4D heart modeling algorithm flowchart.

<p>Using the segmented contours from the first time step, we go through each adjacent pairs of contours and establish the intra-connectivities between them. Using these connections, we reconstruct a 3D mesh model and set it as the generated mesh model of the first time step. For each subsequent time step, the segmented contours are passed through the tree-based connectivity process to establish their inter- and intra-connectivities. They are then compared with the mesh model from the current time step in a sub-mesh by sub-mesh manner. If there is no 1-to-1 contour correspondence, they are then passed through the 2D topological change process before performing the 1-to-1 contour matching process. Finally, the mesh model of the current time step is generated when the mesh is fully deformed.