320排CT头颈联合扫描评价颈动脉血运重建术前后脑血流动力学变化

目的:采用320排CT头颈联合多参数扫描模式,对拟行颈动脉血运重建术的患者进行扫描,探讨颈动脉狭窄解除与脑灌注参数改善间的关系,并进一步探讨脑血流动力学改变,对血运重建术前不同类型患者选择的意义。方法:30例经超声证实颈动脉狭窄并拟行颈动脉血运重建术的患者,分别于术前及术后2w内进行320排CT头颈联合多参数扫描,对颈动脉狭窄程度及脑灌注各参数相对值进行分析。参数包括相对脑血流量(rCBF)、相对脑血容量(rCBV)、相对平均通过时间(rMTT)、相对达峰时间(rTTP)及相对延迟时间(rDelay)。由2名有经验的放射科医生分别根据脑灌注成像结果,将患者定性分为双侧大脑半球灌注对称组12例、双侧大脑半球灌注不对称组18例。结果:颈动脉血运重建术后患侧rTTP及rDelay较术前改善,其余灌注参数手术前后的差异无统计学意义。根据术前脑灌注状态不同,对术前患者进一步分层研究,术前灌注对称组,术后患侧脑灌注各参数数值改善不明显;术前灌注不对称组,术后rCBV、rMTT、rTTP及rDelay较前改善。结论:320排CT头颈联合多参数扫描模式,可以全面地显示颈动脉血运重建术前后,颈动脉狭窄的形态学改变,及其所导致的患侧供血区血流动力学的改变,为患者术前评价、治疗方案的选择及术后疗效的观察提供依据。

Imaging evaluation of the cerebral hemodynamic changes pre and post revascularization by 320 slices CT multiple parameter scan

Objective:To evaluate the relationship between carotid stenosis and brain perfusion changes before and after revascularization,by 320 slices CT multiple segments and parameter scan.Further analysis was done to find which kind of patient can get more benefit form the carotid artery revascularization.Methods:30 patients that the ultrasound result demonstrated carotid artery stenosis underwent carotid artery revascularization.All of them studied with 320 CT multiple parameter scan 2 weeks pre and post carotid revascularization.The degree of carotid artery stenosis and CT perfusion(CTP) parameters,include(cerebral blood flow(CBF),cerebral blood volume(CBV),mean transit time(MTT),time to peak(TTP) and Delay time(Delay) were calculated.The relative value were measured.Patients were divided into two groups,Group 1 symmetry bilateral hemisphere CTP,group 2 asymmetry bilateral hemisphere CTP.Results:The relative value(rTTP、rDelay) changed obviously after carotid artery revascularization,other parameter showed no obvious change.Patients were subdivided into two groups,based on the hemodynamic changes.12 patients included in the symmetry CTP group,the hemodynamic parameters showed no obviously improvement after carotid artery revascularization,18 patients included in the asymmetry CTP group,the hemodynamic parameters(rCBV,rMTT,rTTP,rDelay) improved obviously after the operation.Conclusion:After the carotid revascularization,the morphology change of carotid artery,and the hemodynamic changes of the blood supply area,can be shown by 320 slices CT multiple parameter scan.Carotid artery stenosis patient with asymmetry CTP can get more benefit from the carotid artery revascularization.