What is a carotid ultrasound?
A carotid ultrasound test detects narrowing (stenosis) of the carotid artery that is responsible for TIAs or stroke. The carotid arteries are a pair of major blood vessels that carry blood to the brain through the neck.
A carotid ultrasound is a radiological test done on your carotid arteries. It makes the use of sound waves to detect abnormalities in the carotid artery. The internal carotid artery is the artery that carries blood from your heart to brain.
You will need a carotid ultrasound if you have transient ischemic attacks (TIAs), a condition in which you have symptoms similar to those of a stroke but they last only for a short time. TIA may eventually lead to a stroke. The test detects narrowing (stenosis) of the carotid artery that is responsible for TIAs or stroke.
Your doctor can also recommend a carotid ultrasound if you have medical issues that increase your risk of stroke. These include:
- Diabetes
- A high blood cholesterol level
- A family history of a stroke or heart disease
- Bruit (abnormal sound in the carotid arteries) heard by your doctor using a stethoscope
- Coronary artery disease
A carotid ultrasound is also performed to
- Locate a hematoma (a collection of clotted blood) that may slow and eventually prevent the blood flow.
- Check the state of the carotid artery after carotid endarterectomy (a surgery to remove blockages).
- Confirm the correct placement and efficacy of a metal stent (a mesh tube placed to help the blood flow through an artery).
How does a carotid ultrasound work?
A carotid ultrasound test involves the use of a small hand-held device called a transducer that is placed over a patient’s carotid artery (on the sides of the neck). The transducer emits sound waves, which bounce off the arteries in the form of an echo.
The transducer is connected to a monitor. The echoed sound is translated and displayed on the monitor in the form of black-and-white moving images of the arteries and blood flowing through. A Doppler ultrasound displays the moving images on the monitor. These images show the blood flowing through the arteries.
How is a carotid ultrasound procedure performed?
No special preparation is needed before coming for a carotid ultrasound. You just have to remove any jewelry you are wearing. Here is how a carotid ultrasound is performed:
- You’ll be asked to lie down on your back on a table.
- A technician or radiologist (a specialized doctor) will apply gel to the side of your neck. The radiologist may position you so that they get a better view during the test. Next, they will place the transducer on the area. They will keep on pressing gently with the transducer against the side of the neck while moving along the area.
- The same transducer is used for performing the Doppler ultrasound.
- Finally, the gel is wiped off your skin.
This test is usually completed within 30-45 minutes.
A carotid ultrasound is a painless test and would not cause you any discomfort. If you feel so, tell your radiologist.
What do results of a carotid ultrasound mean?
You may receive the results of a carotid ultrasound in either of the two ways:
- The radiologist may explain to you the results of the test right after the test.
- The radiologist may send the report (which contains the results) to the doctor who had ordered the test. Your doctor will then reveal the results to you and explain what that means.
If the doctor thinks that your results are unclear, they may ask you to undergo additional tests such as a computerized tomography angiogram (CTA) scan or magnetic resonance imaging (MRI).