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 blood vessels.


Other names for a carotid duplex scan are:


carotid artery duplex scan


carotid ultrasound


vascular ultrasound


carotid artery Doppler sonography


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 speech


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.