Carotid (kuh-ROT-id) ultrasound is a safe, painless procedure that uses sound waves to examine the blood flow through the carotid arteries.
Your two carotid arteries are located on each side of your neck. They deliver blood from your heart to your brain.
Carotid ultrasound tests for blocked or narrowed carotid arteries, which can increase the risk of stroke. The results can help your doctor determine a treatment to lower your stroke risk.
A carotid ultrasound is performed to test for narrowed carotid arteries, which increase the risk of stroke.
Carotid arteries are usually narrowed by a buildup of plaque — made up of fat, cholesterol, calcium and other substances that circulate in the bloodstream. Early diagnosis and treatment of a narrowed carotid artery can decrease stroke risk.
Your doctor will recommend carotid ultrasound if you have transient ischemic attacks (TIAs) or certain types of stroke and may recommend a carotid ultrasound if you have medical conditions that increase the risk of stroke, including:
To screen for narrowed or blocked blood vessels in other areas of the body, you may need additional tests, including:
Your doctor may also order imaging tests to detect coronary artery disease.
Your doctor may order a carotid ultrasound to:
You can take the following steps to prepare for your appointment:
Unless your doctor or the radiology lab provides special instructions, you shouldn't need to make any other preparations.
A technician (sonographer) conducts the test with a small, hand-held device called a transducer. The transducer emits sound waves and records the echo as the waves bounce off tissues, organs and blood cells.
A computer translates the echoed sound waves into a live-action image on a monitor. The radiologist may use a Doppler ultrasound, which shows blood flowing through the arteries. In a Doppler ultrasound, the rate of blood flow is translated into a graph.
A carotid ultrasound usually takes about 30 minutes.
You'll likely lie on your back during the ultrasound. The ultrasound technician (sonographer) may position your head to better access the side of your neck.
The sonographer will apply a warm gel to your skin above the site of each carotid artery. The gel helps transmit the ultrasound waves back and forth. The sonographer then gently presses the transducer against the side of your neck.
You shouldn't feel any discomfort during the procedure. If you do, tell the sonographer.
A doctor who specializes in imaging tests (radiologist) will review your test results, then prepare a report for the doctor who ordered the test. This may be your primary care doctor, a doctor trained in heart and blood vessel conditions (cardiologist), or a doctor trained in brain and nervous system conditions (neurologist).
The radiologist may also discuss the results of the test with you immediately after the procedure.
The doctor who ordered the test will explain to you what the carotid ultrasound revealed and what that means for you.
If the test reveals you're at risk of a stroke, your doctor may recommend the following therapies, depending on the severity of blockage in your arteries:
If your doctor ordered the carotid ultrasound as a follow-up to a surgical procedure, your doctor can explain whether the treatment is working, and whether you'll need additional treatment or follow-up exams.
If your results are unclear, your doctor may order additional imaging tests, including:
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