The NeuroMedical Center | Patient Education Library | Carotid Ultrasound & Transcranial Doppler

Carotid Ultrasound Studies (CUS) is a diagnostic exam performed inside The NeuroMedical Center Clinic’s Neurodiagnostic Lab on the 4th floor that captures images of the arteries that carry blood from the heart to the brain. Transcranial Doppler (TCD) is a test that measures the velocity of blood flow through the brain’s blood vessels.  The images and recordings produced from CUS and TCD studies can be used to find out if there is an abnormality or blockage of the carotid artery or blood vessels that could lead to a stroke.


Once arriving for your CUS or TCD, you will be asked to lie face up on an exam table. The sonographer will apply a clear, ultrasound gel to a small, handheld device called a transducer that will be methodically and precisely moved around your neck, eyelids, and temporal area. The harmless ultrasound waves emitted by the transducer will be recorded as they bounce off tissues, organs, and blood cells. A computer will translate the echoed sound waves to a monitor in real-time. You may hear noise during the exam, which is the sound of blood flowing through your arteries. During a CUS or TCD study you will be fully awake and shouldn’t feel any discomfort. If you do, tell the technician. These exams take about 45 minutes to complete.


  • Take medications as directed
  • Eat and drink as you normally do
  • Wear a comfortable shirt with no collar or an open collar
  • Do not wear a necklace or dangling earrings

Unless told otherwise, no additional preparations are required before your CUS or TCD.


Following the recording of the images, the sonographer will wipe off the ultrasound gel from your skin before escorting you out of the lab.

The physician who ordered your CUS or TCD exam will interpret the findings of your test.  A full report may take 2-3 days.