Pub Date : 2010-10-01DOI: 10.1109/NSSMIC.2010.5873734
A. Abba, A. Geraci
We present a digital fully configurable architecture that performs the function of signal generation for emulation of radiation detectors and front-end electronics and the function of processor of signals from radiation detectors. The proposed architecture has been conceived to serve as a general purpose investigation instrument in digital spectroscopy applications, both at hardware and firmware level. It allows the emulation of all parts of an acquisition and processing setup and consequently implements a real and complete hardware and firmware co-design platform. The system has been prototyped and is being fully tested.
{"title":"Configurable digital multi-channel processing for emulation and elaboration of radiation events","authors":"A. Abba, A. Geraci","doi":"10.1109/NSSMIC.2010.5873734","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5873734","url":null,"abstract":"We present a digital fully configurable architecture that performs the function of signal generation for emulation of radiation detectors and front-end electronics and the function of processor of signals from radiation detectors. The proposed architecture has been conceived to serve as a general purpose investigation instrument in digital spectroscopy applications, both at hardware and firmware level. It allows the emulation of all parts of an acquisition and processing setup and consequently implements a real and complete hardware and firmware co-design platform. The system has been prototyped and is being fully tested.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"1 1","pages":"145-152"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87350025","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.2010.5873978
Kan Yang, M. Zhuravleva, H. Rothfuss, C. Melcher
A new family of Ce-containing scintillator materials is introduced. In this work, we report on the crystal growth of KGd2Cl7:Ce and CsGd2Cl7:Ce via the Vertical Gradient Freeze method. Various Ce concentrations from 0.5 to 10 at% have been tested to study the effect of dopant concentration on scintillation performance. Both KGd2Cl7:Ce and CsGd2Cl7:Ce have demonstrated good properties for gamma ray and thermal neutron detection. Scintillation light yield was ∼30,000 ph/MeV for KGd2Cl7: 3% Ce and ∼38,000 ph/MeV for CsGd2Cl7: 3% Ce. The crystals exhibited layered structure with cleavage planes.
{"title":"Crystal growth and Scintillation properties of AGd2Cl7:Ce3+ (A = Cs, K) for gamma and neutron detection","authors":"Kan Yang, M. Zhuravleva, H. Rothfuss, C. Melcher","doi":"10.1109/NSSMIC.2010.5873978","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5873978","url":null,"abstract":"A new family of Ce-containing scintillator materials is introduced. In this work, we report on the crystal growth of KGd<inf>2</inf>Cl<inf>7</inf>:Ce and CsGd<inf>2</inf>Cl<inf>7</inf>:Ce via the Vertical Gradient Freeze method. Various Ce concentrations from 0.5 to 10 at% have been tested to study the effect of dopant concentration on scintillation performance. Both KGd<inf>2</inf>Cl<inf>7</inf>:Ce and CsGd<inf>2</inf>Cl<inf>7</inf>:Ce have demonstrated good properties for gamma ray and thermal neutron detection. Scintillation light yield was ∼30,000 ph/MeV for KGd<inf>2</inf>Cl<inf>7</inf>: 3% Ce and ∼38,000 ph/MeV for CsGd<inf>2</inf>Cl<inf>7</inf>: 3% Ce. The crystals exhibited layered structure with cleavage planes.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"59 1","pages":"1300-1303"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90627839","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.2010.5874560
N. Kawaguchi, T. Yanagida, Y. Fujimoto, Y. Yokota, K. Kamada, K. Fukuda, T. Suyama, Kenichi Watanabe, A. Yamazaki, A. Yoshikawa
Thermal neutron imaging with Ce doped 6LiCaAlF6, which is a novel thermal neutron scintillator, was demonstrated. Ce doped 6LiCaAlF6 single crystal was grown by Czochralski technique and grown crystal was cut and polished to a plate shape. Setup of the thermal neutron imaging consisted of the plate shaped Ce doped 6LiCaAlF6, a position sensitive photomultiplier tube, alphabet-shaped Cd-masks and 252Cf in the polyethylene container. As a result, clear neutron image was successfully observed.
