High Timing Resolution Detector Module for Time-of-Flight PET

描述（由申请人提供）：全身正电子发射断层扫描（PET）成像已成为准确确定许多器官系统原发性和转移性癌性病变状态的重要诊断工具。然而，目前的临床PET扫描仪已经接近灵敏度的极限。越来越需要提高PET中的信噪比，这将导致更好的病变检测、更短的成像时间和/或更低的注射剂量。可以通过改进在探测来自PET中的正电子湮灭的两个背靠背511 keV光子时的符合定时分辨率来获得该改进，使得可以将飞行时间信息结合到图像重建中。飞行时间PET（TOF PET）是唯一已知的能够显著降低噪声水平的方法。该项目的目标是开发一种实用的探测器模块，具有比目前可用的上级定时分辨率，而不影响其在TOF PET中应用的探测511 keV光子的效率。在探测器模块的开发中的关键改进包括用于TOF PET的适当闪烁体材料（LSO）、作为光电探测器的多阳极微通道板光电倍增管（MCP PMT）技术以及闪烁体晶体阵列与多阳极MCP PMT的一对一耦合。虽然具有比LSO更高的光输出和稍微更快的衰减时间的新的掺铈卤化物闪烁体材料（LaBr 3）可能是在检测器模块中产生更好的定时分辨率的闪烁体材料的更好选择，但是其具有比LSO低得多的阻止功率和光电分数，这降低了检测器模块的效率。此外，我们建议开发的探测器技术可以应用于目前正在研究或将来将发现的具有TOF PET突出潜力的其他闪烁体材料。拟议的探测器模块的可行性将通过设计，施工，优化和性能评估的阶段进行彻底的特点。探测器模块的贡献也将通过计算机模拟建模，并通过实验测量进行验证。由此产生的探测器模块，预计将提供出色的定时性能，提高下一代PET扫描仪的成像性能，使TOF。

DESCRIPTION (provided by applicant): Whole-body positron emission tomography (PET) imaging has become an important diagnostic tool for accurately determining the status of primary and metastatic cancerous lesions of many organ systems. However, current clinical PET scanners have approached the limit of sensitivity. There is an increasing need to improve the signal-to-noise ratio in PET, which will lead to better lesion detection, shorter imaging time, and/or lower injected dose. The improvement can be obtained by improving the coincidence timing resolution in the detection of the two back-to-back 511 keV photons from the positron annihilation in PET so that time-of-flight information can be incorporated into the image reconstruction. Time-of-flight PET (TOF PET) holds the only known potential for a significant reduction in the noise levels. The goal of this project is to develop a practical detector module with superior timing resolution than currently available, without compromising its efficiency for detecting 511 keV photons for application in TOF PET. Critical improvements in the development of the detector module include an appropriate scintillator material (LSO) for TOF PET, a multi-anode microchannel plate photomultiplier tube (MCP PMT) technology as the photodetector, and one-to-one coupling of an array of scintillator crystals to the multi-anode MCP PMT. Although the new cerium-doped halide scintillator material (LaBr3) with higher light output and slightly faster decay time than LSO might be a better choice of scintillator material to produce better timing resolution in the detector module, it has much lower stopping power and photoelectric fraction than LSO, which degrades the efficiency of the detector module. Furthermore, the detector technology we propose to develop can be applied to other scintillator materials with outstanding potential for TOF PET that are being currently investigated or will be discovered in the future. The feasibility of the proposed detector module will be thoroughly characterized through the phases of design, construction, optimization, and performance evaluation. The contribution of the detector module will also be modeled through computer simulation and validated by the experimental measurement. The resulting detector module is expected to provide the excellent timing properties needed for improving the imaging performance of next generation PET scanners by enabling TOF.