In-Silico Optimisation of Tileable Philips Digital SiPM Based Thin Monolithic Scintillator Detectors for SPECT Applications

Abstract

Over the last decade one of the most significant technological advances made in the field of radiation detectors for nuclear medicine was the development of Silicon Photomultipler (SiPM) sensors. At present a only small number of SiPM based radiation detectors for Single Photon Emission Computed Tomography (SPECT) applications has been explored, and even fewer experimental prototypes developed. An in-silico investigation into the optimal design of a Philips DPC3200 SiPM photosensor based monolithic scintillator detector for SPECT applications was undertaken using the Monte Carlo radiation transport modelling toolkit Geant4 version 10.5. The performance of the 20 different SPECT radiation detector configurations, 4 scintillator materials (NaI(Tl), GAGG(Ce), CsI(Tl) and LYSO(Ce)) and 5 thicknesses (1 to 5 mm), were determined through the use of six different figures of merit. For SPECT/CT applications it was determined that GAGG(Ce) was an optimal scintillator material, with crystal thicknesses of 3 mm and 5 mm being ideal for SPECT/CT systems with pinhole and parallel hole coded apertures respectively. Conversely for SPECT/MR applications it was determine that CsI(Tl) was an optimal scintillator material, with crystal thicknesses of 3 mm and 5 mm again being ideal for SPECT/MR systems with pinhole and parallel hole coded apertures respectively.