1. From the Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown (K.E.-H., J.H.L., N.Y., E.S.Y., A.D., Y.W., Y.Z., A.C., B.S., C.A.); Department of Neurology (M.D.F., A.M.J.M.v.d.M), and Department of Human Genetics, Leiden University Medical Centre, The Netherlands (A.M.J.M.v.d.M); and Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston (C...