Ultrasonic doppler imaging apparatus.

摘要

Disclosed is an ultrasonic Doppler imaging apparatus in which the velocity of a blood flow in a living body can be computed with high precision without increasing a scale of a signal processing circuit, so that a Doppler color image having satisfactory image quality is displayed. In the apparatus, an ultrasonic pulse signal is transmitted into the living body and is reflected from a target in the living body to be received by an ultrasonic probe (1; 101), and the reception signal is subjected to quadrature phase detection to obtain an I signal and a Q signal. When an amplitude evaluating unit (14) evaluates on the basis of the intensity of the I and Q signals that the reception signal contains many clutter components, a cut-off frequency of high-pass filters (15, 16) is increased by the application of a control signal (A) to thereby eliminate low-frequency clutter components. The outputs of the high-pass filters (15, 16) are converted into blood flow velocity information to be displayed as a Doppler color image.