{"title":"Thermal neutron imaging tests using Ce doped LiCaAlF6 and sealed 252Cf source","authors":"N. Kawaguchi, T. Yanagida, Y. Fujimoto, Y. Yokota, K. Kamada, K. Fukuda, T. Suyama, Kenichi Watanabe, A. Yamazaki, A. Yoshikawa","doi":"10.1109/NSSMIC.2010.5874560","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874560","url":null,"abstract":"Thermal neutron imaging with Ce doped <sup>6</sup>LiCaAlF<inf>6</inf>, which is a novel thermal neutron scintillator, was demonstrated. Ce doped <sup>6</sup>LiCaAlF<inf>6</inf> single crystal was grown by Czochralski technique and grown crystal was cut and polished to a plate shape. Setup of the thermal neutron imaging consisted of the plate shaped Ce doped <sup>6</sup>LiCaAlF<inf>6</inf>, a position sensitive photomultiplier tube, alphabet-shaped Cd-masks and <sup>252</sup>Cf in the polyethylene container. As a result, clear neutron image was successfully observed.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"6 1","pages":"3968-3970"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88166719","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.2010.5873964
A. Enqvist, K. Weinfurther, M. Flaska, S. Pozzi
A measurement system capable of multiplicity measurements for both neutrons and gamma rays has been developed at the University of Michigan. The benefit of such an approach is in the increased number of available measurables. A pure neutron assay results in three measurables for third-order multiples, while a combined neutron/gamma-ray assay results in 9 measurables for the same order of multiples. The idea is to use the additional measurables to achieve greater accuracy when determining unknown parameters of the sample such as the fissile mass. The measurement system is based on liquid scintillation detectors (EJ-309) which feed detected pulses to a digital data-acquisition system. The excellent pulse shape discrimination capabilities of the EJ-309s allow for accurate differentiation between gamma-ray pulses and neutron pulses. The PSD is vital to correctly identify the different multiples up to the third order: n, γ, nn, nγ, γγ, nnn, nnγ, nγγ and γγγ. Previous investigation of the measurement system showed that good counting statistics can be achieved within minutes for spontaneous-fission sources such as 252Cf. In this paper, we present new measurement results and corresponding Monte Carlo simulations aimed at charaterizing the measurement system. Comparison of the measured and simulated multiples count rates is discussed in detailed and a relatively good agreement on trends and count rates is found.
{"title":"Optimization of a mixed multiplicity counter using Monte Carlo simulations and measurements","authors":"A. Enqvist, K. Weinfurther, M. Flaska, S. Pozzi","doi":"10.1109/NSSMIC.2010.5873964","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5873964","url":null,"abstract":"A measurement system capable of multiplicity measurements for both neutrons and gamma rays has been developed at the University of Michigan. The benefit of such an approach is in the increased number of available measurables. A pure neutron assay results in three measurables for third-order multiples, while a combined neutron/gamma-ray assay results in 9 measurables for the same order of multiples. The idea is to use the additional measurables to achieve greater accuracy when determining unknown parameters of the sample such as the fissile mass. The measurement system is based on liquid scintillation detectors (EJ-309) which feed detected pulses to a digital data-acquisition system. The excellent pulse shape discrimination capabilities of the EJ-309s allow for accurate differentiation between gamma-ray pulses and neutron pulses. The PSD is vital to correctly identify the different multiples up to the third order: n, γ, nn, nγ, γγ, nnn, nnγ, nγγ and γγγ. Previous investigation of the measurement system showed that good counting statistics can be achieved within minutes for spontaneous-fission sources such as 252Cf. In this paper, we present new measurement results and corresponding Monte Carlo simulations aimed at charaterizing the measurement system. Comparison of the measured and simulated multiples count rates is discussed in detailed and a relatively good agreement on trends and count rates is found.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"1 1","pages":"1232-1238"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91208104","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.2010.5874228
H. Gemmeke, L. Berger, M. Birk, Georg Göbel, A. Menshikov, D. Tcherniakhovski, M. Zapf, N. Ruiter
We describe the second generation of a 3D-Ultrasound Computer Tomography (USCT) system. After we achieved in the first generation a device with sub-wavelength resolution and three imaging modalities (reflection, attenuation, speed of sound) and tested it with static phantoms, we developed a device for in-vivo imaging. In the new system the geometry of transducers and their spatial distribution is optimized in respect to uniformity and high value of: contrast, resolution, and illumination. Furthermore we developed new electronics which allows faster DAQ (≤ 2 min) and contains larger and faster FPGAs to use their processing power for data pre-processing.
