CT Perfusion Imaging In Patients With Middle Cerebral Artery Stenosis

Objective: To analyze the correlation of middle cerebral artery stenosis with collateral circulation,cerebral perfusion parameters and clinical prognosis based on CTA and CTP,and to provide imaging evidence for ischemic stroke.Methods: A retrospective study was conducted from July 2019 to November 2021 in the Department of Neurology,the Second Affiliated Hospital of Zunyi Medical University,by cranial CTP and CTA confirmed the presence of an anomalous perfusion region due to middle cerebral artery stenosis in 59 patients.The degree of head and neck vessel stenosis was evaluated by artificial intelligence software and an experienced attending physician,and the perfusion parameters(infract core and ischemic penumbra volume)were obtained by CTP postprocessing software.The images of multiphase CTA and the fusion dynamic CTA were obtained by CTP perfusion anomaly region original data processing,and the collateral circulation was evaluated.The Spearman correlation was used to analyze the correlation of the degree of stenosis,the score of collateral circulation,perfusion parameters and prognosis.To evaluate the correlation between the two collateral circulation scores and the ischemic core,perfusion mismatch ratio,and the ability of predicting the prognosis.Logistic single-factor regression analysis was used to screen the factors that could influence the prognosis,draw ROC curve and calculate the cut-off value,sensitivity and specificity.Results:(1)59 patients were included,35 males and 24 females,with a mean of66.1±12.2 years.(2)MCA stenosis was positively correlated with ischemic penumbra volume(r=0.385,P=0.003)and negatively correlated with collateral circulation(r=-0.400,P=0.002),and there was no correlation with prognosis(P=0.147).(3)The collateral circulation score(mp-Menon score,Tan score)was negatively correlated with ischemic core volume in the area of perfusion abnormality(mp-Menon: r=-0.716,P=0.001;Tan: r=-0.426,P=0.001)and with the mismatch rate(ischemic core volume/ischemic penumbra volume)in the area of perfusion abnormality(mp-Menon: r =-0.511,P=0.001;Tan: r=-0.408,P=0.001).(4)Collateral circulation score was negatively correlated with prognosis(mp-Menon score: r=-0.372,P=0.004)and Tan score:r=-0.304,P=0.019).(5)The mp-Menon score was more effective and consistent than the Tan score in predicting the 90-day clinical prognosis of patients(AUC: 0.694 vs.0.626,P=0.011),(k=0.850 vs.k=0.738).Conclusion: Collateral circulation is a prognostic factor in patients with middle cerebral artery stenosis or occlusion.CTP combined with CTA imaging has important value in the treatment decision and prognosis prediction for patients with ischemic stroke.