Computational modelling of multi-head PET/SPECT imaging systems with thick CdZnTe pixelated detectors

Small field-of-view Positron Emission Tomography (PET) and Single-Photon Emission Computed Tomography (SPECT) systems employing pixelated Cadmium Zinc Telluride (CdZnTe) detectors were computationally modelled using a comprehensive framework that integrates Monte Carlo and Finite Element numerical methods. The PET/SPECT systems consisted of multiple detector heads oriented in cylindrical configuration. Realistic and accurate system models were constructed and their performance was computationally investigated using the NEMA standards. The potential use of thick CdZnTe detectors was assessed by employing detector modules with total thickness equal to 15 mm. The outcome of the project will assist in the determination of an optimum configuration for medical imaging applications and the improvement of the read-out electronics.