Reversibility of ischemic core defined by CT perfusion imaging in acute stroke patients receiving thrombolysis within different time windows / 中华神经科杂志

ABSTRACT

Objective To investigate the reversibility of ischemic core defined by CT perfusion imaging in acute ischemic stroke (AIS) patients receiving intravenous thrombolysis within different time windows and influencing factors.Methods The data of AIS patients who received intravenous thrombolysis in the Department of Neurology of Lishui People's Hospital from May 2016 to December 2018 were retrospectively reviewed.All patients had finished multi-model CT imaging before thrombolysis and multi-model MRI examination 24-48 hours after thrombolysis.The baseline ischemic core volume (hypoperfusion area with relative cerebral blood flow (rCBF)＜30％) was quantitatively assessed based on CT perfusion images using MIStar software,and the final ischemic core volume was assessed based on diffusion weighted imaging acquired 24-48 hours after thrombolysis.The reversibility of ischemic core was defined as baseline ischemic core volume-the final infarct volume ≥5 ml.Then the clinical and imaging features of the patients between reversible group and irreversible group were compared,and the predictors of ischemic core reversibility were analyzed by binary Logistic regression analysis.Results Finally,97 patients were enrolled in the present study,of which 64 (66％) patients achieved successful recanalization,51 (53％) patients with reversible baseline ischemic core.For patients with recanalization,the incidence of reversibility was 76％ (26/34),71％ (17/24),2/5 and 0 (0/1) in patients with time window from onset to thrombolysis (ONT) ＜3.0 h,3.0-4.5 h,4.6-6.0 h,and ＞6.0 h,respectively.In the non-recanalization group,six patients were also showed with ischemic core reversibility,including 4 (4/12) in the ONT＜3.0 h group and 2 (2/12) in the ONT 3.0-4.5 h group.It was found that the reversible volume was positively correlated with baseline ischemic core volume (r=0.805,P＜0.001) by Spearman correlation analysis.Finally,binary Logistic regression analysis revealed that the history of hypertension,ONT and recanalization were independent predictors of reversible changes of baseline ischemic core.Conclusions The ischemic core defined by CT perfusion imaging (rCBF＜30％) was considerably inaccurate for patients with ONT＜6.0 h.If recanalization could be achieved within this time window,most of the patients would manifest with ischemic core reversibility,the predictors of which also included hypertension history and ONT.