Department of Cardiology and Angiology, University Hospital of Erlangen-Nuremberg, Erlangen, Germany,
Eur Radiol. 2015 Mar;25(3):736-44. doi: 10.1007/s00330-014-3456-7. Epub 2014 Oct 31.
To establish a dedicated protocol for the three-dimensional (3D) quantification of plaque lipids in apolipoprotein E-deficient (apoE(-/-)) mice using ex vivo MRI.
ApoE(-/-) mice were fed a high-fat diet (n = 10) or normal food (n = 10) for 3 months. Subsequently, a 3D FLASH MRI sequence was used to view the anatomy of the aortic root in the isolated hearts, where a 3D double-echo two-excitation pulse sequence (DIXON sequence) was used to selectively image plaque lipids. The vessel wall, lumen and plaque lipid volumes were quantified by MRI and histology for correlation analysis.
DIXON MRI allowed visualisation and accurate quantification of plaque lipids. When comparing the vessel wall, lumen and plaque lipid sizes in the aortic root, Bland-Altman and linear regression analysis revealed a close correlation between MRI results and the histological data both on a slice-by-slice basis and of the volumetric measurements (vessel wall: r (2) = 0.775, p < 0.001; vessel lumen: r (2) = 0.875; p = 0.002; plaque lipid: r (2) = 0.819, p = 0.003).
The combination of 3D FLASH and DIXON-sequence MRI permits an accurate ex vivo assessment of the investigated plaque parameters in the aortic root of mice, particularly the lipid content.
建立一种专门的协议，使用离体 MRI 对载脂蛋白 E 缺乏（apoE(-/-)）小鼠的斑块脂质进行三维（3D）定量。
apoE(-/-) 小鼠喂食高脂肪饮食（n=10）或正常食物（n=10）3 个月。随后，使用 3D FLASH MRI 序列观察离体心脏主动脉根部的解剖结构，使用 3D 双回波双激发脉冲序列（DIXON 序列）选择性地对斑块脂质成像。通过 MRI 和组织学对血管壁、管腔和斑块脂质体积进行定量分析，并进行相关性分析。
DIXON MRI 允许可视化和准确量化斑块脂质。当比较主动脉根部的血管壁、管腔和斑块脂质大小时，Bland-Altman 和线性回归分析显示 MRI 结果与组织学数据在切片和体积测量上均具有密切相关性（血管壁：r²=0.775，p<0.001；血管腔：r²=0.875；p=0.002；斑块脂质：r²=0.819，p=0.003）。
3D FLASH 和 DIXON 序列 MRI 的结合可准确评估小鼠主动脉根部的斑块参数，特别是脂质含量。
