DocumentCode :
3473585
Title :
Geometrical response modeling in fan-beam collimators. A numerical simulation
Author :
Pareto, D. ; Cot, A. ; Falcon, C. ; Juvells, I. ; Pavia, J. ; Ros, D.
Author_Institution :
Lab. Biofisica i Bioenginyeria, Barcelona Univ., Spain
Volume :
3
fYear :
2000
fDate :
2000
Abstract :
Iterative reconstruction algorithms require modeling of the PSF of the collimator in order to correct the loss of resolution in SPECT. In this paper a method of modeling the geometric response of a fan beam collimator is proposed. The geometric PSF is obtained by numerical simulation based on ray tracing techniques. The versatility of the numerical simulation allows one to generate the array of holes with a distance between holes varying as an angular function, thus being suitable for real distributions of holes. The volume of the simulated PSFs was calculated in order to determine the relative sensitivity and Gaussian functions were fitted to obtain the resolution. Functions depending on the intrinsic parameters of the collimator and of the co-ordinates of the source were fitted to the individual PSF. Thus, the method allows one to determine both the spatial resolution and the sensitivity as a function of the source co-ordinates. The validity of the modelisation functions was checked by comparing the predicted results with those obtained from experimental measurements. The authors´ findings show that the predicted values for the relative sensitivity and for the resolution match accurately the experimental values, with a correlation coefficient of 0.997 for sensitivity and 0.996 for resolution
Keywords :
biomedical equipment; image reconstruction; image resolution; iterative methods; medical image processing; modelling; numerical analysis; single photon emission computed tomography; Gaussian functions; PSF modeling; SPECT resolution loss; angular function; correlation coefficient; holes array; intrinsic parameters; iterative reconstruction algorithms; medical diagnostic imaging; nuclear medicine; ray tracing techniques; source coordinates; spatial resolution; Detectors; Face detection; Hospitals; Numerical simulation; Optical collimators; Predictive models; Ray tracing; Reconstruction algorithms; Solid modeling; Spatial resolution;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Nuclear Science Symposium Conference Record, 2000 IEEE
Conference_Location :
Lyon
ISSN :
1082-3654
Print_ISBN :
0-7803-6503-8
Type :
conf
DOI :
10.1109/NSSMIC.2000.949321
Filename :
949321
Link To Document :
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