Why It Is Done
Doppler ultrasound is done to:
- Find blood clots and blocked or narrowed
blood vessels in almost any part of the body, especially in the neck, arms, and
- Evaluate leg pain
that may be caused by
intermittent claudication, a condition caused by
atherosclerosis of the lower
- Evaluate blood flow after a stroke or other condition
that might be caused by a problem with blood flow. Evaluation of a stroke can
be done through a technique called transcranial Doppler (TCD)
- Evaluate abnormal veins causing
varicose veins or other problems.
- Map veins that may be used for blood vessel grafts. It also can
check the condition of grafts used to bypass blockage in an arm or
- Find out the amount of blood flow to a transplanted kidney or
- Monitor the flow of blood following blood vessel
- Find out the presence, amount, and location of arterial
plaque. Plaque in the carotid arteries can reduce
blood flow to the brain and may increase the risk of stroke.
treatment such as laser or radiofrequency ablation of abnormal
- Check the health of a fetus. Blood flow in the
umbilical cord, through the
placenta, or in the heart and brain of the fetus may
be checked. This test can show if the fetus is getting enough oxygen and
nutrients. Doppler ultrasound may be used to guide decisions during pregnancy
- The fetus is smaller than normal for his or her
gestational age (fetal growth restriction). Blood flow through the large blood
vessel in the umbilical cord (the umbilical artery) can be looked
- Rh sensitization has occurred. Blood flow through a
blood vessel in the brain (the middle cerebral artery, or MCA) can be used to
monitor fetal health.
- The mother has other problems, such as
sickle cell disease.
A transcranial Doppler ultrasound (TCD) may be used in
children with sickle cell disease to evaluate their risk of stroke. In adults,
TCD can be used to evaluate blood flow in the brain.
How To Prepare
You may need to stop using products
that contain nicotine (cigarettes, chewing tobacco) for 30 minutes to 2 hours
before the test. Nicotine causes blood vessels to constrict and may give false
How It Is Done
This test is done by a doctor who
specializes in performing and interpreting imaging tests (radiologist) or
by an ultrasound technologist (sonographer) who is supervised by a radiologist.
It is done in an ultrasound room in a hospital or doctor's office.
You will need to remove any jewelry that might interfere with the Doppler
ultrasound scan. You may need to take off all or most of your clothes,
depending on which area is being examined (you may be allowed to keep on your
underwear if it does not interfere with the test). You will be given a cloth or
paper covering to use during the test.
- For abdominal scans, you will lie on your
- For chest scans, you will lie on your back with your neck
- For head and neck scans, your head may be turned
to one side.
- For an arm or leg scan, your head will be slightly
raised and the exposed arm or leg will be turned slightly outward. Sometimes
for a leg scan, you may be asked to lie on your stomach.
pregnancy, you will lie on your back or on your left side with your belly