1. From the Department of Medicine, University of Melbourne (K.S., M.C., G.T.L., N.J.S., G.A.D., D.W.H.), National Stroke Research Institute (N.J.S., G.A.D., D.W.H.), and Centre for Positron Emission Tomography (U.A., H.J.T.-D., J.I.S.), Austin Health, Melbourne, Victoria, Australia; Department of Neurology, John Hunter Hospital (C.R.L.) Newcastle, New South Wales, Australia; Stroke Unit, Royal Brisbane Hospital (S.J.R.), Queensland, Australia.