of nodes had negative pathologic predictive values of 100% and 86%, respectively. The 3-year regional control and survival rates were not different between patients with CR who had no ND and patients with PR followed by ND. Conclusion: Node-positive patients presenting a CR as determined by CT evaluation 6 to 8 weeks after CRT had a low rate of regional recurrence without ND. This study also suggests that lymph node residual size and percentage of regression on CT after CRT may be useful criteria to guide clinical decisions regarding neck surgery. Those results can help diminish the number of ND procedures with negative results and their associated surgical complications.

Clavel, Sebastien, E-mail: sebastien.clavel@umontreal.ca [Department of Radiation Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Charron, Marie-Pierre [Faculte de medicine, Universite de Montreal, Montreal, Quebec (Canada); Belair, Manon [Department of Radiology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Delouya, Guila; Fortin, Bernard; Despres, Philippe [Department of Radiation Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Soulieres, Denis [Department of Medical Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Filion, Edith [Department of Radiation Oncology, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); Guertin, Louis [Department of Head and Neck Surgery, Centre hospitalier de l'Universite de Montreal, Montreal, Quebec (Canada); and others

2012-02-01T23:59:59.000Z

309

Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem  

SciTech Connect (OSTI)

Neutron radiography and computed tomography are commonly used techniques to non-destructively examine materials. Tomography refers to the cross-sectional imaging of an object from either transmission or reflection data collected by illuminating the object from many different directions.

William Charlton

2007-07-01T23:59:59.000Z

310

Neutron Stimulated Emission Computed Tomography of Stable Isotopes  

E-Print Network [OSTI]

Neutron Stimulated Emission Computed Tomography of Stable Isotopes Carey E. Floyd Jr.*ab , Calvin North Carolina Keywords: imaging, neutrons, tomography, spectroscopy ABSTRACT Here we report on the development of a new molecular imaging technique using inelastic scattering of fast neutrons. Earlier studies

311

Measuring the Kuroshio Current with ocean acoustic tomography Naokazu Taniguchia)  

E-Print Network [OSTI]

Measuring the Kuroshio Current with ocean acoustic tomography Naokazu Taniguchia) Graduate School 29 April 2013) Ocean current profiling using ocean acoustic tomography (OAT) was conducted proportional to temperature) and current in the ocean (Munk et al., 1995). Other than coastal sea studies (e

Frandsen, Jannette B.

312

Multilevel bioluminescence tomography based on radiative transfer equation  

E-Print Network [OSTI]

Multilevel bioluminescence tomography based on radiative transfer equation Part 2: total variation with both l1 and total- variation norm for bioluminescence tomography based on radiative transfer equation, Radiative Transfer (Dover Publications, 1960). 14. K. M. Case and P. F. PF Zweifel, Linear Transport Theory

Soatto, Stefano

313

Dynamic Computed Tomography, an algebraic reconstruction method with  

E-Print Network [OSTI]

in Grenoble. Finally, I wish to thank the people from the department of International Relations of University whilst improving accuracy. Some of its cur- rect research projects are about dynamic tomography . . . . . . . . . . . . . . . . . . . . . 9 2 Basic tools for Computed Tomography 10 2.1 The Radon Transform

Promayon, Emmanuel

314

Total variation based Fourier reconstruction and regularization for computer tomography  

E-Print Network [OSTI]

of the reconstruted image. Insufficiency of data may be caused by the undersampling of projections, by the limitedTotal variation based Fourier reconstruction and regularization for computer tomography Xiao. Index Terms-- Computer tomography, reconstruction, regular- ization, iterative method, Fourier method

Zhang, Xiaoqun

315

Full-wavelet approach for fluorescence diffuse optical tomography  

E-Print Network [OSTI]

Full-wavelet approach for fluorescence diffuse optical tomography with structured illumination Leonardo da Vinci 32, I-20133 Milan, Italy 3 Centre for Medical Image Computing, University College London); published October 28, 2010 We present a fast reconstruction method for fluorescence optical tomography

Boyer, Edmond

316

Propagation Beam Consideration for 3D THz Computed Tomography  

E-Print Network [OSTI]

Propagation Beam Consideration for 3D THz Computed Tomography B. Recur, 1, J.P. Guillet, 2 I. Manek, "Refraction losses in terahertz computed tomography," Opt. Commun. 283, 2050­2055 (2010). 8. S. Nadar, H, "Accelerated image reconstruction using ordered subsets of projection data," IEEE Trans. Med. Imaging 13, 601

Boyer, Edmond

317

Registration of Planar Film Radiographs with Computed Tomography  

E-Print Network [OSTI]

Registration of Planar Film Radiographs with Computed Tomography Lisa M. Gottesfeld Brown lisabHigh University Bethlehem, PA 18015 Abstract In this paper we describe a method to register Computed Tomography, high resolution, three dimensional, structural med- ical images, such as data from X-ray computed

Boult, Terrance E.

318

Cone-based electrical resistivity tomography Adam Pidlisecky1  

E-Print Network [OSTI]

Cone-based electrical resistivity tomography Adam Pidlisecky1 , Rosemary Knight1 , and Eldad Haber2 and transport of the contaminants. Borehole- based electrical resistivity tomography ERT is a geophysical meth. The measurements yield values of resistance that can be inverted to determine the subsurface electrical

Knight, Rosemary

319

Multi-atlas segmentation in head and neck CT scans  

E-Print Network [OSTI]

We investigate automating the task of segmenting structures in head and neck CT scans, to minimize time spent on manual contouring of structures of interest. We focus on the brainstem and left and right parotids. To generate ...

Arbisser, Amelia M

2012-01-01T23:59:59.000Z

320

Obscure pulmonary masses: bronchial impaction revealed by CT  

SciTech Connect (OSTI)

Dilated bronchi impacted with mucus or tumor are recognized on standard chest radiographs because they are surrounded by aerated pulmonary parenchyma. When imaged in different projections, these lesions produce a variety of appearances that are generally familiar. This report characterizes less familiar computed tomographic (CT) findings in eight patients with pathologic bronchial distension of congenital, neoplastic, or infectious etiologies and correlates them with chest films. In seven patients, CT readily revealed dilated bronchi and/or regional lung hypodensity. In four of these cases, CT led to the initial suspicion of dilated bronchi. CT should be used early in the evaluation of atypical pulmonary mass lesions or to confirm suspected bronchial impaction because of the high probability it will reveal diagnostic features.

Pugatch, R.D.; Gale, M.E.

1983-11-01T23:59:59.000Z

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.


321

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

322

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

Science Journals Connector (OSTI)

A fusion reactor is described in which a moving string ... conducting cylinder where the plasma is heated to fusion-producing temperature. The CT then passes into a blanketed region where fusion energy is produce...

Charles W. Hartman; David B. Reisman; Harry S. McLean

2008-06-01T23:59:59.000Z

323

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

SciTech Connect (OSTI)

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

324

Radiation Dose Metrics in CT: Assessing Dose Using the National Quality Forum CT Patient Safety Measure  

Science Journals Connector (OSTI)

Purpose The National Quality Forum (NQF) is a nonprofit consensus organization that recently endorsed a measure focused on CT radiation doses. To comply, facilities must summarize the doses from consecutive scans within age and anatomic area strata and report the data in the medical record. Our purpose was to assess the time needed to assemble the data and to demonstrate how review of such data permits a facility to understand doses. Methods and Materials To assemble the data we used for analysis, we used the dose monitoring softwareeXposure to automatically export dose metrics from consecutive scans in 2010 and 2012. For a subset of 50exams, we also collected dose metrics manually, copying data directly from the PACS into an excel spreadsheet. Results Manual data collection for 50 scans required 2 hours and 15 minutes. eXposure compiled the data in under an hour. All dose metrics demonstrated a 30% to 50% reduction between 2010 and 2012. There was also a significant decline and a reduction in the variability of the doses over time. Conclusion The NQF measure facilitates an institution's capacity to assess the doses they are using for CT as part of routine practice. The necessary data can be collected within a reasonable amount of time either with automatic software or manually. The collection and review of these data will allow facilities to compare their radiation dose distributions with national distributions and allow assessment of temporal trends in the doses they are using.

Jillian Keegan; Diana L. Miglioretti; Robert Gould; Lane F. Donnelly; Nicole D. Wilson; Rebecca Smith-Bindman

2014-01-01T23:59:59.000Z

325

Impact of Four-Dimensional Computed Tomography Pulmonary Ventilation Imaging-Based Functional Avoidance for Lung Cancer Radiotherapy  

SciTech Connect (OSTI)

Purpose: To quantify the dosimetric impact of four-dimensional computed tomography (4D-CT) pulmonary ventilation imaging-based functional treatment planning that avoids high-functional lung regions. Methods and Materials: 4D-CT ventilation images were created from 15 non-small-cell lung cancer patients using deformable image registration and quantitative analysis of the resultant displacement vector field. For each patient, anatomic and functional plans were created for intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). Consistent beam angles and dose-volume constraints were used for all cases. The plans with Radiation Therapy Oncology Group (RTOG) 0617-defined major deviations were modified until clinically acceptable. Functional planning spared the high-functional lung, and anatomic planning treated the lungs as uniformly functional. We quantified the impact of functional planning compared with anatomic planning using the two- or one-tailed t test. Results: Functional planning led to significant reductions in the high-functional lung dose, without significantly increasing other critical organ doses, but at the expense of significantly degraded the planning target volume (PTV) conformity and homogeneity. The average reduction in the high-functional lung mean dose was 1.8 Gy for IMRT (p < .001) and 2.0 Gy for VMAT (p < .001). Significantly larger changes occurred in the metrics for patients with a larger amount of high-functional lung adjacent to the PTV. Conclusion: The results of the present study have demonstrated the impact of 4D-CT ventilation imaging-based functional planning for IMRT and VMAT for the first time. Our findings indicate the potential of functional planning in lung functional avoidance for both IMRT and VMAT, particularly for patients who have high-functional lung adjacent to the PTV.

Yamamoto, Tokihiro, E-mail: Tokihiro@stanford.ed [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); Kabus, Sven; Berg, Jens von; Lorenz, Cristian [Department of Digital Imaging, Philips Research Europe, Hamburg (Germany); Keall, Paul J. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States)

2011-01-01T23:59:59.000Z

326

Computed Tomography-Guided High-Dose-Rate Brachytherapy in Hepatocellular Carcinoma: Safety, Efficacy, and Effect on Survival  

SciTech Connect (OSTI)

Purpose: To determine the saftety and efficacy of computed tomography (CT)-guided brachytherapy in hepatocellular carcinoma (HCC). Methods and Materials: A total of 83 patients were recruited, presenting with 140 HCC- lesions. Treatment was performed by CT-guided high-dose-rate (HDR) brachytherapy with an iridium-192 source. The primary endpoint was time to progression; secondary endpoints included local tumor control and overall survival (OS). A matched-pair analysis with patients not receiving brachytherapy was performed. Match criteria included the Cancer of the Liver Italian Program (CLIP) score, alpha-fetoprotein, presence, and extent of multifocal disease. For statistical analysis, Kaplan-Meier and Cox regression were performed. Results: Mean and median cumulative TTP for all patients (n = 75) were 17.7 and 10.4 months. Five local recurrences were observed. The OS after inclusion reached median times of 19.4 months (all patients), 46.3 months (CLIP score, 0), 20.6 months (CLIP score, 1) 12.7 months, (CLIP score, 2), and 8.3 months (CLIP score, {>=}3). The 1- and 3-year OS were 94% and 65% (CLIP score, 0), 69% and 12% (CLIP score, 1), and 48% and 19% (CLIP score, 2), respectively. Nine complications requiring intervention were encountered in 124 interventions. Matched-pair analysis revealed a significantly longer OS for patients undergoing CT-guided brachytherapy. Conclusion: Based on our results the study treatment could be safely performed. The study treatment had a beneficial effect on OS in patients with advanced HCC, with respect to (and depending on) the CLIP score and compared with OS in a historical control group. A high rate of local control was also observed, regardless of applied dose in a range of 15 to 25 Gy.

