Carotid Artery Duplex Ultrasound

A diagnostic ultrasound, also called a sonography, is a safe, non-invasive medical imaging tool that produces images of structures within the body. Using soundwaves to bounce off the blood vessels in your neck, the carotid artery duplex ultrasound is designed to specifically create images and assess vascular blockages or narrowing in the carotid arteries and its branches. The more narrowed your artery is, the higher you’re at risk for a stroke.

Carotid arteries, one located on the right side of the neck and other on the left, are critical blood vessels which supply blood to the head and brain. The arteries in the neck branch; the internal carotid arteries supply blood to the brain while the external carotid artery supplies blood to the face and neck. 

Performed in Mount Sinai Neurology’s Neurovascular Laboratory, experienced stroke neurologists will perform the ultrasound in person, and/or work with technicians closely, to perform tests and interpret the carotid duplex in the setting of clinical context (including neurological symptoms and exam, brain imaging findings), and communicate with your physician who ordered the tests. A full neurovascular work-up, including a Transcranial Doppler Ultrasound, may also be performed.

The carotid artery duplex ultrasound may be ordered by your physician to check the blood flow and blood vessels in your carotid artery to either diagnose or have a follow-up monitoring, because you may have:

  • Presented with symptoms including vision disturbance, arm or leg weakness, speech abnormalities, dizziness, balance issues, or memory loss
  • Abnormal sound called bruit in the neck region during the physical exam
  • Had a previous stroke or transient ischemic attack (TIA)
  • Previously detected a narrowing in your carotid artery
  • Had surgery on your carotid artery

During Your Exam

With no special preparation needed, the carotid artery duplex ultrasound is painless and harmless as sound waves produce the images of the blood vessels inside of your neck. The exam will take approximately between 15 to 30 minutes.

  • We recommend not wearing necklace, and wearing looser clothing, especially around the neck
  • Warm gel is applied to the neck area
  • Though you’ll feel no pain, you may experience mild pressure as the transducer is pressed against your neck
  • You will hear a "whooshing" sound, which is normal
  • Keep your head still and avoid talking during the exam


After the exam is complete, a vascular neurologist trained specifically in the evaluation and management of cerebrovascular disorders will review the results and determine how open, narrow, or blocked your carotid arteries are.

Normal Results

If your vascular neurologist accesses that your results are normal, it means that there is no issue with the carotid arteries or their branches. Depending on the reason for your exam, you may be requested to come back for additional follow-up tests.

Abnormal Results

If your vascular neurologist accesses that your results are abnormal, it means that there are some issues with the carotid arteries or their branches, including narrowing and blockage, and you may be at a higher risk for stroke.

Conditions that can be detected:

  • Atherosclerosis (plaque buildup in the arteries)
  • Thrombosis (blood clotting)
  • Dissection (tear of the vessel wall)
  • Other cause of narrowing (stenosis) or blockage in the carotid arteries 


Depending on the results of the carotid artery duplex ultrasound and the intensity of the narrowing or blockage, your physician may recommend any of the following:

  • Medications to prevent/slow down the vessel narrowing
  • Lifestyle Change
  • Healthy diet and exercise to prevent hardening of the arteries and plaque buildup
  • Performing of Additional Tests - CT angiography, and magnetic resonance angiography (MRA), cerebral angiography
  • Cerebrovascular Surgery - requiring follow-up testing and repeating of the ultrasound in the future