About Transcranial Doppler (TCD) An intracranial neurovascular exam is also known as a Transcranial Doppler (TCD) study. TCD is a non-invasive, painless ultrasound technique that uses high-frequency sound waves to measure the rate and direction of blood flow inside vessels. Transcranial Doppler Ultrasonography The TCD measures the velocity of blood flow through the major intracranial vessels by emitting a high frequency (>2MHz) wave from an ultrasound probe and detecting a frequency shift between the incident and reflected wave which directly correlates with the speed of the blood (the so called Doppler effect). Although transcranial Doppler imaging is fairly new compared to some other ultrasound applications, it has become increasing popular and useful in recent years and demand for TCD ultrasound machines will only increase in the future. Make sure you Download Our White Paper Guide on "8 Things Find out why a doctor may order a Transcranial Doppler ultrasound, what to expect, and more. Search. MAIN MENU . Transcranial Doppler Ultrasound (Transcranial Duplex Ultrasound) Show/Hide Articles. The Johns Hopkins Consumer Guide to Medical Tests. Simeon Margolis, M.D., Ph.D., Medical Digi-Lite™ is a Digital Transcranial Doppler (TCD) System with an advanced and proprietary M-Mode display. The product is based on the latest technology in digital electronics and software design. The product is based on the latest technology in digital electronics and software design. Transcranial Doppler (TCD) and transcranial color Doppler Ultrasound duplex scanning can provide additional information that may guide therapeutic decisions. The location and severity of arterial narrowings and occlusions can be identified. Doppler ultrasonography is widely used in renal Transcranial Doppler Products. Contact Us; Contact Us. Thank you for your interest in Rimed Products. We invite you to send your requests, questions and suggestions to us. Distributor Doctor Other . First Na