Medial-axis Enhancement of Tubular Structures and its Application in the Extraction of Portal Veins

I In this paper، a new filter is designed to enhance medial-axis of tubular structures. Based on a multi-scale method and using eigenvectors of Hessian matrix، the distance of a point to the edges of the tube is found. To do this، a hypothetical line with a deliberate direction is passed through the point which cuts the tube at its edges. For points which are located on the medial-axis، this distance is symmetric with respect to any deliberate direction. We find samples of the distances in different directions and assign a measure to the points based on this symmetry property. The output of this step is an enhanced image in which noise is removed and tubes can be seen more clearly. Then، we employ the filter developed by Pock et al. to enhance medial axis. Evaluation of the proposed method is performed using 2D/3D synthetic/clinical datasets both quantitatively and qualitatively.