Pub Date : 2001-11-04DOI: 10.1109/NSSMIC.2001.1008494
T. Schweizer, E. Lorenz, Miguel Ángel Martínez, A. Ostankov, D. Paneque
Currently a 17 m diameter air Cherenkov telescope, dubbed MAGIC, for ground based gamma ray astronomy above 30 GeV is under construction on the Canarian island of La Palma. The 577 pixel photomultiplier camera requires precise and regular calibration over a large dynamic range. A system for the optical calibration consisting of a number of very fast and powerful LED light pulsers is presented. We intend to calibrate each individual pixel up to 2000-3000 photoelectrons with different wavelengths, e.g. 370 nm, 460 nm and 520 nm. We aim to achieve an absolute calibration at these three wavelengths by comparing the signal of the pixels with the one of specially prepared and calibrated photomultipliers (PMTs), and in a later stage hybrid photo multipliers (HPD), using the single photon counting mode and a well calibrated attenuation filter ('blind pixels'). The light flux of the pulser is cross calibrated by a 1 cm/sup 2/ PIN diode (Hamamatsu), read out via a charge sensitive preamplifier. The pindiode is calibrated with 60 keV gammas (from an Am 241 source) producing a precise signal of 16570 electron-hole pairs. In addition there will be a computer adjustable continuous light source to simulate and calibrate the response of the PMTs in the camera to the moon and the light of the night sky. This will also help to handle star light in the field of view of the camera in the analysis. Special attention is paid at building a robust field usable device complying with IP 65 standards.
{"title":"The optical calibration of the MAGIC telescope camera","authors":"T. Schweizer, E. Lorenz, Miguel Ángel Martínez, A. Ostankov, D. Paneque","doi":"10.1109/NSSMIC.2001.1008494","DOIUrl":"https://doi.org/10.1109/NSSMIC.2001.1008494","url":null,"abstract":"Currently a 17 m diameter air Cherenkov telescope, dubbed MAGIC, for ground based gamma ray astronomy above 30 GeV is under construction on the Canarian island of La Palma. The 577 pixel photomultiplier camera requires precise and regular calibration over a large dynamic range. A system for the optical calibration consisting of a number of very fast and powerful LED light pulsers is presented. We intend to calibrate each individual pixel up to 2000-3000 photoelectrons with different wavelengths, e.g. 370 nm, 460 nm and 520 nm. We aim to achieve an absolute calibration at these three wavelengths by comparing the signal of the pixels with the one of specially prepared and calibrated photomultipliers (PMTs), and in a later stage hybrid photo multipliers (HPD), using the single photon counting mode and a well calibrated attenuation filter ('blind pixels'). The light flux of the pulser is cross calibrated by a 1 cm/sup 2/ PIN diode (Hamamatsu), read out via a charge sensitive preamplifier. The pindiode is calibrated with 60 keV gammas (from an Am 241 source) producing a precise signal of 16570 electron-hole pairs. In addition there will be a computer adjustable continuous light source to simulate and calibrate the response of the PMTs in the camera to the moon and the light of the night sky. This will also help to handle star light in the field of view of the camera in the analysis. Special attention is paid at building a robust field usable device complying with IP 65 standards.","PeriodicalId":159123,"journal":{"name":"2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129521870","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 : 2001-11-04DOI: 10.1109/NSSMIC.2001.1008634
J. Seidel, J. J. Vaquero, Michael V. Green
PET scanners designed to image animals the size of rats and mice should possess simultaneously high and uniform spatial resolution and high sensitivity. ATLAS (Advanced Technology Laboratory Animal Scanner), an 11.8 cm diameter aperture, 2 cm axial field-of-view ring-type research scanner seeks these goals by surrounding the animal with eighteen 15 mm deep, LGSO (7 mm)/GSO (8 mm) phoswich detector modules. A Monte Carlo simulation was used to compare the variation of resolution across the field-of-view and the absolute central point source sensitivity (ACS) of ATLAS to similar systems comprised only of LSO arrays of different depths with no depth-of-interaction (DOI) capability. For ATLAS radial spatial resolution deteriorated by 27% from the center to 3 cm off-axis. Scanners comprised of 15 mm deep, 10 mm deep and 7 mm deep LSO crystals deteriorated by 100%, 51%, and 20% respectively, over the same distance. Simulated ACS (absorbed energies /spl ges/250 keV) for ATLAS was 2.0% and for the 15 mm, 10 mm deep and 7 mm deep LSO scanners 2.4%, 1.5%, and 0.9%, respectively. Radial resolution loss 3 cm off-axis and ACS measured for the actual ATLAS scanner were similar to the values obtained by simulation (27% resolution loss, 1.8% ACS). The phoswich design thus achieves good resolution uniformity over a 6 cm FOV while preserving sensitivity compared to equivalent non-DOI LSO scanners with a range of crystal depths.
