DEVELOPMENT OF AN ULTRA HIGH COUNT RATE GAMMA CAMERA

描述（改编自申请人摘要）：本项目的目标 是发展技术来提高伽马射线的成像能力 用于平面、SPECT和PET应用的相机。 虽然目前伽马相机 足以成像低诊断剂量的单光子示踪剂， 由于NaI（Tl）探测器中的信号堆积， 伽马辐照时会产生图像伪影、计数损失和图像质量降低 flux很高。 这些情况包括（a）正电子示踪剂成像， 需要注射剂量减少80-90%以避免堆积，（B） 无法成像的用于剂量测定的高剂量放射性核素治疗 由于缺乏快速照相机，（c）动态首过心脏成像， (d)使用寿命很短的示踪剂来减少辐射剂量， 增加病人的吞吐量，以及（e）使用更大的NaI（Tl）探测器， 减少全身扫描时间。 该项目建议开发一个堆积 一种用于伽马照相机的电子防护方法（PPE）， 将最大计数率提高25-50倍。 具体目标是 建议是（一）优化建议的PPE电子设备;（二）建立一个 移动的实验摄像平台。 这将有助于发展 电子设备，并允许在未来测试人类的应用程序;（三） 为了在实验相机平台上开发两个PPE实现， 单区域和多区域。 第二种设计将摄像头拆分为4个 带4个PPE电路的区域，以进一步提高计数率。 (IV)到 评价伽马照相机的成像性能，作为以下函数： 计数率在幻影。 该项目可能允许较低成本的伽马相机， 成像正电子示踪剂没有专用的250万美元的PET相机， 比目前的伽马相机适应性有很大改进的图像质量， 可以注射10倍更高的剂量。 放射性核素治疗直接显像 (RNT)将允许更准确的剂量计算，并改善 了解RNT。 它还允许同时获取 通过一个摄像头和双同位素传输和发射数据， 定量SPECT，衰减校正误差较小。

DESCRIPTION (Adapted from Applicant's Abstract): The goal of this project is to develop the technology to improve the imaging capability of gamma cameras for planar, SPECT and PET application. While present gamma cameras are adequate for imaging low diagnostic doses of single-photon tracers, their low count-rate capability due to signal pileup in the NaI(Tl) detector produces image artifacts, count loss, and lower image quality when gamma flux is high. These situations include (a) positron tracer imaging, which requires an 80-90% reduction in injected dose to avoid pileups, (b) high-dose radionuclide therapy for dosimetry, which can not be imaged because of the lack of fast cameras, (c) dynamic first-pass cardiac imaging, (d) the use of very short-lived tracers to reduce radiation dose and increase patient throughput, and (e) the use of larger NaI(Tl) detectors to reduce whole-body scanning time. This project proposes developing a pileup prevention electronic method (PPE) for use on gamma cameras, which may increase the maximum count rates by 25-50 times. The specific aims of this proposal are (I) to optimize the proposed PPE electronics; (II) to build a mobile experimental camera platform. It would facilitate the development of the electronics and allow testing of human applications in the future; (III) to develop two PPE implementations on the experimental camera platform, a single-zone and a multi-zone. The second design splits the camera into 4 zones with 4 PPE circuits to increase the count-rates even more. (IV) to evaluate the imaging performance of the gamma camera as a function of count-rates in phantoms. This project may allow lower cost gamma cameras to image positron tracers without a dedicated $2.5 million PET camera, and with a much improved image quality over the present gamma camera adaptation since a 10x higher dose may be injected. Direct imaging of radionuclide therapy (RNT) would allow more accurate dosimetry calculations and improve the understanding of RNT. It would also allow simultaneous acquisition of transmission and emission data with one camera head and dual isotopes for quantitative SPECT, with less errors in attenuation correction.