Instrumentation for microSPECT and microPET imaging

2008年，作为迈向新型平板微型PET设备的第一步，核相机团队生产了一种新的用于鼠标成像的双平板投影成像设备。它由两个平板探测器并排组成，能够在便携式设备上快速获得老鼠的投影图像。该系统现已投入使用，并计划进一步开发能够进行明天成像的设备。2010年，开始利用第一个设备，代号为MONICA的移动核成像相机，成为使用两个平行探测器(而不是并排)的低成本投影microPET。该设计结合了两个平板之间的符合扫描，但也有相互作用深度(DOI)测量的能力，允许一些断层成像功能。同样在2010年，将该设备改装成投影microPET MR兼容设备的工作也开始了。测试正在进行中，以确定新晶体承受强磁场影响的能力。Nucelar相机小组及其(基本)合作者开展的开发工作基于定向探索的概念，在研究层面上审查技术机会，但铭记特定的系统层面目标：(A)：成像系统开发方面的研究领域：(B)目前聚焦系统层面的开发项目：用于单光子、高速动态全身生物分布研究的双伽马相机平面投影成像系统。为了说明这种并行性，目前正在LaBr3板材和NaI(Tl)像素化探测器模块和支持电子设备开发(CIT-NIH/RIG)所示的每个领域开展工作；评估新的模块化DAQ系统(托马斯·杰斐逊国家加速器设施(JLAB)，纽波特新闻，弗吉尼亚州/RIG)；使用质心事件定位和高级最大似然(ML)定位创建高速数据处理接口(RIG/CIT)；以及评价用于图像显示和分析的商业系统(RIG/CIT)。这些子系统项目中的每一个都是根据目前的系统级目标进行评估的，即创造一种为老鼠成像的双平面伽马相机设备，同时提供每个技术领域的信息，供我们下一个系统级开发项目使用。例如，其中一个探测器模块将由一个矩形像素化NaI(TL)阵列组成，该阵列耦合到两个并排的Hamamatsu H8500位置灵敏光电倍增管。通过这种组合获得的初始成像结果需要充分利用JLAB DAQ、CIT开发的电子设备和Rig开发的数据处理软件来采集和分析这些数据。因此，在开发新型微型SPECT和微型PET相机方面取得了相当大的进展，这可能会导致未来成像相机的成本大大降低。此外，由于它们的覆盖范围更大，这类设备的灵敏度可能会相当高，从而有可能以更高的灵敏度检测疾病。显然，改进的相机设计可能会对未来的分子成像研究产生重大影响。我们最新的相机设计用于直接拍摄飞行时间图像，这将消除图像重建的需要。这将解除基于Torus PMT架构的设计约束。有了TOF PET成像平板阵列，便可实现便携式PET扫描(例如，在ICU中)。我们计划继续这项探索性工作，目标是将完成的双伽马相机系统移交给MIP科学家，随后审查累积的技术发现并指定下一个系统级项目。

In 2008, as a first step towards a novel flat panel microPET device the Nuclear Camera Team produced a new dual flat panel projection imaging device for mouse imaging. It consists of two flat panel detectors side-by-side with the ability to rapidly obtain projection image in mice on a portable device. This system is now operational and plans are being put in place to further develop devices that allow tomorgraphic imaging. In 2010 work began on leveraging the first device, code named MONICA for Mobile Nuclear Imaging Camera into a low cost projection microPET employing two parallel detectors (rather than side by side). The design incorporates coincidence scanning between the two plates but also the capability for depth of interaction (DOI) measurement allowing some tomographic abilities. Also in 2010 work began on adapting this device to a projection microPET MR compatible device. Testing is ongoing to determine the ability of new crystals to withstand the effects of a strong magnetic field. Development work carried out by the nucelar camera group and its (essential) collaborators is based on the notion of directed exploration where technological opportunities are examined at the research level but with a particular systems level goal in mind (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 each of the areas shown in 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 will be comprised of a rectangular pixelated NaI(Tl) array coupled to two side-by-side Hamamatsu H8500 position-sensitive photomultiplier tubes Initial imaging results obtained with this combination required full use of the JLAB DAQ, CIT developed electronics and RIG-developed data processing software for acquisition and analysis of these data. Thus, considerable progress is being made in the development of novel microSPECT and microPET cameras that could result in much less costly imaging cameras in the future. Moreover, because of their larger coverage, the sensitivity for such devices might be considerably higher leading to the possibility of detecting disease with ever greater sensitivity. Clearly improved camera design could have a significant impact on molecular imaging research in the future. Our latest camera design if for direct time of flight imagingi which will eliminate the need for image reconstruction. This will relieve design constraints based on the torus PMT architecture. With TOF PET imaging flat panel arrays will be possible enabling portable PET scans (for instance, in the ICU). 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.