There were 5 factors which might associate to hematoma expansions including time from onset to admission less than 3 hours (55% before 3h vs 16.7% after 3h, p<0.05), low prothrombine ratio (83.8±12.2% vs 97.7±18%, p<0.05), liver transaminase elevations, heterogeneous hematoma shapes and chấm máu signs on CTA.