DEVELOPMENT OF FAST-TIMING 3-D PHOTODETECTORS FOR PET

该方案的目标是开发一种用于正电子发射成像的新型成像探测器。一个基本的探测器模块将由一个平行管道的LSO闪烁体阵列组成，该阵列耦合到一个尺寸匹配的硅光探测器阵列，该阵列的元素提供了卓越的能量和定时分辨率。光电探测器将使用一种独特的新技术开发，即：三维硅加工。与其他固态探测器相比，这种方法将导致更低的电容、更高的量子效率和更快的载流子收集速度。使用这项技术，我们计划开发2x2cm2(8x8像素)成像模块，利用与新的三维光电探测器(3DP)阵列模块耦合的LSO模块对。新的探测器模块可以消除对昂贵的光电倍增管的需求，并允许电子设备与探测器集成，这将导致较低成本的PET系统。最初，这些设备将被优化用于小型动物PET成像仪。使用小动物和PET成像技术的癌症研究在过去几年中变得越来越重要，并继续成为研究癌症治疗新放射性药物有效性的重要研究工具。拟议的探测器开发计划将具体目标分为两个技术阶段。第一阶段：优化探测器结构，使电子的电子噪声、量子效率、快渡越时间达到目标性能；(2)制作8×8元素的3DP阵列原型；(3)评估探测器参数，包括电容、暗电流、噪声、量子效率、符合分辨时间、对各种放射性核素的光谱响应。这些目标将被用来衡量项目长期目标的可行性。第二阶段：(1)开发和建造一对优化的8 x 8像素LSO/SDP探测器模块和输入电子设备；(2)开发外壳、专门的处理和显示电子设备；以及(3)在加州大学洛杉矶分校医学院模拟临床条件下使用原型探测器系统评估符合成像。建议的商业应用：在第三阶段，我们将在第一阶段和第二阶段努力的基础上，将单探测器和多探测器模块商业化，用于小动物正电子发射成像的临床应用。这些新的探测器将取代目前在PET探测器系统中使用的昂贵的PMT探测器，并将降低总体成本。新的3D硅光电探测器只需要低成本的硅平面处理，并为信号电子与探测器的集成开辟了机会。这些探测器作为PET的PMT替代品有很大的需求和商业应用潜力。

The goal of this proposal is to develop a novel imaging detector for positron emission imaging. A basic detector module will consist of an array of parallel-piped LSO scintillators coupled to a size-matched silicon photodetector array whose elements provide superior energy and timing resolution. The photodetector will be developed using a unique new technology, namely: three-dimensional silicon processing. This approach will lead to lower capacitance, higher quantum efficiency and faster charge carrier collection compared with other solid-state detectors. Using this technology we plan to develop 2 x 2 cm2 (8 x 8 pixel) imaging modules utilizing pairs of LSO modules coupled to the new three- dimensional photodetector (3DP) array modules. The new detector modules could eliminate the need for expensive photomultiplier tubes and allow for integration of the electronics with the detector, which will lead to lower cost PET systems. Initially the devices would be optimized for use in small animal PET imagers. Cancer research using small animals and PET imaging techniques has grown in importance in the last few years and is continuing to become a significant research tool for investigating the efficacy of new radiopharmaceuticals for cancer therapy. The proposed detector development program has specific goals divided into two technical phases. Phase I: Design optimized detector structure leading to the targeted performance for electronic noise, quantum efficiency, fast transit time of electrons; (2) Fabricate prototype eight-by- eight element 3DP array; (3) Evaluate detector parameters including capacitance, dark current, noise, quantum efficiency, coincidence resolving time, spectral response to various radionuclides. These goals will be used to gauge the feasibility of the projects long-term aims. Phase II: (1) Develop and construct a pair of optimized 8 x 8 pixel LSO/SDP detector modules with input electronics; (2) Develop housing, specialized processing and display electronics; and (3) Evaluate coincidence imaging using prototype detector system under simulated clinical conditions at the UCLA School of Medicine. PROPOSED COMMERCIAL APPLICATIONS: In the third phase we will commercialize single and multiple detector modules based upon the Phase 1 and Phase 2 efforts, for clinical use in small animal positron emission imaging. These new detectors will replace the expensive PMT detectors currently used in PET detector systems and will reduce the overall cost. The new 3D silicon photodetector requires only low cost silicon planar processing and opens up the opportunity for integration of the signal electronics with the detector. There are large needs and potential for commercial uses for these detectors as PMT replacements for PET.