Ultrasound imaging, also called ultrasound scanning or sonography, involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body. Ultrasound exams do not use ionizing radiation (as used in x-rays). Because ultrasound images are captured in real-time, they can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels.

Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions.

Vascular ultrasound provides pictures of the body's veins and arteries.

A Doppler ultrasound study may be part of a vascular ultrasound examination.

Doppler ultrasound is a special ultrasound technique that evaluates blood flow through a blood vessel, including the body's major arteries and veins in the abdomen, arms, legs and neck.

Sonography is a useful way of evaluating the body's circulatory system. Vascular ultrasound is performed to:

• help monitor the blood flow to organs and tissues throughout the body.
• locate and identify blockages (stenosis) and abnormalities like plaque or emboli and help plan for their effective treatment.
• detect blood clots (deep venous thrombosis (DVT) in the legs or arms.
• determine whether a patient is a good candidate for a procedure such as angioplasty.
• evaluate the success of procedures that graft or bypass blood vessels.
• determine if there is an enlarged artery (aneurysm).
• determine the source and severity of varicose veins.

Doppler ultrasound images can help the physician to see and evaluate:

• blockages to blood flow (such as clots).
• narrowing of vessels (which may be caused by plaque).
• tumors and congenital malformation.

• Vessels deep in the body are harder to see than superficial vessels. Specialized equipment or other tests such as CT or MRI may be necessary to properly visualize them.
• Smaller vessels are more difficult to image and evaluate than larger vessels.
• Calcifications that occur as a result of atherosclerosis may obstruct the ultrasound beam.
• Sometimes ultrasound cannot differentiate between a blood vessel that is closed versus one that is nearly closed. Even if there is a very small remaining opening, the weak blood flow produces a sometimes undetectable signal.
• The test is specialized and is best performed by a technologist and physician with experience and interest in vascular ultrasound imaging.