Zhixiang is interested in front-end and system-level design of high-performance molecular imaging instrumentation. Currently, he is working on the FPGA based readout system for ToF-PET scanners with 100 ps time resolution.

Stanford Advisors

All Publications

  • Scalable electronic readout design for a 100 ps coincidence time resolution TOF-PET system. Physics in medicine and biology Pourashraf, S. n., Gonzalez-Montoro, A. n., Won, J. Y., Lee, M. S., Cates, J. W., Zhao, Z. n., Lee, J. S., Levin, C. S. 2021


    We have developed a scalable detector readout design for a 100 ps coincidence time resolution (CTR) time of flight (TOF) positron emission tomography (PET) detector technology. The basic scintillation detectors studied in this paper are based on 2×4 arrays of 3×3×10 mm³ "fast- LGSO:Ce" scintillation crystals side- coupled to 6×4 arrays of 3×3 mm² silicon photomultipliers (SiPMs). We employed a novel mixed-signal front-end electronic configuration and a low timing jitter Field Programming Gate Array (FPGA)-based time to digital converter (TDC) for data acquisition. Using a 22 Na point source, >10,000 coincidence events were experimentally acquired for several SiPM bias voltages, leading edge time-pickoff thresholds, and timing channels. CTR of 102.03 ± 1.9 ps full-width-at-half-maximum (FWHM) was achieved using single 3×3×10 mm³ "fast- LGSO" crystal elements, wrapped in Teflon tape and side coupled to a linear array of 3 SiPMs. In addition, the measured average CTR was 113.4 ± 0.7 ps for the side- coupled 2×4 crystal array. The readout architecture presented in this work is designed to be scalable to large area module detectors with a goal to create the first TOF-PET system with 100 ps FWHM CTR.

    View details for DOI 10.1088/1361-6560/abf1bc

    View details for PubMedID 33761476