基于CMOS技术的多通道TOF-PET脉冲时间信息数字化单芯片系统研究

基于CMOS技术的脉冲数字处理系统是全数字TOF- PET最有潜力的方案。精确获取脉冲时间信息是提高成像质量的关键。闪烁脉冲上升/衰减时间仅为纳秒量级，先整形再经ADC的处理方式结构复杂,限制了皮秒量级时间信息的精确获取，制约了成像质量。 基于精确测量脉冲时间信息的多电压阈值法（MVT）不使用ADC，系统架构大幅简化，直接处理脉冲就可获得优异的时间和能量信息。本项目研究基于CMOS技术采用MVT方法精确获取TOF-PET脉冲时间信息的方案，解决其中皮秒级精确触发、时间信息高分辨率数字化及系统自校准等关键问题，探索基于CMOS技术实现多通道TOF-PET脉冲时间信息数字化单芯片系统的方案。 研究成果可以为实现多通道TOF-PET脉冲大规模集成全数字处理系统奠定方法和技术基础，进一步提高TOF-PET的成像分辨率，推动生命科学和临床医学中PET成像技术的发展。

CMOS based pulse digital processing is the most feasible solution for all digital TOF-PET imaging system. High-speed precise digitization of timing information is the key aspect to improve image quality. Considering the rising/fading edge of the scintillation pulses is in the range of nano-second, traditional complex digitization methods involving pulse shaping and ADC sampling limit the timing and reduce image quality. Based on accurate acquisition of timing information, Multi-threshold voltage (MVT) method employs a simple, non-ADC architecture, which directly extracts timing and energy information of the scintillation-pulses with very high resolution. This project will focus on CMOS based MVT solutions for the direct-digitization of the timing information of the TOF-PET pulses. Pico-second accuracy trigger method, high resolution timing information digitization and system offset self-calibration will be studied in detail. This project will also explore the scheme for constructing a high timing resolution integrated system of TOF-PET scintillation-pulse digital processing. Research findings can serve as the basis to realize a very large scale multichannel TOF-PET pulses digital processing system. It can not only further improve the image quality of TOF-PET system, but also contributes to the developing of PET medical imageology in biological science and clinical studies.