2002 IEEE Nuclear Science Symposium Conference Record最新文献_第7页

Deblurring and noise suppression in spatial EPR imaging 空间EPR成像的去模糊和噪声抑制

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239629

B.B. Williams, K. Ichikawa, C. Kao, H. J. Halpem, Xiaochuan Pan

引用次数: 1

The easy way to reduce the surface radiation damage of silicon strip detectors 降低硅条探测器表面辐射损伤的简单方法

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239391

S. Yoshida, T. Ohsugi, K. Yamamura, K. Yamamoto, K. Sato

引用次数: 0

Investigation of spatial resolution and efficiency using pinholes with small pinhole angle 小针孔角针孔空间分辨率和效率的研究

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239663

M. Williams, A. Stolin, B. Kundu

{"title":"Investigation of spatial resolution and efficiency using pinholes with small pinhole angle","authors":"M. Williams, A. Stolin, B. Kundu","doi":"10.1109/NSSMIC.2002.1239663","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239663","url":null,"abstract":"Pinhole collimators are well suited for small animal SPECT, in which high spatial resolution is required over a small field of view (FOV). Typical pinhole collimators have pinhole angles of 90/spl deg/ or more. If their full FOV is used, the trajectories of imaged gamma rays can be more than 45/spl deg/ away from the pinhole axis, and form angles of incidence at the surface of a planar detector greater than 45/spl deg/. The large incident angle produces a depth-of-interaction (DOI) blur thus reducing spatial resolution for these off-axis locations. This loss of resolution is masked by the accompanying improvement of the pinhole point spread function (PSF) due to the reduced effective aperture size. The magnitude of these effects as a function of the angle between the gamma ray trajectory and the pinhole axis depends on detector absorption efficiency, and on the physical parameters of the pinhole collimator, including pinhole type, composition, and size pinhole angle. In addition, the reduced effective pinhole results in reduced efficiency for off-axis source points. In this paper we investigate the angular dependence of these effects for pinhole collimators with different compositions and pinhole angles. Results are compared to theoretical expressions that take into account gamma ray penetration of the pinhole material.","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"239 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":"116394591","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

Initial investigation of circle-plus-arc orbit variants with a dedicated emission mammotomograph 圆形加弧形轨道变异的初步调查与专用发射乳房x线摄影

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239518

C. Archer, M. Tornai, J. Bowsher, M. Bradshaw

{"title":"Initial investigation of circle-plus-arc orbit variants with a dedicated emission mammotomograph","authors":"C. Archer, M. Tornai, J. Bowsher, M. Bradshaw","doi":"10.1109/NSSMIC.2002.1239518","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239518","url":null,"abstract":"A dedicated emission mammotomograph, uniquely capable of imaging in a hemisphere, is utilized to image the breast by way of complex acquisition orbits, completely sampling most of the breast. Orbits such as the circle-plus-arc (CPA) in particular provide for extended viewing times in a specific portion of the breast. This is advantageous in that as a diagnostic rather than screening imaging tool, a long duration of the camera trajectory may be distinctly positioned in the quadrant where the lesion is suspected. However, orbit modifications that distribute the scan time more evenly over the breast may also be effective. As the trajectories conform to the shape of the breast, including dynamic radius-of-rotation control, resolution degradation is minimized. However, for both the arc and the circular portion of the orbit. increased background contamination may result since the line-of-sight of the single photon camera can view unscattered primary radiation, particularly from cardiac and hepatic sources. The effect of azimuthal position of the arc, as well as the degree of the arc, on image quality is investigated by measurements of lesion signal-to-noise ratios and contrasts. Additionally, because the resolution characteristics of the CPA are not uniform throughout breast quadrants, the implementation of a modified orbit, in the shape of a 3D cloverleaf is investigated through measurements of the breast phantom alone with lesions of varying radioactive concentrations, and with additional torso backgrounds. These initial results indicate that polar tilt does affect image quality, with low polar tilt showing little variation in SNRs and contrasts, while increasing tilt decreases SNRs and contrasts by /spl sim/2/spl times/ when torso background is present. Considering the effect of azimuthal arc location, /spl theta/=45/spl deg/ yields the highest SNRs and contrasts for the locations at which SNR was evaluated. Both cloverleaf orbits yield comparable SNRs and contrasts to the CPA orbits.","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"34 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":"124400224","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: 0

