Doppler ultrasonography

n.

Ultrasonography applying the Doppler effect, in which frequency-shifted ultrasound reflections produced by moving targets in the bloodstream, usually red blood cells, are used to determine the direction and velocity of blood flow.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.