Carotid duplex is a simple and painless test that combines two types of ultrasound (sound waves) to look for blockages in your carotid arteries. Your carotid arteries are located along both sides of your neck. Blocked carotid arteries are a major risk factor for stroke.
Conventional ultrasound, or B-mode, uses sound waves that bounce off blood vessels to provide a picture of your blood vessel structure.
Doppler ultrasound uses sound waves that track moving objects so your doctor can see how your blood is moving through your blood vessels.
Carotid duplex may also be called carotid artery duplex scan, carotid ultrasound, vascular ultrasound, and carotid artery Doppler sonography.
As we grow older, our arteries tend to develop a sticky substance called plaque. Plaque buildup is related to:
- lack of exercise
- poor diet high in fat and cholesterol
- being overweight or obese
- high blood pressure
When plaque builds up in the carotid arteries, it is called carotid artery disease. According to the Society for Vascular Surgery, about one percent of adults ages 50 to 59 have carotid artery disease, and10 percent of adults ages 80 to 89 have it (SVS, 2010).
Carotid artery disease is a major risk factor for stroke. The rough plaque buildup in the carotid arteries can create blood clots. When these clots break off, they can travel to the brain and cause a stroke.
Unfortunately, the first symptom of carotid artery disease is typically a stroke or mini-stroke. Some early warning signs can include:
- weakness, numbness, or tingling on one side of the body or in your arm or leg
- inability to move your arm or leg
- inability to speak clearly
- inability to see in one eye
If you experience any of these warning signs, even if they go away, it’s important that you see a doctor immediately. It could mean that you have had—or are about to have—a stroke.
When you see your doctor, he or she will 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, he or she will order a carotid duplex.
You may be asked not to smoke or drink caffeine at least two hours prior to the test. Smoking and caffeine use can shrink 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 gel. Remove any jewelry.
The procedure takes only about 15 to 30 minutes and takes place in an ultrasound lab. You will lie down on the examination table with your head bent slightly backward.
A specially trained ultrasound technician will apply a gel to your neck. He or she will then move a small ultrasound wand along the area where the carotid arteries are located. You may feel slight pressure and hear a “whooshing” noise, which is the sound of your blood moving through your vessels.
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 the body, including during pregnancy.
Most cases of carotid disease will be diagnosed through carotid duplex. It is possible your doctor could order more tests if he or she needs more information.
If you are diagnosed with carotid artery disease, your doctor will recommend treatment based on how severe it is. You may need surgery to remove the plaque in your arteries. Or, you might benefit from angioplasty and stenting.
In this procedure, a doctor threads a catheter to your carotid arteries. The catheter inflates a small balloon to flatten the plaque. Then, a stent (small metal mesh tube) is inserted to keep your arteries open.
Your doctor may also prescribe medications to thin your blood or control blood lipid levels. Lifestyle changes—including quitting smoking, adopting a healthier diet, and exercising—are also important in preventing and treating carotid artery disease.