Event-time determination by waveform analysis for time-of-flight positron emission tomography

With the recent advance of SCA (Switched Capacitor Array) sampling chip, it has become practically feasible to sample the waveforms of the event pulses generated by modern fast PET detectors at high rates (e.g., 5 GS/s or higher). In principle, performing such waveform sampling can maximally maintain the information about an event. In combination with the use of sophisticated processing algorithms to analyze the pulse waveforms, which can be readily implemented and carried out on-the-fly with modern digital electronics, it is likely that more detailed and accurate knowledge about the gamma-ray interactions with the detectors can be extracted. The purpose of this work is to study such perceived advantage of the waveform-sampling (WS) based approach for PET event detection, focusing on timing. Our results indicate that the WS-based approach can ebable the development of fine-tuned processing algorithms that match the response characteristics of PET detectors to yield improved event timing. The results also point to the possibility of performing shape analysis for extracting more event information.