A Dual-Ended Readout Detector Using a Meantime Method for SiPM TOF-DOI PET

We have investigated a dual-ended readout detector based on two silicon photo-multipliers (SiPMs) using a 30 mm long cerium-doped lutetium-yttrium oxyorthosilicate ( ${\rm Lu}_{0.5}{{\rm Y}_{1.4}}{\rm Si}_{0.5}:{\rm Ce}$ , LYSO) crystal to study the feasibility of a time-of-flight (TOF) and depth-of-interaction (DOI) positron emission tomography (PET). To improve the timing resolution in the dual-ended readout detector, a novel meantime measurement was employed. The meantime was obtained by averaging two signal arrival times at two SiPMs, each of which was attached to both ends of the LYSO crystal. The meantime method minimizes the arrival time difference along the crystal. Both timing and DOI resolutions using the meantime method were better than those of a single-ended readout detector.