USPIO增强MRI检测人野生型p53基因转染动脉粥样硬化易损斑块的研究

Role of USPIO-enhanced MRI maging in human wild-type p53 gene transfection of atherosclerotic vulnerable plaque

目的:探讨超微超顺磁氧化铁颗粒(USPIO)增强MRI检测人野生型p53基因转染动脉粥样硬化(AS)易损斑块(VP)的可行性及有效性。方法:选取健康雄性新西兰大白兔40只,通过球囊导管损伤腹主动脉内膜+高脂饮食饲养+人野生型p53基因转染腹主动脉斑块+药物触发方法,建立VP模型;观察USPIO增强前后AS斑块MRI信号表现,分析易损斑块病理组织学特点与MRI影像之间的相关性。结果:38只新西兰大白兔建立动物模型成功。MRI显示,腹主动脉斑块呈扁平状或新月状向管腔内突起,导致管腔狭窄,部分伴斑块内出血,血栓形成。USPIO增强T2*WI表现为斑块中央信号减低,其负性强化峰值出现在注射对比剂后96 h;斑块增强MRI序列与HE染色病理学结果之间有良好的相关性。结论:USPIO增强MRI可通过特异性识别VP中的巨噬细胞浸润而发现VP,是一项对AS病变诊断及斑块稳定性的早期评估有前途的影像技术。

To investigate the feasibility and value of ultra small super paramagnetic iron oxide （USPIO） - enhanced magnetic resonance imaging（MRI） in detection of human wild-type p53 gene transfection of atherosclerotic vulnerable plaque. Methods：Forty rabbits underwent aortic balloon injury combined with cholesterol diet, then the abdominal aortic plagues were injected with human wild-type p53 gene, in this way, vulnerable plague model were established. The plaques signal change were analyzed before and after the injection of USPIO, a correlative study was done between MRI and pathological findings in vulnerable plague. Results： Animal model were successfully established with 38 New Zealand white rabbits ,within the abnormal of lumen, the flat, crescent-shaped, protrusion of the plaque,which leaded stenosis of lumen were found, and some with intraplague hemorrhage or thrombosis in MRI images; The signal of USPIO enhanced T2 ＊ WI in central area of the plaques decreased and the peak of the negtive enhancement occurred 96 h after the injection of contrast agent. The matching of contrast-enhanced MR imaging and HE staining of pathological results were showed good correlation in plague. Conclusions： USPIO-enhanced MRI can specifically recognize the macrophage infiltration in VP, then found it. It＇s a promising imaging technique about diagnosis of AS and early assessment of plaque stability.