The determination of regional cerebral blood flow by means of water labeled with radioactive oxygen 15.
The determination of regional cerebral blood flow by means of water labeled with radioactive oxygen 15.
复制标题
放射性氧标记水测定局部脑血流量15。
作者：
M. M. Ter;J. Eichling;Davis Do;M J Welch;Judith M. Metzger
为局部脑血流 (rCBF) 体内评估而设计的多种方法证明了该参数的难以捉摸。用于此目的的方法之一是将用伽马发射放射性同位素标记的可扩散指示剂注射到受试者的颈内动脉中，然后从外部测量指示剂从大脑的各个区域的冲走率。这种方法 (1, 2) 是 Kety-Schmidt 方法 (3-5) 的改进，最常使用放射性惰性气体的盐溶液，例如氪 85 (1, 2) 和氙 133 (6)。目前，133Xe 似乎是使用最广泛的扩散指示剂，尽管其固有的局限性包括：(a) 在脂质和水中的溶解度不同； (b) 脑血分配系数难以准确评估； (c) 133Xe 的低能电磁辐射。前两个因素使得该指标的绝对流量确定不确定，第三个因素有利于......
THE NUMBER of methods devised for the in vivo evaluation of regional cerebral flow (rCBF) attest to the elusiveness of this parameter. One of the methods for this purpose is the injection, into the internal carotid artery of a subject, of a diffusible indicator labeled with a gammaemitting radioisotope, followed by the external measurement of the rate of washout of the indicator from various regions of the brain. This approach (1, 2), a modification of the Kety–Schmidt method (3–5), has most frequently utilized saline solutions of radioactive inert gases such as krypton 85 (1, 2) and xenon 133 (6). At this time, 133Xe appears to be the most widely used diffusible indicator despite inherent limitations which include: (a) a different solubility in lipids and in water; (b) a brain–blood partition coefficient difficult to evaluate accurately; and (c) the low–energy electromagnetic radiation of 133Xe. The first two factors render absolute flow determinations by this indicator uncertain and the third one favors...