PROBLEM TO BE SOLVED: To provide an ultrasonograph improving an S/N ratio while retaining a frame rate, detecting a low flow-rate blood flow at a large aliasing velocity and displaying it as a Doppler image.SOLUTION: This ultrasonograph is provided with: a scan performing means performing a first scan repeatedly performed at a prescribed period for a B-mode image, and a second scan repeatedly performed at a second period T2 between the periods of the first scan, which is continuously and repeatedly performed a prescribed number of times at a first period T1, for obtaining two-dimensional distribution information of blood information V/P/Var a Doppler signal acquisition means sequentially acquiring Doppler signals from reflected signals acquired by the second scan a storage means storing a time-series unequal-interval Doppler signal train collected at the first period T1 and the second period T2 by the Doppler signal acquisition means a removal means reading the unequal-interval Doppler signal train from the storage means, removing signal components with less movement and providing a blood flow signal and a blood flow information acquisition means acquiring the blood flow information V/P/Var from the blood flow signal.COPYRIGHT: (C)2007,JPO&INPIT【課題】フレームレートを維持しつつS/N比を向上させ、かつより大きな折り返し速度で低流速の血流を検出してドプラ画像として表示可能な超音波診断装置である。【解決手段】超音波診断装置はBモード像用に所定の周期で繰返し行われる第1のスキャンおよび血流情報V/P/Varの2次元分布情報を得るために第1の周期T1で続けて所定数回繰返し行われる第1のスキャンを挟んで第2の周期T2で繰返し行われる第2のスキャンを実行するスキャン実行手段と、第2のスキャンにより得られる反射信号からドプラ信号を順次得るドプラ信号取得手段と、ドプラ信号取得手段により第1の周期T1および第2の周期T2で収集された時系列の不等間隔のドプラ信号列をラスタ方向ごとに記憶する記憶手段と、記憶手段から不等間隔のドプラ信号列を読出して、動きの少ない信号成分を除去して血流信号を得る除去手段と、血流信号から血流情報V/P/Varを得る血流情報取得手段とを備える。【選択図】 図3
