NMR STUDIES OF CEREBRAL BLOOD FLOW AND ENERGY METABOLISM

本研究旨在评估一种新的非侵入性诊断方法。 无放射性脑血流量的测定 追踪器。具体地说，我们使用了一种新的19F核磁共振技术来测量 从大脑中清除氟化惰性气体CHF3。我们测试了 比较脑血流值的新技术 用~(19)F-核磁共振测定脑血流值 同时利用放射性微球技术。大脑皮层 ~(19)F-核磁共振和放射性微球测定血流值 技术相当一致，并显示出相同的反应 动脉二氧化碳水平的变化。我们得出结论，~(19)F核磁共振 这项技术提供了一种脑血流的定量测量方法。 我们使用核磁共振技术来定位19F核磁共振谱(因此 血流量)到大脑中明确定义的4cc体积。使用这个 定位技术，19F核磁共振方法现在是不可回避的，并且 因此适用于临床研究。然而，它有两个缺点 这项技术。首先，空间分辨率相当差， 其次，一次只研究了大脑的一个区域。 这两个问题都被一种新技术绕过了，这种技术是 是在去年开发的。而不是从单一的 局部区域，我们使用核磁共振技术对脑血液进行成像 流经整个大脑。成像的空间分辨率 研究(0.8cc)比使用 以前的技术(4毫升)。

This study was undertaken to assess a new method for the non-invasive determination of cerebral blood flow without the use of radioactive tracers. Specifically, we used a new 19F NMR technique to measure the clearance of a fluorinated inert gas, CHF3, from the brain. We tested the new technique by comparing the cerebral blood flow values determined by 19F NMR with cerebral blood flow values determined simultaneously by radioactive microsphere techniques. The cerebral blood flow values determined by 19F NMR and radioactive microsphere techniques agreed reasonably well, and showed the same response to variations in the arterial CO2 level. We conclude that the 19F NMR technique gives a quantitative measure of cerebral blood flow. We used NMR techniques to localize the 19F NMR spectra (and thus the blood flow) to a well defined 4 cc volume in the brain. Using this localization technique, the 19F NMR approach was now non-evasive, and thus applicable to clinical studies. However, there were two drawbacks to this technique. First, the spatial resolution was rather poor, and second, only one region of the brain was investigated at a time. Both these problems were circumvented by a new technique that was developed in the last year. Instead of obtaining spectra from a single localized region, we used NMR techniques to image the cerebral blood flow over the entire brain. The spatial resolution for the imaging studies (0.8 cc) is much better than the spatial resolution obtained with the previous technique (4 cc).