A Doppler ultrasound uses sound waves to look at blood vessels and analyze blood flow. This test allows physicians to see if there’s a reduction in blood flow to determine a variety of diseases or complications.
How does Doppler Imaging in Ultrasound work?
During a Doppler ultrasound procedure, a handheld device, called the transducer, is used over the area of the blood vessel the physician is trying to look at. The device sends and receives sound waves, which bounce off solid objects such as blood cells or vessel walls. Pitch changes in sound waves indicate movement of blood cells. There is no pitch change if there is no blood flow in the area.
What information can I get from a Doppler ultrasound?
The information received from a Doppler ultrasound can help physicians create images or graphs that depict blood flow. There are three types of Doppler ultrasound including:
- Continuous wave Doppler uses sound wave pitch changes to provide information about blood flow, allowing physicians to listen to and assess blood flow to determine whether there’s a blockage or no blood flow at all.
- Duplex Doppler uses standard ultrasound methods to create an image of a blood vessel. Information from this test is translated into a graph that shows the speed and direction of blood flow.
- Color Doppler is similar to a duplex Doppler test in that it also creates an image of a blood vessel. However, a color Doppler test turns Doppler sounds into colors that are overlaid on the blood vessel image. The different colors show speed and direction of blood flow and can even show blood flow through vessels within organs.
How can I prepare for a Doppler ultrasound test?
Approximately 30 minutes to two hours prior to a Doppler ultrasound procedure, it’s recommended that patients do not use products that enhance blood flow, such as nicotine or caffeine. This can often speed up your blood flow, which will be seen in the ultrasound images and provide an inaccurate analysis of your body’s blood flow. Additionally, it’s best to skip a workout or intense exercise prior to a Doppler ultrasound test.
Make sure to wear loose-fitting clothing to ensure easier access to the areas that will be imaged. A gel will be applied to the skin of the area to be looked at to allow sound waves from the transducer to pass through.
There is usually little to no discomfort during a Doppler ultrasound test. The gel applied to the skin can be warmed up before application for patient comfort.
A Doppler ultrasound test is a great first step to looking at veins and arteries to help diagnose blood clots, venous insufficiencies, or arteriosclerosis in the arms or legs, and it can also help physicians see if there are any vascular injuries, all non-invasively.