Exploring the Benefits of Time-of-Flight PET

描述(由申请人提供)：简单的理论预测，通过使用飞行时间(TOP)信息，PET研究中的成像时间或注射剂量可以减少大约一个数量级。这种减少可以通过提高符合时间分辨率来实现，因此可以在临床和全身研究中实现，使用与现有相机差别很小的PET系统。该方案的目的是在原型PET相机上实现尽可能好的时间分辨率，并通过实验验证性能改善，测量时间分辨率对性能改善的影响。这一发展的潜在影响是巨大的，特别是对大型患者的肿瘤学研究，那里迫切需要它。飞行时间PET在20世纪80年代的S被广泛研究，但在90年代的S去世，因为在不牺牲其他PET性能的情况下，不可能可靠地获得足够好的时间分辨率。最近技术的进步重新引起了人们对TOP PET的兴趣，但在过去十年中，PET的技术和医疗用途的变化意味着，TOP在现代临床PET中的真正好处还没有被很好地了解。通过将这些好处量化为时间分辨率的函数，我们将通过允许他们做出明智的选择来指导未来的商业和学术顶级PET相机设计人员。为了实现这一目标，我们将用LSO闪烁体晶体建造一台单环“演示”PET相机，实现300ps符合时间分辨率。这是比任何基于LSO的PET相机更好的时间分辨率的两倍，简单的估计预测，它将把全身成像中的噪声方差降低8倍。在临床上，这种方差减少可以减少图像噪声，减少注射剂量，缩短成像时间，或者提供这些好处的组合。我们将结合模拟、体模和人体受试者研究，包括临床相关的肿瘤检测和分期任务，将噪声改善量化为时间分辨率的函数。然后，我们将使用新开发的闪烁体(Lul3：Ce)重建相机，该闪烁体具有出色的PET性能(高灵敏度、3%的能量分辨率和125ps的计时分辨率)，并重复这些测量。这种计时分辨率比以往建造或提出的任何顶级相机都要好三倍以上，预计将极大地(18倍)减少噪音差异。

DESCRIPTION (provided by applicant): Simple theory predicts that the imaging time or injected dose in a PET study can be reduced by roughly an order of magnitude by using time-of-flight (TOP) information. This reduction can be obtained by improving the coincidence timing resolution, and so would be achievable in clinical, whole body studies using with PET systems that differ little from existing cameras. The purpose of this proposal is to realize the best possible timing resolution in a prototype PET camera and verify the performance improvement experimentally, measuring how the improvement depends on the timing resolution. The potential impact of this development is large, especially for oncology studies in large patients, where it is sorely needed. Time-of-flight PET was extensively studied in the 1980's but died in the 1990's, as it was impossible to reliably achieve sufficiently good timing resolution without sacrificing other PET performance aspects. Recent improvements in technology have renewed interest in TOP PET, but changes in the last decade in both technology and the medical uses for PET mean that the true benefits of TOP in modern clinical PET are not well understood. By quantifying these benefits as a function of timing resolution, we will guide future commercial and academic TOP PET camera designers by allowing them to make informed choices. To realize this goal, we will construct a single ring "demonstration" PET camera with LSO scintillator crystals that achieves 300 ps coincidence timing resolution. This is a factor of two better timing resolution than any LSO-based PET camera ever constructed or currently proposed, and the simple estimates predict that it would reduce the noise variance by a factor of 8 in whole body imaging. Clinically, this variance reduction could reduce image noise, decrease the injected dose, shorten the imaging time, or provide a combination of these benefits. We will quantify the improvement in noise as a function of timing resolution using a combination of simulation, phantom, and human subject studies, including the clinically relevant tasks of tumor detection and staging. We will then rebuild the camera with a newly developed scintillator (Lul3:Ce) that has exceptional PET performance (high sensitivity, 3% energy resolution, and 125 ps timing resolution) and repeat these measurements. This timing resolution is over three times better than any TOP camera ever built or proposed, and is predicted to give an enormous (18-fold) noise variance reduction.