Understanding Transcranial Doppler

Transcranial Doppler is a kind of imaging test that looks at blood flow in your brain. It uses special sound waves and a computer to see how well blood is moving through blood vessels in real time.

How to say it

tranz-KRAY-nee-uhl DAH-pler

Why transcranial Doppler is done

The procedure is used for many reasons. It can look for:

  • A blood clot that caused a stroke or transient ischemic attack (TIA)

  • Signs of a blood clot going away after treatment

  • Blood vessel problems from sickle cell disease that are a risk for stroke

  • Blood vessel problems after a head injury

  • A blood vessel spasm where there is bleeding on the brain (subarachnoid hemorrhage)

  • Improvements after surgery on a blood vessel in the brain

  • Other signs of blood vessel disease

How transcranial Doppler is done

The procedure may be done in a hospital or medical office, and takes about 30 minutes. During the test:

  • You either lie on an examining table or sit in a chair.

  • Gel is placed on your skin in the areas of your head to be examined. This may include just above your cheekbone (temple) and the back of your neck at the base of your skull. It may also include the side of your neck, under your jaw, and next to or over your eye.

  • The healthcare provider then presses an electronic wand or probe called a transducer onto each of the areas. This is painless. During this part, you’ll need to keep still and not talk. The wand sends and receives high-frequency sounds waves, and is attached to a computer. The computer measures the sound waves that bounce off various substances in the body and creates an image of the speed and direction of blood flow on a monitor.

  • When the test is done, the gel is wiped off and you can go home.

Risks of transcranial Doppler

There are no risks for this test.