Reconstructing Cardiac Shape via Constrained Voronoi Diagram and Cyclic Dynamic Time Wrapping from CMR

Reconstructing cardiac shapes from CMR short axis parallel contours is a prerequisite task for downstreaming analysis and diagnosis. This task, however, is not trivial when the inflow and outflow tract must be taken into account. These tracts are a difficulty for reconstructing whole cardiac shapes from CMR. We aimed to develop a method to reconstruct either left cardiac structure or right cardiac structure with minimal user assistance in a unified geometric framework. Ventricular, atrial, and arteries contours were delineated on short axis images. Cyclic dynamic time wrapping (DTW) method were utilized to triangulate two parallel contours on neighboring imaging slices. Reconstructing three contours on inflow and outflow tracts were divided into two parts. The outer part was reconstructed from the lower contour and the convex hull of two upper contours. The interior part was parobolic surfaces fit to points not existing in the convex hull and the Voronoi cell centroids. All cases were automatically reconstructed successfully with average computational time less than one minute. Reconstructed shape have anatomically reasonable structures.