Pub Date : 1995-10-21DOI: 10.1109/NSSMIC.1995.500255
R. Freifelder, J. Karp
The authors present a design of a PET scanner dedicated to breast imaging. The scanner uses two 2-dimensional position sensitive NaI(Tl) detectors, each with 16 PMTs, placed above and below the breast to detect tumors. The design combines high spatial resolution (3.5 mm) to detect small tumors (/spl ap/0.1 cc), high sensitivity and good energy resolution to suppress scatter background and to detect low contrast masses. Additional views of the breast and lymph nodes will be possible. Simulations show that the proposed design has better lesion detectability than a general purpose whole-body PET scanner. Detector thickness, position algorithms, surface treatments of the NaI(Tl) and PMT arrangements will ensure good performance under high countrate conditions and particularly at the edges of the detector closest to the body. A preliminary investigation of different iterative reconstruction algorithms with limited angle datasets show promise in obtaining good image quality and tumor detectability, the scanner's primary design goals. Simulation results are compared to preliminary phantom measurements.
{"title":"A dedicated PET scanner for breast cancer","authors":"R. Freifelder, J. Karp","doi":"10.1109/NSSMIC.1995.500255","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.500255","url":null,"abstract":"The authors present a design of a PET scanner dedicated to breast imaging. The scanner uses two 2-dimensional position sensitive NaI(Tl) detectors, each with 16 PMTs, placed above and below the breast to detect tumors. The design combines high spatial resolution (3.5 mm) to detect small tumors (/spl ap/0.1 cc), high sensitivity and good energy resolution to suppress scatter background and to detect low contrast masses. Additional views of the breast and lymph nodes will be possible. Simulations show that the proposed design has better lesion detectability than a general purpose whole-body PET scanner. Detector thickness, position algorithms, surface treatments of the NaI(Tl) and PMT arrangements will ensure good performance under high countrate conditions and particularly at the edges of the detector closest to the body. A preliminary investigation of different iterative reconstruction algorithms with limited angle datasets show promise in obtaining good image quality and tumor detectability, the scanner's primary design goals. Simulation results are compared to preliminary phantom measurements.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122789705","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 : 1995-10-21DOI: 10.1109/NSSMIC.1995.510369
B. Baumbaugh, J. Bishop, N. Biswas, L. Coney, J. Marchant, E. Masterson, R. Ruchti, T. Stavish, J. Warchoł, M. Wayne
We have designed, constructed, and operated a small cryostem which supports the operation of 32 channels of visible light photon counters (HISTE-IV VLPCs). The VLPCs are situated within a small enclosure which can be lowered into a 30-100 liter dewar. The enthalpy of the boil-off helium keeps the VLPCs cold, and allows the system to be operated with stability for many days within the desired temperature range of 6.0 K-7.5 K. The cryostem is instrumented with clear fiber waveguides which transport the light from an optical connector situated at the top of the cryostem and outside of the dewar to the photosensors at cryogenic temperatures within the dewar. Electrical signals from the VLPCs are amplified at room temperature using QPA02 preamplifiers. Details of design and performance are reviewed.
