兔早期动脉粥样硬化斑块的MRI表现与组织病理学对照研究

目的通过与组织病理学对照研究，探讨MRI在早期动脉粥样硬化斑块中的诊断价值。方法用高脂饮食方法建立20只新西兰大白兔的早期动脉粥样硬化模型，分别于不同时期（9、18周）对实验兔进行以右肾动脉水平为中心的腹主动脉段MR扫描，数字法随机将所有实验兔编号，按单数、双数将实验兔分为2组，每组10只，在不同时期扫描结束后处死1组实验兔取其相应段血管进行HE染色，与MR图像进行组织病理学对照。扫描序列为常规的SE T1WI及快速自旋回波质子加权成像（FSE—PDWI）脂肪抑制序列，并使用钆喷替酸葡甲胺（GD—DTPA）增强扫描。观察不同序列上的早期斑块在不同时期的影像学表现并与组织病理学对照，评价MRI在早期动脉粥样斑块中的诊断价值，并分析斑块的组织学成分及生理病理学的动态发展变化。结果所有实验兔在高脂饮食后9周，血管内膜即可见明显的局部斑块形成，且具有弱强化性质，SE T1WI序列显示早期病变最佳，18周斑块厚度及范围进一步扩大，斑块及血管壁均可强化，组织病理学显示早期病变主要发生于血管内膜，9周主要以泡沫细胞为主，18周在泡沫细胞周围有大量的基质纤维成分及小的毛细血管存在。结论常规的MR扫描技术能对早期动脉粥样斑块的发生发展进行动态观察，并能从组织学水平对其进行评价。

Control study of MRI and histopathology in early atherosclerotic plaque of rabbits

Objective To explore the diagnostic value of MRI in the early atherosclerosis. Materials and Methods Atherosclerosis was induced in 20 New Zealand White male rabbits with high cholesterol diet. Rabbits underwent serial MRI at 9 and 18 weeks after high cholesterol diet. Axial T, and fatsuppressed PDWI spin echo images of the abdominal aorta were obtained above and below the right renal arteries. The signal intensity and morphologic features of plaque in the various phases after high cholesterol diet in MRIwere analyzed and compared with those of histopathology. Results Plaque could be observed in all animals on MRI at 9 weeks after high cholesterol diet, and mild enhancement of the plaque could be noted on enhanced imaging. Imaging effect was the best at T1 sequence. Plaque size increased gradually at 18 weeks. Plaque and vessel wall were all enrichment. In histopathology, foam cells, collagen and matrix fiber component can be seen in the various phases. Conclusion The conventional MRI technique can be used to assess the formation and development of the early atherosclerosis dynamically and histologically.