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

基本信息

批准号：
8286966
负责人：
RAYMOND ROBERT RAYLMAN
金额：
$ 19.46万
依托单位：
WEST VIRGINIA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-09-01 至 2014-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8286966
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

项目摘要

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）：小动物成像系统正在迅速成为许多生物医学研究项目的组成部分，允许对多种疾病的动物模型进行详细研究。最近，最初为临床开发的多模态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 成像插件，设计用于使用 3T 临床 MRI 对小动物进行定量同步成像。因此，MRI-PET 成像可以提供给那些无法使用当前一代 MRI-PET 插入件的研究人员，该插入件是专为专门的高场、小动物 MRI 系统而设计的，该系统针对小鼠成像进行了优化。该系统的 MR 兼容 PET 组件将利用连续的闪烁体块，通过短光纤光导耦合到位于 MRI 系统孔外的微通道板、位置敏感光电倍增管 (MCP-PSPMT)。光导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 PET 的视场 (FOV)，以便于对比小鼠更大的动物物种（大鼠到兔子）进行快速成像。这种能力在不久的将来可能非常重要，因为这些物种的许多重要疾病模型已经开发出来，并且可能比某些小鼠模型更可取。此外，由于MRI扫描仪的成像区域没有敏感电子元件，因此不需要电屏蔽。因此，MRI FOV 中不会有可能产生涡流的导电材料，而涡流已被证明会影响 MRI SNR。由于光导中的信号衰减而导致的一些 PET 成像性能指标的下降将通过使用连续的极高光输出闪烁体 (LaBr3) 块来抵消。连续块闪烁体的应用允许我们通过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括一个旋转光子源，这将有助于校正光子衰减效应。如果 PET 图像用于量化放射性示踪剂浓度，则此功能至关重要。同时，还将开发和测试两个定制发射/接收 MRI 线圈组。一组线圈专为大鼠的最佳 MR 成像而设计，而另一组则适用于兔子大小的动物。用于获取解剖、功能和光谱 MR 数据的 MRI 方法将适用于我们的新系统。此外，还将实施用于分割 MRI 图像以及共同配准 MRI、fMRI 和 PET 图像的技术。最后，除了最初的模型测试外，还将对少量大鼠和兔子进行成像，以展示新系统的成像能力。该设备的新颖之处包括使用连续的 LaBr3 块、应用 MCP-PSPMT 创建大视场 MRI-PET 系统、采集传输扫描以进行衰减校正、实施利用 MRI 图像结构信息的 PET 图像重建方法以及开发可互换的 MRI-RF 线圈以适应所研究的动物物种的大小。该项目完成后，我们将构建并初步测试用于临床 MRI 3T 扫描仪的大型 FOV MRI-PET 插入件，使更多利用临床前成像的研究人员能够使用这项最先进的技术技术。公共健康相关性：本申请提议开发大视场组合 MRI-PET 动物成像系统。该设备可能有助于发现新药物和新方法，以帮助诊断和治疗大量疾病。