Highly multiplexed DOI PET detector based on SiPM sensors

We present an efficient readout scheme to acquire the outputs from two tiled SiPM detectors forming an 8×4 matrix of pixels capable of efficiently encoding event position, and that has good energy and time resolution, as well as depth of interaction capabilities. The characterization has been done using a 32×32 matrix of 1.3×1.3×12 mm3 LYSO crystals and a GSO/BGO phoswich illuminated with a 22Na source. Preliminary results regarding spatial resolution show that the detector has a resolvability index of 0.31, an energy resolution below 20% for the 511 KeV peak and a good separation between the two different phoswich crystal layers. Given the simplicity and compactness of the proposed readout, we envision an effective replacement for the conventional high performance PS-PMTs based detectors.