基于零相位与光流法的混合超声弹性成像算法的研究

摘要

鉴于超声弹性成像传统的时域互相关算法在估计组织位移时效率低下这一问题,本文提出了一种基于零相位与光流法的混合超声弹性成像方法.首先利用零相位法来获得组织压缩前后的位移场,将结果作为光流法的初始位移;然后采用经典光流法对为位移场进行矫正,抑制由于组织横向形变所带来的去相关;最后采用最小二乘法对位移场进行计算获得了组织的轴向应变.本文利用仿真数据对算法进行了验证,并且定性分析了不同压缩量下的算法的性能.实验结果表明,本论文中提出的零相位和光流法的混合超声弹性成像算法所得纵向位移图和纵向应变图与有限元结果基本一致,证明了算法的正确性.%In view of the problem that the traditional time-domain cross-correlation algorithm of ultrasound elastography in estimating tissue displacement compute-intensive and inefficient, this paper proposed a hybrid method of ultrasound elastography based on phase zero estimation and optical flow method. Firstly, the zero phase was used to estimation method to obtain coarse displacement field, as a result of the initial displacement for optical flow; then the classical optical flow method Horn & Schunck (HS) optical flow method was used to correct for the displacement field; finally the least squares method was used to calculate the displacement field obtained axial strain organizations. In this paper, the simulation data algorithm was validated and the impact of simulation data under different compression on the experimental results was discussed. The experimental results showed that the longitudinal displacement diagram and the longitudinal strain map of the zero-phase and the optical flow method proposed in this paper were consistent with the finite element results, and the correctness of the algorithm was proved.