A scintillation light radial distribution model for monolithic crystal gamma cameras

Gamma imaging systems are often based on monolithic scintillators coupled to a light detector through a certain number of light guides, like glass or grease. In order to predict and optimize gamma camera performance in terms of bias and spatial resolution, accurate Monte Carlo simulations are usually carried out. These kind of simulations require high computational time so only a small number of arrangements are investigated. In this work we propose a mathematical model of scintillation light propagation starting from the gamma interaction point to the detector surface. This model gives the expression for the radial photon density distribution with a computational time 4 order of magnitude shorter than a Monte Carlo simulation. The model has been validated with standard Monte Carlo simulations of five system configurations, showing a percentage error on the quantitative evaluation of photon number lower than 2%.