Mohnike, Konrad; Wieners, Gero; Schwartz, Franziska; Seidensticker, Max; Pech, Maciej; Ruehl, Ricarda [Klinik fuer Radiologie und Nuklearmedizin, Otto von Guericke University, Magdeburg (Germany); Wust, Peter [Klinik fuer Strahlentherapie, Charite Universitaetsmedizin, Berlin (Germany); Lopez-Haenninen, Enrique [Klinik fuer Radiologie und Nuklearmedizin, Martin-Luther-Krankenhaus, Berlin (Germany); Gademann, Guenther; Peters, Nils [Klinik fuer Strahlentherapie, Otto von Guericke University, Magdeburg (Germany); Berg, Thomas [Medizinische Klinik mit Schwerpunkt Hepato-Gastroenterologie, Charite Universitaetsmedizin, Berlin (Germany); Malfertheiner, Peter [Klinik fuer Gastroenterologie und Hepatologie, Otto von Guericke University, Magdeburg (Germany); Ricke, Jens, E-mail: ricke@med.ovgu.d [Klinik fuer Radiologie und Nuklearmedizin, Otto von Guericke University, Magdeburg (Germany)

2010-09-01T23:59:59.000Z

327

Utility of Megavoltage Fan-Beam CT for Treatment Planning in a Head-And-Neck Cancer Patient with Extensive Dental Fillings Undergoing Helical Tomotherapy  

SciTech Connect (OSTI)

The purpose of this study was to demonstrate the potential utility of megavoltage fan-beam computed tomography (MV-FBCT) for treatment planning in a patient undergoing helical tomotherapy for nasopharyngeal carcinoma in the presence of extensive dental artifact. A 28-year-old female with locally advanced nasopharyngeal carcinoma presented for radiation therapy. Due to the extensiveness of the dental artifact present in the oral cavity kV-CT scan acquired at simulation, which made treatment planning impossible on tomotherapy planning system, MV-FBCT imaging was obtained using the HI-ART tomotherapy treatment machine, with the patient in the treatment position, and this information was registered with her original kV-CT scan for the purposes of structure delineation, dose calculation, and treatment planning. To validate the feasibility of the MV-FBCT-generated treatment plan, an electron density CT phantom (model 465, Gammex Inc., Middleton, WI) was scanned using MV-FBCT to obtain CT number to density table. Additionally, both a 'cheese' phantom (which came with the tomotherapy treatment machine) with 2 inserted ion chambers and a generic phantom called Quasar phantom (Modus Medical Devices Inc., London, ON, Canada) with one inserted chamber were used to confirm dosimetric accuracy. The MV-FBCT could be used to clearly visualize anatomy in the region of the dental artifact and provide sufficient soft-tissue contrast to assist in the delineation of normal tissue structures and fat planes. With the elimination of the dental artifact, the MV-FBCT images allowed more accurate dose calculation by the tomotherapy system. It was confirmed that the phantom material density was determined correctly by the tomotherapy MV-FBCT number to density table. The ion chamber measurements agreed with the calculations from the MV-FBCT generated phantom plan within 2%. MV-FBCT may be useful in radiation treatment planning for nasopharyngeal cancer patients in the setting of extensive dental artifacts.

Yang, Claus; Liu Tianxiao; Jennelle, Richard L.; Ryu, Janice K.; Vijayakumar, Srinivasan; Purdy, James A. [Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, CA (United States); Chen, Allen M. [Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, CA (United States)], E-mail: allen.chen@ucdmc.ucdavis.edu

2010-07-01T23:59:59.000Z

328

Oblique Soft X-Ray Tomography as a Non-Destructive Method for Morphology Diagnostics in Degradation of Proton-Exchange Membrane Fuel Cell  

Science Journals Connector (OSTI)

Abstract Diagnostics of performance degradation is important for improving the durability of proton-exchange membrane (PEM) fuel cells. X-ray computed tomography (CT) is a valuable non-destructive method to study the internal structure of PEM fuel cells. However, sample cutting is usually needed for high-resolution observations, which prevents the observer from obtaining information about morphology changes during fuel cell testing. In this study, oblique soft X-ray CT has been developed and its suitability as a non-destructive method for PEM fuel cell diagnostics without sample cutting is demonstrated. The CT images of a membrane-electrode assembly (MEA) were obtained at several stages of cell operation, including hot-pressing, load cycles, wet/dry cycles, and start-up/shutdown (SU/SD) experiments. After SU/SD operation, carbon corrosion with newly generated cracks was observed in the catalyst layer at the cathode outlet of the cell, while no corrosion was observed at the cathode inlet and center and at all anode-side positions. The size of cracks in the microporous layer, especially under the rib area, decreased after cell operation. This study validates that it is possible to observe the cause of fuel cell degradation, i.e., carbon corrosion, at a certain position of the MEA under several stages of operation, without cutting the MEA.

Phengxay Deevanhxay; Takashi Sasabe; Katsunori Minami; Shohji Tsushima; Shuichiro Hirai

2014-01-01T23:59:59.000Z

329

Compact adaptive optic-optical coherence tomography system  

DOE Patents [OSTI]

Badal Optometer and rotating cylinders are inserted in the AO-OCT to correct large spectacle aberrations such as myopia, hyperopic and astigmatism for ease of clinical use and reduction. Spherical mirrors in the sets of the telescope are rotated orthogonally to reduce aberrations and beam displacement caused by the scanners. This produces greatly reduced AO registration errors and improved AO performance to enable high order aberration correction in a patient eyes.

Olivier, Scot S. (Livermore, CA); Chen, Diana C. (Fremont, CA); Jones, Steven M. (Danville, CA); McNary, Sean M. (Stockton, CA)

2012-02-28T23:59:59.000Z

330

Compact adaptive optic-optical coherence tomography system  

DOE Patents [OSTI]

Badal Optometer and rotating cylinders are inserted in the AO-OCT to correct large spectacle aberrations such as myopia, hyperopic and astigmatism for ease of clinical use and reduction. Spherical mirrors in the sets of the telescope are rotated orthogonally to reduce aberrations and beam displacement caused by the scanners. This produces greatly reduced AO registration errors and improved AO performance to enable high order aberration correction in a patient eyes.

Olivier, Scot S. (Livermore, CA); Chen, Diana C. (Fremont, CA); Jones, Steven M. (Danville, CA); McNary, Sean M. (Stockton, CA)

2011-05-17T23:59:59.000Z

331

Laser hazard analysis for LASIRIS Model MAG-501L-670M-1000-45[degree]-K diode laser associated with high resolution pulsed scanner.  

SciTech Connect (OSTI)

A laser hazard analysis and safety assessment was performed for the LASIRISTM Model MAG-501L-670M-1000-45o-K diode laser associated with the High Resolution Pulse Scanner based on the ANSI Standard Z136.1-2000, American National Standard for the Safe Use of Lasers and the ANSI Standard Z136.6-2000, American National Standard for the Safe Use of Lasers Outdoors. The laser was evaluated for both indoor and outdoor use.

Augustoni, Arnold L.

2004-11-01T23:59:59.000Z

332

Development and comparison of algorithms for generating a scan sequence for a random access scanner. [ZAP (and flow charts for ZIP and SCAN), in FORTRAN for DEC-10  

SciTech Connect (OSTI)

Many data acquisition systems incorporate high-speed scanners to convert analog signals into digital format for further processing. Some systems multiplex many channels into a single scanner. A random access scanner whose scan sequence is specified by a table in random access memory will permit different scan rates on different channels. Generation of this scan table can be a tedious manual task when there are many channels (e.g. 50), when there are more than a few scan rates (e.g. 5), and/or when the ratio of the highest scan rate to the lowest scan rate becomes large (e.g. 100:1). An algorithm is developed which will generate these scan sequences for the random access scanner and implements the algorithm on a digital computer. Application of number theory to the mathematical statement of the problem led to development of several algorithms which were implemented in FORTRAN. The most efficient of these algorithms operates by partitioning the problem into a set of subproblems. Through recursion they solve each subproblem by partitioning it repeatedly into even smaller parts, continuing until a set of simple problems is created. From this process, a pictorial representation or wheel diagram of the problem can be constructed. From the wheel diagram and a description of the original problem, a scan table can be constructed. In addition, the wheel diagram can be used as a method of storing the scan sequence in a smaller amount of memory. The most efficient partitioning algorithm solved most scan table problems in less than a second of CPU time. Some types of problems, however, required as much as a few minutes of CPU time. 26 figures, 2 tables.

Eason, R. O.

1980-09-01T23:59:59.000Z

333

Measuring momentum for charged particle tomography  

DOE Patents [OSTI]

Methods, apparatus and systems for detecting charged particles and obtaining tomography of a volume by measuring charged particles including measuring the momentum of a charged particle passing through a charged particle detector. Sets of position sensitive detectors measure scattering of the charged particle. The position sensitive detectors having sufficient mass to cause the charged particle passing through the position sensitive detectors to scatter in the position sensitive detectors. A controller can be adapted and arranged to receive scattering measurements of the charged particle from the charged particle detector, determine at least one trajectory of the charged particle from the measured scattering; and determine at least one momentum measurement of the charged particle from the at least one trajectory. The charged particle can be a cosmic ray-produced charged particle, such as a cosmic ray-produced muon. The position sensitive detectors can be drift cells, such as gas-filled drift tubes.

Morris, Christopher (Los Alamos, NM); Fraser, Andrew Mcleod (Los Alamos, NM); Schultz, Larry Joe (Los Alamos, NM); Borozdin, Konstantin N. (Los Alamos, NM); Klimenko, Alexei Vasilievich (Maynard, MA); Sossong, Michael James (Los Alamos, NM); Blanpied, Gary (Lexington, SC)

2010-11-23T23:59:59.000Z

334

Magnified Weak Lensing Cross Correlation Tomography  

SciTech Connect (OSTI)

