Abstract: An ultrasonic blood flow measuring and imaging system comprises a transmit-receive transducer for transmitting ultrasonic pulses toward and into the human body and for receiving reflected echo signals which are then processed for use in a Doppler blood flow imaging and display system. Multiple ultrasonic pulses are transmitted into the body at each of a number for angles in an area under diagnosis. For each angle, a plurality of reflected echo signals are received during successive predetermined time intervals. Each received echo signal has a tissue motion Doppler component representative of reflection from moving tissue and a blood flow Doppler component representative of relfection from both moving tissue and flowing blood. The reflected echo signals are processed in a system which includes tissue velocity determining elements for estimating the velocity of the tissue motion, and tissue velocity canceller elements for removing a tissue velocity component from the received echo signals.