Qualitative Assessment of Spatial Registration. By enabling the Contours Visible property of the valve 3D Object, an overlay of the 3D Object surfaces is displayed over the images. Accuracy of the spatial registration can be qualitatively assessed. Two cardiac MR images with an overlay (pink) from the valve 3D Object are shown. Panel A shows that the contours of the left atrium, aortic root, and right ventricle align. Panel B shows that the contours of the right atrium, interventricular septum, and lateral left ventricular wall align. Panel B also shows that the mitral valve leaflets from the valve 3D Object align with chordae tendinae in the cardiac MR.