AUTOMATIC TRACKING OF SPAMM GRID AND THE ESTIMATION OF DEFORMATION PARAMETERS FROM CARDIAC MR-IMAGES

In this paper, we present a new approach for the automatic tracking of SPAMM (Spatial Modulation of Magnetization) grid in cardiac MR images and consequent estimation of deformation parameters. The tracking is utilized to extract grid points from MR images and to establish corres pondences between grid points in images taken at consecutive frames. T hese correspondences are used with a thin plate spline model to establ ish a mapping from one image to the next. This mapping is then used fo r motion and deformation estimation. Spatio-temporal tracking of SPAMM grid is achieved by using snakes-active contour models with an associ ated energy functional. We present a minimizing strategy which is suit able for tracking the SPAMM grid. By continuously minimizing their ene rgy functionals, the snakes lock on to and follow the in-slice motion and deformation of the SPAMM grid. The proposed algorithm was tested w ith excellent results on 123 images (three data sets each a multiple s lice 2D, 16 phase Cine study, three data sets each a multiple slice 2D , 13 phase Cine study and three data sets each a multiple slice 2D, 12 phase Cine study).