1. From the Department of Radiology (A.V, A.L, J.S, T.T), University of Cincinnati Medical Center, OH; Department of Public Health Sciences, Medical University of South Carolina, Charleston (L.F, S.Y); Department of Neurology, UCLA Medical Center (D.L); and Department of Clinical Neurosciences (A.D, M.H), Department of Radiology (B.M, E.Q, C.D, M.G, A.D., M.H.), Department of Community Health Sciences (M.H., B.M), and Department of Medicine (M.H.), University of Calgary, Calgary, Alberta, Canada.