{"title":"Resolution uniformity and sensitivity of the NIH ATLAS small animal PET scanner: comparison to simulated LSO scanners without depth-of-interaction capability","authors":"J. Seidel, J. J. Vaquero, Michael V. Green","doi":"10.1109/NSSMIC.2001.1008634","DOIUrl":"https://doi.org/10.1109/NSSMIC.2001.1008634","url":null,"abstract":"PET scanners designed to image animals the size of rats and mice should possess simultaneously high and uniform spatial resolution and high sensitivity. ATLAS (Advanced Technology Laboratory Animal Scanner), an 11.8 cm diameter aperture, 2 cm axial field-of-view ring-type research scanner seeks these goals by surrounding the animal with eighteen 15 mm deep, LGSO (7 mm)/GSO (8 mm) phoswich detector modules. A Monte Carlo simulation was used to compare the variation of resolution across the field-of-view and the absolute central point source sensitivity (ACS) of ATLAS to similar systems comprised only of LSO arrays of different depths with no depth-of-interaction (DOI) capability. For ATLAS radial spatial resolution deteriorated by 27% from the center to 3 cm off-axis. Scanners comprised of 15 mm deep, 10 mm deep and 7 mm deep LSO crystals deteriorated by 100%, 51%, and 20% respectively, over the same distance. Simulated ACS (absorbed energies /spl ges/250 keV) for ATLAS was 2.0% and for the 15 mm, 10 mm deep and 7 mm deep LSO scanners 2.4%, 1.5%, and 0.9%, respectively. Radial resolution loss 3 cm off-axis and ACS measured for the actual ATLAS scanner were similar to the values obtained by simulation (27% resolution loss, 1.8% ACS). The phoswich design thus achieves good resolution uniformity over a 6 cm FOV while preserving sensitivity compared to equivalent non-DOI LSO scanners with a range of crystal depths.","PeriodicalId":159123,"journal":{"name":"2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129746268","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 : 2001-11-04DOI: 10.1109/NSSMIC.2001.1008582
J. Bowsher, M. Tornai, S. Metzler, J. Peter, R. Jaszczak
Two novel pinhole orbits for SPECT breast imaging are investigated using noise-free analytically simulated projection data. The two orbits are designed to more nearly completely sample the breast region while also maintaining close proximity of the pinhole to the breast. The two orbits involve the same trajectory but different angular orientations for the pinhole. For both orbits the pinhole traverses two half circles, which from an anterior perspective thus appear to have the shape of an "X". The orbits differ in that in one case the pinhole is tilted toward a single point throughout the orbit whereas in the other case it is untilted. It is found that both orbits remove the distortions characteristic of purely transverse, single-half-circle orbits. Also investigated is the use of parallel-beam collimators on the remaining cameras of triple-headed SPECT scanners. It is found that these additional parallel-beam measurements greatly improve estimates of torso activity. Determining whether parallel-beam measurements improve estimates of breast activity will require additional studies involving clinical levels of noise in the projection data.
