DEVELOPMENT OF AN MR-PET TOMOGRAPHIC SCANNER

MR-PET扫描仪有可能获得解剖、功能 通过MRI/MRS和代谢活动观察大体代谢组织状态 通过PET。混合扫描仪的最终目标是产生时间 磁共振和正电子发射计算机断层扫描数据的空间配准。这样做的目的是 研究是为了证明开发混合MR-PET的可行性 对生物反应器或小型生物反应器进行MR和PET断层扫描的扫描仪 动物。为了实现这一目标，一段耐磁场的PET 环将在5.0T/40厘米磁共振磁铁的中心起作用。这是一个 通过小额赠款继续开展创新工作 技术，NIH/I-R03-RR07O42-01，实验表明正电子 磁场中的射程挤压。这项建议应该为 设计一种混合MR-PET扫描仪的基础 进行磁共振和正电子发射计算机断层扫描。 在磁场中进行PET实验的一个好处是 固有的面内空间分辨率提高。这一点对于 空间分辨率可能超过本征分辨率的小直径PET环 正电子范围模糊导致的PET图像的空间分辨率。因此， 尤其是对于高能正电子发射体的情况(例如，11-C、15-C O，68-Ga，82-Rb)，获得高分辨率面内的可能性 动物的图像(&lt；2毫米/像素)应该是可能的。正电子射程 磁场是各向异性的。带有动量分量的正电子 横向磁场限制了正电子的射程，而 动量与场共线的正电子不受影响。 将磁共振和正电子发射计算机断层扫描硬件集成到同一扫描仪中绝非易事。宠物 环组件必须对时间相关和时间无关具有容忍性 磁场，即脉冲梯度、射频场(B1)和 分别为强静磁场(B-0)。相反，PET RING可以通过扭曲B-0到 磁化率和涡流相互作用，耦合到射频线圈和 向核磁共振系统注入噪音。虽然MR和PET交互作用是 麻烦的是，我们可以通过适当的工程将这些影响降到最低。 作为实现这种多模式发展的第一步 我们选择的设备主要用于评估MR系统的交互作用 PET系统组件上的组件，反之亦然。这项研究将 最终获得一个正常工作的生物反应器的磁共振-正电子发射计算机断层扫描图像。

An MR-PET scanner has the potential of acquiring anatomical, functional and gross metabolic tissue status through MRI/MRS and metabolic activity through PET. The ultimate goal of a hybrid scanner is to yield temporal and spatial coregistration of MR and PET data. The objective of this research is to demonstrate the feasibility of developing a hybrid MR-PET scanner that performs MR and PET tomography on bioreactors or small animals. To achieve this goal a section of a magnetic field tolerant PET ring will function in the center of a 5.0 T/40cm MR magnet. This is a continuation of the work done through Small Grant for Innovative Technology, NIH/I-R03-RR07O42-01, that experimentally showed positron range squeezing in a magnetic field. This proposal should lay the foundation for engineering a hybrid MR-PET scanner that simultaneously performs MR and PET tomography. An advantage of conducting a PET experiment in a magnetic field is that intrinsic in-plane spatial resolution improves. This is important for small diameter PET rings whose spatial resolution may exceed the intrinsic spatial resolution of a PET image due to positron range blurring. Thus, especially for the case of high energy positron emitters (e.g., 11-C, 15- O, 68-Ga, 82-Rb), the possibility of acquiring high resolution in-plane images (<2 mm/pixel) from animals should be possible. Positron range in a magnetic field is anisotropic. A positron with a momentum component transverse to the magnetic field limits the positron's range whereas a positron whose momentum is co-linear with the field is unaffected. Integrating MR and PET hardware into the same scanner is not trivial. PET ring components must be tolerant to time dependent and time independent magnetic fields, that is, pulsed gradients, radiofrequency fields (B1) and a strong static magnetic field (B-0), respectively. Conversely, the PET ring can degrade MR imaging or spectroscopy by distorting B-0 through susceptibility and eddy current interactions, coupling to the RF coil and injecting noise into the NMR system. Although MR and PET interactions are troublesome we can minimize these effects with proper engineering. As a first step toward realizing the development of such a multimodality device we have chosen to focus on evaluating the interaction of MR system components on PET system components and vice versa. This research will culminate in obtaining an MR-PET image of a functioning bioreactor.