A coupled filtering method to solve feature-motion decorrelation in speckle tracking

In speckle tracking, feature-motion decorrelation is a problem that makes feature tracking results unable to represent the underlying tissue deformation. In this paper, we propose a coupled filtering method to address the feature-motion decorrelation problem. After explicitly modeling image variations caused by tissue deformation, we filter the image before tissue deformation and the warped image after tissue deformation with a pair of filters, respectively. Theoretical derivation show that the two filtered images are identical to each other. Since the coupled filtering method keeps tissue deformation parameters, feature-based tracking is able to accurately estimate the parameters of underlying tissue deformation. Experiments in elastography studies show that our method is superior over previous methods.