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.
Your doctor may recommend a carotid ultrasound if you have medical conditions that increase the risk of stroke, including:
- High blood pressure
- High cholesterol
- Family history of stroke or heart disease
- Recent transient ischemic attack (TIA) or stroke
- Abnormal sound in carotid arteries (bruit), detected by your doctor using a stethoscope
You'll have a Doppler ultrasound that evaluates the blood flow through your carotid arteries.
A carotid ultrasound may be used in combination with other tests to screen for narrowed or blocked blood vessels in other areas of your body, including:
- Abdominal ultrasound. You may have an abdominal ultrasound to test for conditions affecting the blood vessels or organs in your abdominal area.
- Ankle-brachial index test. This test measures and compares your ankle's blood pressure and your arm's blood pressure. The test can indicate reduced or blocked blood flow to your legs.
Other uses of carotid ultrasound
Your doctor also may order a carotid ultrasound to:
- Evaluate the structure and function of the artery after surgery to remove plaques (carotid endarterectomy)
- Evaluate the placement and treatment effect of a stent, a mesh tube used to improve blood flow through an artery by mechanically decreasing the narrowing
- Locate a collection of clotted blood (hematoma) that may inhibit blood flow
- Detect other abnormalities in the structure of a carotid artery that may disrupt blood flow