Since the image data have far higher in-plane resolution than between-plane resolution from the imaging protocol(see above), so do the segmented LV contour stacks. However, since it is more desirable to have roughly equally spaced points in all three dimensions, in order to achieve more reliable curvature estimation, a shape-based contour interpolation becomes necessary.
A shape-based contour interpolation method, using the chamfer distance transformation [22][12], has been implemented. It has several distinctive advantages over some conventional methods such as linear interpolation, and the test results have been very accurate with average error, as defined by [30], less than two percent.