1. From the Cardiac MR CT PET Program, Department of Radiology (G.A.R., U.H., A.A.M.), and the Cardiology Division (C.J.O.), Massachusetts General Hospital, Harvard Medical School, Boston; Federal Foundation School of Medical Sciences of Porto Alegre (G.A.R.), Porto Alegre, Rio Grande do Sul, Brazil; Boston University Department of Mathematics (J.M.M.), Boston, Mass; Department of Cardiology, Boston Medical Center (F.L.R., R.S.V.), Boston, Mass; Framingham Heart Study of the National Heart, Lung, and...