This project carried out a weak lensing tomography (WLT) measurement around rich clusters of galaxies. This project used ground based photometric redshift data combined with HST archived cluster images that provide the WLT and cluster mass modeling. The technique has already produced interesting results (Guennou et al, 2010,Astronomy & Astrophysics Vol 523, page 21, and Clowe et al, 2011 to be submitted). Guennou et al have validated that the necessary accuracy can be achieved with photometric redshifts for our purposes. Clowe et al titled "The DAFT/FADA survey. II. Tomographic weak lensing signal from 10 high redshift clusters," have shown that for the **first time** via this purely geometrical technique, which does not assume a standard rod or candle, that a cosmological constant is **required** for flat cosmologies. The intent of this project is not to produce the best constraint on the value of the dark energy equation of state, w. Rather, this project is to carry out a sustained effort of weak lensing tomography that will naturally feed into the near term Dark Energy Survey (DES) and to provide invaluable mass calibration for that project. These results will greatly advance a key cosmological method which will be applied to the top-rated ground-based project in the Astro2020 decadal survey, LSST. Weak lensing tomography is one of the key science drivers behind LSST. CO-I Clowe is on the weak lensing LSST committee, and senior scientist on this project, at FNAL James Annis, plays a leading role in the DES. This project has built on successful proposals to obtain ground-based imaging for the cluster sample. By 1 Jan, it is anticipated the project will have accumulated complete 5-color photometry on 30 (or about 1/3) of the targeted cluster sample (public webpage for the survey is available at http://cencos.oamp.fr/DAFT/ and has a current summary of the observational status of various clusters). In all, the project has now been awarded the equivalent of over 60 nights on 4-m class telescopes, which gives concrete evidence of strong community support for this project. The WLT technique is based on the dependence of the gravitational shear signal on the angular diameter distances between the observer, the lens, and the lensed galaxy to measure cosmological parameters. By taking the ratio of measured shears of galaxies with different redshifts around the same lens, one obtains a measurement of the ratios of the angular diameter distances involved. Making these observations over a large range of lenses and background galaxy redshifts will measure the history of the expansion rate of the universe. Because this is a purely geometric measurement, it is insensitive to any form of evolution of objects or the necessity to understand the physics in the early universe. Thus, WLT was identified by the Dark Energy Task Force as perhaps the best method to measure the evolution of DE. To date, however, the conjecture of the DETF has not been experimentally verified, but will be by the proposed project. The primary reason for the lack of tomography measurements is that one must have an exceptional data-set to attempt the measurement. One needs both extremely good seeing (or space observations) in order to minimize the point spread function smearing corrections on weak lensing shear measurements and deep, multi-color data, from B to z, to measure reliable photometric redshifts of the background galaxies being lensed (which are typically too faint to obtain spectroscopic redshifts). Because the entire process from multi-drizzling the HST images, and then creating shear maps, to gathering the necessary ground based observations, to generating photo-zs and then carrying out the tomography is a complicated task, until the creation of our team, nobody has taken the time to connect all the levels of expertise necessary to carry out this project based on HST archival data. Our data are being used in 2 Ph.D. theses. Kellen Murphy, at Ohio University, is using the tomography data along with simulations in a thesis expected to be completed in Jun

Ulmer, Melville P., Clowe, Douglas I.

2010-11-30T23:59:59.000Z

335

Characteristics of modified CT injector for JFT-2M  

Science Journals Connector (OSTI)

The HIT-CTI mark II compact toroid (CT) injector employed for the JFT-2M tokamak facility at the Japan Atomic Energy Research Institute (JAERI) has been upgraded to improve injection performance. The nozzle of the mark III injector now has a linear tube in place of the original focus cone to avoid rapid focus and deceleration, and the tapered outer electrode has been replaced with more gentle taper in the compression section in order to facilitate gradual compression. The dependence of CT velocity and electron density on poloidal bias flux and trigger time of CT acceleration have been investigated in the operable range of 70230km/s average CT velocity and electron density of 0.11.0 1022m?3 at an accelerator bank voltage of 25kV. The operation window is broader than that of the mark II injector. Emission of a CT plasmoid from the injector, and transport to the flux conserver as a high-density spheromak magnetic structure have also been confirmed.

N. Fukumoto; H. Ogawa; M. Nagata; T. Uyama; T. Shibata; Y. Kashiwa; Y. Kusama

2004-01-01T23:59:59.000Z

336

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

337

Three-Dimensional Thermal Tomography Advances Cancer Treatment...  

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

Three-Dimensional Thermal Tomography Advances Cancer Treatment (ANL-IN-07-170) Argonne National Laboratory Contact ANL About This Technology

Change in temperature over time...

338

Traveltime tomography in anisotropic mediaI. Theory  

Science Journals Connector (OSTI)

......Traveltime tomography in anisotropic media-II. Application...technique for weakly anisotropic velocity, Geophysics...Velocity anisotropy in shale determined from crosshole...technique for weakly anisotropic velocity, Geophysics...Velocity anisotropy in shale determined from crosshole......

C. H. Chapman; R. G. Pratt

1992-04-01T23:59:59.000Z

339

Functional lung imaging in humans using Positron Emission Tomography  

E-Print Network [OSTI]

This thesis deals with a method of functional lung imaging using Positron Emission Tomography (PET). In this technique, a radioactive tracer, nitrogen-13, is dissolved in saline solution, and injected into a peripheral ...

Layfield, Dominick, 1971-

2003-01-01T23:59:59.000Z

340

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

SciTech Connect (OSTI)

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

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.


341

Scattered neutron tomography based on a neutron transport problem  

E-Print Network [OSTI]

scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...

Scipolo, Vittorio

2005-11-01T23:59:59.000Z

342

NEURAL NETWORKS FOR DISCRETE TOMOGRAPHY K.J. Batenburg a  

E-Print Network [OSTI]

NEURAL NETWORKS FOR DISCRETE TOMOGRAPHY K.J. Batenburg a W.A. Kosters b a Mathematical Institute of crystalline solids at atomic resolution from electron microscopic images can be considered the "holy grail

Kosters, Walter

343

Thickness Estimation with Optical Coherence Tomography and Statistical Decision Theory  

Science Journals Connector (OSTI)

We implement a maximum-likelihood (ML) estimator to interpret Optical Coherence Tomography (OCT) data, based on a Fourier-Domain OCT and a two-interface tear film model. We use the...

Huang, Jinxin; Clarkson, Eric; Kupinski, Matthew; Rolland, Jannick P

344

Frequency comb swept lasers for optical coherence tomography  

E-Print Network [OSTI]

We demonstrate a frequency comb (FC) swept laser and a frequency comb Fourier domain mode locked (FC-FDML) laser for applications in optical coherence tomography (OCT). The fiber-based FC swept lasers operate at a sweep ...

Tsai, Tsung-Han

345

Ultrahigh speed optical coherence tomography for ophthalmic imaging applications  

E-Print Network [OSTI]

Optical coherence tomography (OCT) is a non-contact, non-invasive, micron-scale optical imaging technology that has become a standard clinical tool in ophthalmology. Fourier domain OCT detection methods have enabled higher ...

Liu, Jonathan Jaoshin

2014-01-01T23:59:59.000Z

346

Breast ultrasound tomography with total-variation regularization  

SciTech Connect (OSTI)

Breast ultrasound tomography is a rapidly developing imaging modality that has the potential to impact breast cancer screening and diagnosis. A new ultrasound breast imaging device (CURE) with a ring array of transducers has been designed and built at Karmanos Cancer Institute, which acquires both reflection and transmission ultrasound signals. To extract the sound-speed information from the breast data acquired by CURE, we have developed an iterative sound-speed image reconstruction algorithm for breast ultrasound transmission tomography based on total-variation (TV) minimization. We investigate applicability of the TV tomography algorithm using in vivo ultrasound breast data from 61 patients, and compare the results with those obtained using the Tikhonov regularization method. We demonstrate that, compared to the Tikhonov regularization scheme, the TV regularization method significantly improves image quality, resulting in sound-speed tomography images with sharp (preserved) edges of abnormalities and few artifacts.

Huang, Lianjie [Los Alamos National Laboratory; Li, Cuiping [KARMANOS CANCER INSTIT.; Duric, Neb [KARMANOS CANCER INSTIT

2009-01-01T23:59:59.000Z

347

Computational Inversion of Electron Tomography Images -Gradient Flows  

E-Print Network [OSTI]

Computational Inversion of Electron Tomography Images Using L2 -Gradient Flows Guoliang Xu 1) Ming Computing Institute of Computational Mathematics, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100190, China 2) Department of Computer Sciences and Institute

Texas at Austin, University of

348

ELECTRICAL IMPEDANCE TOMOGRAPHY ON A RESISTIVE NETWORK WITH INTERNAL CURRENTS  

E-Print Network [OSTI]

ELECTRICAL IMPEDANCE TOMOGRAPHY ON A RESISTIVE NETWORK WITH INTERNAL CURRENTS YONG JUNG KIM AND MIN resonance image, electrical density image, electrical impedance tomog- raphy, resistive network, anisotropic from internal currents and the boundary conductivity. An electrically conducting body is discretized

Kim, Yong Jung

349

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

SciTech Connect (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

350

PET/CT-guided Interventions: Personnel Radiation Dose  

SciTech Connect (OSTI)

PurposeTo quantify radiation exposure to the primary operator and staff during PET/CT-guided interventional procedures.MethodsIn this prospective study, 12 patients underwent PET/CT-guided interventions over a 6 month period. Radiation exposure was measured for the primary operator, the radiology technologist, and the nurse anesthetist by means of optically stimulated luminescence dosimeters. Radiation exposure was correlated with the procedure time and the use of in-room image guidance (CT fluoroscopy or ultrasound).ResultsThe median effective dose was 0.02 (range 0-0.13) mSv for the primary operator, 0.01 (range 0-0.05) mSv for the nurse anesthetist, and 0.02 (range 0-0.05) mSv for the radiology technologist. The median extremity dose equivalent for the operator was 0.05 (range 0-0.62) mSv. Radiation exposure correlated with procedure duration and with the use of in-room image guidance. The median operator effective dose for the procedure was 0.015 mSv when conventional biopsy mode CT was used, compared to 0.06 mSv for in-room image guidance, although this did not achieve statistical significance as a result of the small sample size (p = 0.06).ConclusionThe operator dose from PET/CT-guided procedures is not significantly different than typical doses from fluoroscopically guided procedures. The major determinant of radiation exposure to the operator from PET/CT-guided interventional procedures is time spent in close proximity to the patient.

Ryan, E. Ronan, E-mail: ronan@ronanryan.com; Thornton, Raymond; Sofocleous, Constantinos T.; Erinjeri, Joseph P. [Memorial Sloan-Kettering Cancer Center, Department of Radiology (United States); Hsu, Meier [Memorial Sloan-Kettering Cancer Center, Department of Epidemiology and Biostatistics (United States); Quinn, Brian; Dauer, Lawrence T. [Memorial Sloan-Kettering Cancer Center, Department of Medical Physics (United States); Solomon, Stephen B. [Memorial Sloan-Kettering Cancer Center, Department of Radiology (United States)

2013-08-01T23:59:59.000Z

351

On Recent Claims Concerning the R_h=ct Universe  

E-Print Network [OSTI]

The R_h=ct Universe is a Friedmann-Robertson-Walker (FRW) cosmology which, like LCDM, assumes the presence of dark energy in addition to (baryonic and non-luminous) matter and radiation. Unlike LCDM, however, it is also constrained by the equation of state (EOS) p=-rho/3, in terms of the total pressure p and energy density rho. One-on-one comparative tests between R_h=ct and LCDM have been carried out using over 14 different cosmological measurements and observations. In every case, the data have favoured R_h=ct over the standard model, with model selection tools yielding a likelihood ~90-95% that the former is correct, versus only ~5-10% for the latter. In other words, the standard model without the EOS p=-rho/3 does not appear to be the optimal description of nature. Yet in spite of these successes---or perhaps because of them---several concerns have been published recently regarding the fundamental basis of the theory itself. The latest paper on this subject even claims---quite remarkably---that R_h=ct is a vacuum solution, though quite evidently rho is not 0. Here, we address these concerns and demonstrate that all criticisms leveled thus far against R_h=ct, including the supposed vacuum condition, are unwarranted. They all appear to be based on incorrect assumptions or basic theoretical errors. Nevertheless, continued scrutiny such as this will be critical to establishing R_h=ct as the correct description of nature.

