<title>Analysis Of Spect Using Monte Carlo Simulation</title>

Abstract

A Monte Carlo program has been developed to simulate the response of a single photon emission computed tomography (SPECT) system. Phantoms are represented by any number of spheres and cylinders which are placed inside a single, larger cylinder. The phantom, source distribution, and system parameters are specified in an input file. The code permits data acquisition by a stationary or rotating gamma camera. The quality of the images is degraded by scatter and attenuation of radiation by tissue which, in turn, is dependent on object size, shape, composition, and density. The simulation enables control of components which govern the emission and transport of radiation through the source and attenuating medium. Thus, the simulation is useful for analyzing and designing algorithms to compensate for scatter and attenuation. The accuracy of the SPECT simulation is illustrated by measuring the scatter fraction, resolution, ARMS noise, and image contrast. These results are then compared with experimental results to validate the accuracy of the simulation. A method of compensating for the degrading effects of scatter and attenuation is examined.