From the Neurology and Stroke Unit (M. Romoli, M.L.), Nuclear Medicine (F.M., V.M.), Diagnostic Neuroradiology Unit (P.C.), and Interventional Neuroradiology Unit (M. Ruggiero), Bufalini Hospital, AUSL Romagna, Cesena; Cerebrovascular Unit (G.M., N.R., I.C., G.B., A.B., B.S.) and Neuroradiology Unit (M.S.), Fondazione IRCCS Istituto Neurologico Carlo Besta; and Nuclear Medicine Department (L.T., A.C.), Ospedale San Paolo, Milan, Italy.