1. From the Departments of Medicine, Cardiovascular Division (R.M.B., A.S.P., A.V., W.J.M., M.T.J.), Radiology (W.J.M.), Surgery (J.L.), and Pathology (W.Q.), Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Mass; Boston University School of Medicine, Boston, Mass (J.H.); and EPIX Medical Inc, Cambridge, Mass (S.W., A.J.W., E.C.P., A.K., J.A.B., P.B.G., R.M.W.).