1. From the Heart and Vascular Research Center and the Department of Biomedical Engineering, MetroHealth Campus (D.J., L.W., J.Z., I.D., X.Y., D.S.R.) and Case Center for Imaging Research (C.F.), Case Western Reserve University, Cleveland, Ohio; and Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Mass (J.E.S.).