Vascular Ultrasound is another diagnostic test that uses high frequency waves that show blood flow in vessels including the arteries and veins. Ultrasound is used to create images of these soft tissue structures allowing one to detect blockages in the blood vessels. A non-invasive vascular ultrasound method known as a duplex study is used to examine the blood circulation in the upper and lower extremities (arms and legs). Duplex scanning is a combination of doppler and ultrasound. Noninvasive means the procedure does not require the use of needles, dyes, radiation or anesthesia.
During a vascular ultrasound, sound waves are transmitted through the tissues of the area being examined. These sound waves reflect off blood cells moving within the blood vessels, allowing the vascular technologist to calculate their speed. The sound waves are recorded and displayed on a computer screen.
Venous ultrasound provides pictures of the veins throughout the body. Venous exams, such as a lower extremity venous duplex exam is performed to look for thrombus or blood clots in the veins in the legs, the transducer may be used to compress the veins. The ability or inability of the veins to be compressed helps exclude or confirm the presence of clot in the veins.
The carotid arteries are located on each side of the neck and carry blood from the heart to the brain. Ultrasound provides detailed pictures of these blood vessels and information about the blood flowing through them. Blockages of the carotid arteries can lead to stroke. Ultrasound provides a risk free non-invasive way to look at these blood vessels and determine if there is a significant blockage that may require treatment to reduce the risk of a stroke.
There are different types of duplex ultrasound exams. Some include:
- Arterial and venous duplex ultrasound of the abdomen:
examines blood vessels and blood flow in the abdominal area. This is an important test to diagnose the presence of an abdominal aortic aneurysm (AAA)
- Carotid duplex ultrasound:
looks at the carotid artery in the neck.
- Duplex ultrasound of the extremities:
looks at the arms or legs typically used to diagnose peripheral arterial disease (PAD)
- Renal duplex ultrasound:
examines the kidneys and their blood vessels.