Abstract: An ultrasonic imaging system (50) has an array (52) of transducer elements (54-1 through 54-21) for receiving ultrasonic signals reflected from within an inhomogeneous object (16) being examined. The system (50) has a means (80, 84, 88, 94) connected to generate an image in response to the ultrasonic signals. A cross-correlator (70) is connected to compare the signals received by the transducer elements (54-1 through 54-21). An output addressing circuit (130) is connected to inhibit or otherwise modify gain of selected ones of the signals based on the comparison to reduce multipath ultrasonic wave interference, refraction or obstruction image distortion or degradation. A preferred ultrasonic imaging array (52) for this purpose and for time delay image distortion correction has a plurality of segmented, annular transducer elements (54-2 through 54-21). The elements (54-2 through 54-21) are formed as sectors of circles with substantially equal arc lengths.

Abstract: Pulsed real-time B-scan ultrasonic method and apparatus are disclosed together with pulsed Doppler Ulrasonic method and apparatus. The B-scan apparatus includes a pulse operated transmitter and receiver operating at a first frequency, and the Doppler apparatus includes a pulse operated transmitter and receiver operating at a second frequency sufficiently far removed from the B-scan frequency to avoid interference therebetween. A synchronous pulse operation of the B-scan and Doppler systems is provided. The sysem includes a visual display means to which the receiver outputs are connected through a multiplexer operated to pass the B-scan receiver output to the visual display means whenever such B-scan output is present. The Doppler apparatus includes means for temporarily storing the Doppler receiver output, which stored Doppler signals subsequently are read out through the multiplexer to the visual display means between select lines of B-scan display.