Specialist comforting patient

Transcranial Doppler

If you’ve had a brain aneurysm, have a high risk of a stroke or blockage of the blood vessels around your brain, your doctor may order a transcranial doppler ultrasound. It’s a simple and painless procedure that can provide life-saving information about your health. 

A transcranial doppler ultrasound (or TCD) is a non-invasive ultrasound used to check the amount of blood flow to certain areas of your brain. During a TCD, sound waves are transmitted throughout tissues in your skull and reflect off of blood cells. This lets a radiologist see the speed and direction of your blood on a computer screen. 

The ultrasound is a simple, pain-free test that takes about 20 to 30 minutes. Our technologist applies a small amount of gel on either the back of your neck, above your cheek, near your ear or over your eyelid. Your blood flow is recorded using a small device (called a transducer) that’s placed gently on the gelled area. All you have to do is not move your head or talk during the test. 

Ultrasounds are perfectly safe. The test is non-invasive and doesn’t use radiation. You don’t need to drink any type of contrast dye, and there are no side effects.