兔动脉粥样硬化模型的建立及其MR检测

Establishing atherosclerosis model with rabbit and detecting atherosclerotic plaque by MRI

目的探索动脉粥样硬化斑块动物模型的建立;评价MRI检测动脉粥样硬化斑块的能力。方法成年新西兰大白兔(8周龄以上)15只,随机分成两组,对照组2只,实验组13只。麻醉固定后以相同的方法损伤腹主动脉内膜。实验组兔每日每只喂养胆固醇1.5g加基础饲料,并于术后第11、12周皮下注射维生素D500000IU/kg。对照组只喂养基础饲料。术后13周所有动物接受T1WI、T2WI、PDWI、TOF序列检查。检查结束后处死实验动物观察其腹主动脉病理变化。结果实验组动物动脉粥样硬化病变脂质条纹面积和纤维斑块面积的百分比分别为9.64%和1.56%。对照组动脉内膜光滑。全部横断面病理切片共109层,其中实验组动物的86层切片中发现斑块50层,对照组中均未发现斑块层,实验组与对照组相比差异有非常显著性(P<0.001)。MRI检出纤维斑块11层,检出脂质斑块29层,MR对斑块检测总的阳性率为88%,准确率为80%。结论采用兔可成功建立动脉粥样硬化斑块模型,MRI可以较准确地对斑块进行定位及定性。

Objective To probe establishing atherosclerosis model with rabbit and detecting atherosclerotic plaque by MRI. Methods 15 adult New Zealand rabbits （older than 8 weeks） were randomized into two groups, 13 into treatment group and 2 into control group. After fixed and anesthetized, all rabbits underwent hurt to endomembrane of abdominal aorta with the same method. Each rabbit in treatment group fed on 1.Sg cholesterol plus fundamental fodder each day and underwent subcutaneous injection of vitamin D 500000IU/kg at 11 th and 12 th week. Rabbits in control group fed only on fundamental fodder. At 13 th week, all rabbits underwent T1WI, T2WI, PDWI and TOF sequence, and subsequently were sacrificed for pathological examination. Results Rabbits in treatment group had a proportion of fatty strip and fiber plaque 9.64% and 1.56%, respectively. Rabbits in control group had smooth endomembrane. There were 109 pathological slices totally, 50 sfices containing plaque were found in 86 slices of rabbits in treatment group, and no sfices containing plaque was found in rabbits of control group. The difference between two groups was significant （P 〈 0.001）. MRI detected 11 slices that contained fiber plaque, detected 29 slices that contained fatty plaque, with a total positive rate of 88% and accuracy rate of 80%. Conclusion Arteriosclerosis model can be successfully established with rabbit, and MRI is able to locate and qualitatively identify plaques.