Diagnosing Problems of the Blood Vessels: Vascular Ultrasound

Vascular Ultrasound (US) is used to diagnose blood vessel or heart problems. This non-invasive test does not use needles, dyes, radiation or anesthesia. It uses harmless sound waves whose frequencies are too high to be heard by humans. A technologist will administer the test by first putting a water-based gel over the areas to be checked. A transducer (which looks like a small microphone) is placed into the gel and passed over the areas to be examined. This makes an image (or picture) on the US machine. In addition, it measures the blood flow in specific vessels. You will probably hear noises as the technologist moves the transducer around. When the exam is over, a physician reviews and interprets the images and measurements.

Make sure you wear comfortable clothing to the lab. You will be asked to change into a hospital gown to uncover whatever part of you is being examined. The only special preparation is for the abdominal US test. Most exams take 30-60 minutes to complete. You may resume your normal activity after the test. Your health care provider will give you the results when they are available.

Carotid Duplex
Ultrasound is used to evaluate the carotid arteries located in the neck that feed the brain with blood. Gel will be applied to the skin of the neck. A transducer will be placed on the gel-covered areas to obtain images and evaluate and listen to the blood flow in the arteries.

Transcranial Doppler (TCD)
The blood vessels that supply the brain within the skull are evaluated by Transcranial Doppler. This exam is performed with a small transducer that is placed on the skin of the face and head. This exam takes approximately 60 minutes.

Arterial Duplex
Ultrasound is used to evaluate the arteries that feed the arms and legs with blood. Gel will be applied to the skin of the legs or arms. A transducer will be placed on the gel-covered areas to obtain images and listen to the blood flow in the arms or legs.

Venous Duplex
Ultrasound is used to evaluate the veins that carry blood to the heart from the legs or arms. Gel will be applied to the skin of the legs or arms. A transducer will be placed on the gel-covered areas to obtain images and evaluate flow in the veins.

Abdominal Vascular Duplex
Ultrasound is used to evaluate the blood vessels that bring blood to and away from your abdominal organs. Gel will be applied to the abdomen. A transducer will be placed on the gel-covered areas to obtain images and listen to blood flow in the arteries and/ or veins. Prior to your exam, you must fast (nothing by mouth) for 12 hours prior to your scheduled appointment.

Arterial Pressures and Waveforms
Ultrasound and blood pressure cuffs are used to evaluate the arteries that supply the arms and legs with blood. Several blood-pressure cuffs will be placed at different segments of your legs or arms. When inflated, the cuffs will provide blood pressure readings as well as waveforms. This test will locate areas of blockage within the arteries.

This article was excerpted courtesy of the Society for Vascular Ultrasound (SVU)'s "Vascular Testing and You" patient brochure. For more information, visit www.svunet.org.