PROBLEM TO BE SOLVED: To strike a balance between the improvement of a frame rate and the increase of the number of ensemble, and further improve quality of a color Doppler image.SOLUTION: An ultrasonic diagnostic apparatus is provided for performing velocity analysis based on the color flow mapping by selectively driving multiple transducers arranged linearly in an ultrasonic probe and performing ultrasonic transmission/reception to a subject. An ultrasonic wave is transmitted for each of multiple transmission sub-events contained in a single transmission event set, and a receive signal sequence is generated for each of transmission events. The receive signal sequence based on the reflection ultrasonic wave obtained from each observation point is subjected to phasing addition, concerning multiple observation points contained in a main target area and a second target area for each of the transmission events, and an acoustic line signal is generated. In the ultrasonic diagnostic apparatus for calculating average velocity for each of the observation points, a calculation method of the transmission time when the transmitted ultrasonic wave arrives at the observation point is changed according to the depth of the observation point.SELECTED DRAWING: Figure 1【課題】フレームレートの向上とアンサンブル数の増加を両立させ、さらに、カラードプラ画像の品質を向上させる。【解決手段】超音波プローブに列設された複数の振動子を選択的に駆動して被検体に対して超音波送受信を実行し、カラーフローマッピング法による速度解析を行う超音波診断装置において、１回の送信イベントセットに含まれる複数の送信サブイベントごとに超音波を送信し、受信信号列を送信イベントごとに生成し、送信イベントごとに主対象領域と副対象領域とに含まれる複数の観測点について、各観測点から得られた反射超音波に基づく前記受信信号列を整相加算して音響線信号を生成し、観測点ごとに平均速度を算出する超音波診断装置において、送信された超音波が観測点に到達する送信時間の算出方法を観測点の深さに応じて変更する。【選択図】図１
