Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.5874358
C. Nguyen, Jeremy M. C. Brown, R. Lewis, David V. Martin, M. Dimmock, D. Nikulin, J. Gillam
The Pixelated Emission Detector for RadiOisotopes (PEDRO) is a hybrid imaging system designed for the measurement of single photon emission from small animal models. The proof-of-principle device consists of a Compton-camera situated behind a mechanical collimator and is intended to provide optimal detection characteristics over a broad spectral range, from 30 keV to 511 keV. An automated routine has been developed for the optimization of the mechanical collimator which consists of pinholes and open slits. The optimization was tested with a Geant4 model of the experimental prototype. The data were blurred with the expected position and energy resolution parameters and a Bayesian interaction ordering algorithm was applied. The results show that the optimization technique allows the large-area slits to sample fully the primary field of view (FoV). The slits were found to provide truncation of the back-projected cones of response and also an increase in the success rate of the interaction ordering algorithm. These factors resulted in an increase in the contrast and signal-to-noise ratios of the reconstructed image estimates.
{"title":"Hybrid-collimator design for a small animal imager: PEDRO","authors":"C. Nguyen, Jeremy M. C. Brown, R. Lewis, David V. Martin, M. Dimmock, D. Nikulin, J. Gillam","doi":"10.1109/NSSMIC.2010.5874358","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874358","url":null,"abstract":"The Pixelated Emission Detector for RadiOisotopes (PEDRO) is a hybrid imaging system designed for the measurement of single photon emission from small animal models. The proof-of-principle device consists of a Compton-camera situated behind a mechanical collimator and is intended to provide optimal detection characteristics over a broad spectral range, from 30 keV to 511 keV. An automated routine has been developed for the optimization of the mechanical collimator which consists of pinholes and open slits. The optimization was tested with a Geant4 model of the experimental prototype. The data were blurred with the expected position and energy resolution parameters and a Bayesian interaction ordering algorithm was applied. The results show that the optimization technique allows the large-area slits to sample fully the primary field of view (FoV). The slits were found to provide truncation of the back-projected cones of response and also an increase in the success rate of the interaction ordering algorithm. These factors resulted in an increase in the contrast and signal-to-noise ratios of the reconstructed image estimates.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"33 1","pages":"3042-3048"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77278054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.5874363
A. Kapadia, J. Shah, G. Agasthya
Neutron stimulated emission computed tomography (NSECT) has been proposed as an early cancer-detection technique with the capability of 3-D tomographic imaging for identification of malignant tumors. In previous work we have demonstrated the ability of the technique to differentiate between normal and malignant breast tumors based on the concentration of cancer-marking elements in the tissue. Here we present tomographic images from a breast phantom with benign and malignant tumors simulated in GEANT4. A simulated model of the NSECT system was developed in GEANT4, along with phantoms corresponding to the human breast with benign and malignant tumors. Each tumor within the breast was given a different concentration of cancer-marking trace elements based on values reported in literature. The phantom was scanned with a 5-MeV neutron beam over a 180-degree angle. Tomographic images were reconstructed for six elements of interest from 10 different spectral lines. The results showed excellent agreement between the location of the tumor and the concentration of trace element detected in gamma lines from bromine, cesium, sodium and zinc. These results demonstrate the ability of NSECT in quantitative elemental imaging for breast cancer detection.