我们设计、构建并运行了一个支持32通道可见光光子计数器(hste - iv vlpc)操作的小型系统。vlpc位于一个小的外壳内，可以降低到30-100升杜瓦瓶。蒸发氦的焓使vlpc保持低温，并允许系统在6.0 K-7.5 K的期望温度范围内稳定运行许多天。该系统配备了透明光纤波导，它将光从位于系统顶部和杜瓦瓶外部的光学连接器传输到杜瓦瓶内低温下的光传感器。来自vlpc的电信号在室温下使用QPA02前置放大器进行放大。详细的设计和性能进行了审查。
{"title":"Small cryostem for operation of visible light photon counters (VLPC)","authors":"B. Baumbaugh, J. Bishop, N. Biswas, L. Coney, J. Marchant, E. Masterson, R. Ruchti, T. Stavish, J. Warchoł, M. Wayne","doi":"10.1109/NSSMIC.1995.510369","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.510369","url":null,"abstract":"We have designed, constructed, and operated a small cryostem which supports the operation of 32 channels of visible light photon counters (HISTE-IV VLPCs). The VLPCs are situated within a small enclosure which can be lowered into a 30-100 liter dewar. The enthalpy of the boil-off helium keeps the VLPCs cold, and allows the system to be operated with stability for many days within the desired temperature range of 6.0 K-7.5 K. The cryostem is instrumented with clear fiber waveguides which transport the light from an optical connector situated at the top of the cryostem and outside of the dewar to the photosensors at cryogenic temperatures within the dewar. Electrical signals from the VLPCs are amplified at room temperature using QPA02 preamplifiers. Details of design and performance are reviewed.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"272 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122831220","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 : 1995-10-21DOI: 10.1109/NSSMIC.1995.504323
E. Beuville, P. Barale, F. Bieser, W. Hearn, S. Klein, M. Lisa, T. Noggle, H. Ritter, C. Vu, H. Wieman
A 16 channel low noise amplifier shaper has been designed for the STAR particle detector of the RHIC accelerator. The STAR Amplifier-Shaper (SAS) includes a pole/zero network which cancels the long tail of the Time Projection Chamber (TPC) signal. The tail correction can be adjusted depending on the type of gas used in the TPC. The SAS equivalent noise charge is 900 e/sub RMS//sup -/,, with 25 pf detector capacitance (the test board having 7.7 pF of parasitic capacitance), and with 80 ns shaping time (step response). The measured noise slope is 13.7 e/sub RMS//sup -//pF. The shaper pulse FWHM is adjusted at 180 ns (detector response) with /spl plusmn/4% variation over the entire dynamic range. The shaping time and the tail correction are adjusted with external voltages using MOS resistors. The gain is 16 mV/fC with a linearity of 4%. The crosstalk is about 0.36% which have a negligible effect on the position resolution. The circuit also includes an on-chip calibration system in which the test input charge is controlled by a DC voltage. The output buffer drives a 2 V swing on 50 pF output load for a total power consumption of less than 750 mW (/spl plusmn/5 Volt supply). On-chip protection diodes have also been integrated. The full custom chip has been integrated in the CMOS ORBIT 1.2 /spl mu/m technology with double polysilicon capacitors.
{"title":"A low noise amplifier-shaper with tail correction for the STAR detector","authors":"E. Beuville, P. Barale, F. Bieser, W. Hearn, S. Klein, M. Lisa, T. Noggle, H. Ritter, C. Vu, H. Wieman","doi":"10.1109/NSSMIC.1995.504323","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.504323","url":null,"abstract":"A 16 channel low noise amplifier shaper has been designed for the STAR particle detector of the RHIC accelerator. The STAR Amplifier-Shaper (SAS) includes a pole/zero network which cancels the long tail of the Time Projection Chamber (TPC) signal. The tail correction can be adjusted depending on the type of gas used in the TPC. The SAS equivalent noise charge is 900 e/sub RMS//sup -/,, with 25 pf detector capacitance (the test board having 7.7 pF of parasitic capacitance), and with 80 ns shaping time (step response). The measured noise slope is 13.7 e/sub RMS//sup -//pF. The shaper pulse FWHM is adjusted at 180 ns (detector response) with /spl plusmn/4% variation over the entire dynamic range. The shaping time and the tail correction are adjusted with external voltages using MOS resistors. The gain is 16 mV/fC with a linearity of 4%. The crosstalk is about 0.36% which have a negligible effect on the position resolution. The circuit also includes an on-chip calibration system in which the test input charge is controlled by a DC voltage. The output buffer drives a 2 V swing on 50 pF output load for a total power consumption of less than 750 mW (/spl plusmn/5 Volt supply). On-chip protection diodes have also been integrated. The full custom chip has been integrated in the CMOS ORBIT 1.2 /spl mu/m technology with double polysilicon capacitors.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130193834","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 : 1995-10-21DOI: 10.1109/NSSMIC.1995.500275
