DocumentCode :
2052995
Title :
Improved modeling of system response in list mode EM reconstruction of Compton scatter camera images
Author :
Wilderman, Scott J. ; Fessler, J.A. ; Clinthorne, N.H. ; Rogers, W. Les
Author_Institution :
Michigan Univ., Ann Arbor, MI, USA
Volume :
2
fYear :
1999
fDate :
1999
Firstpage :
1052
Abstract :
An improved List Mode EM method for reconstructing Compton scattering camera images has been developed. First, an approximate method for computation of the spatial variation in the detector sensitivity has been derived and validated by Monte Carlo computation. A technique for estimating the relative weight of system matrix coefficients for each gamma in the list has also been employed, as has a method for determining the relative probabilities of emission having some from pixels tallied in each list-mode back-projection. Finally, a technique has been developed for modeling the effects of Doppler broadening and finite detector energy resolution on the relative weights for pixels neighbor to those intersected by the back-projection, based on values for the FWHM of the spread in the cone angle computed by Monte Carlo. Memory issues typically associated with list mode reconstruction are circumvented by storing only a list of the pixels intersected by the back-projections, and computing the weights of the neighboring pixels at each iteration step. Simulated projection data has been generated for a representative Compton camera system (CSPRINT) for several source distributions and reconstructions performed. Reconstructions have also been performed for experimental data for distributed sources
Keywords :
Compton effect; Monte Carlo methods; image reconstruction; medical image processing; modelling; Doppler broadening; back-projection; cone angle spread; distributed sources; finite detector energy resolution; iteration step; list mode reconstruction; medical diagnostic imaging; neighboring pixels weight computation; nuclear medicine; pixels list; representative Compton camera system; simulated projection data; source distributions; Cameras; Detectors; Electromagnetic scattering; Energy measurement; Event detection; Image reconstruction; Monte Carlo methods; Object detection; Particle measurements; Particle scattering;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Nuclear Science Symposium, 1999. Conference Record. 1999 IEEE
Conference_Location :
Seattle, WA
ISSN :
1082-3654
Print_ISBN :
0-7803-5696-9
Type :
conf
DOI :
10.1109/NSSMIC.1999.845842
Filename :
845842
Link To Document :
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