2002 IEEE Nuclear Science Symposium Conference Record最新文献_第8页

Maximum a posteriori (MAP) algorithm with iterative statistical regularization 基于迭代统计正则化的最大后验算法

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239545

N. Denisova

{"title":"Maximum a posteriori (MAP) algorithm with iterative statistical regularization","authors":"N. Denisova","doi":"10.1109/NSSMIC.2002.1239545","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239545","url":null,"abstract":"The problem of image reconstruction in SPECT is considered in the general context of statistical regularization of ill-posed problems. The MAP algorithm with the prior information based on the maximum entropy (MEENT) concept is presented in this work. The MENT method is known as a powerful tool for solving tomography problems. Introduction of prior information entails the necessity of choosing an appropriate regularization parameter. The effectiveness of a reconstruction method depends strongly on the choice of a good parameter. In practice optimal regularization parameters are often found empirically: one needs to test a large number of parameters in order to find a reasonable good one. This paper intends to make some further contribution to the subject in developing some practical regularization parameter choice strategies in SPECT. The method for selecting an optimal regularization parameter based on the theory of a 'laminar ensemble' is studied. This statistical method has an excellent theoretical basis. Numerical tests have shown, that there is a tradeoff between the resolution and noise level of the image that changes with iteration. The regularization parameter enables us to operate the tradeoff. This nice property seems especially useful and important in real applications as it provides a feasible and stable numerical resolution. The optimal regularization parameter was defined at each iteration step automatically without requiring the user to select it. The adaptive chi-square criterion was used to control and stop the iteration process. The MLAP-MENT algorithm has been tested using the 3D heart phantom. The important aim of the work was to evaluate the potential of the algorithm in the defect detection. The defect was modeled as a small region of decreased count density. In numerical experiments we investigated the convergence properties of the algorithm. A comparison to the maximum-likelihood-based (OS EM) algorithm was performed.","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127160102","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}

引用次数: 1

Revised industry guidance in the area of accident monitoring instrumentation for nuclear power generating stations 修订了核电站事故监测仪器领域的行业指南

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239697

G. E. Lang, D. A. Horváth, D. Harmon, B. Marcus, I. Rana

引用次数: 0

Optical design of the Rapid Cycling Medical Synchrotron 快速循环医用同步加速器的光学设计

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239267

J. Cardona, J. Kewisch, S. Peggs

引用次数: 15

Detection properties of a neutron counter based on scintillator, wavelength shifter, and photomultiplier 基于闪烁体、波长移位器和光电倍增管的中子计数器的探测特性

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239352

R. Engels, G. Kemmerling, R. Cooper, J. Schelten

引用次数: 0

Coherent scatter X-ray computed tomography in medical applications 相干散射x射线计算机断层扫描在医学上的应用

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239469

J.-P. Schloraka, A. Harding, G. Harding, U. van Stevendaal, M. Grass

引用次数: 4

X-ray dark field refraction-contrast imaging - a new tool for medical imaging x射线暗场折射对比成像——医学成像的新工具

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239676

V. Protopopov, J. Sobota, A. Tremsin, O. Siegmund

引用次数: 0

Study of scintillating digital hadron calorimeter prototypes 闪烁式数字强子量热计样机的研究

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239376

G. Blazey, D. Chakraborty, A. Dyshkant, D. Hedin, A. Maciel, M.I. Martin, R. McIntosh, V. Rykalin, V. Zutshi

引用次数: 0

Design of a sensor to predict arcing faults in nuclear switchgear 核开关设备电弧故障传感器的设计

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239701

H. B. Land, C. Eddins, L. Gauthier, J. M. Klimek

引用次数: 39

X-ray detector with thick epitaxial GaAs grown by chemical reaction 化学反应生长的厚外延砷化镓x射线探测器

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239333

G. Sun, M. Lenoir, E. Breelle, H. Šamić, J. Bourgoin, H. El-Abbassi, P. Sellin, J. Montagne

引用次数: 15

Investigation of the properties of new scintillator LYSO and recent LSO scintillators for phoswich PET detectors 用于光电PET探测器的新型闪烁体LYSO和新型LSO闪烁体的性质研究

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239410

C. Pepin, A. Perrot, P. Bérard, C. Pepin, D. Houde, R. Lecomte, C. Melcher, H. Dautet

{"title":"Investigation of the properties of new scintillator LYSO and recent LSO scintillators for phoswich PET detectors","authors":"C. Pepin, A. Perrot, P. Bérard, C. Pepin, D. Houde, R. Lecomte, C. Melcher, H. Dautet","doi":"10.1109/NSSMIC.2002.1239410","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239410","url":null,"abstract":"The luminescence and nuclear spectroscopic properties of the new cerium-doped rare-earth scintillator lutetium-yttrium oxyorthosilicate (Lu/sub 0.6/Y/sub 1.4/SiO/sub 5/:Ce, LYSO) were investigated and compared to those of both recent and older LSO crystals. UV-excited luminescent spectra outline important similarities between LYSO and LSO scintillators. The two distinct Ce1 and Ce2 luminescence mechanisms previously identified in LSO are also present in LYSO scintillators. The energy and timing resolutions were measured using avalanche photodiode (APD) and photomultiplier tube (PMT) readouts. The dependence of energy resolution on gamma-ray energy was also assessed to unveil the crystal intrinsic resolution parameters. In spite of significant progress in light output and luminescence properties, the energy resolution of these scintillators appears to still suffer from an excess variance in the number or scintillation photons. Pulse-shape discrimination between LYSO and LSO scintillators has been successfully achieved in phoswich assemblies, confirming LYSO to be a potential candidate for depth-of-interaction determination in multi-crystal PET detectors.","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121642681","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}

引用次数: 9