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What Is a Transcranial Doppler Exam?

Transcranial Doppler (TCD) is an exam that determines blood flow in the arteries supplying blood to your brain. To do this, we place an ultrasound probe over your skin in three areas:

  1. At the base of your skull
  2. In front of your ear
  3. Over your closed eyelid

By taking images of these areas, we can examine several key arteries:

  • Middle cerebral
  • Anterior cerebral
  • Posterior cerebral
  • Ophthalmic
  • Vertebral
  • Basilar

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Reasons Why You Might Need a TCD

  • Passing out or fainting — You may need a TCD if your care team needs to see if the blood is flowing normally to your brain.
  • Stroke or mini-stroke — We may need to examine the arteries in your brain to see if they are narrowing.
  • A dissected artery in your brain — We may need to use a TCD to see if your medication is preventing clots.
  • If your doctor thinks you have patent foramen ovale (a hole in your heart) — A TCD is better at diagnosing this condition than a cardiac ultrasound.
  • Sickle cell anemia — A TCD may help your doctor determine if you need blood transfusions for stroke prevention.

What to Expect at Your TCD

A TCD is a very simple test and only takes a short amount of time. You don't need to do any preparation. Just arrive on the date and time of your appointment. If you want, you can bring a family member or friend to be with the you during the exam.

Before the Exam

We will ask you to give us basic information about your medical and/or surgical history. We may also take your blood pressure.

During the Exam

You will lie down, resting comfortably, in an exam room. An ultrasound technologist will put some gel on the probe that they will place on your skin for the exam. Then the technologist will scan the:

  • base of your skull, 
  • front of your ear, and
  • a closed eyelid.

Once scanning is complete, the technologist will remove the gel from your skin.

After the Exam

In most cases, you will be able to go home after the exam. Occasionally, we may ask you to stay at the imaging center while we share the results with your provider. Depending on your provider’s recommendation, we may need to take additional images.

How Long Does a TCD Take?

Times are different for each patient, but most TCD tests last about 30–45 minutes.

Is a TCD Exam Painful?

You will have no pain during a TCD. It is a non-invasive procedure.

Seeing the Results of Your TCD

Before we send the results, they are analyzed by a specialty-trained provider. Your provider then will receive a report of the results. After this your provider will contact you to discuss any necessary treatments or further tests that you may need.

You should contact your provider if your symptoms get worse in any way.

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