What is a peripheral vascular ultrasound?
A peripheral vascular ultrasound, sometimes called a Doppler study, uses harmless sound waves to look at the arteries and veins outside the heart, most often in the neck, arms and legs. A small probe with gel on it is moved over the skin, and the machine shows both a picture of the vessel and the speed and direction of blood flowing inside it, which you may hear as a whooshing sound. Nothing is injected and no X-rays are used.
Why is it done?
In the neck arteries it looks for fatty build-up that narrows the vessel and increases the risk of stroke. In the legs it is used for cramping pain on walking, cold or discoloured feet, or wounds that will not heal, and it can show where an artery is narrowed or blocked. On the vein side it is the standard test for suspected deep vein thrombosis, for varicose veins and for leg swelling. It is also used to check bypass grafts, stents and the dialysis fistula, and to plan or follow up treatment.
What happens on the day?
Very little preparation is needed. For a study of the abdominal vessels you may be asked not to eat for several hours, and for leg vein studies you should wear clothing that is easy to remove. In the room you lie on a bed, or sometimes stand for a vein study, and the area is exposed and warm gel is applied. The sonographer or doctor moves the probe over the skin with gentle pressure, may ask you to breathe in a particular way, squeeze a muscle or change position, and measures the blood flow at several points. It usually takes twenty to forty-five minutes depending on how much is examined. The gel feels cool and the pressure of the probe may be mildly uncomfortable over a tender leg, but the test is not painful.
What to expect afterwards
The gel is wiped off and you can dress and carry on with your day immediately; you may eat, drive and take your usual medication. There are no after-effects. Your cardiologist reviews the images and measurements and discusses the findings with you, often on the same day, along with what they mean for your treatment, which may include medication, exercise advice, compression stockings, or a further test such as an angiogram.
Possible complications
This is one of the safest tests available. Ultrasound uses sound waves rather than radiation, nothing is injected, and there are no known harmful effects at the levels used. The only discomfort is from the cool gel and from pressure of the probe on a tender or swollen limb. Occasionally the picture is limited by heavy calcium, bowel gas, swelling or a large body habitus, in which case another form of scan may be needed to answer the question fully.
This information does not replace a consultation. Please discuss your own risks and options with your cardiologist.