G. Klein, X. Teng, B. Reutter, R. Huesman, W. Jagust, T. Budinger
Volume of interest extraction for radionuclide and anatomical measurements requires correct identification of the anatomical feature being studied. We have developed a toolset for specifying 3D volumes-of-interest (VOIs) on a multislice Positron Emission Tomography (PET) dataset. The software is particularly suited for specifying cerebral cortex VOIs that represent a particular gyrus or mid-brain structure. A registered 3D magnetic resonance image (MRI) dataset is used to provide high-resolution anatomical information, both as oblique 2D sections and as volume renderings of a segmented cortical surface. Because most clinicians can readily identify specific sulci from high-quality renderings of the cortical surface, a crucial step in quickly identifying sulci in 2D sectional data is providing a feedback mechanism between the renderings and the section data. Our toolkit provides this mechanism by calculating a full depth map and transformation matrix for volume renderings of the cortex. A region drawing environment is then possible where the position of a main drawing cursor on a 2D section can be simultaneously mirrored on the rendered views. The feedback is further enhanced by displaying the projection of the main cursor position on any number of auxiliary 2D sections oriented at orthogonal slicing angles with respect to the principal 2D section. Complete VOIs are specified by drawing a stack of 2D contours subsequently filed together to form closed triangular mesh surface models.
{"title":"A 3D navigational environment for specifying positron emission tomography volumes-of-interest","authors":"G. Klein, X. Teng, B. Reutter, R. Huesman, W. Jagust, T. Budinger","doi":"10.1109/NSSMIC.1995.500275","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.500275","url":null,"abstract":"Volume of interest extraction for radionuclide and anatomical measurements requires correct identification of the anatomical feature being studied. We have developed a toolset for specifying 3D volumes-of-interest (VOIs) on a multislice Positron Emission Tomography (PET) dataset. The software is particularly suited for specifying cerebral cortex VOIs that represent a particular gyrus or mid-brain structure. A registered 3D magnetic resonance image (MRI) dataset is used to provide high-resolution anatomical information, both as oblique 2D sections and as volume renderings of a segmented cortical surface. Because most clinicians can readily identify specific sulci from high-quality renderings of the cortical surface, a crucial step in quickly identifying sulci in 2D sectional data is providing a feedback mechanism between the renderings and the section data. Our toolkit provides this mechanism by calculating a full depth map and transformation matrix for volume renderings of the cortex. A region drawing environment is then possible where the position of a main drawing cursor on a 2D section can be simultaneously mirrored on the rendered views. The feedback is further enhanced by displaying the projection of the main cursor position on any number of auxiliary 2D sections oriented at orthogonal slicing angles with respect to the principal 2D section. Complete VOIs are specified by drawing a stack of 2D contours subsequently filed together to form closed triangular mesh surface models.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133123662","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 : 1995-10-21DOI: 10.1109/NSSMIC.1995.510479
R. Guillemaud, P. Hugonnard, R. Sauze, P. Grangeat
Attenuation compensation is an important issue for SPECT imaging. For this purpose transmission measurements can be acquired on a gamma, but the acquisitions are usually truncated. The truncation results in large artifacts in the attenuation map when reconstructed with usual filtered-backprojection algorithms. These artifacts prevents good attenuation correction of emission map. The authors propose a new efficient method for truncation correction which is based on an iterative reconstruction/reprojection algorithm using extended projections and constraints on the reconstructed map. Extended projections are a combination of truncated and reprojected projections with a continuity constraint at the truncation edge. The constraints on the attenuation map are based on object model. The first one is a large elliptical model, with positivity constraints. During the iterative reconstruction process, the model is refined to a have geometric shape closer to the patient's outline. The refining is an active contour segmentation technique. Additional constraints on the attenuation factors can finally be incorporated. Results on truncation correction obtained for simulated and experimental data are presented and the effect on attenuation compensation in emission reconstruction is discussed.
