The carotid arteries are the principal blood vessels that carry oxygenated blood from the heart to the brain. Each side of the neck has a common carotid artery that branches into an internal carotid artery, supplying the brain, and an external carotid artery, supplying the face and scalp. Carotid duplex ultrasound is one of the most commonly performed vascular studies and is used to evaluate for atherosclerotic plaque, measure the degree of stenosis, and assess stroke risk. The examination combines B-mode imaging to visualize the vessel walls and plaque with Doppler ultrasound to measure blood flow velocities, which correlate with the severity of any narrowing.
Sonography Term