Ischemic stroke thrombolysis beyond the 4.5-hour window: who qualifies with advanced imaging?

A 67-year-old patient woke up with right-sided hemiparesis and aphasia. Time last known well is 9 hours ago. NIHSS is 12. MRI DWI shows small core infarct with large penumbra on perfusion imaging (RAPID software showing mismatch ratio > 1.8). Is extended-window thrombolysis with alteplase appropriate here? What do DAWN and DEFUSE 3 trial criteria say about patient selection for late-window thrombectomy?