Toward a Full-Flexible and Fast-Prototyping TOF-PET Block Detector Based on TDC-on-FPGA
Toward a Full-Flexible and Fast-Prototyping TOF-PET Block Detector Based on TDC-on-FPGA
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DOI：
10.1109/trpms.2018.2874358
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发表时间：
2019-09
影响因子：
4.4
通讯作者：
E. Venialgo;N. Lusardi;F. Garzetti;Angelo Geraci;S. Brunner;D. Schaart;E. Charbon
中科院分区：
文献类型：
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作者：
E. Venialgo;N. Lusardi;F. Garzetti;Angelo Geraci;S. Brunner;D. Schaart;E. Charbon
通常，飞行时间（TOF）正电子发射断层摄影（PET）块检测器使用专用集成电路（ASIC）构建，因为它们以合理的功耗将大量通道集成到小面积中。然而，ASIC的灵活性是有限的，原型设计时间很长，因为在每次设计迭代中都需要半导体制造工艺。或者，快速终端（FT）硅光电倍增管（SiPM）需要一个简化的模拟前端，以实现TOF精度。此外，现场可编程门阵列（FPGA）可以分配时间数字转换器以及复杂的数字读出逻辑。在本文中，我们提出了基于FPGA，FT-SiPM和最小数量的现成组件构建TOF-PET块检测器。通过这种方式，TOF-PET精度可通过完全灵活的快速原型解决方案实现。我们评估了符合解决时间，性能退化，由于通道复用，能量分辨率，和闪烁体像素编码性能的SiPM阵列利用所提出的方法。实验结果表明，最小的定时退化，复用FT时。此外，模拟结果表明，在典型的脑PET放射性剂量的多路复用通道的单计数率的低减少。
Typically, a time-of-flight (TOF) positron emission tomography (PET) block detector is built using application-specific integrated circuits (ASICs), since they integrate a high number of channels at a reasonable power consumption and into a small area. However, ASICs’ flexibility is limited and prototyping times are long because a semiconductor fabrication process is required in every design iteration. Alternatively, fast terminal (FT) silicon photomultipliers (SiPMs) require a simplified analog front-end in order to achieve TOF accuracy. In addition, field-programmable gate arrays (FPGAs) can allocate time-to-digital converters as well as complex digital readout logics. In this paper, we propose building TOF-PET block detectors based on FPGAs, FT-SiPMs, and minimal amount of off-the-shelf components. In this way, TOF-PET accuracy is achieved with a full-flexible and fast prototyping solution. We evaluated the coincidence resolving time, performance degradations due to channel multiplexing, energy resolution, and scintillator pixel encoding performance of SiPM arrays utilizing the proposed approach. Experimental results show minimal timing degradations, when multiplexing FTs. Moreover, simulation results show a low reduction in the singles count rate of multiplexed channels at typical brain-PET radioactive doses.