Importance of computed tomography perfusion on assessing collateral circulation and prognosis of patients with acute anterior circulation large vessel occlusion after endovascular therapy

Abstract

This study probed the importance of computed tomography perfusion (CTP) on assessing collateral circulation and prognosis in patients with acute anterior circulation large vessel occlusion (AAC-LVO) after endovascular therapy (EVT). Retrospective analysis was performed on the case data of 124 AAC-LVO patients who achieved EVT in the First People's Hospital of Lianyungang. All patients received computed tomography (CT) examination. Based on the multi-phase computed tomography angiography (mCTA) score, patients were separated into poor collateral circulation group and good collateral circulation group. Based on modified Rankin scale (mRS) score, patients were separated into good prognosis group and poor prognosis group. The receiver operating characteristic (ROC) curve was used to measure the efficacy of CTP parameters in predicting good collateral circulation or good prognosis. Correlation between CTP parameters with mCTA collateral and 90-day mRS circulation score was analyzed using the Spearman correlation analysis. The age and admission national Institutes of Health stroke scale (NIHSS) scores of the good collateral circulation group were lower than the poor collateral circulation group, and low perfusion area volume with Tmax > 6 s (V_Tmax>6 s), infarct core area volume (V_{CBF<30 %})and hypoperfusion intensity ratio (HIR) were also lower. The mCTA collateral cycle score was negatively related to V_Tmax>6s, V_{CBF<30 %} and HIR. The area under the curve (AUC) values of V_Tmax>6s and V_{CBF<30 %} and HIR for predicting good collateral circulation were 0.763, 0.884 and 0.842, respectively, which suggested that perfusion parameters V_Tmax>6s, V_{CBF<30 %} and HIR could effectively indicate the status of patients' collateral circulation. Relative to the poor prognosis group, patients in the good prognosis group possessed lower admission NIHSS score, younger age, smaller final infarct volume, lower HIR, V_{CBF<30 %}, V_Tmax>6 s, Alberta Stroke Program Early CT(ASPECT) score, and higher mCTA score. Spearman correlation analysis unveiled that ASPECT score, mCTA score and 90-day mRS were negatively correlated. The final infarct volume, perfusion parameters HIR and V_{CBF<30 %} were positively correlated with 90-day mRS. ROC analysis showed that all variates had good prognostic value for acute anterior circulation great vessel occlusion patients, while V_{CBF<30 %} and HIR had high diagnostic value for prognosis. To sum up, CTP can provide a comprehensive imaging assessment of the collateral circulation of patients with AAC-LVO and has a higher predictive value for the prognosis assessment of patients with EVT in terms of V_{CBF<30 %}, HIR score and mCTA collateral circulation score.

Keywords: Acute anterior circulation great vessel occlusion; Collateral circulation; Computed tomography perfusion; Endovascular therapy; Prognosis.