COMPET: High resolution high sensitivity MRI compatible pre-clinical PET scanner

COMPET is a pre-clinical MRI compatible PET scanner which decouples sensitivity and resolution by the use of a novel detector design. The detector has been built using 8 × 8 cm 2 square layers consisting of 30 LYSO crystals ( 2 × 3 × 80 mm 2 ) interleaved with 24 Wavelength Shifting Fibers (WLS) ( 3 × 1 × 80 mm 3 ). By stacking several layers into a module, the point-of-interaction (POI) can be measured in 3D. Four layers form a PET ring where the sensitivity can be increased by stacking several layers. The layers can be stacked so that no inter-crystal or inter-module gap is formed. COMPET has used four assembled layers for module and scanner characterization. The modules are connected to the COMPET data-acquisition chain and the reconstructed images are produced with the novel geometry-independent COMPET image reconstruction algorithm. Time and energy resolution have been resolved and found to be around 4 ns and 14% respectively. Tests for MRI interference and count rate performance have been carried out. The reconstruction algorithm has been verified with data acquired by means of a COMPET full ring PET scanner.