TOF PET detectors employing stripline based readout and MVT digitizer

Recently, we have developed a stripline (SL) readout method and a multi-voltage threshold (MVT) digitizer for PET. The SL readout is a multiplexing method for reading multiple input signals that is easy to implement and can support time-of-flight (TOF) detection. The MVT methods digitally samples a PET signal pulse with respect to a number of voltage thresholds and can be implemented by using the field programmable gate array(FPGA). The use of these two methods can greatly simplify the electronic complexity of a TOF PET detector. In this paper, we investigate the performance properties of the SL readout when applied to different numbers of silicon photomultipliers (SiPM) from SensL. Outputs of the SL readout are acquired by using a 72-ch FPGA MVT board. Our results show that up to 36 pixels per SL can be discriminated, a pixel energy resolution of 11-21% can be obtained, and a coincidence resolving time (CRT) of 520 ps can be achieved. Previously, we obtained 320ps CRT when applied the MVT to a single pixel made of LYSO and SiPM. Therefore, we believe the CRT can be further improved after optimization.