The predictive value of a new BACS-MRA grading system for the infarction caused by basilar artery occlusion

HONG Lichao; QUAN Guanmin; YUAN Tao; CHEN Jun

doi:10.19300/j.2017.L5737zt

Abstract：Objective Basilar artery occlusion is a rare cause of cerebral infraction,which is associated with high risk of mortality and disability.The aim of our study was to explore the feasibility and the value of evaluating neurological function outcome of Basilar Artery and Collateration Score on Magnetic Resonance Angiography (BACS-MRA) which is first proposed.Methods Thirty-six patients (24 male,12 female;age 41-91years,mean age 60±13 years) with subacute cerebral infraction caused by basilar artery occlusion were enrolled and underwent MRI,DWI and MRA.A new sixteen-points grading system (BACS-MRA) was establish based on MRA.Two experienced neuroradiologists who were double-blinded read and graded scores.The association between each scoring method (BACS-MRA,BATMAN,and PC-CS) and outcome of cerebral infarction caused by basilar artery occlusion was tested with Spearman correlation analysis.Compared the prediction efficiency of each scoring method (BACS-MRA,BATMAN,and PC-CS) for poor outcome using receiver operating characteristic (ROC) curve.Differences between two groups were assessed using t-test or Mann-Whitney U test for continuous variables and Fisher's exact test for categorical variables.Results The BACS-MRA score of favorite outcome (mRS ≤ 3,21 cases)was 9±3 among 36 patients with basilar artery occlusion,whereas the score for poor outcome (mRS＞3,15 cases) was 5±3 (P＜0.001).The cut-off value of predicting poor outcome was 8.5,with sensitivity of 0.762,specificity of 0.933 and area under the curve (AUC) of 0.867 (95％CI:0.749-0.984).Correlation analysis showed a moderate negative correlation (r=-0.594) between BACS-MRA and mRS.Compared with PC-CS and BATMAN,BACS-MRA for poor outcome had larger AUC,higher Youden and correlation index.Conlusions The primary study showed that the new BACS-MRA can be evaluated easily and feasibly,as well as with an excellent interobserver agreement,and may be better to predicte outcome of subacute cerebral infarction caused by basilar artery occlusion.