{"title":"Quantitative elemental imaging with neutrons for breast cancer diagnosis: A GEANT4 study","authors":"A. Kapadia, J. Shah, G. Agasthya","doi":"10.1109/NSSMIC.2010.5874363","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874363","url":null,"abstract":"Neutron stimulated emission computed tomography (NSECT) has been proposed as an early cancer-detection technique with the capability of 3-D tomographic imaging for identification of malignant tumors. In previous work we have demonstrated the ability of the technique to differentiate between normal and malignant breast tumors based on the concentration of cancer-marking elements in the tissue. Here we present tomographic images from a breast phantom with benign and malignant tumors simulated in GEANT4. A simulated model of the NSECT system was developed in GEANT4, along with phantoms corresponding to the human breast with benign and malignant tumors. Each tumor within the breast was given a different concentration of cancer-marking trace elements based on values reported in literature. The phantom was scanned with a 5-MeV neutron beam over a 180-degree angle. Tomographic images were reconstructed for six elements of interest from 10 different spectral lines. The results showed excellent agreement between the location of the tumor and the concentration of trace element detected in gamma lines from bromine, cesium, sodium and zinc. These results demonstrate the ability of NSECT in quantitative elemental imaging for breast cancer detection.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"8 1","pages":"3065-3068"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76572101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.5874393
V. Borshchov, D. Burdette, E. Chesi, V. Cindro, N. Clinthorne, E. Cochran, B. Grošičar, K. Honscheid, H. Kagan, C. Lacasta, O. Listratenko, G. Llosá, M. Mikuž, M. Protsenko, V. Stankova, A. Studen, I. Tymchuk, P. Weilhammer, D. Žontar, V. Linhart
Detection and spectroscopic tests of three self-triggered silicon detection modules constructed using Tape Automated Bonding and micro-cable technologies and equipped by VATA read-out chips are presented and compared. Results of these tests are demonstrated using hit maps and pulse-height spectra induced by 133Ba, 241Am, and 57Co radioactive sources of X- and gamma rays. We have observed significant improvement in measurement of hit maps in the cases of first and second detector modules. The hit maps of the first detector module have proven that some problems occur in addressing certain VATA chip channels. Whereas, the hit maps of the second detector module is correct. On the other side, spectroscopic resolution given by the Full Width at Half Maximum (FWHM) of the first detection module is below 2 keV which is compatible with measurements on wire bonded modules. The FWHM of the second module is approximately two times worse.
{"title":"Detection tests of imaging devices based on silicon pixel-array detectors assembled using Tape Automated Bonding and microcable technologies","authors":"V. Borshchov, D. Burdette, E. Chesi, V. Cindro, N. Clinthorne, E. Cochran, B. Grošičar, K. Honscheid, H. Kagan, C. Lacasta, O. Listratenko, G. Llosá, M. Mikuž, M. Protsenko, V. Stankova, A. Studen, I. Tymchuk, P. Weilhammer, D. Žontar, V. Linhart","doi":"10.1109/NSSMIC.2010.5874393","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874393","url":null,"abstract":"Detection and spectroscopic tests of three self-triggered silicon detection modules constructed using Tape Automated Bonding and micro-cable technologies and equipped by VATA read-out chips are presented and compared. Results of these tests are demonstrated using hit maps and pulse-height spectra induced by 133Ba, 241Am, and 57Co radioactive sources of X- and gamma rays. We have observed significant improvement in measurement of hit maps in the cases of first and second detector modules. The hit maps of the first detector module have proven that some problems occur in addressing certain VATA chip channels. Whereas, the hit maps of the second detector module is correct. On the other side, spectroscopic resolution given by the Full Width at Half Maximum (FWHM) of the first detection module is below 2 keV which is compatible with measurements on wire bonded modules. The FWHM of the second module is approximately two times worse.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"6 1","pages":"3194-3196"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79770539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.5874355
J. Bowen, Qiu Huang, G. Gullberg, Youngho Seo
Single photon emission computed tomography (SPECT) has essentially remained an unchanged technology since the introduction of parallel-hole collimation in 1964 and stands to gain significantly from sensitivity improvements. Benefits from improved sensitivity include shorter acquisition times and smaller dose requirements. An order of magnitude increase in sensitivity over conventional technology is possible with the use of multipinhole collimators on conventional SPECT cameras. Here we present MGEANT Monte Carlo simulation results of a dualisotope myocardial perfusion imaging study performed with a pair of focusing 20-pinhole collimators with tungsten apertures demonstrating that a complete rest/stress study is possible in 10 minutes with a reduced 99mTc dose. Two radionuclides were simulated, 99mTc (500 μCi, rest) and 201Tl (200 μCi, stress), with 20% and 30% window sizes, respectively. Full isotropic emission was simulated for 8 gamma-ray lines. The imaging protocol consisted of 2 views per head with 300 s per view. The activity distributions were derived from the mathematical cardiac and torso (MCAT) phantom. Attenuation was modeled using a water phantom. Images were reconstructed using 75 iterations of pixel-based ordered subsets expectation maximization and post-filtered with an 12.5 mm (FWHM) 3D Gaussian filter. Scatter corrections were performed using the triple energy window method. Scatter comprises 37% and 61% of the total counts in the 99mTc and 201Tl energy windows, respectively. 99mTc downscatter contributes 52% of the scatter component in the 201Tl window, though tungsten fluorescence is negligible (0.2%). Reconstructed images are qualitatively in agreement with the input activity distributions.