{"title":"Truncation artifact correction of attenuation map with iterative and model based reconstruction","authors":"R. Guillemaud, P. Hugonnard, R. Sauze, P. Grangeat","doi":"10.1109/NSSMIC.1995.510479","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.510479","url":null,"abstract":"Attenuation compensation is an important issue for SPECT imaging. For this purpose transmission measurements can be acquired on a gamma, but the acquisitions are usually truncated. The truncation results in large artifacts in the attenuation map when reconstructed with usual filtered-backprojection algorithms. These artifacts prevents good attenuation correction of emission map. The authors propose a new efficient method for truncation correction which is based on an iterative reconstruction/reprojection algorithm using extended projections and constraints on the reconstructed map. Extended projections are a combination of truncated and reprojected projections with a continuity constraint at the truncation edge. The constraints on the attenuation map are based on object model. The first one is a large elliptical model, with positivity constraints. During the iterative reconstruction process, the model is refined to a have geometric shape closer to the patient's outline. The refining is an active contour segmentation technique. Additional constraints on the attenuation factors can finally be incorporated. Results on truncation correction obtained for simulated and experimental data are presented and the effect on attenuation compensation in emission reconstruction is discussed.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133778392","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 : 1995-10-21DOI: 10.1109/NSSMIC.1995.500265
M.X.H. Yan, J. Karp
An algorithm is described for estimating attenuation length in 3D from sinogram or projection data, by which 3D attenuation correction can be performed in brain PET imaging for given attenuation coefficients. The algorithm begins with the estimation of scalp contours from sinogram data, based on optimal thresholding, spline smoothing and interpolation and backprojection. A cubic B-spline surface is then introduced to accurately describe the scalp surface by the least squares fitting to the stacked 2D estimated scalp contours. Due to the use of this surface model, an efficient and accurate technique is developed for estimation of a distance between two intersecting points formed by an arbitrary projection ray and the scalp surface. This fully automated and fast algorithm has been applied to sinogram and projection data collected using PENN-PET scanners. It has the potential to be used in routine clinical PET imaging.
{"title":"A fully automated algorithm for estimating attenuation length in 3D from projection data","authors":"M.X.H. Yan, J. Karp","doi":"10.1109/NSSMIC.1995.500265","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.500265","url":null,"abstract":"An algorithm is described for estimating attenuation length in 3D from sinogram or projection data, by which 3D attenuation correction can be performed in brain PET imaging for given attenuation coefficients. The algorithm begins with the estimation of scalp contours from sinogram data, based on optimal thresholding, spline smoothing and interpolation and backprojection. A cubic B-spline surface is then introduced to accurately describe the scalp surface by the least squares fitting to the stacked 2D estimated scalp contours. Due to the use of this surface model, an efficient and accurate technique is developed for estimation of a distance between two intersecting points formed by an arbitrary projection ray and the scalp surface. This fully automated and fast algorithm has been applied to sinogram and projection data collected using PENN-PET scanners. It has the potential to be used in routine clinical PET imaging.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133884293","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 : 1995-10-21DOI: 10.1109/NSSMIC.1995.510435
S. Weber, A. Terstegge, H. Halling, H. Herzog, R. Reinartz, P. Reinhart, F. Rongen, H. Muller-Gartner
A positron emission tomograph (PET) for small animals, e.g. rabbits or rats, is under development at the KFA Juelich as a cooperative effort between the Institute of Medicine which includes a PET center, the Central Laboratory for Electronics and the Institute for Thin Film and Ion Technology (ISI). The first version of the scanner uses arrays of small individual Yttrium Aluminium Perovskit (YAP) scintillator crystals coupled to position sensitive photomultiplier tubes. Special hardware has been built for coincidence detection, position detection and real time data acquisition, which is performed by a PC. The single event data are transfered to workstations, where the radioactivity distribution is reconstructed. The fundamental design features have extensively been simulated. Preliminary studies were carried out by using single NaI:Tl crystals coupled to position sensitive photomultiplier tubes. For the reconstruction of the simulated source configurations and measured data a 3D EM-algorithm has been implemented. The main advantage of the animal PET scanner is its high flexibility, allowing the realization of various detector system configurations. The system is capable of either providing good spatial resolution or high sensitivity for dynamic studies of pharmacokinetics. The reconstruction software is flexible and matches the different choices.
