1. From the Division of Neuroradiology and Department of Medical Imaging (A.E., G.B., K.W., S.P.S., R.I.A.), the Department of Neurology and North and East GTA Regional Stroke Centre (D.J.G.), Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada; and Seaman Family MR Research Centre and Departments of Clinical Neurosciences (D.D., A.M.D.), Foothills Medical Centre, Calgary Health Region, Canada.