METHODS: Blinded assessors coded baseline images for acute ischaemic signs (presence, extent, swelling and attenuation of acute lesions; and hyperattenuated arteries) and pre-existing changes (atrophy, leucoaraiosis and old ischaemic lesions). Logistic regression models assessed associations between imaging features and death at 7 and 90 days; good recovery (modified Rankin Scale scores 0-2 at 90 days) and sICH. Data are reported with adjusted ORs and 95% CIs.

RESULTS: 2916 patients (67±13 years, National Institutes of Health Stroke Scale 8 (5-14)) were included. Visible ischaemic lesions, severe hypoattenuation, large ischaemic lesion, swelling and hyperattenuated arteries were associated with 7-day death (OR (95% CI): 1.52 (1.06 to 2.18); 1.51 (1.01 to 2.18); 2.67 (1.52 to 4.71); 1.49 (1.03 to 2.14) and 2.17 (1.48 to 3.18)) and inversely with good outcome. Severe atrophy was inversely associated with 7-day death (0.52 (0.29 to 0.96)). Atrophy (1.52 (1.08 to 2.15)) and severe leucoaraiosis (1.74 (1.20 to 2.54)) were associated with 90-day death. Hyperattenuated arteries were associated with sICH (1.71 (1.01 to 2.89)). No imaging features modified the effect of alteplase dose.