NONDIAMAGNETIC AGENTS IN IN VIVO 23NA AND 1H20 MR

这里提出的工作将继续探索和演示范围 非抗磁剂的应用对两者的影响 最强的组织核磁共振信号：1H2O和23Naaq。特定的 提出了两个一般类别的项目。 这将证明，人们可以使1H2O磁共振图像的对比度 试剂(CR)直接分配体积。这是一个非常重要的 这是核磁共振尚未实现的目标。它是根本的，也是 对CRS更复杂的应用具有极其重要的意义。新的 松弛成像联合成像技术(CRI) 由这个实验室，是生产分销量的关键 图像。这一点在这份提案中得到了解释。细胞悬浮液的研究 幻影、小鼠和大鼠被建议在 活着。CRI技术是完全通用的，适用于 纵向、横向或旋转框架的核磁共振弛豫，可以 用于研究任何CR，无论是使用超细还是散装 磁化率机制(或两者都有)。纵向松弛 在本方案中，强调超细CRS。酵母细胞 拟议的暂停和啮齿动物研究也将允许量化 隔室水交换程度的测定及应 在活体内许可和制作交换地图。啮齿动物实验 将允许非常定量地测量大脑CR的变化 血脑屏障一过性破坏时的分布体积 通过颈动脉内非致命性高渗输注。 提出了完全相似的~(23)Na核磁共振研究。这些员工将 直接分布体积的光谱成像技术 移位试剂(SRS)的图像。预期的主要区别包括 以下是。脑室内钠离子交换极其缓慢，将 对~(23)Na光谱图像没有影响。电子电荷 体内SR阴离子大于CR阴离子。因此， 有趣的是，如果前者的发行量 与后者相比，完全是受限的。 这项工作涉及到物理、物理和合成化学的各个方面， 生物物理学和生理学，并在许多研究中有分支 包括神经和心血管疾病在内的病理情况 精神错乱。

The work proposed here will continue to explore and demonstrate the range of applications of the effects of non-diamagnetic agents on the two strongest tissue NMR signals: those of 1H2O and 23Naaq. Specific projects in two general categories are proposed. It will be demonstrated that one can make 1H2O MR images of contrast reagent (CR) distribution volumes directly. This is a very important goal that has not yet been achieved in MRI. It is fundamental, and of utmost significance to more sophisticated applications of CRs. The new technique of combined relaxography and imaging (CRI), recently introduced by this laboratory, is key to the production of distribution volume images. It is explained in this proposal. Studies of cell suspension phantoms, mice, and rats are proposed to demonstrate this approach in vivo. The CRI technique is totally general and applicable to longitudinal, transverse, or rotating-frame NMR relaxation and can be used to study any CR, whether employing the hyperfine or the bulk magnetic susceptibility mechanisms (or both). Longitudinal relaxation and hyperfine CRs are emphasized in this proposal. The yeast cell suspension and rodent studies proposed will also allow the quantitative determination of the extent of compartmental H2O exchange and should permit and production of exchange maps in vivo. The rodent experiments will allow very quantitative measurements of changes in brain CR distribution volumes upon transient disruption of the blood-brain-barrier by non-lethal hyperosmolar intracarotid infusion. Completely analogous 23Na MR studies are proposed. These will employ spectroscopic imaging techniques to make direct distribution volume images of shift reagents (SRs). The main differences expected include the following. Compartmental Na+ exchange is extremely slow and will have no effect on the 23Na spectroscopic images. The electronic charges of the in vivo SR anions are greater than those of the CR anions. Thus, it will be interesting to see if the distribution volumes of the former are at all restricted when compared with those of the latter. This work involves aspects of physics, physical and synthetic chemistry, biophysics, and physiology and has ramifications in the study of a number of pathological conditions including neurological and cardiovascular disorders.