GO HIROTOSHI,呉 弘敏,HIROOKA MAMORU,廣岡 衛,KURASHIMA HIROYUKI,倉島 寛行
申请号:
JP2017080474
公开号:
JP2018175480A
申请日:
2017.04.14
申请国别(地区):
JP
年份:
2018
代理人:
摘要:
PROBLEM TO BE SOLVED: To generate and display a tomogram image in which a noise is reduced, in which a restriction of a hardware is decreased compared to a conventional frequency compound method.SOLUTION: A frequency is changed per frames according to a frequency set including an ordered and predefined plurality of frequencies of an ultrasonic beam to be transmitted into a subject, and the change of the frequency is cycled per said predefined plurality of frequencies so as to repeat scanning of the ultrasonic beam into the subject. In chronological frame images generated based on received signal, the chronologically-aligned plurality of frame images are frame-synthesized. Accordingly, a transmission focus position and a scanning deflection angle are liked with the change of transmitted/received frequencies. By repeating a weighted averaging between the plurality of frames, compound of transmitted/received beams and compound of frequencies between the frames of a plurality of bands of the received signal are achieved, thereby reducing a noise such as speckle noise and artifact and displaying a tomogram image of high resolution by the synthesis of a plurality of transmission focuses.SELECTED DRAWING: Figure 7COPYRIGHT: (C)2019,JPO&INPIT【課題】従来の周波数コンパウンド法と比べハードウェア上の制約が少なく、ノイズが低減された断層像を生成して表示する。【解決手段】被検体内に送信する超音波ビームの、順序づけられた予め定められた複数の周波数からなる周波数セットにしたがって周波数をフレームごとに変更し、かつ周波数の変更を上記の予め定められた複数ごとに循環させながら、超音波ビームによる被検体内の走査を繰り返し、受信信号に基づいて生成された時系列的なフレーム画像について、時系列的に並ぶ複数のフレーム画像のフレーム合成により、更に送信焦点位置や走査偏向角度も送受信周波数の変更と連動させ、複数フレーム間の重み付け平均化処理を繰り返すことで、送受信ビームのコンパウンド及び受信信号の複数帯域のフレーム間周波数コンパウンドができ、スペックルノイズやアーチファクト等のノイズが低減され、かつ複数の送信焦点の合成で分解能も高くなる断層像を表示する。【選択図】図7