PET Insert for MAGNETOM Trio

描述（由申请人提供）：本提案要求为一种新的高分辨率PET断层扫描插入物提供资金，以产生一种混合MR/PET系统，允许在人类受试者中真正同时获取PET和MR脑成像数据。PET插入将与现有的3T西门子TRIO MR系统相结合（它是专门设计的）。由此产生的MR/PET混合系统将作为共享资源提供给匹兹堡大学和其他当地机构的研究人员。受益于该仪器的院系包括：精神病学、放射学和放射肿瘤学、物理医学和康复学、神经病学和神经外科、病理学和耳鼻喉科。该系统将设在匹兹堡大学磁共振研究中心，并将由一个内部咨询委员会管理和指导，该委员会由本提案中确定的共同调查人员和主要用户组成。该嵌套采用新型PET探测器技术，采用磁不敏感雪崩光电二极管（apd）代替光倍增管（pmt），并由一个安装在MR孔内的探测器环组成。在小动物成像的临床前系统中建立了apd用于核磁共振兼容PET的应用。所提出的插入物比现有的用于人脑PET成像的仪器性能更好，并且可以在高磁场环境下工作，而不会显著影响MR系统的性能。MR图像可用于PET数据的衰减校正，这样就不会产生电离辐射，而PET或PET/CT成像则不是这样。该系统将提供PET数据集，这些数据集本质上与解剖和功能MR数据集（fMRI， DTI，光谱学）在空间和时间域中共同注册。我们期望该系统能够显著加强研究的领域是：1)功能和生理验证范式（例如BOLD MR信号与[15O]H2O PET脑血流）。2)认知功能（fMRI）与治疗药物和/或急性药理刺激（PET）神经受体占用之间关系的表征。3)危重病或短暂性疾病（如中风、癫痫、多发性硬化症）的研究，这些研究需要同时进行解剖学和功能评估。4)脑及头颈部肿瘤的精确解剖描绘和同步功能评估，为放射治疗计划提供依据，以及对肿瘤解剖和功能反应的纵向评估。5)在基于图谱的脑区描绘、组织分类/分割和体积评估方面，更精确地应用结构MR结果。多模态MR/PET系统的引入预计将对研究神经科学和肿瘤学放射治疗计划和反应评估产生广泛影响。美国国立卫生研究院资助的匹兹堡大学的11个主要研究项目将立即受益于这种新的多模态技术。

DESCRIPTION (provided by applicant): This proposal requests funds for a newly available high resolution PET tomograph insert to produce a hybrid MR/PET system allowing true simultaneous acquisition of PET and MR brain imaging data in human subjects. The PET insert will be combined with an existing 3T Siemens TRIO MR system (for which it is specifically designed). The resulting hybrid MR/PET system will be available as a shared resource to researchers at the University of Pittsburgh and other local institutions. Departments within the University that that will benefit from the instrument include: Psychiatry, Radiology & Radiation Oncology, Physical Medicine & Rehabilitation, Neurology & Neurosurgery, Pathology, and Otolararyngology. The system will be sited in the University of Pittsburgh Magnetic Resonance Research Center and will be managed and directed by an Internal Advisory Committee composed of the co-investigators and major users identified in this proposal. The insert uses new PET detector technology, with magnetically insensitive avalanche photodiodes (APDs) in favor of photo-multiplier tubes (PMTs), and consists of a detector ring that fits inside the MR bore. The use of APDs for MR-compatible PET is established in pre-clinical systems for small animal imaging. The proposed insert performs better than present instrumentation for human brain PET imaging, and can operate within the high magnetic field environment without significantly affecting the performance of the MR system. The MR images may be used for attenuation correction of the PET data such that no ionizing radiation is associated with this purpose, as is not the case for PET or PET/CT imaging. The system will provide PET datasets that are intrinsically co-registered with anatomical and functional MR datasets (fMRI, DTI, spectroscopy) in both spatial and temporal domains. Areas where we expect the system to significantly enhance investigational research are: 1) Functional and physiologic validation paradigms (e.g. BOLD MR signal vs. [15O]H2O PET cerebral blood flow). 2) Characterization of the relationship between cognitive function (fMRI) and neuroreceptor occupancy by therapeutic agents and/or an acute pharmacologic challenge (PET). 3) Studies in critical care or ephemeral conditions (e.g. stroke, epilepsy, MS), for which the highly dynamic physiology demands simultaneous anatomical and functional assessments. 4) Precise anatomic delineation and simultaneous functional assessment of brain and head-and-neck tumors for radiation treatment planning, as well as longitudinal assessments of anatomic and functional tumor response. 5) More precise application of structural MR results with respect to atlas-based delineation of brain regions, tissue classification/segmentation, and volumetric assessments. The introduction of multimodality MR/PET systems is expected to have a broad impact on investigational neuroscience and radiation treatment planning and assessment of response in oncology. 11 Major User NIH-funded research projects at the University of Pittsburgh that will immediately benefit from this new multimodality technology are identified. PUBLIC HEALTH RELEVANCE: