Rothwell P M, Gibson R J, Slattery J, Sellar R J, Warlow C P
Department of Clinical Neurosciences, Western General Hospital, Edinburgh, Scotland.
Stroke. 1994 Dec;25(12):2435-9. doi: 10.1161/01.str.25.12.2435.
There is confusion about how carotid stenosis should be measured on angiograms. If the results of research based on different methods of measurement of stenosis are to be discussed and the results of clinical trials properly applied to routine clinical practice, measurements made by the different methods must be formally compared.
The method of measurement of stenosis used in the European Carotid Surgery Trial (ECST), that used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET), and a method based on measurement of the common carotid (CC) artery lumen diameter were compared. Carotid stenosis was measured by two observers, working independently and using the three different methods of measurement, on the angiographic view of the symptomatic carotid stenosis that showed the most severe disease in 1001 patients from the ECST.
The results of using the ECST and CC methods differed from those of using the NASCET method in the classification of stenoses as mild (0% to 29%), moderate (30% to 69%), or severe (70% to 99%) in 51% of measurements. The ECST and CC methods indicated that twice as many stenoses were severe as did the NASCET method, and classified less than a third of the number of stenoses as mild. The results of the ECST and CC methods differed from each other in 15% of measurements. The relations between measurements made by each method to those made by the others were approximately linear, so a simple equation could be derived to convert measurements made by one method to measurements made by the others.
There were major and clinically important disparities between measurements of stenosis made using different methods of measurement on the same angiograms. However, it is possible to convert measurements made by one method to those of another using a simple arithmetic equation.
关于如何在血管造影片上测量颈动脉狭窄存在混淆。如果要讨论基于不同狭窄测量方法的研究结果，并将临床试验结果正确应用于常规临床实践，就必须对不同方法所做的测量进行正式比较。
比较了欧洲颈动脉外科试验（ECST）中使用的狭窄测量方法、北美症状性颈动脉内膜切除术试验（NASCET）中使用的方法以及一种基于颈总动脉（CC）动脉管腔直径测量的方法。由两名观察者独立工作，使用这三种不同的测量方法，对1001例来自ECST的患者中显示最严重病变的症状性颈动脉狭窄的血管造影图像进行测量。
在51%的测量中，使用ECST和CC方法得出的狭窄分类结果（轻度[0%至29%]、中度[30%至69%]或重度[70%至99%]）与使用NASCET方法的结果不同。ECST和CC方法显示重度狭窄的数量是NASCET方法的两倍，且将不到三分之一的狭窄分类为轻度。ECST和CC方法的结果在15%的测量中彼此不同。每种方法所做测量与其他方法所做测量之间的关系大致呈线性，因此可以推导出一个简单方程，将一种方法所做的测量转换为其他方法所做的测量。
在同一血管造影片上使用不同测量方法进行的狭窄测量之间存在重大且具有临床重要性的差异。然而，使用一个简单的算术方程就可以将一种方法所做的测量转换为另一种方法的测量。
