A Trapezoidal, Slat Crystal PET Detector for Multimodality PET Imaging

描述(由申请人提供)：本提案的主要目标是开发一种高分辨率、高检测效率的正电子发射断层扫描(PET)探测器，其具有相互作用深度(DOI)定位，还将支持多模式成像(例如，PET/MR)。这种探测器的设计可以扩展，以支持从老鼠到人的成像应用。这种PET探测器的主要设计特点是使用梯形盐晶(TSC)和最大似然定位方法，我们称之为基于统计的定位(SBP)。除了独特的晶体几何结构外，该设计还将使用硅光电倍增管(SiPM)阵列。SiPM是盖革模式雪崩光电二极管器件，对于PET探测器，特别是在PET-MR应用中，具有非常吸引人的性能特性。在这份R21提案中，我们将研究为小动物PET成像量身定做的设计。该设计将支持&lt；0.8 mm图像分辨率和&gt；15%的绝对探测效率。可以预见，根据该方案开发的探测器最终将用于制造非常紧凑的PET探测器环，该探测器环将与高场(例如，&GT；4.7T)MR系统中的操作兼容。在这项原型工作中，TSC PET探测器的尺寸将设计为系统内环直径约6.0 cm。该直径将支持专用的PET和PET/MR全身小鼠和大鼠脑成像。这项工作的最终结果是开发和评估一种新的PET探测器设计，该设计将提供最先进的成像性能，并可用作紧凑型独立PET系统的一部分，或用作多模式成像系统(例如，PET/MR)的一部分。我们相信，这一设计将在性能和成本之间取得突出的平衡，并且该设计将可转化为商业改编。这一建议建立在研究人员开发高分辨率离散晶体PET探测器和高分辨率单晶PET探测器的先前工作的基础上。这种新的设计协同地结合了这两种方法的固有优势，即模块化和出色的空间分辨率控制(离散晶体)和较低的制造成本 以及使用单面读出(连续晶体)的固有DOI定位能力。该设计可扩展以支持超高分辨率小动物成像、高分辨率器官特定成像和全身PET成像。此外，该项目还将增加有关如何优化SiPM设备用于核医学成像探测器应用的知识。这项工作的两个具体领域是开发SiPM信号多路复用技术以优化性能与成本，以及开发SiPM器件的温度控制策略和依赖于温度/增益的校准程序。 与公众健康相关：这项提案的总体目标是开发将用于促进PET和多模式PET成像的生物应用的技术。对于临床和研究应用(例如，肿瘤学、心脏病学、神经病学、药物开发、生物分布研究、细胞贩运等)，PET都是一种非常重要的成像方式。当它与高分辨率的解剖成像方式(例如，PET/CT或PET/MR)相结合时，显示出更大的协同作用。任何PET系统的关键部件都是探测器的设计。在这个方案中，我们介绍了一种新的梯形板条晶体(TSC)PET探测器，它可以在小动物成像和人类全身成像之间进行缩放。我们相信，这种设计将提供最先进的成像性能和经济的价格点，使设计将可转化为商业生产。因此，虽然这项建议的重点是具体的PET探测器设计，但这项工作的深远目标 是开发PET成像技术，这将有助于与人类疾病的斗争。

DESCRIPTION (provided by applicant): The principle objective of this proposal is to develop a high resolution, high detection efficiency positron emission tomography (PET) detector with depth-of-interaction (DOI) positioning that will also support multi-modality imaging (e.g., PET/MR). This detector design can be scaled to support imaging applications from mice to man. The key design features of this PET detector are the use of trapezoidal, salt crystals (TSC) and a maximum likelihood positioning method that we call statistics based positioning (SBP). In addition to the unique crystal geometry, the design will utilize silicon photomultiplier (SiPM) arrays. SiPMs are Geiger-mode avalanche photodiode devices that have very attractive performance characteristics for PET detectors, especially for PET-MR applications. In this R21 proposal, we will investigate a design tailored for small animal PET imaging. The design will support <0.8 mm image resolution and >15% absolute detection efficiency. It is envisioned that the detectors developed under this proposal will eventually be used to fabricate a very compact PET detector ring that will be compatible with operation in high field (e.g., >4.7T) MR systems. For this prototype work the TSC PET detector dimensions will be designed for a system inner ring diameter of ~6.0 cm. This diameter will support dedicated PET and PET/MR whole body mouse and rat brain imaging. The net result of this work is the development and evaluation of a new PET detector design that will provide state of the art imaging performance capabilities and that can be used as part of a compact, stand alone PET system or as part of a multi-modality imaging system (e.g., PET/MR). We believe that this design will provide an outstanding balance between performance and cost and that the design will be translatable to commercial adaptation. This proposal builds upon the previous work of the investigators developing high resolution discrete crystal PET detectors and high resolution monolithic crystal PET detectors. This new design synergistically brings together the inherent strengths of both methods, that is, modularity and excellent spatial resolution control (discrete crystals) and lower fabrication costs and inherent DOI positioning capability using single-sided readout (continuous crystals). The design is scalable to support ultra-high resolution small animal imaging; high resolution organ specific imaging; and whole-body PET imaging. In addition, this project will add to the knowledge based on how to optimize the use of SiPM devices for nuclear medicine imaging detector applications. Two specific areas in which this work will contribute are developing SiPM signal multiplexing techniques to optimize performance versus cost and developing temperature control strategies and temperature/gain dependent calibration procedures for SiPM devices. PUBLIC HEALTH RELEVANCE: The overall goal of this proposal is to develop technology that will be used to advance the biological applications of PET and multi-modality PET imaging. PET is a very important imaging modality for both clinical and research applications (e.g., oncology, cardiology, neurology, drug development, biodistribution studies, cell trafficking, etc.). Further great synergism has been demonstrated when it is combined with a high resolution anatomic imaging modality (e.g., PET/CT or PET/MR). The key component of any PET system is the detector design. In this proposal, we introduce a new trapezoidal, slat crystal (TSC) PET detector that is scalable between small animal imaging and human whole body imaging. We believe that this design will provide state of the art imaging performance and an economical price point such that the design will be translatable to commercial production. Therefore while the focus of this proposal is on a specific PET detector design, the far reaching goal of this work is to develop PET imaging technology that will aid in the battle against human disease.