Carotid Ultrasound

Your Care Explained > Tests and Procedures : Carotid Ultrasound

Carotid ultrasound is a noninvasive test used to evaluate the arteries that supply blood from the heart through the neck to the brain.

It’s also called a carotid artery duplex scan because two modes of ultrasound—B-mode and Doppler—are used. B-mode obtains an image of the carotid artery being studied; Doppler evaluates the speed and direction of blood flow in the vessel. Together, the two give physicians information that is helpful in deciding what treatments to use to prevent stroke.

What to Expect:

  • No caffeinated beverages or cigarettes before the test.
  • A dim room helps doctors clearly see monitors.
  • You will hear a “whooshing” sound.
  • The test should last about an hour.
  • You’ll be able to go home on your own.

Preparing for Carotid Ultrasound

Your physician will explain the procedure to you and offer you the opportunity to ask any questions that you might have. You may be asked to sign a consent form acknowledging that you understand the test and giving your permission to do the procedure.

Generally, no prior preparation, such as fasting or sedation, is required. However, you may be asked not to smoke or consume caffeine—both of which constrict blood vessels—for a couple of hours before the test.

Having a Carotid Ultrasound

On the day of your test you’ll be given a short form to fill out and an identification bracelet. The technician will greet you and escort you to the examination room. You will be asked to remove any clothing, jewelry or other objects that may interfere with the scan. If it’s necessary for you to remove your top and undergarments, you’ll be given a gown to wear.

The technician will help you onto a padded examination table and position you with your neck extended. He or she will dab a clear gel on a few spots along your neck.

The transducer will be pressed against the skin and moved around over the area of the artery being studied. You will hear a “whoosh, whoosh” sound from time to time as blood flow is evaluated. The probe will be moved around on both sides of the neck to compare blood flow in different areas of the arteries.

Once the procedure has been completed, the gel will be wiped off. You can dress and go home.

Learning Your Results

A radiologist who specializes in interpreting ultrasound images will evaluate your test and forward the analysis to your doctor. It may be a few days before your doctor contacts you to discuss the results.

Date Last Modified: January 21, 2011

Send Feedback To: BWH Women’s Health at

75 Francis Street, Boston, MA 02115 617.732.5500
harvard medical school partners healthcare © BWH 2011