The Vascular Laboratory utilizes Duplex Ultrasonography in order to perform a variety of diagnostic tests. It utilizes sound waves to produce images of veins and arteries. This technology enables physicians to assess a patient's vascular status without x-rays or puncturing the skin (also referred to as noninvasive testing.) The test is performed by a technologist using a hand held Doppler, which emits sound waves. Sound requires a medium to be transferred through such as liquid or gas. Vascular diagnostic testing utilizes a gel medium to transmit the sound into a patient to receive the images. This is the same technique that is used when an obstetrician views an unborn baby. Through the use of this technology, a real time image is displayed, which shows the location of vessels (arteries and veins). Furthermore, it allows the technologist and physician to measure vessel size, and to pinpoint irregularities such as plaque or a narrowing in the vessel.

The Vascular Laboratory ultrasound machines in the Clinical Center for Vascular Disease are equipped to perform Colorflow Duplex imaging. This technology allows the image to serve as a color-coded map of the area being studied. The screen will display images in blacks, grays, reds, and blues. Typically, the darker colors represent solid tissue, the red shows the arterial flow (away from the heart), and the blue is venous flow (toward the heart).

Colorflow duplex ultrasonagraphy has resulted in major advances in the diagnosis and treatment of vascular disease. Duplex ultrasonagraphy, in some situations has replaced arteriography. There are two major benefits to duplex ultrasonagraphy over arteriography. The first is cost, and the second is it does not require puncturing the skin and injecting a dye. In essence, duplex ultrasonagraphy has provided better patient care in multiple settings. It helps physicians to make determinations about a patient's condition, and it provides a map for physicians to determine the course of action before performing surgery. Also, it allows for post-operative surveillance of patients, thus detecting potential problems for patients who have already undergone a surgical procedure.