High probability crystal pin identification in scintillator matrix-based PET detector with a prototype digital SiPM

We evaluated spatial resolution performance of a 1.51×1.51×10mm³ LYSO:Ce pin based experimental PET module coupled to a prototype, digital silicon photomultiplier device (digital SiPM). Utilizing the spatial oversampling capability of our digital SiPM we were able to achieve high-probability crystal identification. Position histograms were generated using a modified center of gravity algorithm (COG). We found that the distributions of estimated positions of single crystal pins in neighboring positions are separated at least by 15σ. We also tested our digital SiPM with a 7×3 element scintillator array. From the acquired 2D position histogram the pins can be easily identified by using constant pitch grid segmentation. Analysis of average light distribution of a single crystal pin was also performed. The root means square (RMS) radius of the light spots from consecutive measurements were to be found very similar (r_RMS=1.106±0.034 mm).