自1964年引入平行孔准直以来，单光子发射计算机断层扫描(SPECT)基本上保持不变的技术，并且从灵敏度的提高中获得了显着的收益。提高灵敏度的好处包括更短的采集时间和更小的剂量要求。在传统的SPECT相机上使用多针孔准直器可以使灵敏度比传统技术提高一个数量级。在这里，我们展示了MGEANT蒙特卡罗模拟的双同位素心肌灌注成像研究结果，该研究使用一对聚焦20针孔钨孔准直器进行，表明在减少99mTc剂量的情况下，可以在10分钟内完成休息/应力研究。模拟两种放射性核素，99mTc (500 μCi，静息)和201Tl (200 μCi，应力)，窗口大小分别为20%和30%。模拟了8条伽玛射线线的全各向同性发射。成像方案包括每个头部2个视图，每个视图300秒。活动分布来源于数学心脏和躯干(MCAT)幻像。衰减是用水影来模拟的。通过75次基于像素的有序子集期望最大化迭代重建图像，并使用12.5 mm (FWHM)三维高斯滤波器进行后滤波。利用三重能窗法进行散射校正。在99mTc和201Tl能量窗口中，Scatter分别占总计数的37%和61%。99mTc下散射贡献了201Tl窗口中52%的散射分量，尽管钨荧光可以忽略不计(0.2%)。重建图像在质量上与输入活动分布一致。
{"title":"SPECT dual-isotope myocardial perfusion imaging with a 20-pinhole collimator: A simulation study","authors":"J. Bowen, Qiu Huang, G. Gullberg, Youngho Seo","doi":"10.1109/NSSMIC.2010.5874355","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874355","url":null,"abstract":"Single photon emission computed tomography (SPECT) has essentially remained an unchanged technology since the introduction of parallel-hole collimation in 1964 and stands to gain significantly from sensitivity improvements. Benefits from improved sensitivity include shorter acquisition times and smaller dose requirements. An order of magnitude increase in sensitivity over conventional technology is possible with the use of multipinhole collimators on conventional SPECT cameras. Here we present MGEANT Monte Carlo simulation results of a dualisotope myocardial perfusion imaging study performed with a pair of focusing 20-pinhole collimators with tungsten apertures demonstrating that a complete rest/stress study is possible in 10 minutes with a reduced 99mTc dose. Two radionuclides were simulated, 99mTc (500 μCi, rest) and 201Tl (200 μCi, stress), with 20% and 30% window sizes, respectively. Full isotropic emission was simulated for 8 gamma-ray lines. The imaging protocol consisted of 2 views per head with 300 s per view. The activity distributions were derived from the mathematical cardiac and torso (MCAT) phantom. Attenuation was modeled using a water phantom. Images were reconstructed using 75 iterations of pixel-based ordered subsets expectation maximization and post-filtered with an 12.5 mm (FWHM) 3D Gaussian filter. Scatter corrections were performed using the triple energy window method. Scatter comprises 37% and 61% of the total counts in the 99mTc and 201Tl energy windows, respectively. 99mTc downscatter contributes 52% of the scatter component in the 201Tl window, though tungsten fluorescence is negligible (0.2%). Reconstructed images are qualitatively in agreement with the input activity distributions.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"7 1","pages":"3029-3031"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79803313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.5873857
W. Warburton, J. Harris, M. Carpenter, L. Fabris, S. Friedrich
We have developed a very low noise preamplifier that meets the low-cost, high-density requirements for use with superconducting tunnel junction (STJ) arrays. The design allows the STJs' bias points to be digitally set at the μV level. We then trace out noise versus bias curves under computer control and, by showing the correlation between this noise and detector energy resolution, establish the ability to automatically select optimum STJ operating points. Working with a 75 μm × 75 μm STJ with a Ta x-ray absorber, we achieved better than 7 eV FWHM at the 525 eV O-K line with about 2 eV coming from the preamplifier.
