基于投影寻踪的超声彩色血流成像杂波抑制方法

A clutter rejection method based on the projectionpursuit in the ultrasound color flow imaging

为抑制超声彩色血流成像(CFI)中杂波信号对血流速度估计的影响,提出一种基于投影寻踪(PP)的杂波抑制方法。根据回波信号的时域特性,采用投影寻踪法提取主元以降低主元对非血流区域的高强度杂波的敏感度;然后在特征向量空间去除估计得到的杂波成分,从而获得血流信号。将本方法用于计算机仿真信号和人体实测信号。结果表明:与传统的高通滤波器法相比,本方法能更好地保持流速剖面的完整性和血流轮廓;与特征向量法相比,在近似的流速完整度下本方法在非血流区域产生的误差较少,血管内外能量比高出特征向量法约5dB,能够有效地提高彩色血流成像的质量。

In the ultrasound color flow imaging （CFI）, a clutter rejection method based on the projection-pursuit （PP） is proposed to reduce velocity artifacts caused by clutter signals. According to time domain characteristics of echoes, principal components are extracted by the PP to reduce their sensitivity to strong clutter signals originating from non- blood-flow regions. Blood signals are then obtained by removing the estimated clutter space in the eigenvector domain. The proposed method has been applied to both computer simulated data and human experimental data. Results show that this method can achieve a better velocity profile and vessel shape than the conventional high-pass filter. It is also shown that this method causes less velocity artifacts in non-blood-flow regions and achieves an inside to outside blood energy ratio higher than that achieved by eigenvector method by 5 dB. Thus, the flow image quality is expected to be improved effectively.