USPIO增强MRI在兔动脉粥样硬化斑块模型的观察研究

Study on USPIO enhanced MRI in the detection of atherosclerotic plaques in rabbit models

目的探讨单纯高脂饮食建立兔动脉粥样硬化模型的可行性以及超小顺磁性氧化铁(USPIO)增强磁共振成像(MRI)在兔动脉粥样硬化(AS)斑块研究中的价值。方法挑选30只健康的雄性新西兰大白兔作为研究对象,使用随机分组法分为两组,其中实验组20只,对照组10只。实验组通过单纯高脂饲料饲养的方法建立兔AS模型,对照组不作其他干预。观察USPIO增强前后动脉斑块的MRI表现,与病理结果进行比较和分析。结果实验组成功建立兔AS模型,其中14例形成AS斑块,USPIO增强T2W1序列表现为斑块中央信号减低,血管壁信噪比值在96 h降低最低,较增强前信号差异有统计学意义(P<0.05),而对照组在增强前后管壁信号无变化。USPIO增强PJN 2D-TOF序列表现为管壁点状充盈缺损。病理检查显示USPIO颗粒主要沉积在内膜下。结论单纯高脂饮食可以建立兔AS模型,USPIO增强MRI能反映出兔AS斑块情况,有助于对AS病变诊断作出评估。

Objective To evaluate the value of ultrasmall superparamagnetic iron oxide （USPIO） enhanced magnetic resonance imaging（MRI） in the detection of atheroselerotic plaques in rabbits. Methods Thirty male New Zealand white rabbits were randomly divided into two groups： experimental group （n = 20） and control group （n = 10）. The experimental group rabbits were given high-fat diet in order to establish rabbit atherosclerosis models while the control group were given normal diet and without extra intervention. To observe the manifestation of arterial wall under MRI with and without USPIO enhancement to see if there were plaques. Then a pathological section study was made to confirm the existence of arterial plaques. To make a comparison between these two types of examinations. Results Rabbit atheroselerosis models were established successfully. Fourteen rabbits were proved to suffer from atheroselerosis. The central area of the plaques demonstrated a decreased signal with USPIO enhancement. T2WI and the signal-noise ratio value of the vascular wall reach its lowest point after 96 hours, significantly different compared to that before USPIO （ P 〈 0. 05 ） , while control group negative. The plaques showed a dot-like filling defect on USPIO enhanced PJN 2D-TOF image. Pathological results showed that USPIO particles were mainly deposited under the arterial wall. Conclusion Atherosclerosis models can be established by simple high-fat diet on rabbits. USPIO enhanced MRI can display atherosclerotic plaques in rabbit arterial walls, which could be contribute to the diagnosis and evaluation of atherosclerosis.