{"title":"Preamplifier development for superconducting tunnel junction array X-ray detector electronics","authors":"W. Warburton, J. Harris, M. Carpenter, L. Fabris, S. Friedrich","doi":"10.1109/NSSMIC.2010.5873857","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5873857","url":null,"abstract":"We have developed a very low noise preamplifier that meets the low-cost, high-density requirements for use with superconducting tunnel junction (STJ) arrays. The design allows the STJs' bias points to be digitally set at the μV level. We then trace out noise versus bias curves under computer control and, by showing the correlation between this noise and detector energy resolution, establish the ability to automatically select optimum STJ operating points. Working with a 75 μm × 75 μm STJ with a Ta x-ray absorber, we achieved better than 7 eV FWHM at the 525 eV O-K line with about 2 eV coming from the preamplifier.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"44 1","pages":"742-748"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79945847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.5874330
M. Alnowami, E. Lewis, K. Wells, M. Guy
In nuclear medicine, there is a significant research focus in developing a new approach in monitoring, tracking and compensating respiratory motion during image acquisition. We address this by attempting to model the respiratory cycle pattern and finding a method that describes the configuration of the anterior surface which then correlates with the internal position/configuration of the internal organ as a foundation for motion compensation. This paper presents novel work in parameterizing external respiratory motion using a method based on the variation of abdominal vs. thoracic surface markers to investigate inter- and intra-subject variation. The dominant mode of variation of the Abdominal and Thoracic surfaces during respiration using Principle Component Analysis (PCA) is studied. This demonstrates that pattern of TS vs AS motion appears temporally at a global level stable. Thus Although breathing style is consistent within a given subject, we there observe temporal changes in the amplitude and density of the PDF in intra-subject data.
在核医学中，开发一种监测、跟踪和补偿图像采集过程中呼吸运动的新方法是一个重要的研究热点。我们通过尝试模拟呼吸周期模式来解决这个问题，并找到一种方法来描述前表面的结构，然后将其与内部器官的内部位置/配置相关联，作为运动补偿的基础。本文介绍了一种基于腹部和胸部表面标记变化的方法来参数化外部呼吸运动的新工作，以研究受试者之间和受试者内部的变化。利用主成分分析(PCA)研究了呼吸过程中腹部和胸部表面变化的主导模式。这表明TS vs AS运动模式暂时在全局水平上是稳定的。因此，尽管呼吸方式在给定的受试者中是一致的，但我们在受试者内部数据中观察到PDF的振幅和密度的时间变化。
{"title":"Inter- and intra-subject variation of abdominal vs. thoracic respiratory motion using kernel density estimation","authors":"M. Alnowami, E. Lewis, K. Wells, M. Guy","doi":"10.1109/NSSMIC.2010.5874330","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874330","url":null,"abstract":"In nuclear medicine, there is a significant research focus in developing a new approach in monitoring, tracking and compensating respiratory motion during image acquisition. We address this by attempting to model the respiratory cycle pattern and finding a method that describes the configuration of the anterior surface which then correlates with the internal position/configuration of the internal organ as a foundation for motion compensation. This paper presents novel work in parameterizing external respiratory motion using a method based on the variation of abdominal vs. thoracic surface markers to investigate inter- and intra-subject variation. The dominant mode of variation of the Abdominal and Thoracic surfaces during respiration using Principle Component Analysis (PCA) is studied. This demonstrates that pattern of TS vs AS motion appears temporally at a global level stable. Thus Although breathing style is consistent within a given subject, we there observe temporal changes in the amplitude and density of the PDF in intra-subject data.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"30 1","pages":"2921-2924"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79024382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.5873919
J. Velthuis
We have obtained first results in a testbeam for the first 4T Monolithic Active Pixel Sensor for particle physics, FORTIS. We have measured a S/N of more than 100 for MIPs due to the excellent noise performance of the 4T architecture. Two versions of the sensor were tested; with and without deep Pwell areas in-pixel. The deep Pwell areas allow the incorporation of PMOS transistors inside the pixels signal charge loss. The presented results demonstrate that the deep Pwell sensors improve the performance.
