Instrumentation for microSPECT and microPET imaging

国家癌症研究所的分子成像计划（MIP）负责 开发针对与发展相关的途径的化学探针的任务， 癌症的生长和治疗。放射性核素标记的化合物是此类化合物的重要子集。 剂.成功开发的放射性核素标记化合物提供了最终的前景， 用于医学诊断和管理的人体受试者PET、SPECT和平面成像 目的，以及在基础科学中同样强大的应用，当用于探针验证时， 小实验动物MIP放射性核素仪器组支持这一基本的 科学使命，探索和实施新的放射性核素成像技术， 改善或提高MIP小动物成像的状态。联合国开发计划署开展的开发工作 RIG及其（基本）合作者基于以下概念： 定向勘探， 机会在研究层面进行了审查（面板A，图1），但有一个特定的 系统级目标（面板B，图1）。图1. (A)：成像研究领域 系统开发：（B）：当前重点系统级开发项目：双伽马照相机 单光子高速动态全身平面投影成像系统 在小鼠中的生物分布研究。为了说明这种并行性，现在正在进行以下工作： 图1A中所示的每个区域中的RIG：LaBr 3板和NaI（Tl）像素化探测器模块 和支持电子开发（CIT-NIH/RIG）;评估新的模块化DAQ系统 （托马斯杰斐逊国家加速器设施（JLAB），纽波特纽斯，VA/RIG）;创建一个 使用质心事件定位和高级 最大似然（ML）定位（RIG/CIT）;以及商用系统（核 Mac）进行图像显示和分析（RIG/CIT）。对每个子系统项目进行评估 根据创建双平面伽马照相机设备的当前系统级目标， 成像小鼠，同时提供每个技术领域的信息， 在我们的下一个系统级开发项目中使用。例如，其中一个检测器模块 (M1或图1B中的M2）将由矩形像素化NaI（Tl）阵列组成， 两个并排的HamamatsuH 8500位置敏感光电倍增管（PSPMT，图A， 图2）。需要使用该组合获得的初始成像结果（图B，图2） 充分利用JLAB DAQ、CIT开发的电子和RIG开发的数据处理软件 获取和分析这些数据。图2. (A)：NaI（Tl）探测器模块， 支持电子设备（CIT/RIG）;（B）：来自该19 x 42（43 mm）的早期511 keV场泛光图像 x 94 mm）像素模块。请注意，两个图像之间的差距中有2 mm x 2 mm像素的清晰标识。 两个并排的PSPMT一个定制的准直器已被设计为这个阵列，其中每个 像素具有其自己的单独准直器孔。我们计划继续这项探索性工作， 将完成的双伽马相机系统交给MIP科学家的目标， 通过审查累积的技术调查结果和指定下一个系统级项目。

The Molecular Imaging Program (MIP) of the National Cancer Institute is charged with the task of developing chemical probes specific to pathways associated with the development, growth and treatment of cancer. Radionuclide-labeled compounds are an important subset of such agents. Successfully developed radionuclide-labeled compounds offer the ultimate prospect of PET, SPECT and planar imaging in human subjects for medical diagnostic and management purposes, and equally powerful applications in basic science when used for probe validation in small laboratory animals. The MIP radionuclide instrumentation group supports this basic science mission by exploring and implementing new radionuclide imaging technologies that improve or advance the state of MIP small animal imaging. Development work carried out by the RIG and its (essential) collaborators is based on the notion of directed exploration where technological opportunities are examined at the research level (panel A, Figure 1) but with a particular systems level goal in mind (panel B, Figure 1). Figure 1. (A): Research areas in imaging system development: (B): current focused systems level development project: dual gamma camera planar projection imaging system for single photon, high-speed dynamic whole body bio-distribution studies in mice. To illustrate this parallelism, work is now underway in the RIG in each of the areas shown in Figure 1A: LaBr3 slab and NaI(Tl) pixelated detector modules and support electronics development (CIT-NIH/RIG); evaluation of a new, modular DAQ system (Thomas Jefferson National Accelerator Facility (JLAB), Newport News, VA/RIG); creation of a high speed data processing interface using both centroid event positioning and advanced Maximum Likelihood (ML) positioning (RIG/CIT); and evaluation of a commercial system (Nuclear Mac) for image display and analysis (RIG/CIT). Each of these sub-system projects are evaluated in light of the current systems level goal of creating a dual planar gamma camera device for imaging mice while at the same time providing information in each technical area for potential use in our next systems level development project. For example, one of the detector modules (M1 or M2 in Figure 1B) will be comprised of a rectangular pixelated NaI(Tl) array coupled to two side-by-side Hamamatsu H8500 position-sensitive photomultiplier tubes (PSPMTs, panel A, Figure2). Initial imaging results obtained with this combination (panel B, Figure 2) required full use of the JLAB DAQ, CIT developed electronics and RIG-developed data processing software for acquisition and analysis of these data. Figure 2. (A): NaI(Tl) detector module and supporting electronics (CIT/RIG); (B): early 511 keV field flood image from this 19 x 42 (43mm x 94 mm) pixel module. Note clear identification of the 2 mm x 2 mm pixels in the gap between the two side-by-side PSPMTs. A custom collimator has been designed for this array where each pixel has its own individual collimator hole. We plan to continue this exploratory work with the goal of turning over the completed dual gamma camera system to MIP scientists , followed by a review of accrued technical findings and designation of the next systems level project.