Single Slice Model. Spatial registration using point registration requires the selection of multiple fiducials from each data set. Panel A shows segmentation of the mitral valve annulus with a thickness of only one voxel. In Mimics, the image in Panel A cannot be directly used for fiducial selection. Panel B shows the 3D Object rendered from the segmentation in Panel A, which can be used for fiducial selection. Panel C shows the selection of matching fiducials directly from a cardiac MR image.