by Voyatzis D
(Doppler Ultrasonography)


A Doppler ultrasound is a test that can measure blood flow. It uses sound waves that bounce off blood cells.

Reasons for Test

Doppler ultrasound may be used to check blood flow to an area. It may also be needed to check for injuries to blood vessels or assess treatment. Common reasons for use include:

  • Look for cause of blood pooling in legs such as valve problems in your leg veins
  • Heart valve defects and congenital heart disease
  • Blockage in artery
  • Peripheral artery disease
  • Weakening of blood vessel walls called aneurysm
  • Narrowing of an artery, such as carotid artery stenosis
  • Check baby’s blood flow during a pregnancy

Possible Complications

In most cases, there are no complications with this test.

What to Expect

Prior to Test

Your doctor may do the following:

  • A physical exam
  • Blood or urine tests

In some cases your doctor may instruct you to:

  • Fast for 8 to 12 hours before the test. This will decrease the amount of gas in your intestines and make organs easier to see.
  • Have a full bladder before the test. You may need to drink 6 or more glasses of water without going to the bathroom.
  • Avoid smoking . Smoking can interfere with test results.

Description of the Test

You will lie on a table. Your doctor will put a gel on the skin over the area that will be examined. The gel helps the sound waves travel between the machine and your body.

The ultrasound machine has a hand-held device about the size of a bar of soap. The device is pushed against your skin where the gel was applied. The waves from device bounce off blood cells or tissue and echo back to device. The doctor can examines the images during the test. The images can also be saved for later review.

You may be asked to change positions or hold your breath during the exam.

Abdominal Ultrasound
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After Test

The gel will be cleaned from your body. You will be able to return to normal activities in most cases.

How Long Will It Take?

About 30 minutes to 1 hour

Will It Hurt?



A radiologist will examine the images after the test. Your doctor will let you know the results and talk to you about treatment.

Call Your Doctor

After the test, call your doctor if symptoms become worse.

If you think you have an emergency, call for emergency medical services right away.


American Institute of Ultrasound in Medicine 

Radiology Info—Radiologic Society of North America 


Health Canada 

The College of Family Physicians of Canada 


General ultrasound. Radiology Info—Radiologic Society of North America website. Available at: Accessed January 26, 2021.

Ultrasound imaging. US Food & Drug Administration website. Available at: Accessed January 26, 2021.

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