3.0T MRI观察兔腹主动脉粥样硬化斑块演变过程

3.0T MRI in observation on atherosclerotic plaque progression in the abdominal aorta of rabbits

目的探讨MRI在识别兔动脉粥样硬化斑块中的诊断价值。方法 20只新西兰白兔,随机设置实验组16只,对照组4只,结合球囊拉伤腹主动脉和间断高脂饲料喂养,建立动脉粥样硬化模型;在建模后2、3、4个月分别行高分辨MR成像。通过测量腹主动脉管壁厚度和面积、管腔面积、管壁信号增强程度等指标,观察腹主动脉壁的重构过程,并对模型最终的斑块成分进行MRI和组织病理结果对照研究。结果对17只兔(实验组14只,对照组3只)完成3次MR检查,并获得组织病理学结果。MRI显示,实验组腹主动脉管壁厚度和面积逐渐增厚,且与同期对照组相比差异均有统计学意义(P<0.01);实验组腹主动脉管腔进行性扩张,管壁强化程度较对照组增加明显,但演变过程不明显。另外,MRI对兔腹主动脉硬化斑块的成分判别限制在纤维、脂质和钙化斑块,对纤维斑块、脂质斑块识别率较高。结论高分辨MRI可以无创性地观察动脉粥样硬化动物模型腹主动脉管壁重构的演变过程,有助于对动脉硬化斑块的预后和药物干预进行探索。

Objective To visualize plaques progression and monitor arterial remodeling during progression of atherosclerosis in rabbit model with 3.0T MR.Methods Twenty New Zealand white rabbits were randomly allocated into experimental group（n=16） and control group（n=4）.Atherosclerotic lesions were induced in the abdominal aorta by balloon injury and cholesterol feeding.MR examinations were performed at the end of 2nd month,3rd month and 4th month after aortic denudation.Lumen diameter,vessel wall thickness,total vessel area,lumen area and vessel wall area were calculated in MR images,taking histological results as standard reference.Results Seventeen rabbits（14 of experimental group and 3 of control group） received all 3 times MR examination.Compared with control group,vessel wall thickness and area in experimental group increased significantly（P〈0.01）.Lumen area progressive stenosis was not clear,even slight dilation developed in the experimental group.Vessel wall enhancement in experimental group was higher than that of control group,in spite of this progressive was not obviously.Compared with histology,MRI had more good performance in detection lipid and fibrotic plaque other than calcification.Conclusion High-resolution MRI can be used to monitor progression of atherosclerosis in rabbit models,which is helpful for further research of prognosis and intervention therapy