Fulvio Melia

2014-10-17T23:59:59.000Z

352

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

E-Print Network [OSTI]

However, the generated conversion factors were based on fixeis provided by conversion factors based on organ doseswhich established conversion factors applied to the scanner-

Khatonabadi, Maryam

2013-01-01T23:59:59.000Z

353

Weldability and keyhole behavior of Zn-coated steel in remote welding using disk laser with scanner head  

Science Journals Connector (OSTI)

Zinc-coated steels are widely used in automobile bodies. Laser welding which offers a lot of advantages over the conventional welding with metal active gas welding CO2 arc etc. in terms of improved weld quality high-speed and easy automation has been developed for cars. However in laser lap welding of zinc-coated steel sheets without gaps defects such as underfilled beads or porosity were easily formed due to higher pressure of zinc vapor trapped in the molten pool because of the lower boiling point of zinc (1180?K) with respect to the melting point of steel (Fe 1803?K). Laser lap welding results of two Zn-coated steel sheets have been reported. However there are not enough data for welding of three Zn-coated steel sheets. Therefore to understand laser lap weldability of three Zn-coated steel sheets lap welding of two or three sheets with and without gaps was performed using 16?kW disk laser apparatus with a scanner head and molten pool motions spattering and keyhole behavior during welding were observed by high-speed video cameras and x-ray transmission real-time imaging apparatus. Lap welding of three steel sheets was difficult but acceptably good welds were produced in sheets with upper and lower gaps of 0.1 and 0.1?mm 0.1 and 0.2?mm or 0.2 and 0.1?mm respectively. Bubble generation leading to porosity formation was observed and it was confirmed that welding phenomena were different depending upon the gap levels.

Jong-Do Kim

2013-01-01T23:59:59.000Z

354

Quantification of airway thickness changes in smoke-inhalation injury using in-vivo 3-D endoscopic frequency-domain optical coherence tomography  

E-Print Network [OSTI]

J. G. Fujimoto, Optical coherence tomography, Science 254(endomicroscopy using optical coherence tomography, Nat.Fourier domain optical coherence tomography, Opt. Express

2011-01-01T23:59:59.000Z

355

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 -

356

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

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

357

Patient-size-dependent radiation dose optimisation technique for abdominal CT examinations  

Science Journals Connector (OSTI)

......CT dosimetry and radiation safety. Radiol. Soc...Notification. Reducing radiation risk from computed...gov/cdrh/safety/110201-ct...McCollough C. H. Radiation dose in computed...region of interest software available in both......

J. E. Ngaile; P. Msaki; R. Kazema

2012-01-01T23:59:59.000Z

358

E-Print Network 3.0 - abnormal brain ct Sample Search Results  

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

Powered by Explorit Topic List Advanced Search Sample search results for: abnormal brain ct Page: << < 1 2 3 4 5 > >> 1 Hemorrhage Slices Detection in Brain CT Images Ruizhe...

359

Detektion von Phochromozytomen und rekurrenten medullren Schilddrsenkarzinomen mit F18 DOPA PET/CT.  

E-Print Network [OSTI]

??Evaluating [18F]dihydroxyphenylalanine (DOPA) in patients with clinical suspicion for a primary or recurrent pheochromocytoma (pheo) by means of whole body PET/CT. In pheos PET/CT detects (more)

Zeich, Katrin

2009-01-01T23:59:59.000Z

360

Amorphous silicon detectors in positron emission tomography  

SciTech Connect (OSTI)

The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters {epsilon}{sup 2}{tau}'s are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs.

Conti, M. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy) Lawrence Berkeley Lab., CA (USA)); Perez-Mendez, V. (Lawrence Berkeley Lab., CA (USA))

1989-12-01T23:59:59.000Z

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.


361

Investigating Jet Mixing Using Electrical Resistance Tomography  

Science Journals Connector (OSTI)

Coaxial jet and side entry mixers are used in a wide range of industries for a variety of processes including precipitation polymerization and neutralization duties. Jet mixers are characterized by short contact times between the fluids and can be operated continuously or semi?batch. Coaxial and side entry jets can be designed in order to deliver rapid turbulent mixing using short sections of pipeline. As the energy required for mixing is provided by the addition stream the process?side pressure drop required for homogeneity is very low. A key design parameter for jet mixers is the mixing length the length of pipe downstream of the injection point required to achieve a given degree of homogeneity. The mixing length can be affected by the addition geometry (for example coaxial or side entry) orifice size and shape operating conditions and material properties. This paper presents the use of Electrical Resistance Tomography (ERT) to monitor jet mixing via the addition of a conductivity tracer through coaxial and side entry jets. Multiple ERT sensors are fitted along the pipe downstream of the jet addition point. The ERT sensors enable real time non?invasive measurement of conductivity within the pipe furnishing approximately 2500 conductivity measurements per ERT sensor when modeled independently in 3D. The effect of secondary (main pipe) flow rate and jet configuration on the nature of the tracer plume evolution and axial mixing is determined using this technique.

D. R. Stephenson; M. Cooke; A. Kowalski; T. A. York

2007-01-01T23:59:59.000Z

362

ACCELERATING REGULARIZED ITERATIVE CT RECONSTRUCTION ON COMMODITY GRAPHICS HARDWARE (GPU)  

E-Print Network [OSTI]

overhead to very moderate levels. Index Terms-- Iterative Reconstruction, Computed Tomography, Ordered Klaus Mueller Center for Visual Computing, Computer Science Department, Stony Brook University ABSTRACT) is the overall theme in many efforts to lower these exposures. Effective methods here include limiting either

Mueller, Klaus

363

Quantitative CT of lung nodules: Dependence of calibration on patient body size, anatomic region, and calibration nodule size for single- and dual-energy techniques  

SciTech Connect (OSTI)

Calcium concentration may be a useful feature for distinguishing benign from malignant lung nodules in computer-aided diagnosis. The calcium concentration can be estimated from the measured CT number of the nodule and a CT number vs calcium concentration calibration line that is derived from CT scans of two or more calcium reference standards. To account for CT number nonuniformity in the reconstruction field, such calibration lines may be obtained at multiple locations within lung regions in an anthropomorphic phantom. The authors performed a study to investigate the effects of patient body size, anatomic region, and calibration nodule size on the derived calibration lines at ten lung region positions using both single energy (SE) and dual energy (DE) CT techniques. Simulated spherical lung nodules of two concentrations (50 and 100 mg/cc CaCO{sub 3}) were employed. Nodules of three different diameters (4.8, 9.5, and 16 mm) were scanned in a simulated thorax section representing the middle of the chest with large lung regions. The 4.8 and 9.5 mm nodules were also scanned in a section representing the upper chest with smaller lung regions. Fat rings were added to the peripheries of the phantoms to simulate larger patients. Scans were acquired on a GE-VCT scanner at 80, 120, and 140 kVp and were repeated three times for each condition. The average absolute CT number separations between the calibration lines were computed. In addition, under- or overestimates were determined when the calibration lines for one condition (e.g., small patient) were used to estimate the CaCO{sub 3} concentrations of nodules for a different condition (e.g., large patient). The authors demonstrated that, in general, DE is a more accurate method for estimating the calcium contents of lung nodules. The DE calibration lines within the lung field were less affected by patient body size, calibration nodule size, and nodule position than the SE calibration lines. Under- or overestimates in CaCO{sub 3} concentrations of nodules were also in general smaller in quantity with DE than with SE. However, because the slopes of the calibration lines for DE were about one-half the slopes for SE, the relative improvement in the concentration estimates for DE as compared to SE was about one-half the relative improvement in the separation between the calibration lines. Results in the middle of the chest thorax section with large lungs were nearly completely consistent with the above generalization. On the other hand, results in the upper-chest thorax section with smaller lungs and greater amounts of muscle and bone were mixed. A repeat of the entire study in the upper thorax section yielded similar mixed results. Most of the inconsistencies occurred for the 4.8 mm nodules and may be attributed to errors caused by beam hardening, volume averaging, and insufficient sampling. Targeted, higher resolution reconstructions of the smaller nodules, application of high atomic number filters to the high energy x-ray beam for improved spectral separation, and other future developments in DECT may alleviate these problems and further substantiate the superior accuracy of DECT in quantifying the calcium concentrations of lung nodules.

Goodsitt, Mitchell M.; Chan, Heang-Ping; Way, Ted W.; Schipper, Mathew J.; Larson, Sandra C.; Christodoulou, Emmanuel G. [Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109-5842 (United States)

2009-07-15T23:59:59.000Z

364

Assessment of paediatric CT exposure in a Portuguese hospital  

Science Journals Connector (OSTI)

......paediatric CT exposure in a Portuguese hospital A. Neves 1 * A. Nunes 1 M. Rufino...2 Centro Hospitalar Lisboa Central, Hospital de S. Jose, Rua Jose Antonio Serrano...procedures was performed for a Portuguese hospital. Dosimetric data and technical parameters......

A. Neves; A. Nunes; M. Rufino; P. Madeira; P. Vaz; A. Pascoal

2012-09-01T23:59:59.000Z

365

Status and Promise CT's and Magnetized Target Fusion  

E-Print Network [OSTI]

. Hill (LLNL) #12;CT's: Spheromaks & Field Reversed Configurations At LLNL, the SSPX experiment is investigating spheromak formation, sustainment, and confinement issues. (Hill, Mclean, Wood, Ryutov). At UC-Davis, formation and acceleration of spheromaks. (Hwang) At the U of Washington, field reversed configuration

366

On Recent Claims Concerning the R_h=ct Universe  

E-Print Network [OSTI]

The R_h=ct Universe is a Friedmann-Robertson-Walker (FRW) cosmology which, like LCDM, assumes the presence of dark energy in addition to (baryonic and non-luminous) matter and radiation. Unlike LCDM, however, it is also constrained by the equation of state (EOS) p=-rho/3, in terms of the total pressure p and energy density rho. One-on-one comparative tests between R_h=ct and LCDM have been carried out using over 14 different cosmological measurements and observations. In every case, the data have favoured R_h=ct over the standard model, with model selection tools yielding a likelihood ~90-95% that the former is correct, versus only ~5-10% for the latter. In other words, the standard model without the EOS p=-rho/3 does not appear to be the optimal description of nature. Yet in spite of these successes---or perhaps because of them---several concerns have been published recently regarding the fundamental basis of the theory itself. The latest paper on this subject even claims---quite remarkably---that R_h=ct is ...

Melia, Fulvio

2014-01-01T23:59:59.000Z

367

Saturday Workshop 2/7/2009 RS: Molly Burke CT's: Roy Center & Lee Kelly  

E-Print Network [OSTI]

Saturday Workshop 2/7/2009 RS: Molly Burke CT's: Roy Center & Lee Kelly Drosophila Handbook page 1 2/7/2009 RS: Molly Burke CT's: Roy Center & Lee Kelly Drosophila Handbook page 2 Table of Contents Standards 22 #12;Saturday Workshop 2/7/2009 RS: Molly Burke CT's: Roy Center & Lee Kelly Drosophila Handbook

Rose, Michael R.

368

Rapid, automated imaging of mouse articular cartilage by microCT for early detection of osteoarthritis and finite element modelling of joint mechanics  

Science Journals Connector (OSTI)

SummaryObjective Mouse articular cartilage (AC) is mostly assessed by histopathology and its mechanics is poorly characterised. In this study: (1) we developed non-destructive imaging for quantitative assessment of AC morphology and (2) evaluated the mechanical implications of AC structural changes. Methods Knee joints obtained from nave mice and from mice with osteoarthritis (OA) induced by destabilization of medial meniscus (DMM) for 4 and 12 weeks, were imaged by phosphotungstic acid (PTA) contrast enhanced micro-computed tomography (PTA-CT) and scored by conventional histopathology. Our software (Matlab) automatically segmented tibial AC, drew two regions centred on each tibial condyle and evaluated the volumes included. A finite element (FE) model of the whole mouse joint was implemented to evaluate AC mechanics. Results Our method achieved rapid, automated analysis of mouse AC (structural parameters in simulations estimated that AC thinning at early-stages in the DMM model (4 weeks) increases contact pressures (+39%) and Tresca stresses (+43%) in AC. Conclusion PTA-CT imaging is a fast and simple method to assess OA in murine models. Once applied more extensively to confirm its robustness, our approach will be useful for rapidly phenotyping genetically modified mice used for OA research and to improve the current understanding of mouse cartilage mechanics.

