TABLE III.

Effect of 3D Registration on Mean Symmetric Surface Distance (MSD) Between Manually Drawn Contours of End-Systolic and End-Diastolic Cardiac MRI. The Table Compares the SynthMorph (sm-Shapes) and VoxelMorph (vm-ncc) Models Performing Best At This Task Despite Optimization for Brain Registration, Without Retraining. A Reduction in MSD Translates to Better Alignment of the Left Ventricular Structures. SD Abbreviates Standard Deviation, and We Highlight the Best Result for Each Set of Contours in Bold

	Endocardium		Epicardium
	SynthMorph	VoxelMorph	SynthMorph	VoxelMorph
Pairs improved	29/33 (88%)	28/33 (85%)	28/33 (85%)	25/33 (76%)
Mean ± SD (mm)	−0.8 ± 0.1	−0.7 ± 0.1	−0.6 ± 0.1	−0.2 ± 0.1
Mean ± SD (%)	−10.2 ± 1.6	−9.0 ± 1.9	−11.6 ± 1.5	−4.3 ± 1.4
Best pair (%)	−35.4	−33.8	−29.6	−22.5
Worst pair (%)	+3.9	+6.1	+6.0	+13.2