Multimodal MR Evaluation Of Enhanced Extracorporeal Counterpulsation In Patients With Mismatched Perfusion-Diffusion Area After Acute Ischemic Stroke

Objective:In this study,perfusion weighted imaging(PWI),diffusion weighted imaging(DWI),susceptibility weighted imaging(SWI)and fluid-attenuated inversion recovery(FLAIR),Multimodal,quantitative assessment of enhanced extracorporeal counterpulsation(EECP)therapy with perfusion-diffusion mismatch(PDM)region in patients with acute ischemic stroke(AIS),and to explore the possible mechanism of enhanced external counterpulsation in the treatment of ischemic stroke from the perspective of imaging,and to explore the sensitive sequences and parameters of efficacy evaluation.Methods:This study was a prospective study.A total of 64 AIS patients with PDM region in the first imaging examination who were hospitalized in the Department of Neurology of ourhospital from October2021 to May 2022 were included.The patients were divided into EECP group(n = 31)and control group(n = 33)according to doctors’ advice and patients’ wishes.The control group received routine treatment in the acute stage of stroke,while the EECP group was treated with EECP on the basis of routine treatment.Both groups were treated for14 days.MR Examination was performed at admission and 14 days aftertreatment to obtain PWI,DWI,SWI and FLAIR images of stroke patients before and aftertreatment.The brain tissue perfusion parameters of the matched and mismatched regions were measured by manual delineation method,and were calculated by division with the corresponding perfusion parameters of the contralateral normal brain region.Thus,relative cerebral blood flow(rCBF),relative cerebral blood volume(rCBV),relative mean transit time(rMTT)and relative time to peak(rTTP).Subsequently,the differences of each index(ΔrCBF,ΔrCBV,ΔrMTT,ΔrTTP)before and aftertreatment were furthercalculated to characterize the changes of each index.SWI and FLAIR were used to obtain Multiple hypointense vessels(MHV)sign and FLAIR vascularhyperintensity(FVH)sign before and aftertreatment.MHV and FVH were used forvasculargrading score.The National Institute of Health Stroke Scale(NIHSS)was used to evaluate the clinical efficacy of EECP in the treatment of ischemic stroke.Results:1.The baseline data of the two groups were compared,and there were no statistically significant differences in gender,age,body mass index,smoking history,drinking history,hypertension,diabetes,stroke history and otherdemographic factors(P > 0.05).2.The perfusion parameters of PDM area before and aftertreatment and the difference between the two groups were compared and analyzed.Before treatment,there were no statistically significant differences in all parameters between the EECP group and the control group.Aftertreatment,the values of rCBF and rCBV increased,while those of rMTT and rTTP decreased,there were statistical differences in rCBF.Comparison of the difference between the two groups showed that ΔrCBF and ΔrMTT were statistically significant,and the changes in the EECP group were more significant than those in the control group.However,there was no significant difference in ΔrCBV andΔrTTP between the two groups.3.Changes in perfusion parameters in the infarcted core area before and aftertreatment were assessed.Before treatment,there were no significant differences in rCBF,rCBV,rMTT and rTTP between the two groups.Aftertreatment,there were no significant differences in these parameters.There was no significant difference in ΔrCBF,ΔrCBV,ΔrMTT and ΔrTTP between the two groups.4.Before treatment,there was no significant difference in MHV and FVH values between the two groups.Aftertreatment,the MHV vasculargrading score was lowerthan that before treatment,and the EECP group was significantly lowerthan the control group,with statistically significant differences.The differences of ΔMHV and ΔFVH before and aftertreatment were statistically significant.5.ROC curve was used to evaluate the test efficacy of rCBF,rCBV,rMTT,rTTP,SWI,FLAIR forEECP treatment.The results showed that: the rCBF and rMTT values were more sensitive,the sensitivity was 74.2% and80.6%,the specificity was 97.0% and 66.7%,and the area underthe ROC curve(AUC)was 0.865 and 0.796,respectively.6.Comparing the NIHSS scores of the two groups before treatment,the results showed no statistically significant difference.Aftertreatment,the NIHSS scores of both groups decreased,and the EECP group was significantly betterthan the control group,the difference was significant.Before and aftertreatment,the ΔNIHSS scores of the two groups were statistically significant.Conclusions:1.The results of the imaging and NIHSS score studies showed that combined EECP treatment could improve the prognosis of patients with acute ischemic stroke in areas with perfusion-diffusion weighted imaging mismatch compared with conventional treatment alone.2.Multimodal imaging findings suggest that the possible mechanism by which EECP improves the prognosis of acute ischemic stroke patients with perfusion-diffusion-weighted imaging mismatch is that this therapy may increase brain tissue perfusion in patients.3.Compared with rCBV and rTTP,rCBF and rMTT are more sensitive to the effect of EECP treatment on stroke,and are sensitive imaging indicators to evaluate the efficacy.