Evaluation of a technique for simulation of gamma camera images.

Simulation of the gamma camera imaging process has applications in radionuclide imaging in image formation, interpretation and evaluation. Current algorithms are hindered by the length of time taken to perform accurate simulation. In this study an algorithm is developed which uses a number of simplifying approximations to improve speed of operation: restriction of the extent of the primary and scatter point spread functions, coarse sampling of the PSFs in the direction perpendicular to the camera face and use of a circularly symmetric scatter function. The effect of these approximations is assessed qualitatively and quantitatively by comparing simulations with corresponding real measurements. The application of the technique to clinical images using magnetic resonance data is demonstrated. The results show that improvements in speed of about a factor of ten may be achieved at the expense of minimal loss of accuracy. The algorithm should prove useful in speeding up applications of simulation.