1. From the Department of Medicine (P.M.W., A.M.N., S.D.C., T.A.W., A.H.S., G.H., J.S.A., E.K.L., H.Z., S.A.W., G.M.L.), Cardiovascular Magnetic Resonance Laboratories, Washington University School of Medicine, St Louis, Mo; Philips Medical Systems (S.D.C.), Cleveland, Ohio; Bristol-Myers Squibb Medical Imaging (T.D.H.), Billerica, Mass; and the University of Missouri Research Reactor (J.D.R.), Columbia.