What Is a Carotid Duplex Scan?
A carotid duplex scan is
a simple and painless test that combines two types of ultrasound to look for
blockages in your carotid arteries. An ultrasound is a type of scan that uses
sound waves to produce a picture of the inside of your body. Your carotid
arteries are located along both sides of your neck. Blocked carotid arteries
are a major risk factor for stroke.
The two types of
ultrasound used in a carotid duplex scan are conventional ultrasound and
Doppler ultrasound. Conventional, or B-mode, ultrasound uses sound waves that bounce off blood vessels to
provide a picture of the structure of your blood vessel. Doppler ultrasound uses sound waves that track moving
objects. This allows your doctor to see how your blood is moving through your
Other names for a carotid duplex scan are:
- carotid artery duplex scan
- carotid ultrasound
- vascular ultrasound
- carotid artery Doppler sonography
Why Do I Need a Carotid Duplex Scan?
Carotid artery disease is a major risk factor for stroke. The
buildup of cholesterol plaques in your carotid arteries can create blood clots.
If these clots break off, they can travel to your brain and cause a stroke.
The first symptom of carotid artery disease is often a stroke or
ministroke. Some early warning symptoms of a stroke are:
- weakness, numbness, or tingling on one side of
your body or in your arm or leg
- an inability to move your arm or leg
- an inability to speak clearly, or having garbled
- an inability to see in one eye, or tunnel vision
See your doctor immediately if you experience any of these warning
signs, even if they go away. It could mean that you’ve had a stroke or that
you’re about to have one.
When you see your doctor, they’ll ask you questions about your symptoms
and your medical history. Your doctor may also listen to the blood flow in your
neck and will measure your blood pressure. If your doctor thinks you have
carotid artery disease, they’ll order a carotid duplex scan.
What Causes Blockages in Carotid Arteries?
As we age, our arteries tend to develop a sticky substance
called plaque. Plaque
buildup is related to:
- not getting enough exercise
- having high triglyceride (fat) or cholesterol
levels in the blood
- being overweight or obese
- having diabetes
- having certain genetic factors
- having high blood pressure
If plaque builds up in your carotid arteries, it’s called carotid artery disease. According to
for Vascular Surgery, about 1 percent of adults aged 50 to 59 have
carotid artery disease and 10 percent of adults aged 80 to 89 have it.
Getting Ready for Your Carotid Duplex Scan
You may be asked not to smoke or drink caffeine for at least two
hours before the test. Smoking and caffeine use can shrink your blood vessels
and affect the accuracy of the test.
Wear comfortable clothing with an open neck. Avoid turtlenecks or
silk clothing, which could be stained by the ultrasound gel. Remove any
What Happens During a Carotid Duplex Scan?
A carotid duplex scan takes about 15 to 30 minutes and takes
place in an ultrasound lab. The following steps take place during this
- You’ll lie down on the examination table with
your head bent slightly backward.
- An ultrasound technician will apply a gel to
- They’ll then move a small ultrasound wand along
the area where your carotid arteries are located. You may feel slight pressure
and hear a whooshing noise, which is the sound of your blood moving through
- The ultrasound images are sent to a computer and
recorded for your doctor.
Ultrasound is a risk-free method to view changes and
abnormalities in your body, including during pregnancy.
Understanding the Results of a Carotid
Most cases of carotid disease are diagnosed by using a carotid
duplex scan. Your doctor can order more tests if they need more information.
If your doctor diagnoses you with carotid artery disease, they’ll
recommend treatment based on how severe it is. You may need surgery to remove the
plaque in your arteries, or you might need what’s called “carotid angioplasty
During carotid angioplasty and stenting, your doctor threads a
catheter up through your carotid artery to the location of the blockage. The
catheter inflates a small balloon to flatten the plaque. Then, a stent is
inserted to keep your arteries open. A stent is a small, metal mesh tube.
Your doctor may also prescribe medications to thin your blood or
control the levels of lipids in your blood. Lifestyle changes, including quitting
smoking, adopting a healthier diet, and exercising, are also important for
preventing and treating carotid artery disease.