The test is done in the ultrasound or radiology department or in a peripheral vascular lab.

To examine the veins:

A water-soluble gel is placed on a handheld device called a transducer, which directs the high-frequency sound waves to the artery or veins being tested.

To examine the arteries:

Blood pressure cuffs may be put around different parts of the body, including the thigh, calf, ankle, and different points along the arm. A paste is applied to the skin over the arteries being examined. Images are created as the transducer is moved over each area.

You will need to remove clothing from the arm or leg being examined.

There is little or no discomfort associated with this test.

This test is done as an alternative to arteriography and venography. It may help diagnose:

• Arterial occlusion
• Blood clot
• Problems in the carotid artery blood flow caused by narrowing
• Venous insufficiency

The test may also be used to evaluate injury to the arteries and to monitor arterial reconstruction and bypass grafts.

A normal result means the blood vessels show no signs of narrowing or closure, and the arteries have normal blood pressure.

Abnormal results may be due to:

• Blockage in an artery by a blood clot, piece of fat, or an air bubble
• Blood clot in an artery or vein
• Spastic arterial disease (arterial contractions brought on by cold or emotion)
• Venous occlusion (closing of vein)

Additional conditions under which this test may be performed include:

• Aortic dissection
• Arteriosclerosis of the extremities
• Coarctation of the aorta
• Deep venous thrombosis
• Stroke secondary to carotid stenosis
• Superficial thrombophlebitis
• SVC obstruction
• Thromboangiitis obliterans
• Vascular tumors of the arms or legs

There are no risks specifically associated with this procedure.

Cigarette smoking may alter the results of this test, because nicotine can cause the arteries in the extremities to constrict.

Quitting smoking significantly lowers the risk of problems with the heart and circulatory system. Most smoking-related deaths are caused by cardiovascular problems, not lung cancer.