To diagnose vascular problems, doctors use Doppler ultrasound to determine the speed, direction and quality of blood flow and larger ultrasound machines to create images of the blood vessels to assess their condition, according to the American Heart Association. Vascular ultrasound tests usually occur in a vascular lab along with other non-invasive diagnostic tests, such as specialized blood pressure tests.
An ultrasound probe or machine sends sound waves through the body's tissues, states the American Heart Association. The waves travel through different types of tissues at different speeds and then bounce back to return to the ultrasound device. The ultrasound device converts the wave patterns to an image, sound or chart to give the technician information about blood flow and the appearance of the blood vessels.
Technicians use small, handheld Doppler machines to determine blood pressure in the arms and legs, maintains the American Heart Association. This information specifically helps doctors diagnose atherosclerosis of the legs and peripheral arterial disease. During vascular disease diagnosis, the technician may test many of the main arteries of the body depending on the reason for the exam.
During ultrasound testing, the patient typically changes into a gown, and the technician applies gel to the areas he needs to image, reports the American Heart Association. The exam takes from 15 minutes to one hour depending on how many areas require imaging.