Time of flight measurements based on FPGA and SiPMs for PET-MR

摘要

Coincidence time measurements with SiPMs have shown to be suitable for PET/MR systems. The present study is based on 3 × 3 mm~2 SiPMs, LSO crystals and a conditioning signal electronic circuit. A Constant Fraction Discriminator (CFD) is used to digitalize the signals and a TDC FPGA-implemented is employed for fine time measurements. TDC capability allows processing the arrival of multiple events simultaneously, measuring times under 100 ps. The complete set-up for time measurements results on a resolution of 892 ± 41 ps for a pair of detectors. The details of such implementation are exposed and the trade-offs of each configuration are discussed.