Vascular Ultrasound: Artery & Vein Testing

Medically reviewed by Nachiket J. Patel, MD, FACC, FSCAI. Last reviewed July 2026.

Vascular ultrasound uses sound waves to examine blood flow without radiation. It can evaluate leg arteries, deep and superficial veins, carotid arteries, and selected abdominal vessels.

The test on your order determines which blood vessels are examined. Artery, blood clot, vein valve, and carotid studies answer different questions.

At Flow Heart & Vascular, the test is selected to answer the clinical question and the images are interpreted alongside symptoms, pulses, wounds, and prior procedures.

What types of vascular ultrasound are available?

Four common vascular ultrasound studies

Test on your order	What it checks
Leg artery ultrasound (arterial duplex)	Looks for narrowed or blocked arteries and evaluates blood flow in the legs.
Deep vein clot ultrasound (DVT study)	Checks the deep veins for a blood clot, called deep vein thrombosis.
Vein valve ultrasound (venous reflux study)	Checks for backward blood flow when vein valves do not close properly.
Neck artery ultrasound (carotid duplex)	Looks for plaque and narrowing in the carotid arteries in the neck.

Your clinician selects the study that fits your symptoms and the question being investigated. A DVT study and a venous reflux study check different problems, even when both examine leg veins. Follow the instructions for the exact test on your order.

Other vascular studies may check selected stents or prior procedures, or focus on a wound, swelling pattern, or finding from your examination.

What happens during the examination?

A technologist applies gel and moves a transducer over the area being studied. Doppler records blood-flow direction and velocity.

For a DVT study, the technologist gently compresses veins to see whether they close normally. For reflux testing, measurements may be taken while standing or with maneuvers that challenge the valves.

An arterial study may examine many segments from the groin to the ankle and may be paired with an ankle-brachial index (ABI), which compares ankle and arm pressures, or with toe-pressure measurements. A carotid study evaluates both sides of the neck.

How should I prepare?

Most leg and carotid studies require little preparation. Wear loose clothing and avoid applying heavy lotion over the area.

Some abdominal vascular studies require fasting because bowel gas can limit the view. Follow the instructions for the exact order rather than assuming all vascular ultrasounds are the same.

Continue medication unless specific instructions say otherwise. Bring information about prior stents, bypasses, clots, or vascular procedures.

What can arterial ultrasound show?

Arterial duplex can locate a velocity increase associated with narrowing, identify an occlusion, and assess flow beyond a diseased segment. The waveform also provides clues about upstream or downstream disease.

Results are interpreted with ankle or toe pressures, pulses, walking symptoms, rest pain, and wounds. An imaging abnormality alone does not determine whether a procedure is needed.

What can venous ultrasound show?

A DVT study can identify clot location and features suggesting whether it is acute or chronic. A reflux study measures failed valve closure in the superficial and deep systems.

Ultrasound may not fully visualize pelvic veins. Marked one-sided swelling or symptoms that do not fit the leg findings may lead to CT, MR, venography, or intravascular ultrasound.

How are results used?

Dr. Patel reviews the report and images, then explains which finding matches the patient’s symptoms. The next step may be reassurance, medical treatment, compression, walking therapy, another imaging test, or procedural planning.

Urgent findings are handled promptly. A scheduled ultrasound should never delay emergency care for a suddenly cold or weak limb, stroke symptoms, severe one-sided swelling with breathlessness, or another acute problem.

Frequently asked questions

Does vascular ultrasound hurt?

It is noninvasive. Pressure from the transducer or vein-compression maneuvers may be temporarily uncomfortable over a tender area.

Can ultrasound see every vascular blockage?

No. Body habitus, calcification, depth, wounds, bowel gas, and pelvic location can limit views. Another test may be needed.

Is a venous reflux study the same as a DVT ultrasound?

No. Both examine veins, but reflux testing uses a different protocol to assess valve function and often takes longer.

How is ultrasound different from CT or MRI?

Ultrasound shows blood flow in real time without radiation or injected contrast. CT and MRI can show anatomy that ultrasound cannot reach clearly, so the best test depends on the vessel and question.

Related heart and vascular information

• Peripheral Artery Disease (PAD)
• Deep Vein Thrombosis (DVT)
• Carotid Artery Disease (Blocked Neck Artery)
• Varicose Veins & Venous Insufficiency

Schedule an appointment

If you have a stable heart or circulation concern, request an appointment with Flow Heart & Vascular in Mesa, Arizona. Call 911 for emergency symptoms.

This page provides general education and does not replace individualized medical advice.