1. From the Cerebrovascular Disease Center (N.N., L.D., F.P., J.H., P.T.); the Department of Radiology (M.H., J.F.D., H.Y., P.D., J.C.F.); Creatis UMR 5515, CNRS (N.N., M.H., L.D., Y.B., J.C.F.); and the Biostatistical Unit, HCL (P.A.), Hôpital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon, France.