Study Of The Relationship Between Collateral Circulation,infarction Type And CT Perfusion Imaging In Patients With Severe Stenosis Or Occlusion Of Middle Cerebral Artery

Part one:Correlation between collateral circulation and types of infarcted lesion and cerebral perfusion in patients with severe stenosis or occlusion of Middle cerebral arteryObjective:To study the effects of collateral circulation on the types of infarcted lesion and the cerebral perfusion in patients with severe stenosis or occlusion of MCA.Methods:Included 144 cases with severe stenosis or occlusion of MCA diagnosed by the Department of Neurology,Central Theater Command General Hospital of the Chinese People’s Liberation Army from January 2013 to June 2018.According to the collateral circulation,these patients were divided into a good collateral circulation group(67 cases)and poor collateral circulation group(77 cases).Comparative analysis of the incidence of different types of infarcted lesion and cerebral perfusion parameters between the two groupsResults:1.144 cases with severe stenosis or occlusion of MCA,67 cases with good collateral circulation,77 cases with poor collateral circulation.The occurrence of different types of infarction were as follows:18 cases of PAI,11 cases of PI,18 cases of LTI,13 cases of CBZI,33 cases IBZI,13 cases of MT,17 cases of MI and 22 cases of non-infarction(including 14 cases of TIA).In the good collateral circulation group,the incidence of patients with non-infarction was the highest(23.9%)and LTI was the lowest(6.0%),while the incidence of IBZI was the highest(33.8%)and PI was the lowest(5.2%)in the poor collateral circulation group,and there was significant difference in the incidence of different types of infarction between the two groups.(P<0.05).2.The results of comparison of brain perfiusion parameters between the healthy side and the affected side of patients with different collateral circulation showed that patients with good collaterals had significantly increased CBV,prolonged TTP and MTT on the affected side(P<0.05).Patients with poor collateral circulation had significantly prolonged TTP,shortened MTT and increased CBF on the affected side(P<0.05).3.Compared with the ratio of cerebral perfusion parameters among patients with different collateral circulation,rCBV and rMTT in the good collateral circulation group were higher than those in the poor collateral circulation group,while rTTP and rCBF were lower than those in the poor collateral circulation group(P<0.05).Conclusion:Good collateral circulation could compensate for maintaining cerebral perfusion in patients with severe stenosis or occlusion of MCA to prevent cerebral infarction or reduce infarct size.Part two:Lesion types of cerebral infarction in patients with severe stenosis or occlusion of MCA and CTP imaging analysisObjective:To compare the perfusion status of different types of infarction lesions in patients with severe stenosis or occlusion of MCA,and to explore the pathogenesis of different types of infarct lesions from a hemodynamic perspective.Methods:89 patients with severe stenosis or occlusion of MCA diagnosed by 320 row CTA+CTP were enrolled in this study.The perfusion of MCA blood supply area were compared and analyzed in different types of infarct lesions.Results:1.Among 89 patients with severe stenosis or occlusion of MCA,there were 8 cases(9.0%)of PAI,7 cases(7.9%)of PI,7 cases(7.9%)of LTI,43 cases(48.3%)of BZI,13 cases(14.6%)of MI,and 11 cases(12.4%)of non-infarction.2.There were significant differences in rCBF and rTTP between different types of infarction lesions(P<0.05):The rCBF of BZI group was significantly higher than that of LTI group and non-infarction group(P<0.05).The rTTP of LTI group and BZI group were significantly higher than that of non-infarction group and PAI group(P<0.05).The rTTP of MI group was significantly higher than that of non-infarction group(P<0.05).3.The incidence of hypoperfusion in the MCA blood supply area of different types of infarction lesions was the highest in the LTI group(71.4%)and the lowest in the non-infarction group(9.1%),and the difference was statistically significant(jP<0.05).4.There was no significant difference in the perfusion parameters between different subtypes of BZI(P>0.05).The Internal Border-Zone Infarct(IBZI)group had the highest proportion of hypoperfusion(78.3%),while the lowest in the Cortical Border-Zone Infarct(CBZI)group(22.2%).The difference was statistically significant.(P<0.05).Conclusion:BZI was the main type of cerebral infarction in patients with severe stenosis or occlusion of MCA.Different cerebral infarction lesions showed different perfusion status,suggesting different pathogenesis;IBZI hypoperfusion rate was higher,which may be related to the mechanism of perfusion injury.Part three:Follow-up study of patients with severe stenosis or occlusion of MCAObjective:To explore the relationship between secondary preventive drug therapy,cerebral perfusion and stroke recurrence in patients with severe stenosis or occlusion of MCA.Methods:82 cases of patients admitted to the neurology department of Central Theater Command General Hospital of the Chinese People’s Liberation Army from January 2013 to December 2017 who suffered from cerebral ischemic stroke for the first time and underwent 320 row CTA+CTP examination for diagnosis of unilaterajl MCA severe stenosis or occlusion were selected.Secondary prevention treatment,stroke recurrence,intracranial vascular status and cerebral perfusion parameters were followed up regularly to study the relationship between stroke recurrence,eerebral perfusion and secondary prevention and treatment.Results:1.75 cases were followed up with an average follow-up time of 34.1 months.The average mRS score of the last follow-up was 1.00±1.30,66 cases(88.0%)had no recurrence,and 9 cases(12.0%)had recurrence of cerebral ischemic events.2.Secondary prevention:68 cases(90.7%)adhered to antiplatelet aggregation therapy,65 cases(86.7%)adhered to statins,39 cases(64.9%)adhered to anti-hypertensive therapy in 57 cases with hypertension,and 11 cases(61.1%)adhered to anti-hyperglycemia therapy in 18 cases with diabetes.3.29 cases were reexamined with cerebral CTA+CTP.The degree of stenosis of 13 cases remained unchanged,12 cases alleviated and 4 cases aggravated.The collateral circulation of 21 cases remained unchanged,6 cases improved and 2 cases decreased.Reexamination of CTP in 26 cases with no recurrence showed that rCBF(1.12±0.19)was significantly higher than that of the first rCBF(1.03±0.15)(P<0.05).Conclusion:Patients with severe stenosis or occlusion of MCA who adhere to standard ASA secondary prevention and treatment can stabilize or improve the degree of stenosis,collateral circulation and cerebral perfusion,thus preventing the recurrence of cerebral infarction.