兔动脉粥样硬化模型建立及超微超顺磁性氧化铁增强MRI成像技术的研究

目的探讨兔动脉粥样硬化模型制作及超微超顺磁性氧化铁（USPIO）增强MRI成像的方法。方法健康雄性新西兰大白兔30只,随机分为实验组20只,对照组10只。实验组采用球囊导管损伤腹主动脉内膜结合高脂饮食的方法建立兔动脉粥样硬化（AS）模型,对照组不做干预。MRI检查包括平扫、USPIO增强MRI黑血序列和白血序列。观察AS斑块形成特点,比较不同成像线圈、序列及参数对图像质量的影响。结果 12只兔AS模型成功建立,斑块主要位于腹主动脉,在MRI扫描范围内病理检查共发现86个斑块,其中普鲁士蓝染色阳性斑块67个。膝关节线圈成像质量优于其他线圈,MR黑血与白血序列对斑块的检出率无明显差异（P〉0.05）。黑血成像序列对于区分AS斑块成分较白血序列好。结论球囊损伤结合高脂饮食饲养制备兔AS模型成功率高、制作周期短并可控制斑块发生部位。USPIO增强MR成像序列能敏感检出并反映兔AS斑块成分,成像技术优化对于提高图像质量及斑块检出具有重要意义。

Establishment of Atherosclerotic Model and USPIO Enhanced MRI Techniques Study in Rabbits

Objective To explore the methods of establishment of atherosclerotic model and USPIO enhanced MRI techniques in rabbits.Methods Thirty New Zealand male rabbits were divided randomly into two groups：20 animals in the experiment group,10 animals in the control group.Animal model of atherosclerosis was induced with aortic balloon endothelial injury and high-fat diet feeding.There was no intervention with the rabbits in control group.MRI examination included plan scan,USPIO enhanced black-blood sequences and white-blood sequence.The features of the plaques was analyzed in the experimental group and the effection on the image quality of different coils,sequences and parameters and a statistical study was also analyzed.Results Animal model of atherosclerosis was successfully made in 12 rabbits and most plaques located in the abdomen aorta.There were 86 plaques within the scanning scope among which 67 plaques were positive to the Prussian blue staining.The image quality of knee joint coil was better than that of other coils.Although there was no difference in the detection of numbers of AS plaques between USPIO enhanced black-blood sequences and white-blood sequence（P 〉0.05）,blackblood sequences was superior to white-blood sequence in the demonstration of the components of plaque.Conclusion The method of aortic balloon endothelial injury and high-fat diet feeding can easily establish the AS model in rabbits with a shorter period and it may be used for controlling the location of the plaques.USPIO enhanced MRI sequences has high sensitivity in the detection of the AS plauqes and can reveal the component of AS plaques.The optimization of MRI techniques is very important in the improvement of the image quality and the detection of the plaques.