1. From the Departments of Cardiothoracic Surgery (B.K.) and Radiology (S.M.), Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark; Division of Cardiology (B.K., B.F., C.L.S., E.P., Y.D.) and Department of Radiology (D.M.B.), Children's Hospital of Philadelphia, Philadelphia, Pa; and Department of Cardiothoracic Surgery, Copenhagen University Hospital–Rigshospitalet, Copenhagen, Denmark (V.E.H.).