1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference最新文献_第4页

Noise properties of attenuation correction methods for SPECT SPECT衰减校正方法的噪声特性

1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference Pub Date : 1993-10-31 DOI: 10.1109/NSSMIC.1993.373520

E. Soares, H. Barrett, Elizabeth A. Krupinski

{"title":"Noise properties of attenuation correction methods for SPECT","authors":"E. Soares, H. Barrett, Elizabeth A. Krupinski","doi":"10.1109/NSSMIC.1993.373520","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.373520","url":null,"abstract":"The authors investigate the noise properties of SPECT images reconstructed with the attenuation correction methods of Bellini, Chang, and Tretiak and Metz. The general model for the image covariance matrix can be described by two terms, the first representing object variability, the second representing the object-dependent quantum noise. The model assumes the reconstruction operation is non-iterative and linear, and the noise in the projection data is nonstationary. All aspects of digital reconstruction are included in the model. The three attenuation correction methods are tested to demonstrate the noise character of SPECT images for a uniformly emitting and attenuating disk. In addition, image quality assessment is performed for the task of detecting a cold signal on a uniformly emitting and attenuating circular background. Comparing the local noise power spectrums for various pixel locations, it is shown that image noise is both globally and locally nonstationary for all three methods, except for a small, uniform region near the center of the disk. It is also seen that the noise properties of all three methods are similar in this region. The method of Tretiak-Metz increases the noise variance at the edge of the disk, whereas it is reduced with the Bellini and Chang methods. Finally, the ideal, nonprewhitening, and region-of-interest observers are shown to be invariant across reconstruction method, however the human observer performs better with the Bellini attenuation correction method.<<ETX>>","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114518324","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: 12

Theoretical And Experimental Analysis Of Magnetic Field Gradients For MRI 磁共振成像磁场梯度的理论与实验分析

1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference Pub Date : 1993-10-31 DOI: 10.1109/NSSMIC.1993.701859

R. Pascone, T. Vullo, P. Cahill, A. Tankhiwale

引用次数: 6

Human heart motion analysis through normal flow methods [SPECT image analysis] 正常血流法分析人体心脏运动[SPECT图像分析]

1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference Pub Date : 1993-10-31 DOI: 10.1109/NSSMIC.1993.373554

I. Chang, Chung-Lin Huang

引用次数: 1

Lossless data compression for short duration 3D frames in positron emission tomography 正电子发射断层成像中短时间三维帧的无损数据压缩

1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference Pub Date : 1993-10-31 DOI: 10.1109/NSSMIC.1993.373609

K. Baker, W.E. Jones, L. Byars, M. Casey, J. Reed

引用次数: 4

Photostimulated luminescence and thermoluminescence of LSO scintillators LSO闪烁体的光致发光和热致发光

1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference Pub Date : 1993-10-31 DOI: 10.1109/NSSMIC.1993.701642

R. Visser, C. Melcher, J. S. Schweitzer, H. Suzuki, T. Tombrello

引用次数: 63

CdZnTe Detector Arrays For Nuclear Medicine Imaging 核医学成像用CdZnTe探测器阵列

1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference Pub Date : 1993-10-31 DOI: 10.1109/NSSMIC.1993.701724

J. F. Butler, S.J. Friesenhahn, C. Lingren, B. Apotovsky, R. Simchon, F. Doty, W. L. Ashburn, W. Dillon

引用次数: 4

Ripple Distribution In Magnet Strings Of Super Collider 超级对撞机磁串中的纹波分布

1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference Pub Date : 1993-10-31 DOI: 10.1109/NSSMIC.1993.701668

K. Smedley, A. Jayasuriya, C. Christiansen, R. Shafer

{"title":"Ripple Distribution In Magnet Strings Of Super Collider","authors":"K. Smedley, A. Jayasuriya, C. Christiansen, R. Shafer","doi":"10.1109/NSSMIC.1993.701668","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701668","url":null,"abstract":"The voltage ripple in the power supplies of the Collider generate ripple current in the magnet coil that, in turn, generates ripple in the magnetic field of dipoles and quadrupoles. The ripple in the magnetic field will be a function of the and space due to the transmission line effect. The work reported in this paper gives a thorough analysis the frequency spectrum and the spatial propagation pattern of the differential mode ripple in the magnet strings for the injection mode and the collider mode. sub/super harmonics. Therefore, it is necessary to consider the power supply ripple as a spectrum distribution. 151 presented accurate electric characteristics of the superconducting magnets by eGerimenta1 and analytic method. The work reported in this paper gives an analytical, numerical, and experimental combined study and provides thorough information of the frequency and spatial distributions of the differential ripple in the magnet string of collider standard arc for the injection mode and the collider mode. The analysis method is applicable to other magnet strings as well. In Section 11, the waveforms of the power supply voltage with all possibilities of imbalance were simulated, and the spectrum of the power supply voltage was obtained using FFT method. In Section 111, the transfer functions of power supply voltage to the string current and coil current at the drive point were obtained, Section Iv gives the current ripple spatial distribution from the drive point to both ends of the magnet strings. Section V provides an experimental transfer function from the coil current to the magnetic field at any location in the magnet strings. A","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128903305","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

T2 restoration and noise suppression of hybrid MR images using Wiener and linear prediction techniques 基于维纳和线性预测技术的混合MR图像T2恢复和噪声抑制

1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference Pub Date : 1993-10-31 DOI: 10.1109/NSSMIC.1993.373567

Haiguang Chen, H. Avram, L. Kaufman, J. Hale, D. Kramer

引用次数: 9

Monte Carlo Calculations Of Low Background Detector Response 低背景探测器响应的蒙特卡罗计算

1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference Pub Date : 1993-10-31 DOI: 10.1109/NSSMIC.1993.701679

H. Miley

{"title":"Monte Carlo Calculations Of Low Background Detector Response","authors":"H. Miley","doi":"10.1109/NSSMIC.1993.701679","DOIUrl":"https://doi.org/10.1109/NSSMIC.1993.701679","url":null,"abstract":"An implementation of the Electron Gamma Shower 4 code (EGS4)[ I] has been developed to allow convenient simulation of typical gamma ray measurement systems. Coincidence gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra for the purpose of extremely low-level assay. Monte Carlo calculations of this sort can be extremely successful since low background detectors are usually free of significant contributions from poorly localized radiation sources, such as cosmic muons, secondary cosmic neutrons, and radioactive construction or shielding materials. Validation of this code has been obtained from a series of comparisons between measurements and blind calculations. The singles counting efficiency of a particular counting experiment was reproduced within the accuracy of the known dimensions of the detector components. This allowed the complete simulation of a nuclear decay, including two coincident gamma rays with a non-isotropic angular correlation. In addition, text-book efficiency curves have been reproduced for several sizes of sodium iodide detectors. Examples of the use and several spectral results will be presented.","PeriodicalId":287813,"journal":{"name":"1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132893798","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

3D statistical neuroanatomical models from 305 MRI volumes 来自305个MRI体积的3D统计神经解剖学模型

1993 IEEE Conference Record Nuclear Science Symposium and Medical Imaging Conference Pub Date : 1993-10-31 DOI: 10.1109/NSSMIC.1993.373602

Alan C. Evans, D. Collins, S. R. Mills, E. D. Brown, R. L. Kelly, T. Peters

引用次数: 1569