Tracking contrast agents from ultrasound image using texture preserving optical flow estimation

In this paper, we proposed a novel texture preserving optical flow technique to estimate the motion patterns of contrast agent on the ultrasound image. The proposed method estimated the motion fields based on three major steps. Firstly, the proposed method recomposed the original image based on the weighted structure-texture decomposition. Secondly, we applied a slightly nonconvex approximation approach by utilizing the spline interpolation based coarse-to-fine warping scheme to handle the motion discontinuities in ultrasound image. Lastly, after each warping step, we employed the bilateral filter into the numerical framework to minimize the tracking errors in motion estimates. To evaluate the tracking performance of our method, we estimated the motion fields of microbubbles for the tissue mimicking phantom, and compared its results to those of the existing methods. As a result, it was found that the proposed technique provides the most reliable motion patterns of microbubbles, and reduces computational loads, simultaneously. We also confirmed the potential usefulness of our estimation scheme for the microbubble based diagnostic analysis.