1. From the Athinoula A. Martinos Center for Biomedical Imaging (N.M.M., H.A., M.W.Z., C.J.L., A.G.S.), Department of Radiology, Massachusetts General Hospital and the Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Boston, Mass; the Stroke Service (H.A., A.B.S., W.J.K.), Department of Neurology, Massachusetts General Hospital, Boston, Mass; and the Departments of Clinical Radiology and Neurology (J.O.K., Y.L., J.N.), Kuopio University Hospital, Kuopio,...