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)
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 (TCD) ultrasound 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