Application Value Of CT Perfusion Imaging In Early Symptom Improvement After Intracranial Arterial Stenting

Background and Objective:Intracranial atherosclerotic stenosis(ICAS)is one of the most common causes of the first and recurrent cerebral vascular ischemia events in the world.Patients with ICAS had more severe stroke symptoms at admission and required longer hospital stays.Endovascular interventional therapy has become an important treatment for ICAS.However,there are still some disputes about the efficacy,risk and safety of endovascular therapy for ICAS at home and abroad.In particular,there are few studies on whether intracranial artery stenting can achieve early symptom improvement,and lack of imaging reference.The purpose of this study is to explore the related factors affecting the early symptom improvement after intracranial artery stenting by comparing the clinical characteristics and CT perfusion parameters between the intracranial artery stenting group and the non-improvement group,so as to help to select the patients who may benefit from intracranial stenting in clinical practice.Materials and methods:A total of 215 patients who underwent endovascular stenting in the Neurointervention Department of our hospital from January 2018 to December 2021 were retrospectively collected.All patients were diagnosed as unilateral symptomatic severe intracranial artery stenosis by digital subtraction angiography(the stenosis rate of the affected side was≥70%and the contralateral stenosis rate was less than 50%).CTP examination was performed,and the relevant clinical and laboratory results were collected.The patients were divided into two groups according to the difference between the NIHSS score within 7 days after operation and the preoperative NIHSS score≥1.The patients were divided into two groups:symptom improvement group(≥1)and no improvement group(<1).The clinical characteristics and CT perfusion parameters were compared between the two groups.Results:There were 100 cases in the symptom improvement group and 115 cases in the no improvement group.The incidence of hypertension in the symptom improvement group was significantly lower than that in the no improvement group(P<0.05).There was significant difference in Willis ring compensation between symptom improvement group and non-improvement group(P<0.001).The preoperative perfusion parameters of all patients,CBF decreased,CBV increased,MTT,TTP and Tmax prolonged,the difference was statistically significant(P<0.05).In the symptom improvement group,compared with the perfusion parameters of the affected side before and after operation,the CBF of the affected side increased,the CBV decreased,and the MTT,TTP and Tmax shortened(P<0.05).The rCBV ratio,rTmax ratio and Tmax>6s volume of CT perfusion parameters in the symptom improvement group were significantly higher than those in the non-improvement group(P<0.05),but there was no significant difference in rCBF ratio,rMTT ratio,rTTP ratio and Tmax>4s volume between the two groups(P>0.05).The value of rCBV ratio,rTmax ratio and Tmax>6s volume as a single index in predicting symptom improvement was compared and analyzed.RCBV ratio and Tmax>6s volume were superior to rTmax ratio in predicting early symptom improvement.There was no significant difference between rCBV ratio and Tmax>6s volume(P=0.615).No hypertension,good Willis ring compensation,rCBV ratio>1.12 and Tmax>6 seconds volume(>42ml)were the best predictors of early symptom improvement after intracranial artery stenting,and the area under the curve(AUC)was 0.855.Conclusion:This study confirmed that endovascular stenting can improve cerebral blood perfusion on the stenotic side of patients with symptomatic intracranial artery stenosis.The clinical-imaging model established with no hypertension,good Willis ring compensation,rCBV ratio>1.12 and Tmax>6s volume(>42ml)may help to screen patients with obvious improvement of early symptoms after intracranial artery stenting in clinical practice.