P. Das Neves Borges; A.E. Forte; T.L. Vincent; D. Dini; M. Marenzana

2014-01-01T23:59:59.000Z

369

Quantitative cone-beam CT imaging in radiation therapy using planning CT as a prior: First patient studies  

SciTech Connect (OSTI)

Purpose: Quantitative cone-beam CT (CBCT) imaging is on increasing demand for high-performance image guided radiation therapy (IGRT). However, the current CBCT has poor image qualities mainly due to scatter contamination. Its current clinical application is therefore limited to patient setup based on only bony structures. To improve CBCT imaging for quantitative use, we recently proposed a correction method using planning CT (pCT) as the prior knowledge. Promising phantom results have been obtained on a tabletop CBCT system, using a correction scheme with rigid registration and without iterations. More challenges arise in clinical implementations of our method, especially because patients have large organ deformation in different scans. In this paper, we propose an improved framework to extend our method from bench to bedside by including several new components. Methods: The basic principle of our correction algorithm is to estimate the primary signals of CBCT projections via forward projection on the pCT image, and then to obtain the low-frequency errors in CBCT raw projections by subtracting the estimated primary signals and low-pass filtering. We improve the algorithm by using deformable registration to minimize the geometry difference between the pCT and the CBCT images. Since the registration performance relies on the accuracy of the CBCT image, we design an optional iterative scheme to update the CBCT image used in the registration. Large correction errors result from the mismatched objects in the pCT and the CBCT scans. Another optional step of gas pocket and couch matching is added into the framework to reduce these effects. Results: The proposed method is evaluated on four prostate patients, of which two cases are presented in detail to investigate the method performance for a large variety of patient geometry in clinical practice. The first patient has small anatomical changes from the planning to the treatment room. Our algorithm works well even without the optional iterations and the gas pocket and couch matching. The image correction on the second patient is more challenging due to the effects of gas pockets and attenuating couch. The improved framework with all new components is used to fully evaluate the correction performance. The enhanced image quality has been evaluated using mean CT number and spatial nonuniformity (SNU) error as well as contrast improvement factor. If the pCT image is considered as the ground truth, on the four patients, the overall mean CT number error is reduced from over 300 HU to below 16 HU in the selected regions of interest (ROIs), and the SNU error is suppressed from over 18% to below 2%. The average soft-tissue contrast is improved by an average factor of 2.6. Conclusions: We further improve our pCT-based CBCT correction algorithm for clinical use. Superior correction performance has been demonstrated on four patient studies. By providing quantitative CBCT images, our approach significantly increases the accuracy of advanced CBCT-based clinical applications for IGRT.

Niu Tianye; Al-Basheer, Ahmad; Zhu Lei [Nuclear and Radiological Engineering and Medical Physics Programs, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Georgia Radiation Therapy Center, Department of Radiology, Georgia Health Sciences University, Augusta, Georgia 30912 (United States); Nuclear and Radiological Engineering and Medical Physics Programs, George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

2012-04-15T23:59:59.000Z

370

Initial experience with single-source dual-energy CT abdominal angiography and comparison with single-energy CT angiography: image quality, enhancement, diagnosis and radiation dose  

Science Journals Connector (OSTI)

To assess image quality of virtual monochromatic spectral (VMS) images, compared to single-energy (SE) CT, and to evaluate the...

Daniella F. Pinho; Naveen M. Kulkarni; Arun Krishnaraj

2013-02-01T23:59:59.000Z

371

Dictionary-Learning-Based Reconstruction Method for Electron Tomography  

E-Print Network [OSTI]

Electron tomography usually suffers from so called missing wedge artifacts caused by limited tilt angle range. An equally sloped tomography (EST) acquisition scheme (which should be called the linogram sampling scheme) was recently applied to achieve 2.4-angstrom resolution. On the other hand, a compressive sensing-inspired reconstruction algorithm, known as adaptive dictionary based statistical iterative reconstruction (ADSIR), has been reported for x-ray computed tomography. In this paper, we evaluate the EST, ADSIR and an ordered-subset simultaneous algebraic reconstruction technique (OS-SART), and compare the ES and equally angled (EA) data acquisition modes. Our results show that OS-SART is comparable to EST, and the ADSIR outperforms EST and OS-SART. Furthermore, the equally sloped projection data acquisition mode has no advantage over the conventional equally angled mode in the context.

Liu, Baodong; Verbridge, Scott S; Sun, Lizhi; Wang, Ge

2013-01-01T23:59:59.000Z

372

Microwave-induced thermoacoustic tomography: applications and corrections for the effects of acoustic heterogeneities  

E-Print Network [OSTI]

This research is primarily focused on developing potential applications for microwaveinduced thermoacoustic tomography and correcting for image degradations caused by acoustic heterogeneities. Microwave-induced thermoacoustic tomography was first...

Jin, Xing

2009-05-15T23:59:59.000Z

373

E-Print Network 3.0 - agent-enhanced computed tomography Sample...  

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

computed tomography Page: << < 1 2 3 4 5 > >> 1 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: problems X-ray tomography...

374

E-Print Network 3.0 - advanced computed tomography Sample Search...  

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

advanced computed tomography Page: << < 1 2 3 4 5 > >> 1 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: problems X-ray tomography...

375

Comparing Time Domain Reflectometry and Electrical Resistivity Tomography Measurements for Estimating Soil Water Distribution  

E-Print Network [OSTI]

511 Comparing Time Domain Reflectometry and Electrical Resistivity Tomography Measurements compared with electrical resistivity tomography (ERT) measurements along the same cross's interior for the measurements. However, determining the soil water content from the resulting electrical

Sailhac, Pascal

376

Multiplexed absorption tomography with calibration-free wavelength modulation spectroscopy  

SciTech Connect (OSTI)

We propose a multiplexed absorption tomography technique, which uses calibration-free wavelength modulation spectroscopy with tunable semiconductor lasers for the simultaneous imaging of temperature and species concentration in harsh combustion environments. Compared with the commonly used direct absorption spectroscopy (DAS) counterpart, the present variant enjoys better signal-to-noise ratios and requires no baseline fitting, a particularly desirable feature for high-pressure applications, where adjacent absorption features overlap and interfere severely. We present proof-of-concept numerical demonstrations of the technique using realistic phantom models of harsh combustion environments and prove that the proposed techniques outperform currently available tomography techniques based on DAS.

Cai, Weiwei; Kaminski, Clemens F., E-mail: cfk23@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB2 3RA (United Kingdom)

2014-04-14T23:59:59.000Z

377

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

378

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

E-Print Network [OSTI]

dose at CT in pediatric patients. Radiology, 1997. 203(2):Cancer Risk for Pediatric Chest CT. Radiology, 2011. 259(3):

Khatonabadi, Maryam

2013-01-01T23:59:59.000Z

379

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

SciTech Connect (OSTI)

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

380

Inverse scattering for frequency-scanned full-field optical coherence tomography  

E-Print Network [OSTI]

Inverse scattering for frequency-scanned full-field optical coherence tomography Daniel L. Marks-field optical coherence tomography (OCT) is able to image an entire en face plane of scatterers simulta- neously: 100.3010, 110.4500. 1. INTRODUCTION The capabilities of optical coherence tomography1,2 (OCT

Bhargava, Rohit

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

Lung-Cancer Screening with Low-Dose Computed Tomography  

Science Journals Connector (OSTI)

...but complications of invasive testing were not. Across all three rounds of screening, 39% of the participants in the low-dose CT group had at least one positive result; more than 95% of these findings were falsely positive. Most patients with positive screening-test results required follow-up imaging... A large randomized trial showed that low-dose CT screening reduced the risk of lung-cancer death by 20% among long-time smokers. Recent guidelines support consideration of screening but with attention to the possibility of false positive results and associated risks.

Gould M.K.

2014-11-06T23:59:59.000Z

382

Determination of time-course change rate for arterial xenon using the time course of tissue xenon concentration in xenon-enhanced computed tomography  

SciTech Connect (OSTI)

In calculating tissue blood flow (TBF) according to the Fick principle, time-course information on arterial tracer concentration is indispensable and has a considerable influence on the accuracy of calculated TBF. In TBF measurement by xenon-enhanced computed tomography (Xe-CT), nonradioactive xenon gas is administered by inhalation as a tracer, and end-tidal xenon is used as a substitute for arterial xenon. There has been the assumption that the time-course change rate for end-tidal xenon concentration (Ke) and that for arterial xenon concentration (Ka) are substantially equal. Respiratory gas sampling is noninvasive to the patient and Ke can be easily measured by exponential curve fitting to end-tidal xenon concentrations. However, it is pointed out that there would be a large difference between Ke and Ka in many cases. The purpose of this work was to develop a method of determining the Ka value using the time course of tissue xenon concentration in Xe-CT. The authors incorporated Ka into the Kety autoradiographic equation as a parameter to be solved, and developed a method of least-squares to obtain the solution for Ka from the time-course changes in xenon concentration in the tissue. The authors applied this method of least-squares to the data from Xe-CT abdominal studies performed on 17 patients; the solution for Ka was found pixel by pixel in the spleen, and its Ka map was created for each patient. On the one hand, the authors obtained the average value of the Ka map of the spleen as the calculated Ka (Ka{sub calc}) for each patient. On the other hand, the authors measured Ka (Ka{sub meas}) using the time-course changes in CT enhancement in the abdominal aorta for each patient. There was a good correlation between Ka{sub calc} and Ka{sub meas} (r=0.966, P<0.0001), and these two Ka values were close to each other (Ka{sub calc}=0.935xKa{sub meas}+0.089). This demonstrates that Ka{sub calc} would be close to the true Ka value. Accuracy of TBF by Xe-CT can be improved with use of the average value of the Ka map of an organ like the spleen that has a single blood supply (only arterial inflow)

Sase, Shigeru; Takahashi, Hideaki; Ikeda, Hiroki; Kobayashi, Minoru; Matsumoto, Nobuyuki; Suzuki, Michihiro [Anzai Medical Co., Ltd., 3-9-15 Nishi-Shinagawa, Shinagawa-ku, Tokyo 141-0033 (Japan); Department of Internal Medicine, Division of Gastroenterology and Hepatology, School of Medicine, St. Marianna University, 2-16-1 Miyamae-ku, Sugao, Kawasaki 216-5811 (Japan)

2008-06-15T23:59:59.000Z

383

Magnetospheric Constellation and Tomography Mission Concept R. E. Ergun1*  

E-Print Network [OSTI]

Magnetospheric Constellation and Tomography Mission Concept R. E. Ergun1* , D. E. Larson1 , T. Phan]. The interaction between the solar wind and mag- netosphere results with energy and mass transfer across magnetic and stored in the magnetotail. A plasma sheet appears between the two lobes of the magnetotail where energy

California at Berkeley, University of

384

ADVANCES IN IMAGING AND ELECTRON PHYSICS, VOL. 128 Quantum Tomography  

E-Print Network [OSTI]

ADVANCES IN IMAGING AND ELECTRON PHYSICS, VOL. 128 Quantum Tomography G. MAURO D'ARIANO, MATTEO G .............. 277 205 Copyright 9 2003 Elsevier Inc. All r~crhte r~r~r~ #12;206 MAURO D'ARIANO ET AL. VII

D'Ariano, Giacomo Mauro

385

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

E-Print Network [OSTI]

Roadmap: Radiologic Imaging Sciences - Computed Tomography (with AAS Radiologic Technology) - Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-CTRT] Regional College Catalog Year: 2013-2014 Page 1 of 2 | Last Updated: 30-Apr-13/LNHD This roadmap is a recommended semester

Sheridan, Scott

386

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

E-Print Network [OSTI]

Roadmap: Radiologic Imaging Sciences - Computed Tomography (with AAS Radiologic Technology) - Bachelor of Radiologic and Imaging Sciences Technology [RE-BRIT-RIS-CTRT] Regional College Catalog Year: 2012-2013 Page 1 of 2 | Last Updated: 25-Oct-12/LNHD This roadmap is a recommended semester

Sheridan, Scott

387

Constraints on mantle convection from seismic tomography and flow modeling  

E-Print Network [OSTI]

In this thesis I combine high resolution seismic tomography and realistic flow modeling to constrain mantle convection. The bulk of the data used in the tomographic imaging are millions of P, pP and pwP travel time residuals, ...

