Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA.
J Magn Reson Imaging. 2012 Apr;35(4):837-43. doi: 10.1002/jmri.23508. Epub 2011 Nov 16.
To develop and validate a quantitative magnetic resonance imaging (MRI) methodology for phenotyping animal models of obesity and fatty liver disease on 7T small animal MRI scanners.
A new MRI acquisition and image analysis technique, relaxation-compensated fat fraction (RCFF), was developed and validated by both magnetic resonance spectroscopy and histology. This new RCFF technique was then used to assess lipid biodistribution in two groups of mice on either a high-fat (HFD) or low-fat (LFD) diet.
RCFF demonstrated excellent correlation in phantom studies (R(2) = 0.99) and in vivo compared to histological evaluation of hepatic triglycerides (R(2) = 0.90). RCFF images provided robust fat fraction maps with consistent adipose tissue values (82% ± 3%). HFD mice exhibited significant increases in peritoneal and subcutaneous adipose tissue volumes in comparison to LFD controls (peritoneal: 6.4 ± 0.4 cm(3) vs. 0.7 ± 0.2, P < 0.001; subcutaneous: 14.7 ± 2.0 cm(3) vs. 1.2 ± 0.3 cm(3) , P < 0.001). Hepatic fat fractions were also significantly different between HFD and LFD mice (3.1% ± 1.7% LFD vs. 27.2% ± 5.4% HFD, P = 0.002).
RCFF can be used to quantitatively assess adipose tissue volumes and hepatic fat fractions in rodent models at 7T.
开发和验证一种在 7T 小动物 MRI 扫描仪上对肥胖和脂肪肝动物模型进行表型分析的定量磁共振成像（MRI）方法。
开发并验证了一种新的 MRI 采集和图像分析技术，即弛豫补偿脂肪分数（RCFF），该技术通过磁共振波谱和组织学进行验证。然后，使用这种新的 RCFF 技术评估了两种高脂肪（HFD）或低脂肪（LFD）饮食的小鼠的脂质分布。
RCFF 在体模研究中（R(2) = 0.99）和与组织学评估肝三酰甘油（R(2) = 0.90）具有极好的相关性。RCFF 图像提供了具有一致脂肪分数的稳健脂肪分数图（82%±3%）。与 LFD 对照组相比，HFD 小鼠的腹膜和皮下脂肪组织体积显著增加（腹膜：6.4 ± 0.4 cm(3) 比 0.7 ± 0.2，P < 0.001；皮下：14.7 ± 2.0 cm(3) 比 1.2 ± 0.3 cm(3)，P < 0.001）。HFD 和 LFD 小鼠的肝脂肪分数也有显著差异（LFD 为 3.1% ± 1.7%，HFD 为 27.2% ± 5.4%，P = 0.002）。
RCFF 可用于在 7T 下定量评估啮齿动物模型的脂肪组织体积和肝脂肪分数。
