| 摘要 |
PROBLEM TO BE SOLVED: To differentiate various tissues clearly by performing a diagnostic ultrasonic wave imaging utilizing a parametric harmonic imaging, which receives reflection signals center of which lies in a frequency lower than that of a transmission pulse. SOLUTION: A transducer array 10 is provided which consists of individually driven piezoelectric transducer elements 12, and the transducer array 10 is driven to transmit ultrasonic wave energy so that it becomes a direction-oriented focusing beam. Ultrasonic wave energy, which was reflected from a subject and returned to the transducer array 10, is converted into electric signals, which are applied to a receiving means via a pair of transmission/reception switch 18. Pulse center of which lies in a frequency f0 is transmitted, and a reflected and beam-shaped signal is filtered using a band pass filter center of which lies in a frequency lower than that of f0, and then an ultrasonic wave imaging is performed using many harmonic response parameters. |
