Evaluation Of The Effect Of Whole Brain CT Perfusion Combined With CT Angiography On Carotid Artery Stent Implantation

Objective:Because of the different collateral circulation reserve capacity in patients with carotid artery stenosis,the brain tissue blood perfusion impairment is different,and the neurological impairment and clinical manifestations are different.Therefore,the assessment of collateral compensation and blood perfusion in patients with ischemic stroke is of great significance for the selection of treatment and clinical prognosis.In this study,CTP combined with CTA was used to assess the cerebral hemodynamic changes in patients with severe unilateral carotid stenosis,evaluate the diagnostic value of CTA in collateral circulation in patients with carotid stenosis,and explore the differences in cerebral perfusion in patients with severe carotid stenosis of different types of collateral compensation.Methods:A total of 56 patients with unilateral carotid artery stenosis(stenosis rate>70%and contralateral<50%)admitted to our hospital from September 2020 to December 2022 were retrospectively analyzed.Before treatment,whole brain CTP combined with head and neck CTA were performed.DSA results were taken as the gold standard to evaluate the sensitivity,specificity and consistency of CTA in the diagnosis of cerebral collateral circulation.Then the patients were divided into two groups according to collateral compensation types:Group I:primary collateral opening group;Group Ⅱ:secondary collateral opening and mixed opening groups.The perfusion parameters including CBV,CBF,MTT and TTP in the symptomatic and contralateral ROI were obtained from CTP images,and the corresponding rCBV,rCBF,dMTT and dTTP were calculated.The perfusion differences between the two groups were compared.Results:1.392 intracranial collateral vessels(including anterior communicating artery,bilateral posterior communicating artery,ophthalmic artery and leptomeningeal collateral)were evaluated in 56 patients.CTA showed 109 collateral vessels,among which 79 primary collateral vessels and 30 secondary collateral vessels were formed.DSA showed 116 collateral vessels,among which 81 primary collateral vessels and 35 secondary collateral vessels were formed.CTA and DSA have a high degree of consistency in the diagnosis of primary and secondary collateral vessels.2.In patients with severe stenosis or occlusion of unilateral internal carotid artery,CBV,MTT and TTP were significantly higher,CBF,MTT and TTP were significantly lower in the responsible side than in the contralateral side.3.There was no significant difference in rCBV,but significant difference in rCBF,dMTT and dTTP between the two groups.Conclusion:1.CTA has high consistency with DSA in the diagnosis of cerebral collateral vessels in patients with carotid stenosis.2.Abnormal cerebral hemodynamics in patients with severe stenosis and occlusion of unilateral internal carotid artery.3.Primary collateral circulation opening has better cerebral blood flow reserve than secondary collateral circulation opening in patients with unilateral internal carotid artery stenosis and occlusion.Objective:Carotid artery stenting(CAS)is one of the main methods for the treatment of head and neck atherosclerotic stenosis.Severe stenosis and occlusion of cervical vessels often cause hemodynamic changes in brain tissue,so understanding the changes of intracranial blood perfusion before and after surgery has certain significance for preoperative evaluation and postoperative efficacy evaluation.the purpose of this study was to investigate that effect of carotid artery stenting on cerebral hemodynamic and neurological function in patients with cerebral infarction.Methods:A total of 35 patients with unilateral carotid artery stenosis(stenosis rate>70%and contralateral<50%)treated in our hospital from September 2020 to December 2022 and undergoing carotid artery stenting were retrospectively analyzed.All the above patients underwent whole brain CTP combined with head and neck CTA within 1 week before surgery and 3-6 months after surgery.According to the CTP images,the perfusion parameters of the symptomatic side and contralateral ROI were obtained,including CBV,CBF,MTT and TTP.The relative values of perfusion parameters of the same ROI of the responsible vessel side and the healthy side before and after surgery were statistically analyzed.According to the CTA results,the opening of collateral circulation and the integrity of Willis’circle were evaluated.The changes of cerebral hemodynamics before and after surgery were compared.Meanwhile,the MRS scores before and after surgery were recorded and the changes of neurological function were evaluated.Results:1.Before operation,the patients with severe stenosis or occlusion of unilateral carotid artery were in the compensatory state of pre-infarction for a long time.CBV was slightly higher,CBF was significantly lower,MTT and TTP time were significantly longer in the responsible vessel side than that in the healthy side.The difference was statistically significant compared with that in the healthy side.After operation,the cerebral blood perfusion of all patients was improved in different degrees.Compared with the blood perfusion of the contralateral side,the CBV of the operated side was slightly decreased,the CBF was increased,the MTT and TTP of the operated side were decreased,and there was no statistical difference between the operated side and the contralateral side.rCBV decreased,rCBF increased,dMTT and dTTP shortened before and after operation,with significant difference.2.The CTA findings of most patients after stent implantation were as follows:All the collateral vessels opened before the operation showed different degrees of vessel thinness,light visualization,or even disappearance after the operation,which was more obvious in the patients with secondary collateral circulation opened.3.The proportion of patients with severe unilateral carotid artery stenosis or occlusion who had mRS score no higher than 2(good prognosis)increased after carotid artery stenting,and the number showed a significant increase compared with that before surgery.Conclusion:The cerebral hemodynamics and neurological function of patients with severe unilateral carotid artery stenosis or occlusion were significantly improved after carotid artery stenting.The whole brain CTP combined with head and neck CTA imaging can accurately reflect the information of cerebral tissue blood perfusion and other information before and after carotid artery stenosis stent implantation,which provides objective imaging basis for surgical efficacy and clinical prognosis.