Carotid stenosis is the narrowing of a carotid artery, most commonly the internal carotid artery, due to the buildup of atherosclerotic plaque. Duplex ultrasound is the primary screening and diagnostic tool for carotid stenosis because it can both visualize the plaque directly and measure blood flow velocities, which increase as the vessel narrows. Specific velocity thresholds are used to classify stenosis as mild, moderate, or severe: for example, a peak systolic velocity greater than 230 centimeters per second in the internal carotid artery generally indicates a stenosis of 70 percent or more. This level of narrowing significantly increases stroke risk, and identifying it with ultrasound is critical because patients with severe carotid stenosis may benefit from surgical intervention to reduce their stroke risk.
Sonography Term