DEVELOPMENT OF AN MR-PET TOMOGRAPHIC SCANNER

MR-PET扫描仪具有获取解剖、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 以及MR和PET数据的空间配准。的目的 研究是为了证明开发混合MR-PET的可行性， 在生物反应器或小型生物反应器上执行MR和PET断层扫描的扫描仪 动物为了实现这一目标， 环将在5.0 T/40 cm MR磁体的中心发挥作用。这是一 继续通过小额赠款进行的工作， 技术，NIH/I-R 03-RR 07 O 42 -01，实验表明正电子 磁场中的距离压缩这一建议将奠定 为设计混合MR-PET扫描仪奠定了基础， 进行MR和PET断层扫描。 在磁场中进行PET实验的优点在于， 提高了固有的平面内空间分辨率。这是非常重要的 小直径PET环，其空间分辨率可能超过固有分辨率 由于正电子范围模糊，PET图像的空间分辨率降低。因此，在本发明中， 特别是对于高能正电子发射体的情况（例如，11-C，15- O，68-Ga，82-Rb），获得高分辨率面内的可能性 图像（<2毫米/像素）从动物应该是可能的。A中的正电子范围 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范围， 动量与场共线的正电子不受影响。 将MR和PET硬件集成到同一台扫描仪中并非易事。宠物 环形元件必须能够承受时间相关和时间无关 磁场，即脉冲梯度、射频场（B1）和 强静磁场（B-0）。相反，PET 环可通过以下方式使B-0失真，从而降低MR成像或波谱 磁化率和涡流相互作用，耦合到RF线圈， 将噪声注入NMR系统。虽然MR和PET的相互作用 我们可以通过适当的工程设计将这些影响降到最低。 作为实现这种多形式发展的第一步， 我们选择的器械主要用于评价MR系统的相互作用 PET系统组件上的组件，反之亦然。这项研究将 最终获得功能生物反应器的MR-PET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.