1. From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (C.T., C.N.D.C., M.H.A., T.M.D., R.R.B., S.E.L., U.J.S.), and Division of Cardiology, Department of Medicine (R.R.B., S.E.L., D.H.S., U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29425-2260.