An active contour model algorithm for tracking endocardiac boundaries in echocardiographic sequences

The use of active contour models to track the boundaries of anatomic struct ures in medical images is a technique that has attracted a great number of efforts during the last decade. Segmentation techniques based in deformable active contours were proposed first by Kass et al.(1) Because of the probl ems appearing using these models, some solutions have been introduced, such as balloon force(2) or Gradient Vector Flow force (GVF), derived from the Gradient Vector Flow vectorial field.(3) Results obtained with these forces in the tracking endocardiac task in echocardiographic sequences were not a dequate. We have designed a new external force called hybrid force, which, by combining both forces, joins the main features of each one.