Time window

Imaging

Imaging criteria

Wake-up stroke

>4.5 hours from last seen well, no upper limit

MRI DWI-FLAIR mismatch

DWI lesion and no FLAIR lesion

Wake-up stroke or unknown onset time

>4.5 hours from last seen well, and within 9 hours of the midpoint of sleep.  The midpoint of sleep is the time halfway between going to bed and waking up

CT or MRI core-perfusion mismatch

Suggested: mismatch ratio greater than 1.2, a mismatch volume greater than 10 mL, and an ischemic core volume <70 mL

Known onset time

4.5-9 hours

CT or MRI core-perfusion mismatch

Suggested: mismatch ratio greater than 1.2, a mismatch volume greater than 10 mL, and an ischemic core volume <70 mL