Vascular ultrasound is a test to see if you have blood flow problems or clots in your veins. Ultrasound uses harmless sound waves to take pictures of the inside of your body. A device (transducer) is held up against your body to capture these pictures. The continually changing images can be recorded on videotape or film. Diagnostic ultrasound imaging may also be called sonography or ultrasonography.
There are different types of vascular ultrasound exams. An aortic ultrasound can show enlargement of the artery (aneurysm) or masses. A carotid ultrasound can show if there is blockage (atherosclerosis) of the large arteries in the neck that supply most of the blood to the brain.
Vascular ultrasound may be used almost anywhere throughout the body. Some of the most common sites where it is used are in the neck, heart, abdomen, and legs. There are several types of ultrasound, including:
Continuous wave Doppler ultrasound. This type of ultrasound uses the change in pitch of the sound waves to provide information about blood flow through a blood vessel. Your caregiver listens to the sounds produced by the transducer.
Duplex ultrasound. This type of ultrasound uses standard ultrasound methods to produce a picture of a blood vessel and surrounding organs. In addition, a computer provides added information about the speed and direction of blood flow through the blood vessel. With this type of ultrasound it is possible to see the structures inside the body and to evaluate blood flow within those structures at the same time. Blood flow in individual blood vessels is most commonly evaluated by duplex ultrasound.
Color Doppler ultrasound. This type of ultrasound uses standard ultrasound methods to produce a picture of a blood vessel. In addition, a computer converts the Doppler sounds into colors that are overlaid on the image of the blood vessel. These colors represent the speed and direction of blood flow through the vessel.
Power Doppler ultrasound. This type of ultrasound is up to 5 times more sensitive than color Doppler ultrasound. Power Doppler ultrasound can also get images that are difficult or impossible to get using standard color Doppler ultrasound. Power Doppler ultrasound is used most commonly to evaluate blood flow through vessels within organs, such as the liver or kidneys.
RISKS AND COMPLICATIONS
Ultrasound has been used for many years and has never shown any harmful effects. Studies in humans have shown no direct link between the use of ultrasound and future problems from the ultrasound.
BEFORE THE PROCEDURE
For most Doppler ultrasound exams, no preparation is necessary. Your caregiver may ask you not to eat the morning of your exam if the ultrasound scan involves your upper abdomen.
There is no pain in an ultrasound exam. A gel is applied to your skin and the transducer is then placed on the area to be examined. The gel may feel cool. The gel wipes off easily, but it is a good idea to wear clothing that is easily washable.
The images from inside your body are displayed on one or more monitors, which look like small television screens. The room is usually darkened during the exam. This makes it easier to see the images on the monitor.
The ultrasound exam should take 30 to 60 minutes. The length of the exam depends on many things including the portion of your body to be examined and the complexity of your body's anatomy. An ultrasound that looks at hardening of the arteries (arteriosclerosis) may take more scanning time.
AFTER THE PROCEDURE
You can safely drive home and return to regular activities immediately after your exam. In many cases, follow-up exams are necessary to check on your condition or your response to therapy. Ask when your test results will be ready. Make sure you get your test results.