{"title":"Hardware setup for the next generation of 3D Ultrasound Computer Tomography","authors":"H. Gemmeke, L. Berger, M. Birk, Georg Göbel, A. Menshikov, D. Tcherniakhovski, M. Zapf, N. Ruiter","doi":"10.1109/NSSMIC.2010.5874228","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874228","url":null,"abstract":"We describe the second generation of a 3D-Ultrasound Computer Tomography (USCT) system. After we achieved in the first generation a device with sub-wavelength resolution and three imaging modalities (reflection, attenuation, speed of sound) and tested it with static phantoms, we developed a device for in-vivo imaging. In the new system the geometry of transducers and their spatial distribution is optimized in respect to uniformity and high value of: contrast, resolution, and illumination. Furthermore we developed new electronics which allows faster DAQ (≤ 2 min) and contains larger and faster FPGAs to use their processing power for data pre-processing.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"73 1","pages":"2449-2454"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91248034","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.2010.5873884
M. Proissl, B. Azmoun, S. Boose, M. Durham, T. Hemmick, A. Milov, S. Polizzo, M. Purschke, C. Woody
The PHENIX Hadron Blind Detector (HBD) is a high-performance Cherenkov counter used to detect electrons in relativistic heavy ion collisions at RHIC. A High Voltage Control and Monitoring System (HVC) was developed to provide optimal control over the detector for maximal performance and protection against damage from possible discharges. The HVC comprises several novel hardware components including a voltage divider board and trip detection/protection boards for each power supply module, while actual control of the HV is maintained by a software suite which incorporates Modern Optimal Control Theory and Artificial Intelligence concepts. The software suite is made up of several concurrently operating subsystems, which periodically processes measurements fed back from the HV mainframe, the HBD gas pressure (P) and temperature (T) sensors, analyzes the GEM module behavior in reference to its performance over time, determines a custom response and modifies the HV when necessary. Since the HBD gain is very sensitive to P/T fluctuations, the HVC automatically modifies the GEM/Mesh voltage accordingly in order to keep the gain variations within a nominal operating range of +/− 10%. Both hardware and software components of the HVC will be described, along with the successful performance results throughout the commissioning p+p Run-9 and the HBD's final and most important Au+Au Run-10.
{"title":"An intelligent HV control and monitoring system for the PHENIX Hadron Blind Detector at the relativistic heavy ion collider","authors":"M. Proissl, B. Azmoun, S. Boose, M. Durham, T. Hemmick, A. Milov, S. Polizzo, M. Purschke, C. Woody","doi":"10.1109/NSSMIC.2010.5873884","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5873884","url":null,"abstract":"The PHENIX Hadron Blind Detector (HBD) is a high-performance Cherenkov counter used to detect electrons in relativistic heavy ion collisions at RHIC. A High Voltage Control and Monitoring System (HVC) was developed to provide optimal control over the detector for maximal performance and protection against damage from possible discharges. The HVC comprises several novel hardware components including a voltage divider board and trip detection/protection boards for each power supply module, while actual control of the HV is maintained by a software suite which incorporates Modern Optimal Control Theory and Artificial Intelligence concepts. The software suite is made up of several concurrently operating subsystems, which periodically processes measurements fed back from the HV mainframe, the HBD gas pressure (P) and temperature (T) sensors, analyzes the GEM module behavior in reference to its performance over time, determines a custom response and modifies the HV when necessary. Since the HBD gain is very sensitive to P/T fluctuations, the HVC automatically modifies the GEM/Mesh voltage accordingly in order to keep the gain variations within a nominal operating range of +/− 10%. Both hardware and software components of the HVC will be described, along with the successful performance results throughout the commissioning p+p Run-9 and the HBD's final and most important Au+Au Run-10.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"23 1","pages":"865-870"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89508395","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.2010.5873821
V. Anghel, J. Armitage, J. Botte, K. Boudjemline, D. Bryman, E. Charles, T. Cousins, A. Erlandson, G. Gallant, C. Jewett, G. Jonkmans, Z. Liu, S. Noel, G. Oakham, T. Stocki, M. Thompson, D. Waller
The smuggling of illicit Special Nuclear Materials (SNM) and Radiological Materials (RM) is a major security concern. Current radiation detection systems for cargo are not sensitive to well-shielded nuclear materials. The Muon Scattering Tomography (MST) method that we are developing might be a solution to this problem. It is based on the measurement of multiple scattering of cosmic ray-induced muons, traversing high-Z materials such as uranium and plutonium. This is possible due to the muons' highly penetrating nature. The technique involves measuring the angular deflections of these muons with charged particle tracking detectors placed around the object to be probed. One candidate detector is the single wire drift chamber. It can measure the 2-D impact position of a muon. The CRIPT (Cosmic Ray Inspection and Passive Tomography) collaboration has performed computer simulations of detectors designed to detect SNM via MST. We have also worked on the development of image reconstruction algorithms, and simulated the performances of different muon spectrometer designs and the response of the drift chambers. In addition to these efforts, the collaboration has built three prototypes which are being tested.