{"title":"The design of an animal PET: flexible geometry for achieving optimal spatial resolution or high sensitivity","authors":"S. Weber, A. Terstegge, H. Halling, H. Herzog, R. Reinartz, P. Reinhart, F. Rongen, H. Muller-Gartner","doi":"10.1109/NSSMIC.1995.510435","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.510435","url":null,"abstract":"A positron emission tomograph (PET) for small animals, e.g. rabbits or rats, is under development at the KFA Juelich as a cooperative effort between the Institute of Medicine which includes a PET center, the Central Laboratory for Electronics and the Institute for Thin Film and Ion Technology (ISI). The first version of the scanner uses arrays of small individual Yttrium Aluminium Perovskit (YAP) scintillator crystals coupled to position sensitive photomultiplier tubes. Special hardware has been built for coincidence detection, position detection and real time data acquisition, which is performed by a PC. The single event data are transfered to workstations, where the radioactivity distribution is reconstructed. The fundamental design features have extensively been simulated. Preliminary studies were carried out by using single NaI:Tl crystals coupled to position sensitive photomultiplier tubes. For the reconstruction of the simulated source configurations and measured data a 3D EM-algorithm has been implemented. The main advantage of the animal PET scanner is its high flexibility, allowing the realization of various detector system configurations. The system is capable of either providing good spatial resolution or high sensitivity for dynamic studies of pharmacokinetics. The reconstruction software is flexible and matches the different choices.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115077312","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 : 1995-10-21DOI: 10.1109/NSSMIC.1995.501913
B. Xu, C. Chen, J. Aarsvold, C. Kao, J. Chen, X. Pan
In recent years, various approaches to overcome the problems associated with iterative statistical image reconstruction methods have been investigated, including issues such as slow convergence rate, costly computational time and nonuniform correction efficiency. A multiscale Bayesian image reconstruction algorithm based on a 1-D wavelet technique is proposed. In this approach, the authors first apply a wavelet transform to the sinogram measurements, which yields a multiresolution object representation. The image is reconstructed at the corresponding grid by the Bayesian image reconstruction algorithm for each scale level in the frequency space; the backprojector is also modified to match each corresponding resolution scale. After the low-frequency components of the image have been recovered sufficiently on the coarser scale level, the resulted image is used as the starting point for the finer level at a new iteration. An important feature in the authors' new approach is that the wavelet decomposition is carried out in the sinogram space, while multiple grids are also used in the reconstructed image space.
