Key Points

• Carotid ultrasound is a test that uses high-frequency sound waves to create images of the insides of the two large arteries in your neck. These arteries, called carotid arteries, supply your brain with blood.
• A carotid ultrasound can show whether buildup of a fatty material called plaque has narrowed one or both of your carotid arteries and reduced blood flow to your brain.
• If your carotid arteries are narrowed by plaque, you may be at risk for having a stroke, depending on how much of your artery is blocked and how much blood flow is restricted.
• You may need a carotid ultrasound if you had a stroke or ministroke recently or are at high risk for having a stroke.
• Carotid ultrasound is a painless test done in a doctor's office or hospital. It usually doesn't take more than 30 minutes and requires no preparation or followup.
• There are no risks linked to having a carotid ultrasound, because the test uses harmless sound waves.