Krason, Hrafnkell, 1970-

2002-01-01T23:59:59.000Z

388

A SIGNAL SYNTHESIS PROCEDURE DESIGNED FOR DISCREET OCEAN ACOUSTIC TOMOGRAPHY  

E-Print Network [OSTI]

the detection probability of active emis- sions by a nearby unknown interceptor. Finally, this procedure is ap in ship noise with the constraint to have an accurate estimation of the channel parameters. Results tomography, parameter estimation, sig- nal detection, optimization, performance analysis 1. INTRODUCTION

Boyer, Edmond

389

A new concept of ocean acoustic tomography Lionel CROS(1)  

E-Print Network [OSTI]

a synthetic signal in ship noise with the con- straint to have an accurate estimation of the channel: discreet acoustic tomography, estimation, detection, optimization, performance analysis. R´ESUM´E COURT: La disc`ete, estimation, d´etection, optimisation, analyse de perfor- mance. 1 INTRODUCTION Ocean acoustic

Boyer, Edmond

390

Adaptive optics enhanced simultaneous en-face optical coherence tomography  

E-Print Network [OSTI]

Adaptive optics enhanced simultaneous en-face optical coherence tomography and scanning laser ophthalmoscopy David Merino and Chris Dainty Applied Optics Group, Department of Experimental Physics, National and Adrian Gh. Podoleanu Applied Optics Group, School of Physical Sciences, University of Kent at Canterbury

Dainty, Chris

391

Spherical radon transforms and mathematical problems of thermoacoustic tomography  

E-Print Network [OSTI]

The spherical Radon transform (SRT) integrates a function over the set of all spheres with a given set of centers. Such transforms play an important role in some newly developing types of tomography as well as in several areas of mathematics...

Ambartsoumian, Gaik

2009-06-02T23:59:59.000Z

392

Neutrino tomography: Tevatron mapping versus the neutrino sky  

Science Journals Connector (OSTI)

... adequate reconstruction for noninvasive imaging in medicine. Geophysical densities follow from the mapping of the Radon or Fourier transform of certain neutrino projections, and not from the Volkova-Zatsepin scheme, ... problem was first addressed by Radon24 who derived what has now become known as the Radon transform. Tomography10'19'20'25 can be defined as reconstructive imaging by means of ...

Thomas L. Wilson

1984-05-03T23:59:59.000Z

393

3-D seismic tomography of the Adelaide fold belt  

Science Journals Connector (OSTI)

......the major factor. Temperature-induced P-wave...which smoothes the temperature contrast, resulting...structure of the eastern Snake River Plain and its...1996. Upper mantle temperatures from teleseismic tomography...implications for regolith development, 3rd Australian Regolith......

Peter Clifford; Stewart Greenhalgh; Greg Houseman; Frank Graeber

2008-01-01T23:59:59.000Z

394

3D Tomography from Few Projections in Experimental Fluid Dynamics  

E-Print Network [OSTI]

3D Tomography from Few Projections in Experimental Fluid Dynamics Stefania Petra, Andreas Schr projections due to both limited optical access to wind and water tunnels and cost S. Petra, C. Schn projection data. The latter are the pixel entries in the recorded 2D images that represent the integration

Schnörr, Christoph

395

Volumetric Reconstruction in the MicroCAT Tomography System  

E-Print Network [OSTI]

of projection data . . . . . . . . . . . . . . . . . . . . . . . . . 30 3.2 Illustration of Feldkamp filteredVolumetric Reconstruction in the MicroCAT Tomography System A Thesis Presented for the Master essential data and an intimate knowledge of the MicroCAT system. Dr. Sam Jordan of the University

Cates, Josh

396

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

SciTech Connect (OSTI)

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

397

Local Therapeutic Results of Computed Tomography-Guided Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma: Results of 265 Tumors in 79 Patients  

SciTech Connect (OSTI)

Purpose. To elucidate the local therapeutic results of computed tomography (CT)-guided transcatheter arterial chemoembolization (TACE) as initial treatment for hepatocellular carcinoma (HCC), and to verify factors which affect local therapeutic results. Methods. From 1992 to 2002, 265 tumors of 79 HCC patients were treated by 139 sessions of CT-guided TACE as initial treatment. Among these 265 tumors, 182 constituted multiple new lesions, and the remaining 83 tumors were single new lesions. Local recurrence was retrospectively ascertained on follow-up CT images obtained after TACE. Results. The overall local recurrence-free rates (LR-FRs) after a single TACE session at 6, 12, and 36 months were 67%, 49%, and 28%; those of the single new lesions were 80%, 66%, and 32%; and those of tumors with complete lipiodol accumulation were 82%, 68%, and 41%, respectively. LR-FRs of tumors of the single new lesions, and those of tumors with complete lipiodol accumulation, were significantly higher than the LR-FRs of multiple new lesions and tumors with incomplete lipiodol accumulation, respectively. For single new lesions {<=}4 cm and the tumors that were one of multiple new lesions, there were no significant differences in the LR-FRs regarding the number of TACE sessions on the basis of patient, tumor location, or tumor size. Conclusion. Local therapeutic results of single new lesions were better than those of multiple new lesions, and the local therapeutic effect of TACE was not affected by the number of treatments on the basis of patient, tumor location, or tumor size.

Hayashi, Keiji [Graduate School, Tokyo Medical and Dental University, Division of Oral Health Sciences, Department of Head and Neck Reconstruction, Section of Diagnostic Radiology and Oncology (Japan)], E-mail: kjh@hte.highway.ne.jp; Ina, Hiroyasu; Tezuka, Mikio [Nakano General Hospital, Department of Radiology (Japan); Okada, Yoichi [Tokyo Metropolitan Toshima Hospital, Department of Radiology (Japan); Irie, Tetsuya [Nakano General Hospital, Department of Internal Medicine (Japan)

2007-11-15T23:59:59.000Z

398

Chapter 7 - Horizontally Integrated Remote Measurements of Ocean Currents Using Acoustic Tomography Techniques  

Science Journals Connector (OSTI)

Abstract This chapter begins with a discussion of the comparative difficulty of measuring horizontally integrated subsurface oceanic current and vorticity measurements. This is followed by a discussion of computer-assisted tomography techniques used in the medical, geophysical, and seismic branches of science and their adaptation and extension to acoustic tomography for subsurface oceanographic investigations. In particular, the following aspects pertaining to the application of acoustic methods for probing the oceans interior water temperature and current structure, as well as their adaptations for measuring horizontally averaged water currents from straits, coastal water bodies, estuaries, and rivers, are addressed: (1) one-way tomography, (2) two-way tomography (reciprocal tomography), (3) acoustic tomographic measurements from straits, (4) coastal acoustic tomography (CAT), (5) river acoustic tomography (RAT), (6) acoustic tomographic measurements of vorticity, and (7) horizontally integrated current measurements using space-time acoustic scintillation analysis technique.

Antony Joseph

2014-01-01T23:59:59.000Z

399

Multimodal registration of three-dimensional maxillodental cone beam CT and photogrammetry data over time  

E-Print Network [OSTI]

change over time. Dentomaxillofacial Radiology (2012) 0, 1­9. doi: 10.1259/dmfr/22027087 Keywords: three) scanner] may suffice to solve some clinical dental issues, in more general cases, dentists must deal@interchange.ubc.ca Received 2 January 2012; revised 12 April 2012; accepted 20 April 2012 Dentomaxillofacial Radiology (2012

Alberta, University of

400

Vocal tract changes caused by phonation into a tube: A case study using computer tomography and finite-element modeling  

Science Journals Connector (OSTI)

Phonation into a glass tube is a voice training and therapy method that leads to beneficial effects in voice production. It has not been known however what changes occur in the vocal tract during and after the phonation into a tube. This pilot study examined the vocal tract shape in a female subject before during and after phonation into a tube using computer tomography(CT). Three-dimensional finite-elementmodels (FEMs) of the vocal tract were derived from the CTimages and used to study changes in vocal tract input impedance. When phonating on vowel [a:] the data showed tightened velopharyngeal closure and enlarged cross-sectional areas of the oropharyngeal and oral cavities during and after the tube-phonation. FEM calculations revealed an increased input inertance of the vocal tract and an increased acoustic energy radiated out of the vocal tract after the tube-phonation. The results indicate that the phonation into a tube causes changes in the vocal tract which remain also when the tube is removed. These effects may help improving voice production in patients and voice professionals.

Tom Vampola; Anne-Maria Laukkanen; Jaromr Hor?ek; Jan G. vec

2011-01-01T23:59:59.000Z

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.


401

Rotational micro-CT using a clinical C-arm angiography gantry  

SciTech Connect (OSTI)

Rotational angiography (RA) gantries are used routinely to acquire sequences of projection images of patients from which 3D renderings of vascular structures are generated using Feldkamp cone-beam reconstruction algorithms. However, these systems have limited resolution (<4 lp/mm). Micro-computed tomography (micro-CT) systems have better resolution (>10 lp/mm) but to date have relied either on rotating object imaging or small bore geometry for small animal imaging, and thus are not used for clinical imaging. The authors report here the development and use of a 3D rotational micro-angiography (RMA) system created by mounting a micro-angiographic fluoroscope (MAF) [35 {mu}m pixel, resolution >10 lp/mm, field of view (FOV)=3.6 cm] on a standard clinical FPD-based RA gantry (Infinix, Model RTP12303J-G9E, Toshiba Medical Systems Corp., Tustin, CA). RA image sequences are obtained using the MAF and reconstructed. To eliminate artifacts due to image truncation, lower-dose (compared to MAF acquisition) full-FOV (FFOV) FPD RA sequences (194 {mu}m pixel, FOV=20 cm) were also obtained to complete the missing data. The RA gantry was calibrated using a helical bead phantom. To ensure high-quality high-resolution reconstruction, the high-resolution images from the MAF were aligned spatially with the lower-dose FPD images, and the pixel values in the FPD image data were scaled to match those of the MAF. Images of a rabbit with a coronary stent placed in an artery in the Circle of Willis were obtained and reconstructed. The MAF images appear well aligned with the FPD images (average correlation coefficient before and after alignment: 0.65 and 0.97, respectively) Greater details without any visible truncation artifacts are seen in 3D RMA (MAF-FPD) images than in those of the FPD alone. The FWHM of line profiles of stent struts (100 {mu}m diameter) are approximately 192{+-}21 and 313{+-}38 {mu}m for the 3D RMA and FPD data, respectively. In addition, for the dual-acquisition 3D RMA, FFOV FPD data need not be of the highest quality, and thus may be acquired at lower dose compared to a standard FPD acquisition. These results indicate that this system could provide the basis for high resolution images of regions of interest in patients with a reduction in the integral dose compared to the standard FPD approach.

