A Transcranial Doppler (TCD) is an ultrasound procedure that uses soundwaves to examine blood flow in the brain.

Your attending physician ordered a TCD for the purpose of diagnosing a medical condition that affects blood flow to and within your brain. They also may have ordered the test for the purpose of monitoring the effectiveness of certain treatments.

A physician will interpret the study afterward and a report will be sent to your referring provider. Expect to hear from your ordering physician/provider after the test.

After the test is completed, you are free to resume normal activities. If you were sleep-deprived, you may want someone to drive you home after the test.

First, you will be asked to lie down on an exam table or sit in a chair. The technician will apply some gel to the areas to be examined, which may consist of the temples, the base of the skull, back of the neck area, or eyelids.

Next, a device called a transducer will be placed in direct contact with your skin. During a TCD, the tissues of your skull are bombarded with sound waves, which reflect off blood cells moving within the blood vessels. The information gleaned from a TCD allows the neurologist to interpret the speed and direction of the blood cells in your brain.

After the examination is completed, the gel will be washed off.

Transcranial Doppler is a painless test, and there is little to no discomfort during the examination. For the test to be successful, you will need to keep your head still and refrain from speaking during the examination.