Digital signal processing techniques to improve time resolution in positron emission tomography

Coincidence time resolution is one of the most important issues in PET detectors. Improving this resolution is required to increase true event coincidence rates that reduce the noise in the reconstructed images. The aim of this work is to obtain a better time resolution for our PET system designing the most appropriate time extraction digital algorithm. The experimental setup used for this research is composed by two monolithic LSO crystals+PSPMT detectors and an FPGA based PET data acquisition system (DAQ) for 16 heads. The acquired signals are sampled using a 12-bit 70MHz ADC per channel. The setup has no centralized electronics for trigger and event time extraction. Consequently, each detector head is processed independently and all the signals are acquired in the same way.