Prognostic Value and Reproducibility of Measurements of Carotid Stenosis A Comparison of Three Methods on 1001 Angiograms

Background and Purpose The use of three methods of measuring carotid stenosis, which produce different values on the same angiograms, has caused confusion and reduced the generalizability of the results of research. If the results of future studies are to be properly applied to clinical practice, and if noninvasive methods of imaging are to be properly validated against angiography, a single, standard method of measurement of stenosis on angiograms must be adopted. This standard method should be selected on the bases of its ability to predict risk of ipsilateral carotid distribution ischemic stroke and its reproducibility. Methods The method of measurement of carotid 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 the measurement of the common carotid (CC) lumen diameter were studied. Their use in the prediction of ipsilateral carotid distribution ischemic