1. From the Departments of Radiology (L.J.J., A.K., D.D.) and Cardiology (N.S.T., P.D., P.A., K.A.C., A.T.Y.), St Michael’s Hospital, 30 Bond St, Toronto, ON, Canada M5B 1W8; and Departments of Radiology (C.V.G.F., A.O., L.C.T.K., B.C.) and Cardiology (N.B.D., S.M.S., I.R.), Sunnybrook Health Sciences Centre, Toronto, Canada.