Stduy Of Ultrasound Elastography Algorithms In Different Methods

Elastography is an imaging method which is able to display the distribution of elastic properties of soft tissue, and provide valuable diagnostic information. For example, with tumor growing, the elasticity of tissue will change. Elasgotraphy can detect the disease early. The doctor detected the stiffness information of biological tissue by palpation method which is subjective. This method may be less effective when tumor is small. In recent year, elastography has become a hot spot in ultrasound imaging areas. In this paper, we compared 1D motion estimation with 2D motion estimation for elastography and present a framework combined with weighted phase separation(WPS) and 2D cross-correlation for displacement estimation. Our work is shown as follow:Firstly, we studied the basic knowledge of Theory of elasticity. Elastography was studied in this paper. And we use the finite element method to study the simulation of compression organization. We also use the Field II to simulate the soft tissue.Secondly, We studied 1D algorithm. In this paper, We studied the classical 1D cross-correlation algorithm and overcame its weaknesses that the maximum value of correlation was located in sampling point by using sub-sample time delay estimation.Thirdly, taking into account the influence of tissue side-slipping, we presented a 2D cross-correlation method firstly to apply to the RF signals and then used WPS method to calculate more precise axial displacements. We also compared images qualities and efficiency of 1D algorithm and 2D algorithm by simulations and phantom experiments. It is shown that this method is fast and robust to relatively complex tissue motions and could improve SNRe. This method will have some potential for the latter experiments and clinical applications.