Provided is an ultrasonic diagnostic apparatus capable of measuring hardness information of a subject with high temporal resolution and spatial resolution. An ultrasonic probe 1 and a displacement generation unit 10 for displacing the inside of the subject are provided, and a displacement detection ultrasonic beam is transmitted from the ultrasonic probe 1 to a plurality of detection positions of the subject for detection. Using the reflection signal detected by the unit 20, the control unit 3 detects the shear wave velocity based on the displacement of the plurality of detection positions and outputs the hardness information of the subject. The displacement detection ultrasonic beam is transmitted to one of the plurality of detection positions, the waveform analysis unit 26 of the control unit 3 analyzes the shear wave generated by the displacement, and the displacement detection ultrasonic beam is applied to the other one of the plurality of detection positions. Switching control is performed so as to transmit a sound beam. Thereby, the shear wave velocity can be measured with high temporal resolution and spatial resolution, and the hardness information of the subject can be obtained with high accuracy.高い時間分解能かつ空間分解能で被検体の硬さ情報の計測が可能な超音波診断装置を提供する。 超音波探触子１と、被検体の内部を変位させる変位生成部１０を備え、超音波探触子１から、被検体の複数の検出位置に変位検出用超音波ビームを送信して、検出部２０で検出した反射信号を用いて、制御部３で、複数の検出位置の変位に基づくせん断波速度を検出し被検体の硬さ情報を出力する。複数の検出位置の一つに変位検出用超音波ビームを送信し、制御部３の波形解析部２６は変位によって生じるせん断波を解析し、複数の検出位置の他の一つに変位検出用超音波ビームを送信するよう切替え制御を行う。これにより、高い時間分解能かつ空間分解能でせん断波速度の計測が可能となり、被検体の硬さ情報を高精度に得ることができる。
