You have 2 carotid arteries in your neck that bring blood from your heart to your brain. The test may also look at the vertebrobasilar artery, which also brings blood to your brain.
Your healthcare provider uses a device called a transducer to make pictures of the arteries. The transducer sends out sound waves that bounce off your blood vessels. The sound waves are too high-pitched for you to hear. The transducer then picks up the bounced sound waves and translates them into pictures.A duplex scan means that the provider uses 2 transducers. The second one (Doppler) lets your provider hear the sound waves the transducer sends out. He or she can hear how fast blood is flowing through a blood vessel and in which direction it is flowing. No sound or a faint sound may mean that you have a blockage in the flow.
You may need this scan if your healthcare provider thinks you may have:
A blockage may be caused by a buildup of fatty material (plaque), a blood clot (thrombus), or other substances.
Symptoms of blockage may include:
These symptoms may be early warning signs of a stroke.
You may also need this scan even if you have no symptoms but your healthcare provider hears an abnormal sound (bruit) in an artery. This abnormal sound may mean that you have a problem with blood flow in the artery.
Here are other reasons you may have this scan:
Your healthcare provider may have other reasons to recommend a carotid artery duplex scan.
This scan has no risk from radiation. The transducer usually causes no discomfort when put on your skin.
You may have risks depending on your specific health condition. Be sure to talk with your provider about any concerns you have before the scan.
Certain things can make this scan less accurate. These include:
You may have this scan as an outpatient or as part of your stay in a hospital. The way the test is done may vary depending on your condition and your healthcare provider's practices.
Generally, a carotid artery duplex scan follows this process:
The carotid artery duplex scan is not painful. But you may have some discomfort from lying still during the test. The technologist will use all possible comfort measures and finish the procedure as quickly as possible to minimize any discomfort.
You do not need any special care after a carotid artery duplex scan. You may go back to your usual diet and activities unless your doctor tells you otherwise.
Your healthcare provider may give you other instructions, depending on your situation.
Before you agree to the test or the procedure make sure you know: