A duplex or doppler venous ultrasound of the lower extremities is a noninvasive medical test that is used to search for blood clots, in the veins of the legs. This condition is often referred to as deep vein thrombosis or DVT. These clots may break off and pass into the lungs, where they can cause a dangerous condition called pulmonary embolism. If the blood clot in the leg is found early enough, treatment can be started to prevent it from passing to the lungs.
A venous ultrasound study is also performed to determine the cause of long standing leg swelling, possibly due to a condition in people with varicose veins. Patients with this condition can develop venous insufficiency in which the veins become dilated and the valves that keep blood flowing back to the heart in the right direction may become damaged.
What happens during the exam?
The patient lies on a table with the legs covered with a drape or blanket. The sonographer (technologist who performs the exam) will put a warm water-based gel on the skin surface. The gel helps to transmit the sound waves by excluding air. An instrument called a transducer, which is about the size of a microphone, will be moved over the skin surface by the sonographer.
How do I prepare for this test?
No preparation is needed.
How long will it take?
About twenty minutes.
Will it hurt?
How will I learn the results?
You may call your doctor to discuss the results.