1. From the Department of Radiology (C.R., N.M.W., M.J.-H., P.P., N.P.), Fairview-University Medical Center, Minneapolis, Minn; Division of Pediatric Cardiology (J.W.), University of Hamburg-Eppendorf, Hamburg, Germany; and the Hypertrophic Cardiomyopathy Center (S.A.C., A.G.Z., B.J.M.), Minneapolis Heart Institute Foundation, Minneapolis, Minn.