Comparison between MRI screening and CT-plus-MRI screening for thrombolysis within 3h of ischemic stroke

Abstract: Background and purpose: Although MRI may provide much information on brain pathology to aid in patient selection for thrombolysis, the concern remains that MRI screening may increase time-to-treatment. We hypothesized that CT-plus-MRI screening might be a valuable time-efficient alternative for selection of patients requiring thrombolysis. Methods: We reviewed acute stroke patients who received intravenous tissue plasminogen activator (tPA) (with or without intra-arterial urokinase) initiated within 3h of stroke between March 2004 and March 2007. MRI was the routine screening imaging employed until November 2005. Thereafter, CT-plus-MRI screening was performed; tPA of 0.6mg/kg was infused intravenously after exclusion of hemorrhage by CT screening, and subsequently a further decision on thrombolysis (i.e., intravenous tPA of 0.3mg/kg, or intra-arterial urokinase) was made after MRI screening. We compared times-to-treatment and clinical outcomes between MRI screening and CT-plus-MRI-screening groups, and identified factors associated with good clinical outcome (modified Rankin Scale ≤2 at 3months). Results: Eighty-nine patients were included in the analysis; 43 were MRI-screened, and 46 were CT-plus-MRI-screened. Although the MRI-screening group had a longer door-to-needle time (p <0.001), these patients showed better 3-month outcomes compared to CT-plus-MRI-screening group (p =0.01). Multivariate analysis showed that MRI screening (odds ratio 3.97, 95% confidence interval 1.30–12.17, p =0.02) was independently associated with a good outcome at 3months. In CT-plus-MRI-screening group, although time-to-initial imaging and time-to-tPA were shorter, time-to-MRI and time-to-additional thrombolysis were delayed. Conclusion: These results suggest that early patient selection using MRI may be more effective than reduction of times-to-treatment in improvement of thrombolytic outcomes. [Copyright &y& Elsevier]