Doppler Ultrasound

Medically Reviewed By William C. Lloyd III, MD, FACS
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What is a Doppler ultrasound?

An ultrasound is a type of imaging exam that uses painless sound waves to produce images of body structures and organs. A Doppler ultrasound is a special kind of ultrasound. It uses the Doppler effect—a specific effect of waves, such as sound—to detect motion in your blood vessels.

The Doppler effect is the change in pitch you hear when objects or observers are in motion. It’s the reason a train horn or a siren sounds different when it is approaching you compared to after it passes you. A Doppler ultrasound can detect differences in pitch as blood cells move through your blood vessels. Then, it converts this sound data into a picture or graph. This lets doctors see how blood is flowing in the arteries and veins of your body. It can also show them if blood is not moving in a particular area—the pitch will not change.

There are three types of Doppler ultrasound:

  • Color Doppler ultrasound displays the speed and direction of blood flow as a colored picture.

  • Power Doppler ultrasound can show more detailed information about blood flow than a regular color Doppler ultrasound. This can be helpful for an area with greatly reduced blood flow.

  • Spectral Doppler ultrasound displays blood flow graphically.

Why is Doppler test performed?

Your doctor may recommend a Doppler test to help diagnose conditions that affect blood flow. Doppler ultrasound diagnostic testing is important in these cases:

Doctors can also use the technique to:

  • Check blood flow to transplanted organs

  • Evaluate blood flow during pregnancy between the mother and baby and in the baby’s organs

  • Guide treatments, such as vein ablations

  • Map veins for grafting

  • Monitor blood flow during surgery

Who performs the Doppler ultrasound test?

A sonographer, or an ultrasound technician or technologist, will perform your Doppler ultrasound. A radiologist will read and interpret the Doppler ultrasound results. Radiologists perform and interpret imaging exams, including ultrasound, MRI and others. Sometimes, the radiologist will perform a Doppler ultrasound. Then, the radiologist will either review the Doppler test results with you or send a report to your doctor who will share it with you.

How is Doppler ultrasound performed?

Ultrasounds usually take place in dimly lit rooms. This allows the sonographer to best view the image display. The specific details of your Doppler ultrasound procedure will depend on the reason you need the exam and the body part, such as your neck, abdomen or legs.

In general, you wear either loose-fitting clothing or a patient gown and covering. You lie down on an exam table and the sonographer will help you into the right position. For some exams, you’ll be on your back. For others, you may need to be on your side or on your belly.

The sonographer will apply a water-based gel to help the transducer maintain contact with your skin. The gel wipes off easily when the exam is complete. The transducer is a handheld instrument that transmits the sound waves. The sonographer will move the transducer over your skin, which automatically sends the imaging data to the computer. This process is painless, but you may feel pressure at times.

A Doppler ultrasound procedure typically takes 30 to 60 minutes.

What are the risks and potential complications of Doppler ultrasound?

There are no known risks with an ultrasound, including a Doppler ultrasound. It does not use ionizing radiation like X-rays, so it is safe for developing babies and others who should avoid exposure to radiation.

As with any imaging exam, false results are possible and certain factors can affect the quality of the images. Your doctor may recommend repeating the test or using a different imaging exam if the results are not helpful. Factors that can cause issues with the results include:

  • Cold extremities and open wounds in the area, which can affect blood flow patterns

  • Excessive movement during the exam

  • Intestinal gas or nearby bones, which can interfere with the imaging

  • Irregular heart rhythms, which can affect blood flow patterns

  • Severe obesity

How do I prepare for a Doppler ultrasound?

If you smoke or use nicotine products, talk with your doctor about it. You may need to avoid nicotine for up to two hours before the test. Nicotine constricts blood vessels, which can interfere with the exam. Your results may not be accurate if you use nicotine too close to your appointment.

What can I expect after a Doppler ultrasound?

You should be able to resume your normal activities right after a Doppler ultrasound. Ultrasound exams are painless, but you may feel pressure at points during the exam if the sonographer needs to press the transducer into your skin. If anything causes pain during the exam, let the sonographer know.

How do I get the results?

If a radiologist performs the ultrasound, you may get the results immediately after the exam. Otherwise, the radiologist sees the images later and sends them to your doctor. It may take a few days for your doctor to receive the final report from the radiologist. Once the report is available, your doctor will share the results of the test with you. The results will guide your next steps, such as having additional tests or exploring treatment options.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Dec 3
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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  4. Ultrasound – Venous (Extremities). Radiological Society of North America.
  5. What Is a Doppler Ultrasound? Mayo Foundation for Medical Education and Research.