A Monte Carlo study of depth of interaction in PET

In this work, we present a Monte Carlo simulation program for the investigation of reconstruction of the entrance point and angle of incidence of γ-rays incident on a crystal by using the light output from the adjacent crystals. Initially, the Monte Carlo simulator was used to obtain the light response function (LRF) of each crystal in a detector array with respect to the entrance position and angle of incidence of the incident γ-rays. Later, the simulator was used to determine the spatial resolution of a 3-layer detector ring consisting of 200 crystals per layer.