Length Increasing Active Contour for the Segmentation of Small Blood Vessels

A new level-set based active contour method for the segmentation of small blood vessels and other elongated structures is presented. Its main particularity is the presence of a length increasing force in the contour driving equation. The effect of this force is to push the active contour in the direction of thin elongated shapes. Although the proposed force is not stable in general, our experiments show that with few precautions it can successfully be integrated in a practical segmentation scheme and that it helps to segment a longer part of the structures of interest. For the segmentation of blood vessels, this may reduce the amount of user interactivity needed: only a small region inside the structure of interest need to be specified.