{"title":"SPECT breast imaging using more nearly complete orbits and combined pinhole-parallel-beam collimation","authors":"J. Bowsher, M. Tornai, S. Metzler, J. Peter, R. Jaszczak","doi":"10.1109/NSSMIC.2001.1008582","DOIUrl":"https://doi.org/10.1109/NSSMIC.2001.1008582","url":null,"abstract":"Two novel pinhole orbits for SPECT breast imaging are investigated using noise-free analytically simulated projection data. The two orbits are designed to more nearly completely sample the breast region while also maintaining close proximity of the pinhole to the breast. The two orbits involve the same trajectory but different angular orientations for the pinhole. For both orbits the pinhole traverses two half circles, which from an anterior perspective thus appear to have the shape of an \"X\". The orbits differ in that in one case the pinhole is tilted toward a single point throughout the orbit whereas in the other case it is untilted. It is found that both orbits remove the distortions characteristic of purely transverse, single-half-circle orbits. Also investigated is the use of parallel-beam collimators on the remaining cameras of triple-headed SPECT scanners. It is found that these additional parallel-beam measurements greatly improve estimates of torso activity. Determining whether parallel-beam measurements improve estimates of breast activity will require additional studies involving clinical levels of noise in the projection data.","PeriodicalId":159123,"journal":{"name":"2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128595225","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 : 2001-11-04DOI: 10.1109/NSSMIC.2001.1008501
J. Maia, J. Veloso, R. Morgado, J. D. dos Santos, C. Conde
We report the performance characteristics of a new microstructure, the Micro-Hole-and-Strip Plate (MHSP), operated initially as an X-ray proportional counter. The MHSP is a combination of the features of a microstrip plate (MSP) and a gas electron multiplier (GEM) in a single microstructure. Like the GEM, the MHSP is fabricated using flexible printed circuit board technology. The MHSP provides two independent charge-amplification stages: a first stage consisting of slotted holes, operated as a GEM, and a second stage, the MSP anodes, that also function as the final charge-collection electrodes. Two obvious benefits accrue from this design: for a given total gain, the MSP anode-to-cathode voltage can be maintained well below the breakdown threshold, and the charge-amplification stages are optically isolated, in anticipation of future applications as a photosensor. Full electron transmission and total gains up to 1000 were achieved, with slotted-hole gains as high as 14. The best energy resolution achieved thus far for 5.9-keV X-rays is 23%. Measurements of gains, electron transmission, and energy resolution, as functions of biasing voltages, are reported.
{"title":"The micro-hole- and -strip plate gas detector: experimental results","authors":"J. Maia, J. Veloso, R. Morgado, J. D. dos Santos, C. Conde","doi":"10.1109/NSSMIC.2001.1008501","DOIUrl":"https://doi.org/10.1109/NSSMIC.2001.1008501","url":null,"abstract":"We report the performance characteristics of a new microstructure, the Micro-Hole-and-Strip Plate (MHSP), operated initially as an X-ray proportional counter. The MHSP is a combination of the features of a microstrip plate (MSP) and a gas electron multiplier (GEM) in a single microstructure. Like the GEM, the MHSP is fabricated using flexible printed circuit board technology. The MHSP provides two independent charge-amplification stages: a first stage consisting of slotted holes, operated as a GEM, and a second stage, the MSP anodes, that also function as the final charge-collection electrodes. Two obvious benefits accrue from this design: for a given total gain, the MSP anode-to-cathode voltage can be maintained well below the breakdown threshold, and the charge-amplification stages are optically isolated, in anticipation of future applications as a photosensor. Full electron transmission and total gains up to 1000 were achieved, with slotted-hole gains as high as 14. The best energy resolution achieved thus far for 5.9-keV X-rays is 23%. Measurements of gains, electron transmission, and energy resolution, as functions of biasing voltages, are reported.","PeriodicalId":159123,"journal":{"name":"2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129251334","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 : 2001-11-04DOI: 10.1109/NSSMIC.2001.1008526
