A MICRO CT/PET SCANNER FOR IN VIVO SCREENING OF MICE

描述（由申请人提供）：本提案的目标是开发用于小鼠成像的集成微ct /微pet扫描仪。小动物成像技术开始在生物医学研究中发挥重要作用，提供了以完全无创的方式对完整实验动物的生物过程进行重复测量的机会。与单独使用任何一种方式相比，将分子成像（PET）与高分辨率解剖成像（CT）相结合，在数据解释和数据量化方面都具有优势。这种独特的多模态设备的应用将包括人类癌症小鼠模型中肿瘤动力学和转移的研究，基因传递和表达的成像，以及体内标记细胞的跟踪。我们建议建立一个集成系统，该系统结合了非晶硒（a- se） x射线探测器技术，紧凑的x射线源和高分辨率闪烁探测器，在共面几何结构中允许同时获取CT和PET数据。初步研究表明这种方法是可行的。在本提案中，对x射线光谱和过滤影响的详细研究将确定适当的x射线管设置/过滤器，以在最低辐射剂量下产生最高的对比度与噪声比。将对a-Se探测器进行表征，并与广泛使用的基于荧光粉/CCD的探测器技术进行比较。将测量CT扫描对小鼠的辐射剂量，并研究其生物效应（如果有的话）。CT和PET检测器组件将安装在一个适合于对幻影和小鼠进行初步成像研究的龙门架上。将研究利用CT数据校正光子衰减和PET数据中的部分体积效应。最后，成像解剖学和代谢的再现性将在同一主题的重复研究和跨主题的单独研究中进行评估。

DESCRIPTION (provided by applicant): The objective of this proposal is to develop an integrated microCT/microPET scanner for mouse imaging. Small animal imaging technologies are starting to play an important role in biomedical research, offering the opportunity to make repeated measurements of biological processes in intact laboratory animals in a completely non-invasive fashion. Combining molecular imaging (PET) with high resolution anatomic imaging (CT) offers advantages both in data interpretation and in data quantification compared with using either modality independently. Applications for this unique multi-modality device would include studies of tumor kinetics and metastasis in mouse models of human cancer, imaging of gene delivery and expression, and tracking of labeled cells in vivo. We propose to build an integrated system that incorporates amorphous selenium (a-Se) x-ray detector technology, a compact x-ray source and high resolution scintillation detectors in a co-planar geometry allowing CT and PET data to be acquired simultaneously. Preliminary studies have indicated the feasibility of this approach. In this proposal, detailed studies of x-ray spectra and the influence of filtration will determine appropriate x-ray tube settings/filters that produce the highest contrast to noise ratio for the lowest radiation dose. The a-Se detector will be characterized and compared with widely used phosphor/CCD based detector technology. The radiation dose to the mouse from the CT scan will be measured, and its biological effect, if any, investigated. The CT and PET detector components will be mounted into a gantry suitable for preliminary imaging studies in phantoms and in mice. The use of the CT data for correcting photon attenuation and for partial volume effects in the PET data will be investigated. Finally, the reproducibility of imaging anatomy and metabolism will be assessed both in repeat studies of the same subject, and in individual studies across subjects.