{"title":"First beam test results of the FORTIS sensor","authors":"J. Velthuis","doi":"10.1109/NSSMIC.2010.5873919","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5873919","url":null,"abstract":"We have obtained first results in a testbeam for the first 4T Monolithic Active Pixel Sensor for particle physics, FORTIS. We have measured a S/N of more than 100 for MIPs due to the excellent noise performance of the 4T architecture. Two versions of the sensor were tested; with and without deep Pwell areas in-pixel. The deep Pwell areas allow the incorporation of PMOS transistors inside the pixels signal charge loss. The presented results demonstrate that the deep Pwell sensors improve the performance.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"38 1","pages":"1017-1020"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79396104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.5874225
J. Matthews, G. Angelis, F. Kotasidis, P. Markiewicz, A. Reader
Direct application of the expectation maximisation (EM) algorithm to the spatiotemporal maximum likelihood problem results in a convenient separation of the image based problem from the projection based problem. This enables any spatiotemporal 4D image model to be incorporated into MLEM image reconstruction with relative ease, only requiring tailored calculation of the fitting weights. As a preliminary example, assessment using direct estimation of spectral analysis coefficients is presented, exploiting an image based non-negative least squares algorithm, where a specially-weighted least squares update is equivalent to the required update towards the maximum likelihood estimate. The proposed approach demonstrates a reduced root mean square error (RMSE) in the estimates of volume of distribution. Future work will include the exploration of alternative spatiotemporal models.
{"title":"Direct reconstruction of parametric images using any spatiotemporal 4D image based model and maximum likelihood expectation maximisation","authors":"J. Matthews, G. Angelis, F. Kotasidis, P. Markiewicz, A. Reader","doi":"10.1109/NSSMIC.2010.5874225","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874225","url":null,"abstract":"Direct application of the expectation maximisation (EM) algorithm to the spatiotemporal maximum likelihood problem results in a convenient separation of the image based problem from the projection based problem. This enables any spatiotemporal 4D image model to be incorporated into MLEM image reconstruction with relative ease, only requiring tailored calculation of the fitting weights. As a preliminary example, assessment using direct estimation of spectral analysis coefficients is presented, exploiting an image based non-negative least squares algorithm, where a specially-weighted least squares update is equivalent to the required update towards the maximum likelihood estimate. The proposed approach demonstrates a reduced root mean square error (RMSE) in the estimates of volume of distribution. Future work will include the exploration of alternative spatiotemporal models.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"17 1","pages":"2435-2441"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81500970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.5873889
V. Revol, C. Kottler, R. Kaufmann, F. Cardot, P. Niedermann, I. Jerjen, T. Luthi, U. Straumann, U. Sennhauser, C. Urban
Ultra small angle scattering is a powerful tool for the study of the micro-structure of materials at a length scale below the resolution of standard x-ray detectors. Current methods like Small Angle X-ray Scattering (SAXS) are usually slow and therefore inadequate to industrial environments. A recently developed x-ray imaging method based on the Talbot-Lau interferometer allows for the full field measurement of the refraction and local small angle scattering of the x-ray beam within the object. The method is compatible with standard x-ray tubes and as such, a good candidate for industrial implementation. In the following manuscript, we report on the use of the x-ray Talbot-Lau interferometer for the measurement of the local small angle scattering power. Two applications relevant to homeland security are presented. First, we show how the measurement of the local small angle scattering power complements the conventional absorption-based radiography and helps to distinguish explosives from standard fail objects. Finally, we demonstrate that information can be coded within the scattering pattern of a manufactured marker. Such marker can be placed in critical objects, such as drugs boxes or luxury goods, in order to avoid the circulation of fakes.