S. Yoshida, K. Yamanaka, T. Ohsugi, H. Masuda, T. Mizuno, Y. Fukazawa, Y. Iwata, T. Murakami, H. Sadrozinski, K. Yamamura, K. Yamamoto, K. Sato
We investigated the damage of silicon strip sensors due to heavy-ion radiation, as a check of the in-orbit stability of silicon strip sensors under cosmic-ray irradiation in the 5 year GLAST mission. In order to study single-event effects (SEE), we used Fe ions slowed-down in an absorber, with a resulting LET of 8 MeV/(mg/cm/sup 2/) on the surface of the sensor. The total doses achieved in two runs were about 8 krd and 22 krd, corresponding to a fluence of about 5*10/sup 7/ and 1.5*10/sup 8/ ions/cm/sup 2/, respectively. Silicon strip sensor with two different crystal orientations, <111> and <100>, were irradiated. We measured leakage currents and capacitances before and after irradiation to evaluate the damage. The leakage current was found to increase by about 10 nA/cm/sup 2//krd, as expected for the ionizing irradiation. No significant changes of capacitances were found. In addition, no coupling capacitors were broken. The observed effects are well within the in-orbit requirements of the GLAST mission.
{"title":"Heavy ion irradiation on silicon strip sensors for GLAST","authors":"S. Yoshida, K. Yamanaka, T. Ohsugi, H. Masuda, T. Mizuno, Y. Fukazawa, Y. Iwata, T. Murakami, H. Sadrozinski, K. Yamamura, K. Yamamoto, K. Sato","doi":"10.1109/NSSMIC.2001.1008526","DOIUrl":"https://doi.org/10.1109/NSSMIC.2001.1008526","url":null,"abstract":"We investigated the damage of silicon strip sensors due to heavy-ion radiation, as a check of the in-orbit stability of silicon strip sensors under cosmic-ray irradiation in the 5 year GLAST mission. In order to study single-event effects (SEE), we used Fe ions slowed-down in an absorber, with a resulting LET of 8 MeV/(mg/cm/sup 2/) on the surface of the sensor. The total doses achieved in two runs were about 8 krd and 22 krd, corresponding to a fluence of about 5*10/sup 7/ and 1.5*10/sup 8/ ions/cm/sup 2/, respectively. Silicon strip sensor with two different crystal orientations, <111> and <100>, were irradiated. We measured leakage currents and capacitances before and after irradiation to evaluate the damage. The leakage current was found to increase by about 10 nA/cm/sup 2//krd, as expected for the ionizing irradiation. No significant changes of capacitances were found. In addition, no coupling capacitors were broken. The observed effects are well within the in-orbit requirements of the GLAST mission.","PeriodicalId":159123,"journal":{"name":"2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124695915","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 : 2001-11-04DOI: 10.1109/NSSMIC.2001.1009660
M. Khamzin, J. Valentine, Junqiang Li
For the energy-subtraction Compton scatter camera, a critical requirement is the efficient selection of true preferred events, which will directly affect image contrast. To be able to distinguish preferred events, a set of selection criteria, based on different physical restrictions for different scenarios, is used. However, due to finite energy and timing resolution of the detector systems, some false preferred events will pass all the criteria. In this study, we attempt to identify major sources of false preferred events and their fraction among preferred events. Results from this analysis can be used to develop a weighting scheme indicative of the likelihood that an event, which passes all of the criteria, is actually a preferred event. This extension is purely analytical and based on the solution of the photon transport problem prescribed by the ESCSC. Two major contributors to false preferred events - source volume scatters, and chance coincidences - are identified. For a sample geometric model, the fractions of false preferred events are calculated for various system energy and timing resolutions. Recommendations on optimal source energy and preferred event weighting function are given.
