QUANTITATIVE IMAGING OF CEREBRAL BLOOD FLOW AND OXYGEN CONSUMPTION

本课题的主要目的是研制一种新型的集成磁共振示踪剂 用于成像人类脑血流和代谢的方法，以及 应用这种方法来研究生理学和药理学 精神病患者的功能障碍。 集成MR示踪剂方法 类似于15 O PET方法，因为它使用经典示踪剂理论 基于凯蒂-施密特方程 然而，除了使用 放射性示踪剂，MR方法使用扰动磁自旋状态 稳定同位素，如17 O（在17 O2和H217 O中）和1H（在1H 2 O中）， 追踪器 该项目的前期工作已导致开发和验证 17 O MR方法用于脑耗氧量成像， 开发了一种利用“自旋”成像脑血流的技术， 动脉水的标记。 特别是一些重大问题 排除了定量脑血流量的计算 在人类的图像已经确定，和理论和方法 已经开发和测试了克服这些问题的方法。 使用这些方法，脑血流量的平均值， 正常人志愿者的灰质和白色物质计算为 分别为81 ± 20 cc/100 g/min和23 ± 7 cc/10 g/min。 这些值 与以前使用15 O（PET）测定的值非常一致 接近。 未来两年的工作将集中在MR示踪剂的应用上 局部脑血流异常的成像方法 精神病患者，在“休息”和“激活”条件下， 开发MR示踪剂方法， 生理和代谢的变化，由于扰动的具体 受体系统，例如，多巴胺受体系统

The major aim of this project is to develop a new integrated MR tracer approach for imaging cerebral blood flow and metabolism in humans, and to apply this approach to study physiological and pharmacological dysfunction in psychiatric patients. The integrated MR tracer approach is similar to 15O PET approaches in that it uses classical tracer theory based on the Kety-Schmidt equation. However, instead of using radioactive tracers, the MR approach uses perturbed magnetic spin states of stable isotopes such as 17O (in 17O2 and H217O) and 1H (in 1H2O) as tracers. Previous work in this project has led to the development and validation of the 17O MR approach for imaging cerebral oxygen consumption, and the development of a technique to image cerebral blood flow, using "spin tagging" of arterial water. In particular, a number of major problems that had precluded the calculation of quantitative cerebral blood flow images in humans have been identified, and theoretical and methodological approaches to overcome these problems have been developed and tested. Using these approaches, the average values for cerebral blood flow in grey and white matter in normal human volunteers were calculated to be 81 + 20 cc/100g/min and 23 + 7 cc/10g/min, respectively. These values agree very well with previous values determined using 15O (PET) approaches. Work in the upcoming two years will focus on the application of MR tracer approaches for imaging regional cerebral blood flow abnormalities in psychiatric patients, under "resting" and "activated" conditions, and on the development of MR tracer approaches for following regional physiological and metabolic changes due to perturbations in specific receptor systems, e.g., the dopamine receptor system.