An Inexpensive High Resolution PET Detector Development

描述（申请人提供）：正电子发射断层扫描（PET）独特的体内分子成像能力可用于加强癌症基因表达/治疗研究和药物开发研究，并通过定位人体小肿瘤来提高临床诊断，从而提高分期和治疗计划的准确性。我们项目的长期目标是降低成本，提高PET的成像性能。PET相机的检测系统决定了其成像质量和成本。提出了继续发展高分辨率、低成本PET检测器的设计理念和高速电子器件。在上一个资助期内，提出并研究了一种廉价的高分辨率PET探测器概念（PQS）。在该研究中，PQS探测器的概念被证明在技术上和实践上是可以实现的，使用传统的BGO闪烁探测器。我们建议使用更新更快的LSO和GSO闪烁晶体进一步发展PQS方法，这可以进一步显著提高PET分辨率和成本效益。本课题的具体目的是：(1)研究LSO和GSO在PQS设计中的应用。LSO/GSO更高的光输出可以很好地为人类和小鼠应用带来1-2毫米的超高PET分辨率。开发LSO-PQS和GSO-PQS原型探测器；(2)研究开发一种新型高效的探测器生产方法，可将超高分辨率PET昂贵的探测器生产劳动力降低90%。(3)开发一种快速自动PET探测器调谐方法，该方法可以在不到5分钟的时间内平衡PET中所有光电倍增管（1000个）的放大倍数，而不是1-4小时，因此PET可以在患者加载期间进行调谐，从而在扫描患者之前最大化PET成像性能。该方法避开了传统的外部辐射源，(4)开发了一种实用的方法(a)测量PQS探测系统中每个检测到的伽马射线的相互作用深度，(b)在没有机械运动的情况下加倍空间数据采样。(5)将上一阶段开发的高速防堆电子器件应用于快速LSO/GSO PQS探测器，进一步提高了这些探测器的高辐射水平成像能力。

DESCRIPTION (provided by applicant): Positron emission tomography's (PET'S) unique in vivo molecular imaging ability can be deployed to enhance research on gene expression/therapy for cancer and drug development research, and it improves clinical diagnosis by localizing small tumors in human, thus improving the accuracy of staging and treatment planning. The long-term objective of our project is to lower the cost and improve the imaging performance of PET. The detection system of a PET camera dictates its image quality and cost. Continued development of our high resolution, lower cost PET detector design concept and high-speed electronics is proposed. In the last funding period, an inexpensive high-resolution PET detector concept (PQS) was proposed and studied. In that study, the PQS detector concept was demonstrated to be technically and practically achievable using traditional BGO scintillation detectors. We propose to further develop the PQS approach with the newer and faster scintillation crystals of LSO and GSO, which can further improve PET resolution significantly and cost-effectively. The specific aims of the project are: (1) To study the application of LSO and GSO to the PQS design. The much higher light output of LSO/GSO could well lead to ultrahigh PET resolution of 1-2 mm for human and mouse applications. Prototype LSO-PQS and GSO-PQS detectors will be developed, (2) To study and develop a new, highly efficient detector-production method that can lower the costly detector-production labor of ultrahigh resolution PET by 90%. This method reduces the processing of 160,000 small detectors to 1000 much larger units, (3) To develop a fast automatic PET detector-tuning method that can equalize the amplifications of all the photomultipliers (1 000) in a PET in less than 5 minutes instead of 1-4 hrs, so that a PET can be tuned during patient loading to maximize PET imaging performance before scanning a patient. This method shuns the conventional external radiation sources, (4) To develop a practical method of (a) measuring the depth-of-interaction for each detected gamma ray in a PQS detection system and (b) doubling the spatial-data sampling without mechanical motion. It utilizes a 2-layer offset detector design to further improve the image resolution of a PET, (5 ) To adapt the high-speed-pileup-prevention electronics developed in the last period to the fast LSO/GSO PQS detectors to further enhance the high radiation level imaging capability of these detectors. This electronics can eliminate image artifacts due to detector signal-pileups and shorten patient scan time.