1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record最新文献_第7页

An application of the maximum entropy method for assessments of residual radioactivity at contaminated sites 最大熵法在污染场地残余放射性评价中的应用

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.504293

M. Reginatto, P. Shebell, K. M. Miller

引用次数: 3

Using IEEE standard 1057 for testing analog-to-digital converters 使用IEEE 1057标准测试模数转换器

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.504224

H. Crawley, R. Mckay, W. Meyer, E. Rosenberg, W. D. Thomas

引用次数: 4

A method for calibrating 3D PET without scatter correction 一种无需散射校正的三维PET标定方法

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.510444

D. Bailey, T. Jones

{"title":"A method for calibrating 3D PET without scatter correction","authors":"D. Bailey, T. Jones","doi":"10.1109/NSSMIC.1995.510444","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.510444","url":null,"abstract":"Calibration for 3D PET using a uniform cylinder and cross-calibration with aliquots requires correction for scatter and attenuation. Thus the accuracy of the calibration is dependent on the scatter correction method, and on the applicability of the scatter correction for different regions of the body. A method has been developed which provides a calibration which does not require correction for scatter or attenuation, making it generally applicable and independent of the scatter correction. The method has been previously described for measurement of the absolute sensitivity of tomographic devices. This approach has been extended to give a calibration of the PET camera 'in air' in units of kBq/pixel. The reconstructed images are multiplied by this factor to give accurate activity concentrations, after attenuation and scatter correction. The method has been used with a fully 3D filtered-backprojection (reprojection) algorithm and iterative convolution-subtraction scatter correction on data from an ECAT 953B. Using this method 3D PET images have been calibrated to within 5% accuracy, but this is highly dependent on the accuracy of the scatter correction. The method described here is practical and provides a means of calibrating a 3D PET system without needing correction for scatter or attenuation of the calibration data.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"52 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":"130641291","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: 2

Reducing the effect of non-stationary resolution on activity quantitation with the frequency distance relationship in SPECT 利用SPECT的频率距离关系降低非平稳分辨率对活度定量的影响

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.510497

P. H. Pretorius, Matt A. King, S. Glick, Tin-Su Pan, D. Luo

{"title":"Reducing the effect of non-stationary resolution on activity quantitation with the frequency distance relationship in SPECT","authors":"P. H. Pretorius, Matt A. King, S. Glick, Tin-Su Pan, D. Luo","doi":"10.1109/NSSMIC.1995.510497","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.510497","url":null,"abstract":"The determination of quantitative parameters such as the maximum and total counts in a volume are influenced by the partial volume effect. The magnitude of this effect varies with the non-stationary spatial resolution inherent in SPECT imaging compared to the size and shape of the object, and the relative concentration of the object to its background. The objective of this investigation was to determine if the FDR (Frequency Distance Relationship) restoration filtering can reduce the impact of distance dependent spatial resolution on the quantitation of activity. An analytical projector which incorporates attenuation and distance dependent blurring was used to simulate small hot spherical objects in an cylindrical attenuator as imaged with a LEUHR collimator. FDR restoration filtering regularized using different Gaussian and parametric Wiener filters, was employed after attenuation correction with Bellini's method. Projections were also processed using Bellini's attenuation correction method followed by filtered backprojection and 3D Butterworth filtering with different cut-off frequencies. CCR's (Center Count Ratios) and TCR's (Total Count Ratios) were determined as the observed counts over true counts. Results show that after FDR restoration the CCR and TCR become approximately position invariant. However, when regularizing the FDR inverse filter with a Gaussian function, CCR's become highly unstable as the standard deviation (/spl sigma/) decreased below that at the center of rotation. The use of the Gaussian and parametric Wiener filters to regularize FDR filtering introduce noise in the CCR's but improve recovery of TCR's over that of the center of rotation.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"14 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":"131938493","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: 25

A refined mathematical model for positron emission tomography 正电子发射层析成像的精细数学模型

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.510482

B. Mair, M. Rao, J. Anderson

引用次数: 2

Modified convolution-subtraction scattering correction technique for 3D PET 三维PET的改进卷积-减散射校正技术