Patel, V.; Hoffmann, K. R.; Ionita, C. N.; Keleshis, C.; Bednarek, D. R.; Rudin, S. [Toshiba Stroke Research Center, Department of Physics, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Neurosurgery, Department of Physics, Department of Physiology and Biophysics, Department of Mechanical and Aerospace Engineering, and Department of Computer Science, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Neurosurgery, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Electrical Engineering, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Radiology, Department of Neurosurgery, Department of Physics, and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Radiology, Department of Neurosurgery, Department of Physiology and Biophysics, Department of Mechanical and Aerospace Engineering, and Department of Electrical Engineering, State University of New York at Buffalo, Buffalo, New York 14214 (United States)

2008-10-15T23:59:59.000Z

402

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

Open Energy Info (EERE)

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:...

403

Quantification of liver iron content with CTadded value of dual-energy  

Science Journals Connector (OSTI)

To evaluate the value of dual-energy CT (DECT) with use of an ... decomposition algorithm for the quantification of liver iron content (LIC).

Michael A. Fischer; Caecilia S. Reiner; Dimitri Raptis; Olivio Donati

2011-08-01T23:59:59.000Z

404

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

E-Print Network [OSTI]

selecta bibliografa, 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

405

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

SciTech Connect (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

406

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:

407

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

408

Low-cost diffuse optical tomography for the classroom  

Science Journals Connector (OSTI)

Diffuse optical tomography (DOT) is an emerging imaging modality with potential applications in oncology neurology and other clinical areas. It allows the non-invasive probing of the tissue function using relatively inexpensive and safe instrumentation. An educational laboratory setup of a DOT system could be used to demonstrate how photons propagate through tissues basics of medical tomography and the concepts of multiple scattering and absorption. Here we report a DOT setup that could be introduced to the advanced undergraduate or early graduate curriculum using inexpensive and readily available tools. The basis of the system is the LEGO Mindstorms NXT platform which controls the light sources the detectors (photo-diodes) a mechanical 2D scanning platform and the data acquisition. A basic tomographic reconstruction is implemented in standard numerical software and 3D images are reconstructed. The concept was tested and developed in an educational environment that involved a high-school student and a group of post-doctoral fellows.

Taisuke Minagawa; Peyman Zirak; Udo M. Weigel; Anna K. Kristoffersen; Nicolas Mateos; Alejandra Valencia; Turgut Durduran

2012-01-01T23:59:59.000Z

409

Quantum tomography meets dynamical systems and bifurcations theory  

SciTech Connect (OSTI)

A powerful tool for studying geometrical problems in Hilbert spaces is developed. We demonstrate the convergence and robustness of our method in every dimension by considering dynamical systems theory. This method provides numerical solutions to hard problems involving many coupled nonlinear equations in low and high dimensions (e.g., quantum tomography problem, existence and classification of Pauli partners, mutually unbiased bases, complex Hadamard matrices, equiangular tight frames, etc.). Additionally, this tool can be used to find analytical solutions and also to implicitly prove the existence of solutions. Here, we develop the theory for the quantum pure state tomography problem in finite dimensions but this approach is straightforwardly extended to the rest of the problems. We prove that solutions are always attractive fixed points of a nonlinear operator explicitly given. As an application, we show that the statistics collected from three random orthonormal bases is enough to reconstruct pure states from experimental (noisy) data in every dimension d ? 32.

Goyeneche, D., E-mail: dardo.goyeneche@cefop.udec.cl [Departamento de Fisca, Universidad de Concepcin, Casilla 160-C, Concepcin, Chile and Center for Optics and Photonics, Universidad de Concepcin, Casilla 4012, Concepcin (Chile); Torre, A. C. de la [Departamento de Fsica, Universidad Nacional de Mar del Plata, IFIMAR-CONICET, Dean Funes 3350, 7600 Mar del Plata (Argentina)

2014-06-15T23:59:59.000Z

410

Coral Extension Rate Analysis Using Computed Axial Tomography  

E-Print Network [OSTI]

CORAL EXTENSION RATE ANALYSIS USING COMPUTED AXIAL TOMOGRAPHY A Thesis by ELEANOR ANN YUDELMAN Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE Chair of Committee, Niall Slowey Committee Members, Deborah Thomas Benjamin Giese George P. Schmahl Head of Department, Deborah Thomas May 2014 Major Subject: Oceanography Copyright 2014 Eleanor Ann Yudelman ii ABSTRACT...

Yudelman, Eleanor Ann

2014-01-10T23:59:59.000Z

411

Recent developments in guided wave travel time tomography  

SciTech Connect (OSTI)

The concept of predictive maintenance using permanent sensors that monitor the integrity of an installation is an interesting addition to the current method of periodic inspections. Guided wave tomography had been developed to create a map of the wall thickness using the travel times of guided waves. It can be used for both monitoring and for inspection of pipe-segments that are difficult to access, for instance at the location of pipe-supports. An important outcome of the tomography is the minimum remaining wall thickness, as this is critical in the scheduling of a replacement of the pipe-segment. In order to improve the sizing accuracy we have improved the tomography scheme. A number of major improvements have been realized allowing to extend the application envelope to pipes with a larger wall thickness and to larger distances between the transducer rings. Simulation results indicate that the sizing accuracy has improved and that is now possible to have a spacing of 8 meter between the source-ring and the receiver-ring. Additionally a reduction of the number of sensors required might be possible as well.

Zon, Tim van; Volker, Arno [TNO, Stieltjesweg 1, P.O. box 155 2600 AD Delft (Netherlands)

2014-02-18T23:59:59.000Z

412

Real Time Tomography at the Swiss Light Source  

SciTech Connect (OSTI)

The penetrating power of X-rays coupled with the high flux of 3rd generation synchrotron sources makes X-ray tomography to excel among fast imaging methods . To exploit this asset of synchrotron sources is the motivation for setting up an ultra-fast tomography endstation at the TOMCAT beamline. The state of the art instruments at synchrotron sources offer routinely a temporal resolution of tens of seconds in tomography. For a number of applications, for example biomedical studies, the relevant time scales (breathing, heartbeat) are rather in the range of 0.5-2 seconds. To overcome motion artifacts when imaging such systems a new ultra-fast tomographic data acquisition scheme is being developed at the TOMCAT beamline. We can acquire a full set of projections at sub-second timescale in monochromatic or white-beam configuration. We present a feasibility study with the ultimate aim to achieve sub-second temporal resolution in 3D without significant deterioration of the spatial resolution. For the first time, the 3D dynamics of the very early stages of a quickly aging liquid foam can be visualised with high quality and sufficiently large field of view.

Mokso, R.; Marone, F. [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen (Switzerland); Stampanoni, M. [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen (Switzerland); Institute for Biomedical Engineering, University and ETH Zurich, Zurich (Switzerland)

2010-06-23T23:59:59.000Z

413

Comparison of x ray computed tomography number to proton relative linear stopping power conversion functions using a standard phantom  

SciTech Connect (OSTI)

Purpose: Adequate evaluation of the results from multi-institutional trials involving light ion beam treatments requires consideration of the planning margins applied to both targets and organs at risk. A major uncertainty that affects the size of these margins is the conversion of x ray computed tomography numbers (XCTNs) to relative linear stopping powers (RLSPs). Various facilities engaged in multi-institutional clinical trials involving proton beams have been applying significantly different margins in their patient planning. This study was performed to determine the variance in the conversion functions used at proton facilities in the U.S.A. wishing to participate in National Cancer Institute sponsored clinical trials. Methods: A simplified method of determining the conversion function was developed using a standard phantom containing only water and aluminum. The new method was based on the premise that all scanners have their XCTNs for air and water calibrated daily to constant values but that the XCTNs for high density/high atomic number materials are variable with different scanning conditions. The standard phantom was taken to 10 different proton facilities and scanned with the local protocols resulting in 14 derived conversion functions which were compared to the conversion functions used at the local facilities. Results: For tissues within 300 XCTN of water, all facility functions produced converted RLSP values within 6% of the values produced by the standard function and within 8% of the values from any other facility's function. For XCTNs corresponding to lung tissue, converted RLSP values differed by as great as 8% from the standard and up to 16% from the values of other facilities. For XCTNs corresponding to low-density immobilization foam, the maximum to minimum values differed by as much as 40%. Conclusions: The new method greatly simplifies determination of the conversion function, reduces ambiguity, and in the future could promote standardization between facilities. Although it was not possible from these experiments to determine which conversion function is most appropriate, the variation between facilities suggests that the margins used in some facilities to account for the uncertainty in converting XCTNs to RLSPs may be too small.

Moyers, M. F., E-mail: MFMoyers@roadrunner.com [Shanghai Proton and Heavy Ion Center, Shanghai, China 201321 (China)

2014-06-15T23:59:59.000Z

414

Validation of Plaster Endocast Morphology Through 3D CT Image Analysis  

E-Print Network [OSTI]

Validation of Plaster Endocast Morphology Through 3D CT Image Analysis P. Thomas Schoenemann,1 by creating endo- casts out of rubber latex shells filled with plaster. The extent to which the method questions. Pairs of virtual endocasts (VEs) created from high-resolution CT scans of corresponding latex/plaster

Schoenemann, P. Thomas

415

Bone Surface Reconstruction From CT/MR Images Using Fast Marching and Level Set Methods1)  

E-Print Network [OSTI]

Bone Surface Reconstruction From CT/MR Images Using Fast Marching and Level Set Methods1) Istv surfaces reconstructed from MR volumes are shown. 1 Outline of the project One of our current projects steps of bone surface reconstruction from CT/MR slice images. 2 Main steps of reconstruction 2.1

Chetverikov, Dmitry

416

Multi-atlas Segmentation in Head and Neck CT Scans Amelia M. Arbisser  

E-Print Network [OSTI]

Multi-atlas Segmentation in Head and Neck CT Scans by Amelia M. Arbisser B.S., Computer Science of Engineering Thesis Committee #12;2 #12;Multi-atlas Segmentation in Head and Neck CT Scans by Amelia M, we employ an atlas of labeled training images. We register each of these images to the unlabeled

Golland, Polina

417

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

418

A direct method for air kermalength product measurement in CT for verification of dose display calibrations  

Science Journals Connector (OSTI)

......kerma-length product measurement in CT for verification of dose display calibrations...kerma-length product measurement in CT for verification of dose display calibrations...practice, this means doing measurements in the standard phantoms......

Katja Merimaa; Hannu Jrvinen; Mika Kortesniemi; Juhani Karppinen

2010-08-01T23:59:59.000Z

419

A Novel Markerless Technique to Evaluate Daily Lung Tumor Motion Based on Conventional Cone-Beam CT Projection Data  

SciTech Connect (OSTI)

Purpose: In this study, we present a novel markerless technique, based on cone beam computed tomography (CBCT) raw projection data, to evaluate lung tumor daily motion. Method and Materials: The markerless technique, which uses raw CBCT projection data and locates tumors directly on every projection, consists of three steps. First, the tumor contour on the planning CT is used to create digitally reconstructed radiographs (DRRs) at every projection angle. Two sets of DRRs are created: one showing only the tumor, and another with the complete anatomy without the tumor. Second, a rigid two-dimensional image registration is performed to register the DRR set without the tumor to the CBCT projections. After the registration, the projections are subtracted from the DRRs, resulting in a projection dataset containing primarily tumor. Finally, a second registration is performed between the subtracted projection and tumor-only DRR. The methodology was evaluated using a chest phantom containing a moving tumor, and retrospectively in 4 lung cancer patients treated by stereotactic body radiation therapy. Tumors detected on projection images were compared with those from three-dimensional (3D) and four-dimensional (4D) CBCT reconstruction results. Results: Results in both static and moving phantoms demonstrate that the accuracy is within 1 mm. The subsequent application to 22 sets of CBCT scan raw projection data of 4 lung cancer patients includes about 11,000 projections, with the detected tumor locations consistent with 3D and 4D CBCT reconstruction results. This technique reveals detailed lung tumor motion and provides additional information than conventional 4D images. Conclusion: This technique is capable of accurately characterizing lung tumor motion on a daily basis based on a conventional CBCT scan. It provides daily verification of the tumor motion to ensure that these motions are within prior estimation and covered by the treatment planning volume.

