兔颈动脉粥样硬化模型的建立及MR成像的实验研究

目的建立兔血管内膜损伤性颈动脉粥样硬化模型,并探讨用临床应用型MRI检测动脉粥样硬化的形成过程。方法用动脉球囊介入扩张兔一侧颈总动脉后高脂饲养12周,分别在球囊扩张前及扩张后2、4、8、12周末取外周血检测血脂水平并MRI检查;同时在球囊扩张后12h、6周、12周末取损伤血管进行病理学检查。结果高脂喂养后第2周开始,血脂水平进行性升高;球囊扩张后6周起MRI显示,患侧均出现不同程度的血管壁高信号,12周后,MRI表现为损伤血管壁高信号区增厚并管腔狭窄,对应病理学检查显示:到第6周时,血管平滑肌层增厚,内膜面有少量泡沫细胞形成,血管腔轻度狭窄;12周后,损伤侧颈总动脉明显粥样斑块形成,符合动脉粥样硬化特点。结论用介入动脉球囊扩张损伤加高脂饲养方法可成功建立兔颈动脉粥样硬化狭窄模型,临床应用型MRI可成功检测兔颈动脉粥样硬化的形成过程。

Construction and MR imaging of endothelium injured carotid artery atherosclerosis in rabbit model

Objective To establish endothelial injured carotid artery atherosclerosis model in rabbits and visualize the atherosclerosis formation process by MR imaging. Methods Rabbits were fed with high lipid diet for 12 weeks after carotid arteries were injured by balloons. The serum levels of triglyceride and cholesterol were examined before and after the operation of 2nd, 4th, 8th, 12th week. The formation of atherosclerosis process in the injured arteries was observed by MRI. The animals were killed separately at the end of 12h, 6th and 12th week after operation and the pathologic changes in bilateral carotid arteries were observed. Results After two weeks of high lipid diet, the serum levels of triglyceride and cholesterol were increased; MRI showed in high signal in the vessel wall of the injured arteries after 6th week, the high signal areal range was increased and the lumen of blood vessel was stenosed after 12th week. The pathological study showed that in the end of 6th week, vascular smooth muscle(VSM) were unregulately proliferated and the lumen of the blood vessel stenosed in slightly, but after 12th week, there were formations of atherosclerosis in the injured arteries and the lumen of the blood vessel stenosed in obviously. Conclusion Injuring the intima of the carotid artery by interventional balloon plus fed with high lipid diet can successfully establish carotid artery atherosclerosis in rabbits model, MR images with a conventional 1.5T MR system are able to visualize the atherosclerosis formation process.