A Digital Pulse Library for the Optimization of Signal Processing in PET

In this work, we developed a comprehensive digital pulse library as a reference data set, against which the performance of pulse processing algorithms can be evaluated. The pulses are directly recorded from real measurements with scintillation detectors multiplexed by a resistor divider network. This way, the pulses better represent systematic variations of detection sensitivity for detector panels due to differences in light sharing, light collection and crystal scatter among other effects. The pulse shapes exactly represent the signals to be processed in the data acquisition and signal processing unit, but for which the ground truth regarding energy, position and timing can be known. A conventional pulse pileup rejection method called leading edge rejection (LER) was evaluated with the help of the pulse library. The simulated pulse library based results show that the LER method can effectively suppress most of the pileup caused mispositioned events, while it also trades off against sensitivity loss. Physical measurements agree with the pulse library simulation results. In conclusion, the proposed evaluation method based on digital pulse library can significantly reduce the time and effort invested in the development and optimization of various signal processing algorithms.