MicroPET-MR scanner for preclinical molecular imaging

描述（由申请人提供）：本申请申请资金用于购买由Sedecal公司生产的Super Argus正电子发射断层扫描-磁共振（PET-MR）成像系统，用于临床前小动物多模态成像，以支持马萨诸塞州总医院（MGH）放射科的研究工作。该设备是美国第一个商用临床前微型PET-MR系统，完全集成了最先进的高分辨率PET和最先进的高分辨率MR功能。系统的跨轴视野为68毫米的两个组件，允许小鼠和大鼠成像。PET采集具有亚毫米级的空间分辨率，每片的灵敏度是任何商用系统中最高的，并且均匀性高。优化后的算法使得3D OSEM的快速重建时间小于2分钟，滤波后的反投影的快速重建时间小于5秒。MR采集模块基于一种新型无低温设计，超导3T磁体，磁梯度强度为125mT/m。该系统具有用于PET和MR采集的集成图形用户界面。这台扫描仪将大大提高研究工作的不同组的NIH资助的研究人员。该系统将提供高分辨率多模态成像能力，用于对MR试剂和PET放射性示踪剂分布进行无创系列评估，以促进新型多模态分子示踪剂的研究；提供高分辨率的相关解剖MR图像，用于早期评估对新疗法的反应，通过测量亚器官水平的放射性示踪剂摄取变化来评估；并为测试新的多模态动力学建模和改进的图像重建算法提供了平台。与单独的PET和MR设备相比，该系统具有用于啮齿动物成像的三个主要优点。首先，该组合装置可以实现两种模式的时间分辨率，如果动物需要在成像系统之间移动，则无法实现；这对于多模式agent开发和多模式动力学建模都是至关重要的。其次，空间共定位通过组合系统得到了极大的改善，这对于脑受体研究和基因工程小鼠疾病模型的评估至关重要。第三，吞吐量大大提高，无需在系统之间移动动物，从而改善了数据收集。该应用程序包含的项目包括代表不同学科（放射学/核医学、化学/放射化学、肿瘤学、神经学、基因工程小鼠建模、动力学建模、图像重建、治疗性干细胞输送和组织工程）和NIH资金来源（NCI、NIBIB、NHLBI、NINDS、NIDA、NIMH、NIAMS）的广泛用户基础。必要的行政和技术指导已经到位，以确保有效利用这一工具。这将是第一个这样的系统，商业或其他，在大波士顿地区。它将提供一个平台来测试已开发的药剂和成像范例，这将补充MGH的人类PET-MR工作，并将成为该地区由NIH资助的大型研究人员社区的主要资产。

DESCRIPTION (provided by applicant): This proposal requests funding for the purchase of a Super Argus Positron Emission Tomography-Magnetic Resonance (PET-MR) imaging system made by Sedecal Inc. for preclinical small animal multimodal imaging to support the research efforts in the Department of Radiology at the Massachusetts General Hospital (MGH). The device is the first commercial preclinical microPET-MR system available in the United States, and has fully integrated state-of-the-art high-resolution PET and state-of-the-art high-resolution MR capabilities. The system transaxial field of view is 68 mm for both components allowing both mouse and rat imaging. The PET acquisition has sub-millimeter spatial resolution, the highest sensitivity per slice of any commercial system, and high uniformity. Optimized algorithms result in rapid reconstruction of less than 2 min for 3D OSEM and less than 5 sec for filtered back projection. The MR acquisition module is based on a novel cryogen-free design, superconducting 3T magnet, with magnetic gradient strength of 125mT/m. The system has an integrated graphical user interface for both PET and MR acquisitions. This scanner will significantly enhance the research efforts of a diverse group of NIH funded investigators. The system will provide high-resolution multimodal imaging capabilities for non-invasive serial evaluation of MR agent and PET radiotracer distribution to facilitate research in new multimodal molecular tracers; provide high resolution correlative anatomic MR images for early assessment of response to novel therapies evaluated with changes in radiotracer uptake measured at the sub-organ level; and provide a platform for testing novel multimodality kinetic modeling and improved image reconstruction algorithms. The system has three major advantages over separate PET and MR devices for rodent imaging. First, the combined device can achieve temporal resolution for both modalities not attainable if animals are required to be moved between imaging systems; this is vital for both multimodal agent development and multimodal kinetic modeling. Second, spatial co-localization is greatly improved with a combined system, which is vital for brain receptor studies and assessment of genetically engineered mouse models of disease. Third, throughput is greatly enhanced without the need to move animals between systems, improving data collection. The application contains projects that comprise a broad base of users representing various disciplines (radiology/nuclear medicine, chemistry/radiochemistry, oncology, neurology, genetically engineered mouse modeling, kinetic modeling, image reconstruction, therapeutic stem cell delivery, and tissue engineering) and NIH funding sources (NCI, NIBIB, NHLBI, NINDS, NIDA, NIMH, NIAMS).The necessary administrative and technical direction is already in place to ensure efficient utilization of this instrumentation. This will be the first such system, commercial or otherwise, in the greater Boston area. It will provide a platform to test developed agents and imaging paradigms that will complement the human PET-MR efforts at MGH, and will be major asset to a large community of NIH funded investigators in the region.