{"title":"Cosmic ray muon tomography system using drift chambers for the detection of Special Nuclear Materials","authors":"V. Anghel, J. Armitage, J. Botte, K. Boudjemline, D. Bryman, E. Charles, T. Cousins, A. Erlandson, G. Gallant, C. Jewett, G. Jonkmans, Z. Liu, S. Noel, G. Oakham, T. Stocki, M. Thompson, D. Waller","doi":"10.1109/NSSMIC.2010.5873821","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5873821","url":null,"abstract":"The smuggling of illicit Special Nuclear Materials (SNM) and Radiological Materials (RM) is a major security concern. Current radiation detection systems for cargo are not sensitive to well-shielded nuclear materials. The Muon Scattering Tomography (MST) method that we are developing might be a solution to this problem. It is based on the measurement of multiple scattering of cosmic ray-induced muons, traversing high-Z materials such as uranium and plutonium. This is possible due to the muons' highly penetrating nature. The technique involves measuring the angular deflections of these muons with charged particle tracking detectors placed around the object to be probed. One candidate detector is the single wire drift chamber. It can measure the 2-D impact position of a muon. The CRIPT (Cosmic Ray Inspection and Passive Tomography) collaboration has performed computer simulations of detectors designed to detect SNM via MST. We have also worked on the development of image reconstruction algorithms, and simulated the performances of different muon spectrometer designs and the response of the drift chambers. In addition to these efforts, the collaboration has built three prototypes which are being tested.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"21 1","pages":"547-551"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89990176","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.2010.5874118
J. Jakubek, C. Granja, O. Jakel, M. Martišíková, Stanislav Pospicil
The interaction of proton and hadron beams of relativistic energy in matter is accompanied by the production of penetrating highly energetic secondary particles and nuclear reaction products which can affect the desired highly localized deposition of energy of the primary high LET particles for radiotherapy purposes. The observation of all ionizing particles arising from and accompanying the primary radiation as well as the direct measurement of particle energy loss, trajectory, local energy deposition and lateral straggling can be directly provided by the semiconductor pixel detector Timepix. This device operates as an active nuclear emulsion providing on-line visualization of particle traces. Results of a pilot experiment are presented with proton and carbon ion beams in the energy range 48–220 MeV/u and 88–430 MeV, respectively produced at the Heavy Ion Therapy HIT facility in Heidelberg.
