Transcranial Doppler Ultrasound
A Transcranial Doppler, or TCD, is a diagnostic test using ultrasound waves to produce images of the blood flow within the brain's arteries. This procedure is often done in conjunction with a carotid Doppler ultrasound.
The results of a TCD ultrasound are used to assess the risk of a stroke. This procedure can also be used during surgical procedures to monitor blood flow in the brain.
Reasons for a TCD Ultrasound
A TCD ultrasound can show blood clots and can be used to assess a patient's risk of stroke. It can also be used to diagnose other conditions, including:
- Subarachnoid hemorrhage
The TCD Ultrasound Procedure
The patient will either be asked to lie down on a padded examination table or sit down in a chair. A small amount of clear gel will be applied to the patient's skin over the site of the ultrasound. Usually, the gel is applied on the back of the neck, above the cheek bone, in front of the ear and over the eyelid.
The technician will place a transducer, a small hand-held device, on the surface of the skin, over the gel, which will record images and transmit them to a nearby monitor. The patient will need to remain still during the test, which takes less than 30 minutes to complete. The gel is wiped off of the skin at the end of the test.
A radiologist will examine the images and report the results to the doctor, who will later discuss them with the patient.