{"title":"Multiscale Bayesian image reconstruction in positron emission tomography","authors":"B. Xu, C. Chen, J. Aarsvold, C. Kao, J. Chen, X. Pan","doi":"10.1109/NSSMIC.1995.501913","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.501913","url":null,"abstract":"In recent years, various approaches to overcome the problems associated with iterative statistical image reconstruction methods have been investigated, including issues such as slow convergence rate, costly computational time and nonuniform correction efficiency. A multiscale Bayesian image reconstruction algorithm based on a 1-D wavelet technique is proposed. In this approach, the authors first apply a wavelet transform to the sinogram measurements, which yields a multiresolution object representation. The image is reconstructed at the corresponding grid by the Bayesian image reconstruction algorithm for each scale level in the frequency space; the backprojector is also modified to match each corresponding resolution scale. After the low-frequency components of the image have been recovered sufficiently on the coarser scale level, the resulted image is used as the starting point for the finer level at a new iteration. An important feature in the authors' new approach is that the wavelet decomposition is carried out in the sinogram space, while multiple grids are also used in the reconstructed image space.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115433479","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 : 1995-10-21DOI: 10.1109/NSSMIC.1995.510359
H. Hogl, A. Kugel, J. Ludvig, R. Manner, K. Noffz, R. Zoz
Two years of experience with the two prototype FPGA processors Enable-1 and DecPeRLe-1 reveal that field programmable processors are the best choice for realizing a data-driven second level (L2) trigger for ATLAS. This paper presents Enable++, a modular and thus scalable 2nd generation FPGA processor that offers several substantial enhancements to the previous systems: In order to meet the varying demands of all ATLAS subdetectors Enable++ is structured into three different state-of-the-art modules for providing computing power, flexible and high-speed I/O communication and powerful intermodule communication with a raw bandwidth of 3.2 GByte/s by an active backplane. The computing core offers scalable computing power by virtue of a configurable processor topology, a 4/spl times/4 FPGA array and 12 MByte of distributed RAM. For building new applications the system provides a comfortable programming and debugging environment consisting of a compiler for the C-like hardware description language spC, a simulator and a source level debugger for hardware design. The most computing intensive tasks in L2 triggering are the feature extraction algorithms. From experience with Enable-1 we expect that Enable++ surpasses modern RISC processors by a factor of 100 to 1000.
{"title":"Enable++: a general-purpose L2 trigger processor","authors":"H. Hogl, A. Kugel, J. Ludvig, R. Manner, K. Noffz, R. Zoz","doi":"10.1109/NSSMIC.1995.510359","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.510359","url":null,"abstract":"Two years of experience with the two prototype FPGA processors Enable-1 and DecPeRLe-1 reveal that field programmable processors are the best choice for realizing a data-driven second level (L2) trigger for ATLAS. This paper presents Enable++, a modular and thus scalable 2nd generation FPGA processor that offers several substantial enhancements to the previous systems: In order to meet the varying demands of all ATLAS subdetectors Enable++ is structured into three different state-of-the-art modules for providing computing power, flexible and high-speed I/O communication and powerful intermodule communication with a raw bandwidth of 3.2 GByte/s by an active backplane. The computing core offers scalable computing power by virtue of a configurable processor topology, a 4/spl times/4 FPGA array and 12 MByte of distributed RAM. For building new applications the system provides a comfortable programming and debugging environment consisting of a compiler for the C-like hardware description language spC, a simulator and a source level debugger for hardware design. The most computing intensive tasks in L2 triggering are the feature extraction algorithms. From experience with Enable-1 we expect that Enable++ surpasses modern RISC processors by a factor of 100 to 1000.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114544458","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 : 1995-10-21DOI: 10.1109/NSSMIC.1995.504197
H. Cho, W. Hong, N. Palaio, J. Kadyk, K. Luk, V. Perez-mendez
Hydrogenated amorphous silicon carbide (a-Si:C:H) has been used as an insulating support pedestal for the anode strip in microgap gas chambers (MGCs) in an attempt to make a thicker high quality insulating layer. MGCs having 2.3 or 4.6 /spl mu/m thick a-Si:C:H and 2.0 /spl mu/m thick SiO/sub 2/ insulating layers have been built and tested. In this paper, the results of gas gains, strip damage by discharges, and preliminary aging studies are presented.
{"title":"Microgap gas chamber studies","authors":"H. Cho, W. Hong, N. Palaio, J. Kadyk, K. Luk, V. Perez-mendez","doi":"10.1109/NSSMIC.1995.504197","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.504197","url":null,"abstract":"Hydrogenated amorphous silicon carbide (a-Si:C:H) has been used as an insulating support pedestal for the anode strip in microgap gas chambers (MGCs) in an attempt to make a thicker high quality insulating layer. MGCs having 2.3 or 4.6 /spl mu/m thick a-Si:C:H and 2.0 /spl mu/m thick SiO/sub 2/ insulating layers have been built and tested. In this paper, the results of gas gains, strip damage by discharges, and preliminary aging studies are presented.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"132 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114650159","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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