动脉粥样硬化兔模型磁性纳米颗粒增强MR价值初探:与传统增强MR比较  

Magnetic Nanoparticles Enhanced MR Imaging vs Tradition Enhanced MR Imaging

作　　者：沈亚琪[1] 王秋霞[1] 冯定义[1] 冯友梅[2] 周洁[2] 胡道予[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院放射科,武汉430030 [2]华中科技大学同济医学院基础医学院生物化学与分子生物学系,武汉430030

出　　处：《华中科技大学学报（医学版）》2010年第5期653-657,共5页Acta Medicinae Universitatis Scientiae et Technologiae Huazhong

基　　金：湖北省科技攻关计划资助项目(No.2005AA301C07);国家"863"计划资助项目(No.2003BA310A13)

摘　　要：目的使用自制超小超顺磁性氧化铁颗粒(USPIO)探索动脉粥样硬化斑块内炎性浸润的磁共振征象及其价值,并以钆喷酸葡胺对比剂(Gd-DTPA)增强作为对比。方法 25只雄性新西兰大白兔高脂饮食诱导建模,同期对照10只,分别于10、12、14、16、18周采用1.5 T磁共振扫描仪常规成像观察(T1WI,T2WI,T2*WI),及USPIO增强和Gd-DTPA增强观察。USPIO使用剂量为0.5 mmol Fe/kg体重,而Gd-DTPA使用剂量为0.25 mmol/kg体重。磁共振图像与病理结果相对照。结果高脂饮食可以成功诱导动物发生动脉粥样硬化病变。磁共振连续常规观察,可观察到血管壁增厚表现及脂质核心、纤维帽等斑块成分,USPIO增强后脂质核心信号下降,纤维帽显示更佳,提示斑块内有炎性细胞浸润,并且普鲁士蓝染色及电镜均证实纳米铁颗粒被斑块内活性巨噬细胞所吞噬。Gd-DTPA增强显示斑块成分不佳。结论动脉粥样硬化的进展过程可通过常规成像进行监测。USPIO增强能帮助鉴定斑块内成分,同时也直接反映斑块内的炎性过程。因为具有更低的毒性和更宽的观察窗,USPIO较Gd-DTPA更适用于动脉粥样硬化患者。Objective To explore inflammation in plaques with the help of USPIO on 1.5 T MR scanner by using Gd-DTPA-enhanced MR imaging as a control.Methods Twenty-five male New Zealand white rabbits were induced by atherogenic diet to set up the models,and 10 rabbits fed on the normal diet served as the control group.All of them were observed on a 1.5 T MR scanner on the 10th,12th,14th,16th,18th week,including T1WI,T2WI,T2＊WI,USPIO-enhanced imaging,and Gd-DTPA-enhanced imaging.USPIO was injected intravenously at a dose of 0.5 mmol Fe/kg body weight,and Gd-DTPA at a dose of 0.25 mmol/kg body weight.MR images were correlated with histopathologic results.Results Atherogenic diet could successfully induce the atherosclerotic lesions in rabbits.The thickening of the vessel wall could be observed on series routine MR imaging,so did the lipid core and the fibrous cap.The signal intensity of lipid core became fade and the fibrous cap became clear on the USPIO-enhanced images,which indicated infiltration of macrophages in the plaque.The results of Prussian blue staining and electron microscopy proved that iron particles were swallowed by the activated macrophages in the plaque.Conclusion The progress of artherosclerosis can be monitored on routine MR imaging.USPIO-enhanced MR imaging can provide useful information to define the composition of plaques and also reveal a direct MR feature of the inflammation in plaques.As having a lower toxic effect and wider observing window,USPIO-enhanced imaging should be more suitable for the atherosclerosis patients to use than Gd-DTPA do.

关 键 词：动脉粥样硬化 磁共振成像 斑块 对比剂 

分 类 号：R445.2[医药卫生—影像医学与核医学]