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Transcranial Doppler Ultrasound

Medically reviewed by Last updated on May 2, 2022.

Transcranial doppler (TCD) ultrasound is a test that uses sound waves to measure blood flow in your brain. It shows the speed and direction of blood through the blood vessels. It may also show how the blood vessels react to medicines or position changes.


Call your doctor if:

  • You have new or worsening signs or symptoms.
  • You have questions or concerns about your condition or care.

Follow up with your doctor or neurologist as directed:

Ask to see the results of your test at your visit. Write down your questions so you remember to ask them during your visits. Keep all appointments for any other tests you may need.

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The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.