利用先验估计自适应加窗的准静态超声弹性成像位移估计算法

Displacement estimation algorithm based on a priori estimation of adaptive window for ultrasonic elastography

准静态弹性成像技术是基于组织压缩前和压缩后超声回波射频信号进行组织运动重构的弹性成像技术。提出了一种基于先验估计的自适应窗函数算法,在位移估计过程中,使用已估计的临近窗的时延值作为先验信息,自动调整截取压缩后射频信号段的截取窗函数,提高了互相关运算所需的压缩前和压缩后信号段之间的相关性。仿真实验结果表明,该算法不仅大大提高了成像速度,而且提高了信噪比较低时的成像质量,同时该算法具有更宽的应变通带。

The quasi-static elastic imaging technique is based on ultrasonic echo radio frequency （RF） signal before and after compression for the tissue reconstruction. A adaptive algorithm based on priori estimates for the window function is proposed, using the time delay estimation close to the window values as a priori information in displacement estimation process and adjusting the interception window function of the RF signal after the compression, which can improve the correlation between the cross-correlation operations required for pre- and post compression signal segments. The simulation results show that the algorithm not only greatly improves the imaging speed, but also improves the imaging effect at low Signal-to-Noise Ratio （SNR）. At the same time, the algorithm has a wider strain passband.