经颅多普勒脉动指数与病理改变相关性的实验研究

目的 探讨经颅多普勒(TCD)脉动指数(PI)与病理改变的相关性.方法 采用24只健康雄性新西兰大白兔作实验动物,对其进行高脂饲料喂养及一侧肾动脉狭窄致高血压处理制备动脉粥样硬化模型.分别在实验前、实验第8周、第16周用TCD对颈内动脉及大脑中动脉进行血流速度的检测,然后进行相关病理改变检测.结果 颈内动脉在动脉粥样硬化过程中PI值逐渐升高,当PI值>0.86(P<0.05)时,病理切片可观察到内皮不完整,有脱落,内弹力层断裂,平滑肌细胞增加,管腔明显变小;大脑中动脉在动脉粥样硬化过程中PI值的改变在各检测点均无统计学意义,病理切片没有明显改变.结论 在脑动脉硬化进程中,PI值的改变与动脉的硬化程度及病理变化有较好的相关性.

Experimental Study on Correlation between Pulsatility Index of Transcranial Doppler and the Pathological Change in Atherosclerosis

Objective To investigate the relationship between pulsatility index(PI) of transcranial Doppler and the pathological change in atherosclerosis(AS).Methods Twenty-four male New Zealand rabbits were selected,and rabbit atherosclerosis models were established by feeding high fat diet and unilateral renal artery stenosis.The blood inflow velocities of internal carotid artery(ICA) and middle cerebral artery(MCA) were detected by TCD before experiment and after 8 weeks,16 weeks of experiment.The pathological changes were observed.Results Accompany with the procession of carotid atherosclerosis,PI was continuously elevated.When PI was more than 0.86,pathogenesis showed that there was the formation of endothelial damage and destruction of the internal elastic layer,smooth muscle cells increased and the cavity became narrow.In the procession of MCA atherosclerosis,there was no differences in PI at different time point,and there was no changes of pathological changes.Conclusion There were correlation between PI and the severity degree of atherosclerosis and pathogenesis in the procession of cerebral atherosclerosis.