A Novel High-Performance Detector Module for Time-of-Flight PET

项目摘要/摘要 这个项目的目标是开发一种新的探测器技术，它可以产生显著的 临床飞行时间正电子发射断层扫描(TOF PET)扫描仪的改进 符合时间分辨率(CTR)的PET探测器模块。改进CTR在TOF PET中的主要好处 扫描仪允许飞行时间信息被合并到飞行时间重建中，导致 信噪比(SNR)有了很大的提高。在过去十年中使用 物理模体和临床研究都表明，这种改进可以用来改善 PET的成像性能，通过提高病变检测能力、减少扫描时间或 注射剂量，以及更准确和精确的肿瘤摄取测量。TOF-PET的临床应用价值 已经被清楚地证明了，但TOF PET的最终好处还没有实现，因为 目前商用的TOF PET扫描仪的CTR仍然限制在400-500ps FWHm左右。所有商用PET 探测器模块仅从晶体的一端读出闪烁光(即，单端读出)， 当应用于使用长效晶体的实际系统时，它有两个严重的限制：1)它们不 测量相互作用深度(DOI)，无法补偿湮灭和光学光子的变化 中转时间；以及2)空间分辨率有限，因为它们不能补偿视差误差 从成像场的中心。所提出的使用双端读出的探测器技术克服了 通过校正所有与深度相关的影响并使用更好的统计方法 估计到达时间。结果，CTR和DOI可以得到显著改善 决议。这个项目的动机是基于我们最近的模拟研究，这些研究表明，阅读 采用高性能硅的晶体两端闪烁光(即双端读出) 光电倍增管(SiPM)光电探测器将为TOF PET带来前所未有的CTR探测器模块 申请。我们希望在SNR方面实现至少两倍的改善，这相当于 灵敏度提高了四倍。我们将通过组合高级FAST来实现这一目标 闪烁体材料、高性能SiPM光电探测器、高性能读出电子设备和 基于逆方差加权平均的算法，给出了一种创新的时间分辨率 双端读出探测器模块。这项提议的结果将是高性能的TOF PET 时间分辨率大幅提高的探测器模块，这是证明 下一代临床TOF PET扫描仪的开发。

Project Summary/Abstract The objective of this project is to develop a novel detector technology that can yield significant improvements in clinical time-of-flight positron emission tomography (TOF PET) scanners by improving the coincidence time resolution (CTR) of PET detector modules. The main benefit of improved CTR in TOF PET scanners is allowing time-of-flight information to be incorporated into the time-of-flight reconstruction, leading to a large improvement in the signal-to-noise ratio (SNR). Investigations performed over the last decade using both physical phantoms and clinical studies have shown that this improvement can be used to improve the imaging performance of PET, through a combination of improved lesion detectability, reduced scan time or injected dose, and more accurate and precise tumor uptake measurements. The clinical benefits of TOF PET have been clearly demonstrated, but the ultimate benefits of TOF PET have yet to be realized because the CTR of current commercial TOF PET scanners is still limited to about 400–500 ps fwhm. All commercial PET detector modules read out the scintillation light from only one end of the crystal (i.e., single-ended readout), which has two serious limitations when applied to practical system using long efficient crystals: 1) they do not measure depth-of-interaction (DOI) and cannot compensate for variations in annihilation and optical photon transit times; and 2) the spatial resolution is limited because they do not compensate for parallax error away from the center of the imaging field. The proposed detector technology using dual-ended readout overcomes both of these limitations by correcting for all depth-dependent effects and using a better statistical approach in estimating the arrival time. As a result, significant improvement can be achieved in the CTR and DOI resolution. The motivation for this project is based on our recent simulation studies that show that reading the scintillation light from both ends of the crystal (i.e., dual-ended readout) with high-performance silicon photomultiplier (SiPM) photodetectors will lead to detector modules with unprecedented CTR for TOF PET applications. We expect to achieve at least a factor of two improvement in the SNR, which corresponds to a factor of four improvement in the sensitivity. We will accomplish this through a combination of advanced fast scintillator materials, high-performance SiPM photodetectors, high-performance readout electronics, and an algorithm based on the inverse variance weighted average to give the best time resolution in an innovative dual-ended readout detector module. The outcome of this proposal will be high-performance TOF PET detector modules with a dramatic improvement in the time resolution, which is needed to justify the development of the next generation of clinical TOF PET scanners.