{"title":"False preferred event analysis for the energy-subtraction Compton scatter camera","authors":"M. Khamzin, J. Valentine, Junqiang Li","doi":"10.1109/NSSMIC.2001.1009660","DOIUrl":"https://doi.org/10.1109/NSSMIC.2001.1009660","url":null,"abstract":"For the energy-subtraction Compton scatter camera, a critical requirement is the efficient selection of true preferred events, which will directly affect image contrast. To be able to distinguish preferred events, a set of selection criteria, based on different physical restrictions for different scenarios, is used. However, due to finite energy and timing resolution of the detector systems, some false preferred events will pass all the criteria. In this study, we attempt to identify major sources of false preferred events and their fraction among preferred events. Results from this analysis can be used to develop a weighting scheme indicative of the likelihood that an event, which passes all of the criteria, is actually a preferred event. This extension is purely analytical and based on the solution of the photon transport problem prescribed by the ESCSC. Two major contributors to false preferred events - source volume scatters, and chance coincidences - are identified. For a sample geometric model, the fractions of false preferred events are calculated for various system energy and timing resolutions. Recommendations on optimal source energy and preferred event weighting function are given.","PeriodicalId":159123,"journal":{"name":"2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129441945","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 : 2001-11-04DOI: 10.1109/NSSMIC.2001.1008405
P. Lecoq, M. Korzhik
In this paper the results of one year of effort to develop the production technology of LuAP crystals will be presented. As already advertised since several years Lu based compounds doped with trivalent Ce which show fast and bright scintillation seem to be the most promising scintillators for a new generation of PET scanners. Two crystals. namely LSO:Ce and LuAP:Ce are already in the phase of mass production technology development but there is still an interest to search for materials with better combination of price/performance. As already mentioned in our contribution to the IEEE2000 conference in Lyon, the Crystal Clear Collaboration strategy is to look for a host where Lutetium is associated to another heavy cation to reduce the cost of the material. In our present study we paid attention to the compounds containing rare earth and Ba, Zr, Hf, which being doped with Ce show a very bright and fast luminescence in the blue-green region. Materials have been synthetized with a the same time an increase of the effective charge of the host matrix and a decrease or even a complete suppression of the Lu fraction. In our report we discuss spectroscopic and scintillation properties of several new heavy compounds such as Lu/sub 2/Hf/sub 2/O/sub 7/, La/sub 2/Hf/sub 2/O/sub 7/ and Ba/sub 3/Lu/sub 4/O/sub 9/ doped with Ce and the possibilities of their industrial production.
{"title":"New inorganic scintillation materials development for medical imaging","authors":"P. Lecoq, M. Korzhik","doi":"10.1109/NSSMIC.2001.1008405","DOIUrl":"https://doi.org/10.1109/NSSMIC.2001.1008405","url":null,"abstract":"In this paper the results of one year of effort to develop the production technology of LuAP crystals will be presented. As already advertised since several years Lu based compounds doped with trivalent Ce which show fast and bright scintillation seem to be the most promising scintillators for a new generation of PET scanners. Two crystals. namely LSO:Ce and LuAP:Ce are already in the phase of mass production technology development but there is still an interest to search for materials with better combination of price/performance. As already mentioned in our contribution to the IEEE2000 conference in Lyon, the Crystal Clear Collaboration strategy is to look for a host where Lutetium is associated to another heavy cation to reduce the cost of the material. In our present study we paid attention to the compounds containing