Imaging
Carotid Ultrasound
A carotid ultrasound uses sound waves to check the carotid arteries in the neck for narrowing caused by fatty deposits, which can raise the risk of stroke.
Quick answer
Carotid Ultrasound: what it is and what the results mean
A carotid ultrasound (carotid Doppler) is a painless scan that uses high-frequency sound waves to image the carotid arteries — the main vessels carrying blood to the brain — and to measure the speed of blood flow through them.
- Why it is done: It is most often done after a mini-stroke (TIA) or stroke, or when a doctor hears an abnormal sound (bruit) in the neck, to see whether the arteries are narrowed by atherosclerosis and whether treatment or surgery is needed.
- Understanding results: The scan reports the degree of narrowing in each artery, often as a percentage.
What it is
A carotid ultrasound (carotid Doppler) is a painless scan that uses high-frequency sound waves to image the carotid arteries — the main vessels carrying blood to the brain — and to measure the speed of blood flow through them.
Why it is done
It is most often done after a mini-stroke (TIA) or stroke, or when a doctor hears an abnormal sound (bruit) in the neck, to see whether the arteries are narrowed by atherosclerosis and whether treatment or surgery is needed.
What to expect
You lie back with your neck exposed. A sonographer applies gel and moves a small handheld probe over each side of your neck. It is painless and usually takes about 15–30 minutes.
Understanding the results
The scan reports the degree of narrowing in each artery, often as a percentage. Significant narrowing may lead to medicines, lifestyle advice or an operation (carotid endarterectomy or stenting) to reduce stroke risk.
Good to know
Risks and limitations
Ultrasound is very safe with no radiation. It mainly assesses the accessible neck arteries; further imaging such as CT or MR angiography may be needed for vessels higher up or inside the skull.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Carotid Ultrasound: frequently asked questions
Does a carotid ultrasound hurt?
No. It is completely painless — you only feel the cool gel and gentle pressure of the probe on your neck.
What counts as significant carotid narrowing?
Narrowing is graded by percentage. Higher-grade narrowing (often quoted as above 50–70%) on the same side as stroke symptoms is more likely to lead to consideration of surgery; your specialist will explain your result.
Related tests
Other imaging investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Royal College of Radiologists / relevant professional body
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