A small-animal PET design using SiPMs and Anger logic with intrinsic DOI

In this study a miniature, high-resolution detector head for a small-animal PET imaging system that has intrinsic depth of interaction (DOI) information is proposed. The design is hased upon the classic Anger camera principle, i.e. one detector module layer consists of a continuous slab of scintillator, viewed by a new type of compact silicon photodetector. The photodetector is the recently developed Silicon Photomultiplier (SiPM) that as well as being very compact has many other attractive properties: high gain at low bias voltage, excellent single-photoelectron resolution and fast timing. A detector head of 4×4 cm² in area is proposed, constructed from three module layers of the continuous detector described above. Here, a simulation study is carried out, using the Monte Carlo simulation package GEANT4. The simulation results are used to determine the performance of a single detector head and to optimize the geometry of the detector, resulting in a spatial resolution of up to ∼0.6 mm full-width at half maximum (FWHM).