rare earth and Ba, Zr, Hf, which being doped with Ce show a very bright and fast luminescence in the blue-green region. Materials have been synthetized with a the same time an increase of the effective charge of the host matrix and a decrease or even a complete suppression of the Lu fraction. In our report we discuss spectroscopic and scintillation properties of several new heavy compounds such as Lu/sub 2/Hf/sub 2/O/sub 7/, La/sub 2/Hf/sub 2/O/sub 7/ and Ba/sub 3/Lu/sub 4/O/sub 9/ doped with Ce and the possibilities of their industrial production.","PeriodicalId":159123,"journal":{"name":"2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129660621","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 : 2001-11-04DOI: 10.1109/NSSMIC.2001.1009228
Y. Ikoma, Hinako Toyama, K. Uemura, A. Uchiyama
The kinetic analysis for dual tracer injection with 2-input compartment model is challenging in order to assess the two different functions In the same time and same situation. In this study, we investigated the possibility of kinetic analysis with two tracers, /sup 18/F-FDG and /sup 11/C-flumazenil (FMZ), by means of the computer simulation. The reliability of estimated parameters was Investigated for various injection protocols and noise levels. Simulated decaying tissue time activity curves were generated for various injection protocols with input function of FDG and FMZ and true k-values by using the 2-input 3-tissue compartment 5-parameter model, i.e. 2-tissue compartment 3-parameter for FDG and 1-tissue compartment 2-parameter for FMZ. The injection Interval of two tracers was changed from 0 to 20 minutes. The noise was generated depending on the total collected count and added each decaying tissue time activity curve. The rate constants for FDG and FMZ were estimated by nonlinear least square method. The reliability of parameter estimates was evaluated by mean absolute difference between true and estimated value of one thousand runs for each injection protocol and noise level. As a result, it was found that parameters were estimated most reliably when FDG was injected 15 minutes later than FMZ injection. In 5% last frame noise, the mean absolute difference between true and estimated value of Ki, reflecting the uptake of FDG, was about 8%, that of DV, distribution volume of FMZ, was 7%. The reliability was independent on the ratio of administration dose of FDG to that of FMZ. In the simulation study, the possibility of kinetic analysis for dual tracer injection was shown.
为了在同一时间、同一情况下评估两种不同的功能，双示踪剂注射的动力学分析具有挑战性。本研究通过计算机模拟研究了/sup 18/F-FDG和/sup 11/ c -氟马西尼(FMZ)两种示踪剂进行动力学分析的可能性。研究了各种注射方案和噪声水平下估计参数的可靠性。采用2输入3组织室5参数模型，即FDG为2组织室3参数，FMZ为1组织室2参数，FDG为2组织室3参数，FMZ为1组织室2参数，以FDG和FMZ为输入函数和真k值，生成不同注射方案的模拟组织时间活性衰减曲线。将两种示踪剂的注射间隔从0分钟改为20分钟。根据收集到的总计数产生噪声，并将每个衰减的组织时间活性曲线相加。用非线性最小二乘法估计了FDG和FMZ的速率常数。参数估计的可靠性是通过对每个注入方案和噪声水平进行1000次运行的真实值与估计值的平均绝对差来评估的。结果发现，FDG注射时间比FMZ注射时间晚15分钟时，参数估计最可靠。在最后一帧噪声为5%时，反映FDG吸收的Ki值的真实值与估估值的平均绝对差值约为8%，反映FMZ分布体积的DV值的平均绝对差值为7%。信度与FDG给药剂量与FMZ给药剂量之比无关。通过模拟研究，证明了双示踪剂注入动力学分析的可能性。
{"title":"Evaluation of the reliability in kinetic analysis for dual tracer injection of FDG and flumazenil PET study","authors":"Y. Ikoma, Hinako Toyama, K. Uemura, A. Uchiyama","doi":"10.1109/NSSMIC.2001.1009228","DOIUrl":"https://doi.org/10.1109/NSSMIC.2001.1009228","url":null,"abstract":"The kinetic analysis for dual tracer injection with 2-input compartment model is challenging in order to assess the two different functions In the same time and same situation. In this study, we investigated the possibility of kinetic analysis with two tracers, /sup 18/F-FDG and /sup 11/C-flumazenil (FMZ), by means of the computer simulation. The reliability of estimated parameters was Investigated for various injection protocols and noise levels. Simulated decaying tissue time activity curves were generated for various injection protocols with input function of FDG and FMZ and true k-values by using the 2-input 3-tissue compartment 5-parameter model, i.e. 2-tissue compartment 3-parameter for FDG and 1-tissue compartment 2-parameter for FMZ. The injection Interval of two tracers was changed from 0 