Study of low-Q PZT as a radiation detector 低q PZT作为辐射探测器的研究

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239257

T. Miyachi, N. Hasebe, H. Ito, T. Masumura, H. Yoshioka, N. Yamashita, O. Okudaira, T. Murakami, Y. Uchihori, M. Sato, T. Tou

引用次数: 0

Detection of respiratory movement during SPECT/PET data acquisition SPECT/PET数据采集过程中呼吸运动的检测

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239622

K. Tamagawa, K. Ogawa, M. Nakajima

引用次数: 4

Readout and performance of thick CZT strip detectors with orthogonal coplanar anodes 正交共面阳极CZT厚条探测器的读数和性能

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239356

J. Macri, B. Donmez, L. Hamel, Manuel Julien, M. McClish, M. McConnell, R. S. Miller, J. Ryan, M. Widholm

引用次数: 5

Design optimization of the PMT-ClearPET prototypes based on simulation studies with GEANT3 基于GEANT3仿真研究的PMT-ClearPET原型设计优化

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239415

U. Heinrichs, U. Pietrzyk, K. Ziemons

{"title":"Design optimization of the PMT-ClearPET prototypes based on simulation studies with GEANT3","authors":"U. Heinrichs, U. Pietrzyk, K. Ziemons","doi":"10.1109/NSSMIC.2002.1239415","DOIUrl":"https://doi.org/10.1109/NSSMIC.2002.1239415","url":null,"abstract":"Within the Crystal Clear Collaboration four centres are developing 2/sup nd/ generation high performance small animal PET scanners for different kinds of animals and medical applications. The first prototypes are PMT-based systems including depth of interaction (DOI) detection by using a phoswich layer of LSO and LuYAP. The aim of these simulation studies is to optimize sensitivity and spatial resolution of given designs, which vary in FOVs caused by different detector configurations (ring/octagon) and sizes. For this purpose the simulation tool GEANT3 (CERN) was used. The simulations have shown that all PMT designs with one-to-one coupling of crystals have a very nonlinear axial sensitivity profile. By shifting every other PMT 1/4 of a PMT length in axial direction the sampling of the FOVs became more homogeneous. At an energy threshold of 350keV the regression coefficient increases from 0.818 for the non-shifted to 0.993 for the shifted design. Simulations of a point source centred in the FOV (threshold: 350keV) resulted in sensitivities of 4.2% for a 4/spl times/20PMT (LSO/LuYAP a 10mm) and 3.8% for a 4/spl times/16PMT (LSO/LuYAP a 8mm) ring design. The 3D-MLEM reconstruction of a point source shows the enormous improvement of resolution using a crystal double layer with DOI (3.1mm at 40mm from CFOV) instead of a 20mm single layer (11.9mm).","PeriodicalId":385259,"journal":{"name":"2002 IEEE Nuclear Science Symposium Conference Record","volume":"36 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":"124821707","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: 40

Evaluation of scatter compensation strategies and their impact on human detection performance in Tc-99m myocardial perfusion imaging Tc-99m心肌灌注成像中散射补偿策略的评价及其对人体检测性能的影响

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239611

M. V. Narayanan, Matt A. King, P. H. Pretorius, S. Dahlberg, J. Leppo, N. Botkin, J. Krasnow, W. Berndt, E. C. Frey

引用次数: 26

Simulation of the output from a scintillator/photodiode detector using Monte Carlo techniques and spice circuit simulation 利用蒙特卡罗技术和spice电路模拟闪烁体/光电二极管探测器的输出

2002 IEEE Nuclear Science Symposium Conference Record Pub Date : 2002-11-10 DOI: 10.1109/NSSMIC.2002.1239465

S. McCallum, P. Clowes, A. Welch

引用次数: 7