The MINDView brain PET detector, feasibility study based on SiPM arrays

The Multimodal Imaging of Neurological Disorders (MINDView) project aims to develop a dedicated brain Positron Emission Tomography (PET) scanner with sufficient resolution and sensitivity to visualize neurotransmitter pathways and their disruptions in mental disorders for diagnosis and follow-up treatment. The PET system should be compact and fully compatible with a Magnetic Resonance Imaging (MRI) device in order to allow its operation as a PET brain insert in a hybrid imaging setup with most MRI scanners. The proposed design will enable the currently-installed MRI base to be easily upgraded to PET/MRI systems. The current design for the PET insert consists of a 3-ring configuration with 20 modules per ring and an axial field of view of ~15cm and a geometrical aperture of ~33cm in diameter. When coupled to the new head Radio Frequency (RF) coil, the inner usable diameter of the complete PET-RF coil insert is reduced to 26cm. Two scintillator configurations have been tested, namely a 3-layer staggered array of LYSO with 1.5mm pixel size, with 35×35 elements (6mm thickness each) and a black-painted monolithic LYSO block also covering about 50×50mm2 active area with 20mm thickness. Laboratory test results associated with the current MINDView PET module concept are presented in terms of key parameters׳ optimization, such as spatial and energy resolution, sensitivity and Depth of Interaction (DOI) capability. It was possible to resolve all pixel elements from the three scintillator layers with energy resolutions as good as 10%. The monolithic scintillator showed average detector resolutions varying from 3.5mm in the entrance layer to better than 1.5mm near the photosensor, with average energy resolutions of about 17%.