High Resolution PET Detectors for Combined PET-MR Small Animal Imaging

描述（由申请人提供）：理想的生物成像系统将提供生命系统的非侵入性、高分辨率、高灵敏度的三维（3D）图像。正电子发射断层扫描（PET）通过使用靶向放射性标记探针，对一系列生物过程提供高灵敏度。不幸的是，由于低空间分辨率和缺乏解剖信息，精确的信号定位非常困难。磁共振成像（MRI）可以提供高空间分辨率和良好的软组织对比度，但信号强度差导致灵敏度低。所提议的努力的总体目标是将PET和MR模式的最佳特征结合到一个单一的成像仪器中，该仪器将几乎同时记录两种成像模式的数据。融合系统最直接的好处将是为muPET研究提供高分辨率的解剖背景。这将有助于更好地全面了解PET信号的来源。“内配准”MR图像将用于计算muPET图像中的散射和衰减，也用于估计低分辨率PET扫描中的部分体积误差，从而有助于PET信号的量化。这种融合系统将带来许多目前独立技术无法实现的机会。例如，在小动物身上进行fMRI和muPET神经受体脑图谱的联合研究是可能的。拟议的第一阶段项目的目标是研究PET探测器的设计，该设计足以与MR系统集成，用于PET-MR联合成像。

DESCRIPTION (provided by applicant): The ideal biological imaging system would provide non-invasive, high-resolution, high-sensitivity, three-dimensional (3D) images of living systems. Positron Emission Tomography (PET) offers high sensitivity to a range of biological processes through the use of targeted radiolabeled probes. Unfortunately, precise signal localization can be extremely difficult due to low spatial resolution and the lack of anatomical information. Magnetic Resonance Imaging (MRI) can provide high spatial resolution and excellent soft tissue contrast, but suffers from poor signal strength leading to low sensitivity. The overall goal of the proposed effort is to combine the best features of PET and MR modalities for small animal studies into a single imaging instrument that will record data in both imaging modalities near simultaneously. The most immediate benefit of the melded system will be to provide high-resolution anatomical context for muPET studies. This will lead to better overall understanding of the origin of the PET signals. The 'in-register' MR images will be used to compute scatter and attenuation in the muPET images and also to estimate partial volume errors in the lower-resolution PET scans, thus aiding quantification of the PET signal. The melded system will open up a number of opportunities not possible with current independent technologies. For example, combined fMRI and muPET neuroreceptor brain mapping studies in small animals would be possible. The goal of the proposed Phase I project is to investigate PET detector design that is adequate for integration with an MR system for combined PET-MR imaging.