Key Points

• Carotid ultrasound is a test that uses high-frequency sound waves to create pictures of the insides of the two large arteries in your neck. These arteries, called carotid arteries, supply your brain with oxygen-rich blood.
• A carotid ultrasound can show whether a fatty substance called plaque has narrowed one or both of your carotid arteries and reduced blood flow to your brain.
• If plaque is narrowing your carotid arteries, 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.
• A standard carotid ultrasound shows the structure of your carotid arteries. A Doppler ultrasound is a special test that shows the movement of blood through your blood vessels.
• Your doctor often will need the results from both types of ultrasound to fully assess whether there's a problem with blood flow through your carotid arteries.
• Your doctor may recommend a carotid ultrasound if you had a stroke or mini-stroke recently or are at high risk of having a stroke. During a mini-stroke, you may have some or all of the symptoms of stroke. However, the symptoms usually go away on their own within 24 hours.
• A carotid ultrasound also may be used to see whether carotid artery surgery (also called carotid endarterecomy) has been successful, whether a stent has been placed correctly, or as a preventive screening test.
• Carotid ultrasound is a painless test done in a doctor's office or hospital. It often doesn't take more than 30 minutes and usually requires no preparation or followup.
• Often, your doctor will be able to tell you the results of the carotid ultrasound when it occurs or soon after.
• There are no risks linked to having a carotid ultrasound because the test uses harmless sound waves.