ABSTRACT
Objective To establish abdominal aortic dissection model in ApoE-/-mice, and to evaluate the ability of 7.0T MR to detect the abdominal aortic artery aneurysms in ApoE-/-mice in vivo. Methods ApoE-/-mice aged 10 months were infused with angiotensin Ⅱ with 14 days Osmotic minipump after 10 weeks of high lipid diet. Two different doses of angiotensin Ⅱ were given to mice, i.e. 1000 ng/(kg·min) and 500 ng/(kg·min), respectively. The contrast group was infused with saline water. The abdominal aortic artery was observed in vivo with MR before and within 14 days infusion. At last, the pathological changes of the abdominal artery were compared with MRI findings. Results After 6 or 7 days higher dose of angiotensin Ⅱ infusion, aortic dissection was seen. MR T2WI showed crescent-shaped high signal in the vessel wall of one side，the pathological study identified the hematoma between media and adventitia. Abdominal aortic dissection aneurysms were also found in the mice 13 or 14 days after lower dose of angiotensin Ⅱ infusion, which were consistent with pathological studies. Besides, the signal of the vessel wall was significantly higher in both T2WI and PDWI sequences. There was excellent agreement between MR and histopathology. 〖WTHZ〗 Conclusion Abdominal aortic dissection aneurysms model can be successfully established with different doses (1000 ng/(kg·min) and 500 ng/(kg·min)) of angiotensin Ⅱ infusion into ApoE-/-mice fed with high lipid diet. High-resolution MR is able to visualize the abdominal aortic dissection aneurysm formation in vivo.