摘要
目的:建立家兔动脉粥样硬化模型,探讨动脉粥样硬化斑块的MRI表现.方法:选择健康雄性日本大白兔20只,高脂饮食喂养3～5个月.于2个半月开始,每月对实验兔的主动脉行MRI扫描.选择T1WI、T2WI及T2WI/FS序列,并对3只家兔行增强扫描.依照病变的进展情况处死兔子,制作主动脉的病理切片.结果:MRI发现具有动脉粥样硬化改变的兔子有6只(阳性率32%),其余13只动物(68%)MRI未见明显异常.正常兔子血管壁在MRI上呈中等到稍低信号,边缘光整.6只家兔于3个半月时发现有动脉粥样硬化脂质斑块,在SET1WI和FSE T2WI上表现为稍高信号,增强扫描后不强化呈稍低信号;病理上表现为脂质条纹.于4个半月时MRI显示斑块明显增厚,病理上显示仍为脂质条纹.第5个半月时发现有纤维斑块形成,斑块于FSE T2WI/FS序列上表现为内部呈稍低信号、表面为弧形线样高信号,镜下可见斑块表面纤维帽形成及其大量的泡沫细胞、细胞外脂质及基质.结论:MRI多种序列的综合应用能显示动物体内的动脉粥样硬化斑块,对其成份的判定亦有一定价值.
Objective： To set up aortic atherosclerotic plaque models with experimental hyperlipidemic rabbits, and to study their signal intensity manifestations on magnetic resonance imaging （MRI）. Methods：Twenty Japanese rabbits induced by atherogenic diet for 3 ～5 months were served as the experimental model of atherosclerosis. Starting from 2.5months, MRI was performed once a month. Routine sequences included SE Tl WI^·and FSE T2WI. Three rabbits had axial plane Tl WI after Gd-DTPA administration. MR findings were correlated with histopathology. Results：Of the 19 experimental hyperlipidemic rabbits sacrificed and studied, there were 6 rabbits （32%） showing atherosclerotic plaque on MRI, the other 13 rabbits did not have MRI abnormalities. Moderate to low signal intensity and well-defined contour were shown on MRI with normal aortic wall. Of the 6 rabbits having atherosclerotic plaque, starting at 3.5 months, the lipid rich core appeared as high signal intensity on T1WI and T2WI, with no enhancement after contrast medium administration. These plaques were obviously thickened at 4.5 months. At 5.5 months,there were collagenous cap formation and large amount of foamy cells,extracellular lipidic material and stroma on histology. Heterogeneous signal intensities （interior hypointensity and exterior curvilinear hperintensity） on FSE T2WI were shown. T2WI provides a unique modality for discriminating collagenous cap from lipid rich atheosclerosis plaque. Excellent agreement can be obtained between MRI and histopathology. Conclusion.. MRI with multi-sequence examination （especially FSE T2WI） is a noninvasive imaging modality which is helpful in depicting atherosclerotic plaque as well as its size and interior components in vivo.
出处
《放射学实践》
2005年第9期818-821,共4页
Radiologic Practice
关键词
磁共振成像
动脉硬化
模型
动物
Magnetic resonance imaging
Atherosclerosis
Models, aninal
