Kuruc A, Treves S, Welch K, Merlino D
J Neurosurg. 1984 Feb;60(2):361-4. doi: 10.3171/jns.1984.60.2.0361.
Flow of cerebrospinal fluid through a surgically implanted valve may be estimated by analyzing the disappearance curve resulting from the injection of a radiotracer into the valve. The standard method for estimating flow assumes an exponential disappearance of the tracer from the valve. This method models the valve as a single well-mixed compartment. Experimental evidence, showing that estimates of flow were dependent upon the site of injection, is at variance with this assumption. An alternative method of analyzing the disappearance curves, based on the area to height ratio (A/H) of the curves, was found to be more consistent with the experimental evidence and resulted in greater precision than the exponential method. It was concluded that optimal results are obtained using the A/H method with a fixed injection technique.
通过分析向手术植入瓣膜中注入放射性示踪剂后产生的消失曲线，可估算脑脊液通过该瓣膜的流量。估算流量的标准方法假定示踪剂从瓣膜呈指数形式消失。该方法将瓣膜模拟为一个充分混合的单一隔室。实验证据表明流量估算值取决于注射部位，这与该假设不一致。基于曲线面积与高度比（A/H）分析消失曲线的另一种方法，被发现与实验证据更一致，并且比指数法具有更高的精度。得出的结论是，采用固定注射技术的A/H方法可获得最佳结果。
