Development of a Combined MRI-PET System for Contemporaneous Functional Imaging

开发用于同步功能成像的 MRI-PET 组合系统

• 批准号: 8096561
• 负责人: RAYMOND ROBERT RAYLMAN
• 金额: $ 39.27万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8096561
• 关键词: Affect; Algorithms; Animal Experimentation; Animal Model; Animals; Area; Attention; Beds; Biology; Biomedical Research; Bromides; Caliber; Clinical; Coupled; Custom; Data; Detection; Development; Devices; Diagnosis; Disease; Disease model; Elements; Fiber Optics; Functional Imaging; Functional Magnetic Resonance Imaging; Future; Generations; Goals; Health; Image; Imaging Techniques; Investigation; Lanthanum; Least-Squares Analysis; Light; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Measurement; Measures; Mechanics; Methods; Metric; Modality; Morphologic artifacts; Mus; Neurosciences; Oryctolagus cuniculus; Output; Performance; Pharmaceutical Preparations; Photons; Physiologic pulse; Positioning Attribute; Positron-Emission Tomography; Procedures; Process; RF coil; Radiation; Radiopharmaceuticals; Rattus; Research; Research Personnel; Resolution; Sampling; Scanning; Shapes; Signal Transduction; Small Animal Imaging Systems; Source; System; Target Populations; Techniques; Technology; Testing; Tissues; Tube; Weight; Work; attenuation; clinical application; design; detector; expectation; image reconstruction; image registration; imaging modality; improved; in vivo; innovation; interest; magnetic field; mouse model; multimodality; novel; oncology; photomultiplier; pre-clinical; programs; radiotracer; reconstruction; transmission process; uptake

DESCRIPTION (provided by applicant): Small animal imaging systems are rapidly becoming integral elements of many biomedical research programs, allowing the detailed study of animal models of a number of diseases. Recently, the multimodality imaging techniques originally developed for clinical use have been applied to pre-clinical applications. In this project we propose to create a combined MRI-PET imaging insert designed for quantitative contemporaneous imaging of small animals using a 3T clinical MRI. Thus, MRI-PET imaging can be made available to researchers who do not have access to the current generation of MRI-PET inserts designed for specialized high field, small animal MRI systems optimized for the imaging of mice. The MR-compatible PET component of the system will utilize continuous blocks of scintillator, coupled to microchannel plate, position-sensitive photomultiplier tubes (MCP- PSPMTs) located outside the bore of the MRI system via short fiber optic light guides. The use of light guides allows us to use high gain, large area photomultiplier tubes, which will maximize the field-of-view (FOV) of the PET to facilitate rapid imaging of animal species larger than mice (rats to rabbits). This capability is likely to be very important in the near future since a number of important disease models in these species have been developed and may be preferable to some mouse models. In addition, since there are no sensitive electrical components in the imaging area of the MRI scanner, no electrical shielding is required. Thus, there will be no conductive material in the MRI FOV that may produce eddy currents, which have been shown to affect MRI SNR. Degradation in some PET imaging performance metrics caused by attenuation of signal in the light guides will be offset by the use continuous blocks of a very high light output scintillator (LaBr3). Application of continuous block scintillator permits us to measure depth of photon interaction by using the shape of the light pulses. Furthermore, our system will include a rotating photon source in its design that will facilitate correction of photon attenuation effects. This capability is critical if the PET images are to be used for quantification of radiotracer concentration. In parallel, two custom transmit/receive MRI coil sets will be developed and tested. One coil set is designed for optimal MR imaging of rats, while the other is intended for animals up to the size of rabbits. MRI methods for acquiring anatomical, functional and spectroscopic MR data will be adapted for use with our new system. In addition, techniques will be implemented for segmenting the MRI images and co- registering the MRI, fMRI, and PET images. Finally, in addition to initial phantom testing, a small number of rats and rabbits will be imaged to demonstrate the imaging capabilities of the new system. The novel aspects of this device include the use continuous blocks of LaBr3, application of MCP-PSPMTs to create a large FOV MRI-PET system, acquisition of transmission scans for attenuation correction, implementation of PET image reconstruction methods that utilize structural information from MRI images and the development of interchangeable MRI-RF coils to fit the size of the animal species under investigation. At the completion of this project we will have built and initially tested a large FOV MRI-PET insert for use in clinical MRI 3T scanners, making this state-of-the-art technology available to an expanded number of researchers utilizing pre-clinical imaging techniques. PUBLIC HEALTH RELEVANCE: This application proposes the development of a large field-of-view combined MRI-PET animal imaging system. This device could be instrumental in the discovery of new drugs and methods to aid in the diagnosis and treatment of a large number of diseases.

描述（由申请人提供）：小型动物成像系统正迅速成为许多生物医学研究计划的组成部分，从而详细研究了许多疾病的动物模型。最近，最初用于临床用途开发的多模式成像技术已应用于临床前应用。在这个项目中，我们建议创建一个组合的MRI-PET成像插入物，旨在使用3T临床MRI对小动物进行定量的同时成像。因此，可以向无法访问专门为专门的高场，小动物MRI系统的MRI-PET插入物提供的研究人员提供MRI-PET成像，该插入物已优化用于小鼠成像。该系统的MR兼容PET组件将利用闪烁体的连续块，与微通道板，位置敏感的光电倍增管（MCP-PSPMTS）耦合，位于MRI系统孔通过短光纤轻型导线。使用轻轨的使用使我们能够使用高增益，大面积的光电倍增管，这将最大化宠物的视野（FOV），以促进大于小鼠（大鼠到兔子）的动物物种的快速成像。在不久的将来，由于已经开发了许多重要的疾病模型，并且可能比某些小鼠模型更可取，因此这种能力可能非常重要。此外，由于MRI扫描仪的成像区域中没有敏感的电气组件，因此无需电气屏蔽。因此，MRI FOV中不会有可能产生涡流的导电物质，这些电流已显示出会影响MRI SNR。通过轻度指南衰减引起的一些PET成像性能指标的降解将被非常高光输出闪烁体的连续块所抵消（LABR3）。连续块闪烁体的应用允许我们使用光脉冲的形状来测量光子相互作用的深度。此外，我们的系统将在其设计中包含一个旋转的光子源，以促进光子衰减效果的校正。如果要使用PET图像来定量放射性示意剂浓度，则此功能至关重要。同时，将开发和测试两个自定义的传输/接收MRI线圈集。一个线圈集设计用于最佳的大鼠MR成像，而另一个旨在用于兔子大小的动物。获取解剖，功能和光谱MR数据的MRI方法将适用于我们的新系统。此外，将实施用于分割MRI图像并共同注册MRI，fMRI和PET图像的技术。最后，除了初始幻影测试外，还将成像少数大鼠和兔子以证明新系统的成像功能。该设备的新颖方面包括使用LABR3的连续块，MCP-PSPMT的应用来创建大型FOV MRI-PET系统，获取传输扫描以进行衰减校正，实施了使用MRI图像中的结构信息的PET图像重建方法以及可互换的MRI-RF COIL的开发来适应动物尺寸的可互换MRI-RF COIL，以适应动物尺寸的尺寸。该项目完成后，我们将建立并最初测试了一个大型FOV MRI-PET插入物，用于用于临床MRI 3T扫描仪，这使得该最先进的技术可用于扩展的研究人员，利用了临时成像技术。公共卫生相关性：该应用程序提出了开发大型视野合并的MRI-PET动物成像系统。该装置可能对发现新药和方法有助于诊断和治疗大量疾病。