Vanderbilt University Institute of Imaging Science, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; Chemical and Physical Biology Program, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
J Magn Reson Imaging. 2014 Feb;39(2):485-91. doi: 10.1002/jmri.24156. Epub 2013 Apr 17.
To test the hypothesis that a whole-body fat-water MRI (FWMRI) protocol acquired at 3 Tesla combined with semi-automated image analysis techniques enables precise volume and mass quantification of adipose, lean, and bone tissue depots that agree with static scale mass and scale mass changes in the context of a longitudinal study of large-breed dogs placed on an obesogenic high-fat, high-fructose diet.
Six healthy adult male dogs were scanned twice, at weeks 0 (baseline) and 4, of the dietary regiment. FWMRI-derived volumes of adipose tissue (total, visceral, and subcutaneous), lean tissue, and cortical bone were quantified using a semi-automated approach. Volumes were converted to masses using published tissue densities.
FWMRI-derived total mass corresponds with scale mass with a concordance correlation coefficient of 0.931 (95% confidence interval = [0.813, 0.975]), and slope and intercept values of 1.12 and -2.23 kg, respectively. Visceral, subcutaneous and total adipose tissue masses increased significantly from weeks 0 to 4, while neither cortical bone nor lean tissue masses changed significantly. This is evidenced by a mean percent change of 70.2% for visceral, 67.0% for subcutaneous, and 67.1% for total adipose tissue.
FWMRI can precisely quantify and map body composition with respect to adipose, lean, and bone tissue depots. The described approach provides a valuable tool to examine the role of distinct tissue depots in an established animal model of human metabolic disease.
验证假设，即在 3T 磁共振全身脂肪-水（FWMRI）协议结合半自动图像分析技术的条件下，是否能够精确地定量分析脂肪、瘦体和骨组织容量和质量，以及与大型犬高脂肪、高果糖致肥胖饮食纵向研究中，静态秤重和秤重变化相吻合。
6 只健康成年雄性犬在饮食方案的第 0 周（基线）和第 4 周时分别进行两次扫描。使用半自动方法对 FWMRI 衍生的脂肪组织（总、内脏和皮下）、瘦体和皮质骨体积进行定量。使用已发表的组织密度将体积转换为质量。
FWMRI 衍生的总质量与秤重质量具有高度一致性，相关系数为 0.931（95%置信区间 [0.813, 0.975]），斜率和截距值分别为 1.12 和 -2.23 kg。从第 0 周到第 4 周，内脏、皮下和总脂肪组织质量显著增加，而皮质骨和瘦体组织质量无显著变化。这一点可以从内脏脂肪组织的平均百分比变化 70.2%、皮下脂肪组织的平均百分比变化 67.0%和总脂肪组织的平均百分比变化 67.1%得到证明。
FWMRI 可以精确地定量和描绘与脂肪、瘦体和骨组织相关的身体成分。所描述的方法为检查特定组织在已建立的人类代谢疾病动物模型中的作用提供了有价值的工具。
