Figure 1From: Clinical trials for carotid stenosis revascularization and relation to methods of stenosis quantification Shows a conceptualized drawing of the calculation of % stenosis = (1 – N/D)100, with N as the narrowest observed diameter and D as the diameter of the “normal” internal carotid diameter well beyond the bulb where the walls are parallel. Reproduced with permission from Radiology [3].Back to article page