Optimization of a monolithic detector block design for a prototype human brain PET scanner

We are presently developing a novel PET scanner for human brain functional imaging based on monolithic scintillator crystals read by APD matrices, capable of being inserted into an MRI system. In this work we report on the detailed study that has been made of the design of the detector blocks, aiming at defining the most suitable geometrical and readout configuration for optimizing the overall performance of the entire scanner. Both parallel and trapezoidal geometries have been simulated, featuring two layers of active scintillator material with different or similar thickness and APD readout on the front or back side. Results of this study indicate that a trapezoidal geometry with equal thickness of both layers is the best solution for improving the expected scanner performance.