{"title":"Detection and track visualization of primary and secondary radiation in hadron therapy beams with the pixel detector Timepix","authors":"J. Jakubek, C. Granja, O. Jakel, M. Martišíková, Stanislav Pospicil","doi":"10.1109/NSSMIC.2010.5874118","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874118","url":null,"abstract":"The interaction of proton and hadron beams of relativistic energy in matter is accompanied by the production of penetrating highly energetic secondary particles and nuclear reaction products which can affect the desired highly localized deposition of energy of the primary high LET particles for radiotherapy purposes. The observation of all ionizing particles arising from and accompanying the primary radiation as well as the direct measurement of particle energy loss, trajectory, local energy deposition and lateral straggling can be directly provided by the semiconductor pixel detector Timepix. This device operates as an active nuclear emulsion providing on-line visualization of particle traces. Results of a pilot experiment are presented with proton and carbon ion beams in the energy range 48–220 MeV/u and 88–430 MeV, respectively produced at the Heavy Ion Therapy HIT facility in Heidelberg.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"16 1","pages":"1967-1969"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90008408","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.2010.5874217
Qingyang Wei, Yaqiang Liu, Tianyu Ma, Yan Xia, Shi Wang, Zhaoxia Wu, Yongjie Jin
Block detector using crystals coupled to circular photomultipliers (PMTs) is commonly used in positron emission tomography (PET). We design a novel PET block detector with cross-shape PMT layout (CSPL). The block detector consists of 9×9 lutetium orthosilicate (LSO) pixelated crystal array (2.2mm×2.2mm×10mm) and five PMTs (four 3/4 inch with circular envelope, one 3/8 inch with square envelope) arranging in a cross-shape layout with the small one in the middle. The crystals are separated by Teflon reflectors and optical grease to control the light distribution. Monte Carlo simulation package GATE is used to simulate the processes of both gamma ray interaction and light spread in LSO crystals. Impact of major resolution limiting parameters, including inter-crystal scattering, parallax effect and light spread in the crystals on the performance of the proposed detector design is investigated. Simulation results show that the proposed block detector design could get higher light collection and better position profile.
{"title":"PMT- cross-display scintillator block detector design and Monte Carlo study","authors":"Qingyang Wei, Yaqiang Liu, Tianyu Ma, Yan Xia, Shi Wang, Zhaoxia Wu, Yongjie Jin","doi":"10.1109/NSSMIC.2010.5874217","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874217","url":null,"abstract":"Block detector using crystals coupled to circular photomultipliers (PMTs) is commonly used in positron emission tomography (PET). We design a novel PET block detector with cross-shape PMT layout (CSPL). The block detector consists of 9×9 lutetium orthosilicate (LSO) pixelated crystal array (2.2mm×2.2mm×10mm) and five PMTs (four 3/4 inch with circular envelope, one 3/8 inch with square envelope) arranging in a cross-shape layout with the small one in the middle. The crystals are separated by Teflon reflectors and optical grease to control the light distribution. Monte Carlo simulation package GATE is used to simulate the processes of both gamma ray interaction and light spread in LSO crystals. Impact of major resolution limiting parameters, including inter-crystal scattering, parallax effect and light spread in the crystals on the performance of the proposed detector design is investigated. Simulation results show that the proposed block detector design could get higher light collection and better position profile.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"11 1","pages":"2400-2402"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90867802","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.2010.5874341
P. Pretorius, J. M. O'Connor, R. Licho, J. Brankov
Different implementations of the receiver operator characteristic (ROC) method in cardiac perfusion SPECT have been described. However, none has attempted to independently assess cardiac function. The aim of this study was, therefore, to design and execute a human observer ROC study that includes the evaluation of cardiac function and perfusion. Due to the lack of a gold standard, our initial design used an improved Mathematical Cardiac Torso (MCAT) phantom to generate normal and abnormal regional function. Abnormal heart function included hypokinesis, akinesis, and dyskinesis. Two heart sizes (124 ml and 100 ml left ventricular cavities) were used for male and female patients, respectively. Eight different locations around the LV myocardium were selected and perfusion defects of various sizes generated. Sixteen gated hearts across the cardiac cycle with abnormal cardiac function according to the different motion models were generated. The SIMIND Monte Carlo package was used to simulate a clinical Tl-201 perfusion SPECT acquisition protocol on the 3-headed IRIX gamma camera (Philips Medical Systems, Cleveland, Ohio). Data were reconstructed using the rescaled block iterative (RBI) technique with 17 subsets (4 projections/subset) and 5 iterations. Three sets of sixty-five cases were shown to an observer, the first 10 cases were used as training while the remainder (55 cases) were read and scored. The readings of the total 165 observed cases served as input data for ROC curve generation. The observer read the data in two ways. In the first reading the observer gave a confidence rating for regional myocardial function followed by a separate confidence rating for a perfusion defect. In the second reading, the order was reversed. ROC curves and areas under curve (AUCs) were determined separately for each reading approach. ROCs and AUCs were calculated for the three coronary artery territories as well as an overall calculation for the heart. While several ideas to further improve the methodology were generated during this study, we believe that we have clearly demonstrated that one can perform an independent quantitative task based assessment of cardiac function.
