Carotid Artery Duplex Scan | Tampa General Hospital

Carotid Duplex 

A carotid duplex is a vascular ultrasound study used to assess a narrowing or blockage in a carotid artery. 

A carotid duplex scan is a relatively simple diagnostic test that utilizes both conventional and Doppler ultrasound. The results can help a physician evaluate the flow of blood through the two carotid arteries in the neck, which supply blood to the brain.  

Conditions Diagnosed 

A physician may order a carotid duplex scan to investigate a suspected narrowing or blockage in a carotid artery, which may be related to a blood clot or a buildup of cholesterol plaque on the arterial walls. The signs of a narrowed or blocked carotid artery include: 

  • Mental confusion 
  • Unexplained drowsiness 
  • Dizziness 
  • Headache 
  • A temporary inability to see, speak or move 

    Additionally, a physician may use a carotid duplex scan to evaluate the flow of blood through the carotid arteries before major heart surgery, such as a bypass or heart valve replacement procedure, or after angioplasty. 

    Procedure Details 

    While the patient lies on an examination table with his or her head tilted slightly back, a sonographer will apply a clear gel to the skin over the carotid arteries. Next, the technician will gently glide a handheld Doppler transducer over the gel. The transducer will generate high-frequency sound waves, which will bounce off circulating blood cells. 

    The transducer will receive the reflected sound waves and send them to an amplifier, which will make them audible to the sonographer. If the sound is faint or absent, an obstruction may be present. The bounced sound waves will also be used to create images, which will be produced in graphical form to show the speed and direction of the blood flow. 

    What to Expect 

    A carotid artery duplex scan does not involve radiation exposure or the associated risks. Most patients do not experience any discomfort when the transducer is passed over their skin. 


    A carotid duplex ultrasound can reveal a narrowing or blockage in a carotid artery, both of which can increase the risk of heart attack and stroke. Certain factors can reduce the accuracy of the test, including arrhythmias, heart disease and obesity. 

    The specialists in Tampa General Hospital’s Heart & Vascular Institute are skilled and experienced in diagnosing vascular disease utilizing the most advanced technologies, including carotid duplex.