Correlation between perfusion weighted imaging-diffusion weighted imaging mismatch and early reperfusion after intravenous thrombolysis in acute ischemic stroke / 中华神经科杂志

ABSTRACT

Objective To investigate the impact of the pretreatment perfusion weighted imaging (PWI)-diffusion weighted imaging (DWI) mismatch on reperfusion and early neurological improvement after intravenous thrombolysis in acute ischemic stroke.Methods We retrospectively reviewed our collected clinical,laboratory,and radiologic data in patients receiving intravenous recombinant tissue plasminogen activator therapy,who had performed multimodal MRI in both pretreatment and 24 h post-treatment in our hospital..The target mismatch of PWI-DWI was defined as a PWI lesion that was 10 ml or more and 120％ or more of the DWI lesion,with DWI lesion less than 70 ml and PWI lesion less than 140 ml.The smalllesion was defined as a DWI and PWI volume both less than 10 ml.The others were termed non-target mismatch.Reperfusion required a 30％ or greater reduction in PWI lesion volume on the 24-hour follow-up scar.The early neurological improvement was defined as the patients with an NIHSS score of 0 to 4 or 6-point or greater improvement at 7 days.Results Among 45 patients analyzed,19(41％) patients presented target mismatch,of which 8 patients were treated over 4.5 h.The rate of reperfusion and early neurological improvement after thrombolysis in target mismatch group were both significantly increased comparing with non-target mismatch group( 16/19 vs 5/12,x2 =6.092,P ＜0.05 and 13/19 vs 2/12,x2 =7.888,P ＜ 0.05,respectively ),although the recanalization rate demonstrated no significant difference between two groups.The pooled OR for reperfusion was 6.4(95％ CI 1.156-35.437,P =0.034),and the pooled OR for favorable clinical response was 21.7 ( 95％ CI 2.234-210.110,P =0.008 ) in target mismatch patients.Among the target mismatch group,13/16 of patients with reperfusion had early neurological improvement,while no patients without reperfusion had neurological improvement.The rate of recanalization,reperfusion and neurological improvement after thrombolysis demonstrated no significant difference between target mismatch group treated within 4.5 h and beyond 4.5 h.Conclusion Patients with target mismatch profile before thrombolysis had a high reperfusion rate and were prone to get early neurological improvement,indicating that the evaluation of PWI-DWI mismatch may facilitate the selection of patients who may benefit from thrombolysis beyond the time window.