RESUMO
Objective To explore the value of time-invariant CTA in assessing collateral circulation of patients with acute ischemic stroke and assisting clinicians in predicting clinical outcomes.Methods The score of collateral circulation was compared between single-phase and time-invariant CTA.NIHSS score was calculated at admission and two weeks after admission.A 50% or greater decrease in NIHSS score over two weeks was considered as major neurologic improvement,which showed good clinical outcome;otherwise,it indicated bad outcome.The predictive ability of time-invariant CTA for clinical outcomes was assessed based on ROC curves.Results Compared with single-phase CTA,more collateral vessels could be viewed on time-invariant CTA.The average score of collateral circulation on time-invariant and single-phase CTA was 1.50±0.69 and 1.15±0.49 respectively (P=0.006<0.05 ).Time-invariant CTA had the moderate predictive ability for clinical outcomes in patients with acute ischemic stroke (AUC=0.810;P=0.032<0.05). Conclusion The time-invariant CTA showed potential value in assessing collateral circulation of patients with acute ischemic stroke and assisting clinicians in predicting clinical outcomes.