1. From the MR-Center (S.A.T., W.Y.K.), Aarhus University Hospital Skejby, Aarhus N, Denmark; Vascular Imaging Lab (C.Y., M.O.), University of Washington, Seattle, Wash; Department of Cardiothoracic and Vascular Surgery (N.E., A.K., W.P.P.), Department of Cardiology (E.F., W.Y.K.), Interdisciplinary Nanoscience Center (J.V.N.), Aarhus University, Aarhus N, Denmark.