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.500270

L. Shao, J. Karp

引用次数: 5

Application of lead and tungsten pinhole inserts to I-131 SPECT tumor imaging: a Monte Carlo investigation 应用铅和钨针孔插入到I-131 SPECT肿瘤成像:蒙特卡罗研究

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.500317

M. Smith, R. Jaszczak, H. Wang, J. Li

{"title":"Application of lead and tungsten pinhole inserts to I-131 SPECT tumor imaging: a Monte Carlo investigation","authors":"M. Smith, R. Jaszczak, H. Wang, J. Li","doi":"10.1109/NSSMIC.1995.500317","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.500317","url":null,"abstract":"The potential use of lead and tungsten pinhole inserts for high resolution SPECT imaging of intratumor activity in I-131 radioimmunotherapy is investigated using experimental point source measurements, and raytracing and Monte Carlo simulations. I-131 imaging is challenging because the primary photon emission is at 364 keV and penetration through the insert near the pinhole aperture is significant. Point source response functions (PSRFs) for Pb and W pinhole inserts are measured and are modeled using raytracing simulations. More accurate simulation of the PSRFs may require the modeling of scatter within the pinhole insert and of higher energy emissions at 637 and 723 keV. A numerical study of geometrically identical pinhole inserts made of Pb and W shows narrower point source response functions for the W insert due to reduced penetration. Monte Carlo modeling was used to compare these inserts for SPECT pinhole imaging of 3 cm diameter tumors with a central core and 3-5 mm thick shells. The shell:core activity concentration ratio was 5:1. The tumor shells are resolved for the W insert but not for the Pb insert. As a result, shell:core activity ratios are more accurate with the use of the W pinhole insert. Experimental SPECT acquisitions are needed to confirm the potential advantages of a W insert over a Pb insert suggested by this study.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"1 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":"128833605","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

Design of a variable field prototype PET camera 可变场PET相机样机的设计

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.510429

W. Wong, J. Uribe, WeiZhao Lu, Guoji Hu, K. Hicks

引用次数: 38

A class of analytical methods that compensate for attenuation and spatially-variant resolution in 2D SPECT 一类补偿二维SPECT中衰减和空间变分辨率的分析方法

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.501915

X. Pan, C. Metz, C.-T. Chen

{"title":"A class of analytical methods that compensate for attenuation and spatially-variant resolution in 2D SPECT","authors":"X. Pan, C. Metz, C.-T. Chen","doi":"10.1109/NSSMIC.1995.501915","DOIUrl":"https://doi.org/10.1109/NSSMIC.1995.501915","url":null,"abstract":"An infinite class of closed-form methods was developed by the authors in 1994 for image reconstruction in 2D SPECT with uniform attenuation. In the work reported here, the authors extended their approach to develop a class of closed-form methods that compensate for the effects of both photon attenuation and distance-dependent spatial resolution in 2D SPECT. These methods, which are characterized by an index n that can be assigned any real number, are exact in the absence of noise but propagate noise differently. The authors implemented this class of methods for SPECT image reconstruction in both computer-simulation and real-data studies. The results demonstrate that this class of methods corrects effectively for the aforementioned effects. Extensive computer simulation studies indicate that the method obtained with n=2, which the authors had proved to be the optimal choice of n in 2D SPECT when only attenuation is present, also provides the smallest global image variance among the methods in the class when compensation for both uniform attenuation and distance-dependent spatial resolution is performed.","PeriodicalId":409998,"journal":{"name":"1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record","volume":"36 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":"126687577","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: 14

An application of microstrip gas proportional counter for a X-ray polarimeter 微带气体比例计数器在x射线偏振计中的应用

1995 IEEE Nuclear Science Symposium and Medical Imaging Conference Record Pub Date : 1995-10-21 DOI: 10.1109/NSSMIC.1995.504216

T. Tamura, H. Sugeno, H. Sakurai, M. Noma, S. Gunji, Gertenbort

引用次数: 0