to 20 minutes. The noise was generated depending on the total collected count and added each decaying tissue time activity curve. The rate constants for FDG and FMZ were estimated by nonlinear least square method. The reliability of parameter estimates was evaluated by mean absolute difference between true and estimated value of one thousand runs for each injection protocol and noise level. As a result, it was found that parameters were estimated most reliably when FDG was injected 15 minutes later than FMZ injection. In 5% last frame noise, the mean absolute difference between true and estimated value of Ki, reflecting the uptake of FDG, was about 8%, that of DV, distribution volume of FMZ, was 7%. The reliability was independent on the ratio of administration dose of FDG to that of FMZ. In the simulation study, the possibility of kinetic analysis for dual tracer injection was shown.","PeriodicalId":159123,"journal":{"name":"2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130375196","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 : 2001-11-04DOI: 10.1109/NSSMIC.2001.1008509
I. Alexandrov, A. Amorim, E. Badescu, D. Burckhart-Chromek, M. Caprini, M. Dobson, P. Duval, R. Hart, R. Jones, A. Kazarov, S. Kolos, V. Kotov, D. Liko, L. Lucio, L. Mapelli, M. Mineev, L. Moneta, M. Nassiakou, L. Pedro, A. Ribeiro, V. Roumiantsev, Y. Ryabov, D. Schweiger, I. Soloviev, H. Wolters
The Process Management component of the Online Software of the future ATLAS experiment data acquisition system is presented. The purpose of the Process Manager is to perform basic job control of the software components of the data acquisition system. It is capable of starting, stopping and monitoring the status of those components on the data acquisition processors independent of the underlying operating system. Its architecture is designed on the basis of a server client model using CORBA based communication. The server part relies on C++ software agent objects acting as an interface between the local operating system and client applications. Some of the major design challenges of the software agents were to achieve the maximum degree of autonomy possible, to create processes aware of dynamic conditions in their environment and with the ability to determine corresponding actions. Issues such as the performance of the agents in terms of time needed for process creation and destruction, the scalability of the system taking into consideration the final ATLAS configuration and minimizing the use of hardware resources were also of critical importance. Besides the details given on the architecture and the implementation we also present scalability and performance tests results of the Process Manager system.
{"title":"Process management inside ATLAS DAQ","authors":"I. Alexandrov, A. Amorim, E. Badescu, D. Burckhart-Chromek, M. Caprini, M. Dobson, P. Duval, R. Hart, R. Jones, A. Kazarov, S. Kolos, V. Kotov, D. Liko, L. Lucio, L. Mapelli, M. Mineev, L. Moneta, M. Nassiakou, L. Pedro, A. Ribeiro, V. Roumiantsev, Y. Ryabov, D. Schweiger, I. Soloviev, H. Wolters","doi":"10.1109/NSSMIC.2001.1008509","DOIUrl":"https://doi.org/10.1109/NSSMIC.2001.1008509","url":null,"abstract":"The Process Management component of the Online Software of the future ATLAS experiment data acquisition system is presented. The purpose of the Process Manager is to perform basic job control of the software components of the data acquisition system. It is capable of starting, stopping and monitoring the status of those components on the data acquisition processors independent of the underlying operating system. Its architecture is designed on the basis of a server client model using CORBA based communication. The server part relies on C++ software agent objects acting as an interface between the local operating system and client applications. Some of the major design challenges of the software agents were to achieve the maximum degree of autonomy possible, to create processes aware of dynamic conditions in their environment and with the ability to determine corresponding actions. Issues such as the performance of the agents in terms of time needed for process creation and destruction, the scalability of the system taking into consideration the final ATLAS configuration and minimizing the use of hardware resources were also of critical importance. Besides the details given on the architecture and the implementation we also present scalability and performance tests results of the Process Manager system.","PeriodicalId":159123,"journal":{"name":"2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123867390","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 : 2001-11-04DOI: 10.1109/NSSMIC.2001.1009285
