What Is a Carotid Ultrasound?

Carotid artery disease matters because plaque and narrowing can contribute to ischemic stroke risk. Plaque may reduce blood flow toward the brain, and pieces of plaque or clot can travel from the artery to the brain. That is why carotid findings are always considered alongside other stroke risk factors rather than on their own.

A neurologist may order a carotid ultrasound in several situations:

This does not mean everyone should receive a carotid ultrasound as routine stroke screening. Testing is most useful when the result will help answer a specific clinical question.

During a carotid artery ultrasound, gel is placed on the neck and an ultrasound probe is moved over the carotid arteries. The test is noninvasive, does not use radiation, and typically requires little preparation.

Doppler measurements allow clinicians to evaluate blood-flow velocity. When an artery is narrowed, blood flows through it faster, and the velocity measured with a carotid Doppler ultrasound helps estimate whether an artery is significantly narrowed.

Carotid stenosis means narrowing of a carotid artery, most commonly from atherosclerotic plaque — the same fatty, inflammatory material that builds up in arteries elsewhere in the body. Results may be described according to the estimated degree of narrowing, such as mild, moderate, or severe stenosis.

The right next step does not follow from a specific percentage alone. Management depends on multiple factors, including:

An abnormal result does not automatically mean someone needs surgery. Depending on the findings and the clinical situation, additional evaluation may include CTA or MRA of the arteries. Treatment may involve management of vascular risk factors and medications, while selected patients with significant carotid disease may be evaluated for procedures such as carotid endarterectomy or carotid artery stenting.

Controlling blood pressure, cholesterol, diabetes, and tobacco exposure remains important for reducing vascular and stroke risk — whatever the ultrasound shows. You can read more in our overviews of what is a TIA and what is a stroke, and in our guide to stroke and TIA follow-up care, which covers prevention planning and risk factor control.

Stroke warning signs are always an emergency. Sudden face drooping, arm weakness, speech difficulty, or other new neurological symptoms warrant calling 911 right away — do not wait to schedule imaging.