Yang Yin; Zhong Zichun; Guo Xiaohu [Department of Computer Science, University of Texas at Dallas, Richardson, TX (United States); Wang Jing; Anderson, John; Solberg, Timothy [Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390 (United States); Mao Weihua, E-mail: weihua.mao@utsouthwestern.edu [Department of Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390 (United States)

2012-04-01T23:59:59.000Z

420

Software-defined Radio Based Wireless Tomography: Experimental Demonstration and Verification  

SciTech Connect (OSTI)

This letter presents an experimental demonstration of software-defined-radio-based wireless tomography using computer-hosted radio devices called Universal Software Radio Peripheral (USRP). This experimental brief follows our vision and previous theoretical study of wireless tomography that combines wireless communication and RF tomography to provide a novel approach to remote sensing. Automatic data acquisition is performed inside an RF anechoic chamber. Semidefinite relaxation is used for phase retrieval, and the Born iterative method is utilized for imaging the target. Experimental results are presented, validating our vision of wireless tomography.

Bonior, Jason D [ORNL; Hu, Zhen [Tennessee Technological University; Guo, Terry N. [Tennessee Technological University; Qiu, Robert C. [Tennessee Technological University; Browning, James P. [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Wicks, Michael C. [University of Dayton Research Institute

2015-01-01T23:59:59.000Z

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.


421

E-Print Network 3.0 - aids computed tomography Sample Search...  

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

of Mathematics, Tufts University Collection: Mathematics 2 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: problems X-ray tomography...

422

E-Print Network 3.0 - attenuated vector tomography Sample Search...  

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

Kansas State University Collection: Mathematics 2 CAT scan and RadonX-ray transform Relations with the Fourier transform. Dual Radon Summary: Optical Tomography Novel...

423

Video-rate fluorescence diffuse optical tomography for in vivo sentinel lymph node imaging  

Science Journals Connector (OSTI)

We have developed a fiber-based, video-rate fluorescence diffuse optical tomography (DOT) system for noninvasive in vivo sentinel lymph node (SLN) mapping. Concurrent acquisition of...

Solomon, Metasebya; White, Brian R; Nothdruft, Ralph E; Akers, Walter; Sudlow, Gail; Eggebrecht, Adam T; Achilefu, Samuel; Culver, Joseph P

2011-01-01T23:59:59.000Z

424

Quantitative and dynamic measurements of biological fresh samples with X-ray phase contrast tomography  

Science Journals Connector (OSTI)

Quantitative measurements of biological fresh samples based on three-dimensional densitometry using X-ray phase contrast tomography are presented.

Hoshino, M.

2014-10-08T23:59:59.000Z

425

Hydraulic conductivity imaging from 3-D transient hydraulic tomography at several pumping/observation densities  

E-Print Network [OSTI]

of transport and design and operation of ground- water remediation systems, are crucially dependent transient hydraulic tomography at several pumping/observation densities, Water Resour. Res., 49, 7311

Barrash, Warren

426

Mapping higher-order brain function and resting-state networks with diffuse optical tomography  

Science Journals Connector (OSTI)

We present integrative advances in high-density diffuse optical tomography imaging arrays, large field-of-view instrumentation, and anatomical head modeling. The system was tested by...

Eggebrecht, Adam T; Ferradal, Silvina L; Robichaux-Viehoever, Amy; Hassanpour, Mahlega S; Dehghani, Hamid; Snyder, Abraham; Hershey, Tamara; Culver, Joseph P

427

Velocity Variation Assessment of Red Blood Cell Aggregation with Spectral Domain Doppler Optical Coherence Tomography  

E-Print Network [OSTI]

J. G. Fujimoto. Optical coherence tomog- raphy. Science 254:spectral domain low coherence interferometry and retinalsedimentation on optical coherence tomography signals from

Xu, Xiangqun; Yu, Lingfeng; Chen, Zhongping

2010-01-01T23:59:59.000Z

428

Four-dimensional optical coherence tomography imaging of total liquid ventilated rats  

Science Journals Connector (OSTI)

Optical coherence tomography (OCT) can be utilized for the spatially and temporally resolved visualization of alveolar tissue and its dynamics in rodent models, which allows the...

Kirsten, Lars; Schnabel, Christian; Gaertner, Maria; Koch, Edmund

429

Quantitative measurements of strain and birefringence with common-path polarization-sensitive optical coherence tomography  

Science Journals Connector (OSTI)

We demonstrate the first system for optical coherence tomography (OCT) that enables simultaneous measurement of quantitative birefringence and strain in biological samples using a...

Marvdashti, Tahereh; Duan, Lian; Lurie, Kristen L; Smith, Gennifer T; Ellerbee, Audrey K

2014-01-01T23:59:59.000Z

430

Using synchroton radiation-based micro-computer tomography (SR ?-CT) for the measurement of fibre orientations in cellulose fibre-reinforced polylactide (PLA) composites  

Science Journals Connector (OSTI)

The present work deals with the measurement of fibre orientation angles in composites. A study by Bax and Mssig [1] investigated the mechanical properties (tensile and impact characteristics) of injection-moulde...

Nina Graupner; Felix Beckmann; Fabian Wilde; Jrg Mssig

2014-01-01T23:59:59.000Z

431

3D Reconstruction of Intricate Archean Microbial Structures Using Neutron Computed Tomography and Serial SectioningIN43B-0331 Abstract Project Goals  

E-Print Network [OSTI]

Tomography and Serial SectioningIN43B-0331 Abstract Project Goals Background Methods Neutron Computed using both serial sectioning and neutron computed tomography (NCT). Reconstruction techniques vary mechanisms for ancient microbial communities Neutron Computed Tomography Serial Sectioning Samples were

Hamann, Bernd

432

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

E-Print Network [OSTI]

Trimester Fetal Radiation Dose Estimation in 16-MDCT Withoutsimulations for radiation dose estimations discussed in thisspecific radiation dose and cancer risk estimation in CT:

Zhang, Di

2012-01-01T23:59:59.000Z

433

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

E-Print Network [OSTI]

retrospective review. Pediatric Radiology, 2010 May;40(5):pediatric CT: effect of technical factors and phantom size and shape. Radiology

Zhang, Di

2012-01-01T23:59:59.000Z

434

Assessment of dedicated low-dose cardiac micro-CT reconstruction algorithms using the left ventricular volume of small rodents as a performance measure  

SciTech Connect (OSTI)

Purpose: Phase-correlated microcomputed tomography (micro-CT) imaging plays an important role in the assessment of mouse models of cardiovascular diseases and the determination of functional parameters as the left ventricular volume. As the current gold standard, the phase-correlated Feldkamp reconstruction (PCF), shows poor performance in case of low dose scans, more sophisticated reconstruction algorithms have been proposed to enable low-dose imaging. In this study, the authors focus on the McKinnon-Bates (MKB) algorithm, the low dose phase-correlated (LDPC) reconstruction, and the high-dimensional total variation minimization reconstruction (HDTV) and investigate their potential to accurately determine the left ventricular volume at different dose levels from 50 to 500 mGy. The results were verified in phantom studies of a five-dimensional (5D) mathematical mouse phantom. Methods: Micro-CT data of eight mice, each administered with an x-ray dose of 500 mGy, were acquired, retrospectively gated for cardiac and respiratory motion and reconstructed using PCF, MKB, LDPC, and HDTV. Dose levels down to 50 mGy were simulated by using only a fraction of the projections. Contrast-to-noise ratio (CNR) was evaluated as a measure of image quality. Left ventricular volume was determined using different segmentation algorithms (Otsu, level sets, region growing). Forward projections of the 5D mouse phantom were performed to simulate a micro-CT scan. The simulated data were processed the same way as the real mouse data sets. Results: Compared to the conventional PCF reconstruction, the MKB, LDPC, and HDTV algorithm yield images of increased quality in terms of CNR. While the MKB reconstruction only provides small improvements, a significant increase of the CNR is observed in LDPC and HDTV reconstructions. The phantom studies demonstrate that left ventricular volumes can be determined accurately at 500 mGy. For lower dose levels which were simulated for real mouse data sets, the HDTV algorithm shows the best performance. At 50 mGy, the deviation from the reference obtained at 500 mGy were less than 4%. Also the LDPC algorithm provides reasonable results with deviation less than 10% at 50 mGy while PCF and MKB reconstruction show larger deviations even at higher dose levels. Conclusions: LDPC and HDTV increase CNR and allow for quantitative evaluations even at dose levels as low as 50 mGy. The left ventricular volumes exemplarily illustrate that cardiac parameters can be accurately estimated at lowest dose levels if sophisticated algorithms are used. This allows to reduce dose by a factor of 10 compared to today's gold standard and opens new options for longitudinal studies of the heart.

Maier, Joscha, E-mail: joscha.maier@dkfz.de [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)] [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Sawall, Stefan; Kachelrie, Marc [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Institute of Medical Physics, University of ErlangenNrnberg, 91052 Erlangen (Germany)] [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany and Institute of Medical Physics, University of ErlangenNrnberg, 91052 Erlangen (Germany)

2014-05-15T23:59:59.000Z

435

Remote Tomography Via von Neumann-Arthurs-Kelly Interaction  

E-Print Network [OSTI]

Teleportation usually involves entangled particles 1,2 shared by Alice and Bob, Bell-state measurement on particle 1 and system particle by Alice, classical communication to Bob, and unitary transformation by Bob on particle 2. We propose a novel method: interaction-based remote tomography. Alice arranges an entanglement generating von Neumann-Arthurs-Kelly interaction between the system and two apparatus particles, and then teleports the latter to Bob. Bob reconstructs the unknown initial state of the system not received by him by quadrature measurements on the apparatus particles .

S. M. Roy; Abhinav Deshpande; Nitica Sakharwade

2013-08-23T23:59:59.000Z

436

Pulsed homodyne Gaussian quantum tomography with low detection efficiency  

E-Print Network [OSTI]

Pulsed homodyne quantum tomography usually requires a high detection efficiency limiting its applicability in quantum optics. Here, it is shown that the presence of low detection efficiency ($<50\\%$) does not prevent the tomographic reconstruction of quantum states of light, specifically, of Gaussian type. This result is obtained by applying the so-called "minimax" adaptive reconstruction of the Wigner function to pulsed homodyne detection. In particular, we prove, by both numerical and real experiments, that an effective discrimination of different Gaussian quantum states can be achieved. Our finding paves the way to a more extensive use of quantum tomographic methods, even in physical situations in which high detection efficiency is unattainable.

Martina Esposito; Fabio Benatti; Roberto Floreanini; Stefano Olivares; Francesco Randi; Kelvin Titimbo; Marco Pividori; Fabio Novelli; Federico Cilento; Fulvio Parmigiani; Daniele Fausti

2014-02-19T23:59:59.000Z

437

CT effective dose per dose length product using ICRP 103 weighting factors  

SciTech Connect (OSTI)

Purpose: To generate effective dose per unit dose length product (E/DLP) conversion factors incorporating ICRP Publication 103 tissue weighting factors. Methods: Effective doses for CT