R. Tomie, K. Hitomi, T. Shoji, Y. Hiratate
Cadmium telluride (CdTe) radiation detectors applied three-electrode and pixel structure have been fabricated from commercially available CdTe crystals (2 mm thick). In case of a three-electrode detector, the cathode was 6/spl times/6 mm/sup 2/, the anode was 0.5 mm in diameter and the third electrode surrounding the anode was I mm width. The gap between the third electrode and the anode was 0.25 mm. In case of pixel detectors, the anodes were 9 pixels and the guardring surrounded the pixels. One pixel detector has rectangular 1.35/spl times/1.35 mm/sup 2/ pixels with 1.45 mm pitch and the other pixel detector has rectangular 0.7/spl times/0.7 mm/sup 2/ pixels with 0.8 mm pitch. All electrodes were formed on the crystals by vacuum evaporation of Au. Pulse height spectra of gamma-rays emitted from a /sup 137/Cs source were acquired with the fabricated detectors. The three-electrode detectors were operated with the anode voltage of +10 V, the cathode voltage of -540 V and the third electrode grounded. An energy resolution of 6.0 keV FWHM was recorded for 662 keV gamma-rays at room temperature. The pixel detectors with 1.35/spl times/1.35 mm/sup 2/ pixels and with 0.7/spl times/0.7 mm/sup 2/ pixels have exhibited energy resolutions of 16.7 keV and 12.3 keV FWHM at 662 keV, respectively. The pixel detectors were operated at 600 V and at room temperature. Detailed discussions about the device fabrication, operation and characterization are given in this paper.
{"title":"High-resolution CdTe radiation detectors with single-polarity charge sensing technique","authors":"R. Tomie, K. Hitomi, T. Shoji, Y. Hiratate","doi":"10.1109/NSSMIC.2001.1009285","DOIUrl":"https://doi.org/10.1109/NSSMIC.2001.1009285","url":null,"abstract":"Cadmium telluride (CdTe) radiation detectors applied three-electrode and pixel structure have been fabricated from commercially available CdTe crystals (2 mm thick). In case of a three-electrode detector, the cathode was 6/spl times/6 mm/sup 2/, the anode was 0.5 mm in diameter and the third electrode surrounding the anode was I mm width. The gap between the third electrode and the anode was 0.25 mm. In case of pixel detectors, the anodes were 9 pixels and the guardring surrounded the pixels. One pixel detector has rectangular 1.35/spl times/1.35 mm/sup 2/ pixels with 1.45 mm pitch and the other pixel detector has rectangular 0.7/spl times/0.7 mm/sup 2/ pixels with 0.8 mm pitch. All electrodes were formed on the crystals by vacuum evaporation of Au. Pulse height spectra of gamma-rays emitted from a /sup 137/Cs source were acquired with the fabricated detectors. The three-electrode detectors were operated with the anode voltage of +10 V, the cathode voltage of -540 V and the third electrode grounded. An energy resolution of 6.0 keV FWHM was recorded for 662 keV gamma-rays at room temperature. The pixel detectors with 1.35/spl times/1.35 mm/sup 2/ pixels and with 0.7/spl times/0.7 mm/sup 2/ pixels have exhibited energy resolutions of 16.7 keV and 12.3 keV FWHM at 662 keV, respectively. The pixel detectors were operated at 600 V and at room temperature. Detailed discussions about the device fabrication, operation and characterization are given in this paper.","PeriodicalId":159123,"journal":{"name":"2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)","volume":"11 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123884072","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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