Compact detector modules for high resolution PET imaging with LYSO and avalanche photodiode arrays

We have developed compact detector modules for high-resolution PET imaging. The modules consist of arrays of four by four 20 mm long LYSO crystals whose scintillation signals are read by avalanche photodiode arrays. The scintillator arrays are instrumented at both ends to facilitate depth-of-interaction determination by measuring the pulse-height ratio between the two ends of the LYSO crystal. To process the diode signals, we have developed a custom multi-channel integrated readout chip designed for excellent coincidence time resolution and low power dissipation. The IC offers various configuration options to allow for a high degree of flexibility in the design of the imaging system