PROBLEM TO BE SOLVED: To provide an inspector with information necessary for proper propagation of a shear wave in an ultrasonic diagnostic apparatus which evaluates the hardness of a tissue by using the shear wave.SOLUTION: An ultrasonic diagnostic apparatus which transmits a push pulse to a specific site in a subject by using an ultrasonic probe and detects a process of propagation of a shear wave to an adjacent tissue by repeating transmission of an ultrasonic wave to the subject and reception of a reflection ultrasonic wave from the subject, comprises: a displacement detection part which obtains a plurality of reception signals in time-series with transmission of the ultrasonic wave subsequent to the push pulse to the subject and reception of the reflection ultrasonic wave from the subject to detect respective displacements of the tissue in the subject at the respective times at which the plurality of reception signals are acquired； a wave surface extraction part which extracts the wave surface of the shear wave at the respective times on the basis of the displacements of the tissue at the respective times at which the plurality of reception signals are acquired； and a wave surface image processing part which generates images of the wave surface at the respective times at which the plurality of reception signals are acquired as wave surface images.SELECTED DRAWING: Figure 1【課題】せん断波を用いて組織の硬さを評価する超音波診断装置において、せん断波が適切に伝播するために必要な情報を検査者に提供する。【解決手段】超音波探触子を用い、被検体内の特定部位にプッシュパルスを送信して、せん断波が隣接組織へと伝播する過程を、超音波の被検体への送信と、被検体からの反射超音波の受信とを繰り返すことによって検出する超音波診断装置であって、プッシュパルスに続く超音波の被検体への送信と被検体からの反射超音波の受信により時系列に複数の受信信号を得て、複数の受信信号が取得された各時刻における被検体内の組織の変位をそれぞれ検出する変位検出部と、複数の受信信号が取得された各時刻における組織の変位に基づいて、当該時刻における前記せん断波の波面を抽出する波面抽出部と、複数の受信信号が取得された各時刻における波面を波面画像として生成する波面画像加工部とを備える。【選択図】図１
