Coincidence Imaging with a Custom-built Waveform Sampling Data Acquisition System for Time-of-flight PET

We describe a dedicated high spatial resolution time-of-flight-capable breast PET scanner and its intrinsic performance. The PET scanner comprises of two detector heads, each composed of a 4×2 arrangement of PET detectors, and with each detector housing a 32 × 32 array of 1.5×1.5×15 mm
³
LYSO crystals. With a target TOF resolution <400 ps, we have developed a waveform sampling data acquisition system for the scanner. The data acquisition (DAQ) is modular and uses the DRS4 chip to perform waveform sampling at up to 5 Gsps. Performance evaluation demonstrates good crystal discrimination, energy resolution, and timing resolution of ~400 ps FWHM; indicating that the DAQ meets the needs of the TOF breast PET scanner.