Carotid ultrasound is a painless and harmless test to look for disease in the two main blood vessels that provide blood flow to the brain. Ultrasound uses sound waves instead of radiation to generate snapshots or moving pictures of structures inside the body.
You have two common carotid arteries, one on each side of your neck. They each divide into internal and external carotid arteries. The internal carotid arteries supply oxygen-rich blood to your brain. The external carotid arteries supply oxygen-rich blood to your face, scalp, and neck.
The primary purpose of a carotid ultrasound is to test for narrowed carotid arteries that indicate an increased risk of stroke. Narrowing of carotid arteries is usually caused by plaque — a buildup of fat, cholesterol, calcium and other substances that circulate in the bloodstream. Early detection of narrowed carotid arteries enables your doctor to begin treatments to improve blood flow to your brain and decrease your risk of stroke.