What is it?
Ultrasound imaging, also called ultrasound scanning or sonography, involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body.
An ultrasound of the body's two carotid arteries, which are located on each side of the neck and carry blood from the heart to the brain, provide detailed pictures of these blood vessels.
A Doppler ultrasound study is usually part of a carotid ultrasound examination.
Doppler ultrasound is a special ultrasound technique that evaluates blood as it flows through a blood vessel, including the body's major arteries and veins in the neck, abdomen, arms, and legs. How is the test performed?
For most ultrasound exams, the patient is positioned lying face-up on an examination table that can be tilted or moved.
A clear gel is applied to the area of the body being studied to help the transducer make secure contact with the body and eliminate air pockets between the transducer and the skin. The sonographer (ultrasound technologist) or radiologist then presses the transducer firmly against the skin and sweeps it back and forth over the area of interest.
The transducer emits high-frequency, ultrasound waves that pass into the body and bounce off the carotid arteries and the red blood cells moving through them. The sound waves are reflected differently by different parts of the body. The transducer detects the different reflections of the sound waves, which are then measured and converted by a computer into live pictures of the arteries and the blood flow. What can the test tell my doctor?
The major goal of carotid ultrasound is to screen patients for blockage or narrowing (stenosis) of their carotid arteries, which, if present, may increase their risk of having a stroke. Once the diagnosis is made a comprehensive treatment plan may be initiated.
It may be performed if a patient has had a stroke or transient ischemic attack (TIA) or a carotid bruit - an abnormal sound in the neck that is heard with the stethoscope. Are there risks?
For standard diagnostic ultrasound there are no known harmful effects on humans.
In nearly 50 years of experience, carotid ultrasound has proved to be a risk-free procedure, according to the RadiologyInfo Web site
-- Carotid Ultrasound Imaging
-- The Internet Stroke Center