Marcus M L, Busija D W, Bischof C J, Heistad D D
Fed Proc. 1981 Jun;40(8):2306-10.
Difficulties in measuring total and regional cerebral flow have hindered advances in knowledge concerning the regulation of the cerebral circulation. Now, however, we can accurately measure total and regional cerebral blood flow with the labeled microsphere method. With this method, flow to cerebral and non-cerebral tissues in the head can be completely separated, and by using microspheres labeled with different radionuclides, six measurements can be obtained in each experiment. A disadvantage of the microsphere method is that flow is not monitored continuously. Therefore, transient changes in flow (less than 20 seconds) cannot be measured accurately, and it is difficult to determine the time course of changes in cerebral blood flow in response to a given stimulus. A new method, simultaneous measurements of velocity and diameter in a pial artery, complements the microsphere approach. With this new method, nearly continuous, accurate measurements of cerebral blood flow are obtainable. Now that several methods for measuring cerebral blood flow are available and appear to be valid, knowledge concerning the regulation of cerebral blood flow should advance more rapidly.
测量全脑和局部脑血流量的困难阻碍了有关脑循环调节知识的进展。然而，现在我们可以用标记微球法准确测量全脑和局部脑血流量。用这种方法，可以完全区分流向头部脑和非脑组织的血流，并且通过使用标记有不同放射性核素的微球，每次实验可以获得六次测量结果。微球法的一个缺点是血流不是连续监测的。因此，无法准确测量血流的瞬时变化（小于20秒），并且难以确定脑血流量对给定刺激的变化时间过程。一种新方法，即同时测量软脑膜动脉中的速度和直径，补充了微球法。用这种新方法，可以获得几乎连续、准确的脑血流量测量值。既然有几种测量脑血流量的方法可用且似乎有效，那么有关脑血流量调节的知识应该会更迅速地取得进展。