{"title":"Sensing small angle scattering with an X-ray grating interferometer","authors":"V. Revol, C. Kottler, R. Kaufmann, F. Cardot, P. Niedermann, I. Jerjen, T. Luthi, U. Straumann, U. Sennhauser, C. Urban","doi":"10.1109/NSSMIC.2010.5873889","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5873889","url":null,"abstract":"Ultra small angle scattering is a powerful tool for the study of the micro-structure of materials at a length scale below the resolution of standard x-ray detectors. Current methods like Small Angle X-ray Scattering (SAXS) are usually slow and therefore inadequate to industrial environments. A recently developed x-ray imaging method based on the Talbot-Lau interferometer allows for the full field measurement of the refraction and local small angle scattering of the x-ray beam within the object. The method is compatible with standard x-ray tubes and as such, a good candidate for industrial implementation. In the following manuscript, we report on the use of the x-ray Talbot-Lau interferometer for the measurement of the local small angle scattering power. Two applications relevant to homeland security are presented. First, we show how the measurement of the local small angle scattering power complements the conventional absorption-based radiography and helps to distinguish explosives from standard fail objects. Finally, we demonstrate that information can be coded within the scattering pattern of a manufactured marker. Such marker can be placed in critical objects, such as drugs boxes or luxury goods, in order to avoid the circulation of fakes.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"31 1","pages":"892-895"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81631294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.6036247
J. Bodnarik, D. Burger, A. Burger, L. Evans, S. Floyd, L. Lim, T. McClanahan, M. Namkung, S. Nowicki, A. Parsons, J. Schweitzer, R. Starr, K. Stassun, J. Trombka
The current gamma ray/neutron instrumentation development effort at NASA Goddard Space Flight Center¿s Astrochemistry Laboratory aims to extend the use of neutron interrogation techniques, using a 14 MeV Pulsed Neutron Generator (PNG) combined with neutron and gamma ray detectors, to probe the surface and subsurface of planetary bodies in situ without the need to drill. One aspect of the current work includes the development of taking timed tagged event-byevent data using our custom designed software with the Canberra Lynx Digital Signal Analyzer to provide a unique three-dimensional master data set with channel/energy, time, and intensity information. Since the master data set is not limited to predetermined coincidence timing gates set for a specific nuclear process, the user is allowed the flexibility to slice the data cube in a multitude of ways without loss of information or experimental time due to the need for additional acquisition windows. Time tagged event-by-event data allows the user to isolate a particular energy line from the spectrum over a specific window in time with respect to the PNG pulse, analyze a gamma ray spectrum resulting from either neutron capture, between the burst, or inelastic scattering events, during the neutron burst, and extract data for engineering purposes to optimize timing windows to look at specific elements in different environments. In this paper, we will present the results of our experimental data using the time tagged event-by-event data analysis technique compared with non-time-gated data taken at the test facility at NASA Goddard Space Flight Center. Comparison of these data will show the advantages and validity of this method to obtain more precise, sensitive, and accurate elemental composition measurements.
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