在心脏灌注SPECT中不同的接受者算子特征(ROC)方法被描述。然而，没有人试图独立评估心功能。因此，本研究的目的是设计并实施一项人体观察ROC研究，包括心功能和灌注的评估。由于缺乏金标准，我们最初的设计使用改进的数学心脏躯干(MCAT)模型来产生正常和异常的区域功能。心功能异常包括运动不足、运动不足和运动障碍。两种心脏大小(124毫升和100毫升左心室腔)分别用于男性和女性患者。选取左室心肌周围8个不同位置，产生大小不一的灌注缺损。根据不同的运动模型，生成了16个心脏周期内心功能异常的门控心脏。使用SIMIND蒙特卡罗封装在3头IRIX伽马相机(Philips Medical Systems, Cleveland, Ohio)上模拟临床Tl-201灌注SPECT采集方案。采用重尺度块迭代(RBI)技术重构数据，共17个子集(4个投影/子集)，5次迭代。向观察者展示三组65个案例，前10个案例被用作训练，而其余的(55个案例)被阅读并评分。165例观察病例的读数作为ROC曲线生成的输入数据。观察者以两种方式读取数据。在第一次阅读中，观察者给出了局部心肌功能的置信度评级，随后是灌注缺陷的单独置信度评级。二读时，顺序颠倒了。每种阅读方法分别测定ROC曲线和曲线下面积(auc)。计算三个冠状动脉区域的roc和auc以及心脏的总体计算。虽然在这项研究中产生了一些进一步改进方法的想法，但我们相信我们已经清楚地证明了可以对心功能进行独立的定量任务评估。
{"title":"Task based assessment of cardiac function in Monte Carlo simulated gated Tl-201 perfusion SPECT: A human observer study","authors":"P. Pretorius, J. M. O'Connor, R. Licho, J. Brankov","doi":"10.1109/NSSMIC.2010.5874341","DOIUrl":"https://doi.org/10.1109/NSSMIC.2010.5874341","url":null,"abstract":"Different implementations of the receiver operator characteristic (ROC) method in cardiac perfusion SPECT have been described. However, none has attempted to independently assess cardiac function. The aim of this study was, therefore, to design and execute a human observer ROC study that includes the evaluation of cardiac function and perfusion. Due to the lack of a gold standard, our initial design used an improved Mathematical Cardiac Torso (MCAT) phantom to generate normal and abnormal regional function. Abnormal heart function included hypokinesis, akinesis, and dyskinesis. Two heart sizes (124 ml and 100 ml left ventricular cavities) were used for male and female patients, respectively. Eight different locations around the LV myocardium were selected and perfusion defects of various sizes generated. Sixteen gated hearts across the cardiac cycle with abnormal cardiac function according to the different motion models were generated. The SIMIND Monte Carlo package was used to simulate a clinical Tl-201 perfusion SPECT acquisition protocol on the 3-headed IRIX gamma camera (Philips Medical Systems, Cleveland, Ohio). Data were reconstructed using the rescaled block iterative (RBI) technique with 17 subsets (4 projections/subset) and 5 iterations. Three sets of sixty-five cases were shown to an observer, the first 10 cases were used as training while the remainder (55 cases) were read and scored. The readings of the total 165 observed cases served as input data for ROC curve generation. The observer read the data in two ways. In the first reading the observer gave a confidence rating for regional myocardial function followed by a separate confidence rating for a perfusion defect. In the second reading, the order was reversed. ROC curves and areas under curve (AUCs) were determined separately for each reading approach. ROCs and AUCs were calculated for the three coronary artery territories as well as an overall calculation for the heart. While several ideas to further improve the methodology were generated during this study, we believe that we have clearly demonstrated that one can perform an independent quantitative task based assessment of cardiac function.","PeriodicalId":13048,"journal":{"name":"IEEE Nuclear Science Symposuim & Medical Imaging Conference","volume":"1 1","pages":"2972-2976"},"PeriodicalIF":0.0,"publicationDate":"2010-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89617212","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}
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