[1] Univ Helsinki, Cent Hosp, Dept Clin Neurosci, Memory Res Unit,HYKS, FIN-00029 Helsinki, Finland
[2] Univ Helsinki, Cent Hosp, Dept Clin Neurosci, Stroke Unit, FIN-00029 Helsinki, Finland
[3] Univ Helsinki, Cent Hosp, Dept Radiol, FIN-00029 Helsinki, Finland
[4] Kuopio Univ Hosp, Dept Clin Radiol, SF-70210 Kuopio, Finland