Clinical Neurology Specialists Clinical Neurology Specialists Diagnostics Hyperbaric Institute of Nevada

Services Provided

Transcranial Doppler Ultrasound (TCD)

TCD is a non-invasive ultrasound method used to examine the blood circulation within the brain. Your physician has recommended that you have this test to determine the amount of blood flow to certain areas of your brain.

TCD ultrasound images help in the diagnosis of a wide range of conditions affecting blood flow to the brain and within the brain. During TCD, sound waves, inaudible to the human ear, are transmitted through the tissues of the skull. These sound waves reflect off blood cells moving within the blood vessels, allowing their speed to be calculated.

  • Please have clean dry hair.
  • Do not apply makeup on face, eyelids and around neck areas.
  • Turn cell phones and electronic devices off.
  • Inform the sonographer if you had recent eye surgery.
  • A small amount of water-soluble ultrasound gel is applied to the skin over the areas to be studied. The gel does not h arm your skin or clothing.
  • A small device (transducer) is used and held to the skin until the testing is completed for that area.
  • During the exam you will need to remain still and avoid speaking to guests or asking the sonographer questions.
  • For some specialized tests a needle is used. See the TCD Bubble Procedure link below for a visual on using agitated saline injection with the TCD Bubble study.

Click Here to view a TCD Bubble Procedure on MSNBC

Click Here to view education slides with sound on using TCD for detecting PFO


The American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) has published a recommended policy for Electrodiagnostic Medicine to improve the quality of patient care, to encourage appropriate utilization of the procedures involved, and to assist Medicare Carrier Advisory Committees and other insurance carriers in developing policy regarding EDX testing. Unfortunately, EDX studies are poorly understood by many in the medical and lay communities. Please visit the EDX Edu section for more information on how to be a better informed prior to having EDX and other laboratory services.

Prior-authorization for services by your insurance company does not guarantee payment of medical services. Patients should call their insurance to verify that these services are a covered benefit.

EDX Services and Quick Links