A Monte Carlo simulation of Compton scattering in positron emission tomography.

A Monte Carlo technique was used to simulate some of the important physical processes involved in the coincidence detection of gamma rays by a positron emission tomograph. The major effect considered here is the detection of Compton scattered gamma rays as coincidence counts. The Compton scattering of gamma rays in a H2O filled phantom was simulated using the Klein-Nishina cross section. Results obtained in the form of profiles of activity were compared to a model which represents scatter as the convolution of the true signal with an exponential.