A Study Of Ct Perfusion And CT Angiography In Patients With Severe Carotid Artery Stenosis Before And After Treatment

Objective: application of CTA and CTP joint assessment unilateral carotid artery stenosis in patients with cerebral perfusion and collateral blood flow circulation situation, and discusses the differences of cerebral perfusion between symptomatic group and asymptomatic group, and unilateral collateral compensatory type patients with severe carotid stenosis, the connection between the clinical manifestations.Methods: retrospectively collected in the hospita,neurosurgery joint CTP and CTA examination of 76 cases of severe unilateral carotid artery stenosis(stenosis rate > 70% and the contralateral < 50%) of patients, according to the clinical and imaging findings in asymptomatic groups(30 cases) and the symptom group(46 cases), are calculated respectively with side/health side the perfusion parameters of MCA blood supply area, including CBV, CBF, determined by MTT and TTP, and calculate the corresponding r CBV, r CBF, d MTT, d TTP, compare the two perfusion, and on the basis of CTA collateral compensatory type in two groups of patients, and assess Willis ring opening.Results: 1, the comparison of two groups of patients with cerebral perfusion, asymptomatic group with the symptomatic of r CBF, d MTT, d TTP all have significant differences, r CBV there was no significant difference. 2, the primary collateral circulation in the proportion of open, symptomatic are much smaller than asymptomatic group, with significant difference(p =0.017). Subprime collateral circulation in proportion to the open, the symptom is greater than the asymptomatic group, with significant difference(p = 0.022), common open junior secondary collateral ratio, the symptom is greater than the asymptomatic group, with significant difference(p = 0.027). 3,For opening ratio of the fore-communicating artery, the symptomic group is greater than the asymptomatic group, with significant difference(p = 0.013). For opening ratio of the posterior-communicating artery, symptomatic group and asymptomatic group have no significant difference(p = 0.382).Conclusion: 1, two groups of preoperative r CBF, d MTT, d TTP have significant differences, prompt preoperative symptomatic group has more significant damage of the cerebral blood flow. 2, unilateral collateral compensatory in patients with severe carotid stenosis is closely related to the clinical symptomatic, primary intracranial collateral circulation is the early and the main way of collateral circulation compensatory, subprime collateral circulation appears usually indicates intracranial exist serious cerebral ischemia. 3, in the primary compensatory, the opening of fore-communicating artery is more closely with the incidence of ischemic symptomaticatic, there was no significant correlation with the opening of the posterior-communicating artery and incidence of ischemic symptomsBackground and objective: Carotid artery stenting has become a safe and reliable procedure in the treatment of carotid artery stenosis, and its target population has expanded to severe carotid artery stenosis patients without cerebral infarction. In this paper, CT perfusion imaging combined with CTA was used to evaluate the changes in cerebral perfusion after stenting in the non-cerebral infarction group and the cerebral infarction group respectively, followed by comparison of the differences between them.Materials and methods: Fifty-nine patients with unilateral severe stenosis(stenosis rate>70% and the contralateral side< 50%), who underwent carotid artery stenting, were retrospectively collected with 23 cases in the non-cerebral infarction group and 36 cases in the cerebral infarction group. CT perfusion imaging combined with CTA was performed in all patients at one week before and after the surgery. The perfusion parameters of MCA supplying area at the affected side/the healthy side, including CBV, CBF, MTT and TTP, as well as their corresponding r CBV, r CBF, d MTT and d TTP, were calculated respectively. Based on the evaluation of changes in cerebral hemodynamics after stenting, the differences were compared between the non-cerebral infarction group and the cerebral infarction groupResults: Intra-group comparison showed that the perfusion parameters in the patients of the cerebral infarction group were significantly improved, with increased r CBF(0.84�0.03) and reduced r CBV(1.03�0.04), d MTT(1.46�0.22), and d TTP(2.38�0.20). After surgery, d TTP(1.21�0.26) was reduced in the non-cerebral infarction group, while no significant changes in r CBV, r CBF and d MTT were reported. The inter-group comparison showed that the differences in preoperative r CBF, d MTT and d TTP were statistically significant whereas the difference in postoperative r CBV was statistically significant, where all of P values were <0.05. The differences in other parameters were not statistically significant.Conclusion: 1) Carotid artery stenting significantly improves the cerebral blood perfusion in both groups; 2) compared with the non-cerebral infarction group, the significantly lower postoperative r CBV in the cerebral infarction group indicates the presence of impaired cerebral blood flow autoregulation in the cerebral infarction group;...