QUANTITATIVE IMAGING OF CEREBRAL BLOOD FLOW AND OXYGEN CONSUMPTION

本项目的主要目标是开发一种新型的集成化mr示踪器。 成像人类脑血流和代谢的方法，以及 将这一方法应用于生理学和药理学研究 精神病患者的功能障碍。综合磁共振示踪方法 类似于15O正电子发射计算机断层扫描方法，因为它使用经典示踪剂理论 基于凯蒂-施密特方程。但是，它不是使用 放射性示踪剂，MR方法使用微扰的磁自旋态 稳定同位素，如17O(17O2和H217O)和1H(1H2O)As 追踪器。 这个项目之前的工作已经导致了开发和验证 17O磁共振成像脑耗氧量的方法，以及 一种使用“自旋”成像脑血流的技术的发展 动脉水的标记。尤其是，一些主要问题 这就排除了定量脑血流量的计算 人类中的图像已经被识别出来，并在理论和方法上 已经开发并测试了克服这些问题的方法。 使用这些方法，脑血流量的平均值在 正常人志愿者的灰质和白质被计算为 分别为81+20cc/100g/min和23+7cc/10g/min。这些值 与之前使用150度(PET)确定的值非常一致 接近了。 未来两年的工作将集中在磁共振示踪剂的应用上 脑局部血流异常的影像诊断方法探讨 精神病人，在“休息”和“活跃”状态下，以及 磁共振示踪方法在以下区域的发展 特异度摄动引起的生理代谢变化 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.