Time mark estimators for MD-SiPM and impact of system parameters

The accuracy of the time of arrival is crucial for time-of-flight PET scanners to improve the quality of the reconstructed image. Since the introduction of the multi-channel digital SiPM, it is possible to measure several time stamps that corresponds to the fastest light photons. The time mark of the gamma photon can be estimated from the measured light photon time stamps. In many ways, this paper presents a comprehensive study of these estimators. We analyze the impact on coincidence resolving time by PET detector module parameters, such as dark count rate, jitter, energy resolution and number of detected primary photons. The results show that all of the estimators are very sensitive to jitter and the number of detected primary photons. Furthermore, energy resolution and dark count rate do not affect CTR significantly.