Why is a carotid artery duplex scan used?

A carotid artery duplex scan (a type of vascular ultrasound study) is used to assess occlusion (blockage) or stenosis (narrowing) of the carotid arteries of the neck and/or the branches of the carotid artery. Plaque (a buildup of fatty materials), thrombus (blood clot), and other substances in the bloodstream may cause a disturbance in the blood flow through the carotid arteries.

When the carotid arteries become blocked, symptoms may include dizziness, confusion, drowsiness, headache, momentary blindness in one eye, and/or a brief loss of ability to speak or move. These symptoms may indicate early warning signs of a possible stroke (brain attack, or cerebrovascular accident [CVA]).

A carotid artery duplex scan may also be performed when no symptoms of occlusion are present, yet an abnormal blood flow sound called a bruit is heard with a stethoscope over the artery. This may indicate a possible condition of abnormal blood flow in the artery.

Additional reasons for the procedure include, but are not limited to, the following:
  • evaluation of previous procedures to restore blood flow to the area (such as an angioplasty to open up an artery that was blocked or surgery to bypass a blocked artery)
  • evaluation of carotid blood flow prior to a major cardiovascular surgical procedure, such as coronary artery bypass grafting or heart valve repair/replacement
  • location of a hematoma (a collection of clotted blood that may slow and eventually stop blood flow)
  • detect dissection of the carotid artery, a split between layers of the artery wall that may lead to obstruction of blood flow or a weakening of the wall of the artery
There may be other reasons for your physician to recommend a carotid artery duplex scan.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.