Arkansas Children's Nutrition Center, Little Rock, Arkansas, USA.
Obesity (Silver Spring). 2011 Oct;19(10):2089-95. doi: 10.1038/oby.2011.215. Epub 2011 Jul 21.
Quantitative nuclear magnetic resonance (QMR) is being used in human adults to obtain measures of total body fat mass (FM) with high precision. The current study assessed a device specially designed to accommodate infants and children between 3 and 50 kg (EchoMRI-AH). Body composition of 113 infants and children (3.3-49.9 kg) was assessed using dual-energy X-ray absorptiometry (DXA), air displacement plethysmography (ADP, PeaPod for infants ≤ 8 kg and BodPod for children ≥ 6 years) and QMR. Results were compared with the deuterium oxide dilution technique (D(2)O) and a four-compartment model (4-C). The percentages of compliance were: 98% QMR; 75% DXA; 94% BodPod; and 95% PeaPod. Although QMR precision was high (coefficient of variation = 1.42%), it overestimated FM ~10% compared to the 4-C model and underestimated FM by ~4% compared to the deuterium method in children ≥ 6 years. QMR was less concordant with 4-C or D(2)O models for infants ≤ 8 kg. Thus, a piece-wise defined model for mathematically fitting the QMR data to the D(2)O data was employed and this adjustment improved the accuracy relative to D(2)O and 4-C for infants. Our results suggest that the pediatric QMR with appropriate mathematical adjustment provides a fast and precise method for assessing FM longitudinally in infants and in children weighing up to 50 kg.
定量磁共振（QMR）正被用于成年人，以高精度获得全身脂肪量（FM）的测量值。目前的研究评估了一种专门设计用于容纳 3 至 50 公斤婴儿和儿童的设备（EchoMRI-AH）。使用双能 X 射线吸收法（DXA）、空气置换体描记法（ADP，PeaPod 用于体重 ≤ 8 公斤的婴儿和 BodPod 用于年龄 ≥ 6 岁的儿童）和 QMR 对 113 名婴儿和儿童（3.3-49.9 公斤）的身体成分进行了评估。结果与氘水稀释技术（D（2）O）和四室模型（4-C）进行了比较。符合率分别为：QMR 为 98%；DXA 为 75%；BodPod 为 94%；PeaPod 为 95%。尽管 QMR 精度很高（变异系数=1.42%），但与 4-C 模型相比，它高估了 FM10%，与氘法相比，6 岁以上儿童低估了 FM4%。对于体重 ≤ 8 公斤的婴儿，QMR 与 4-C 或 D（2）O 模型的一致性较差。因此，采用了一种分段定义的模型，用于将 QMR 数据数学拟合到 D（2）O 数据，这种调整提高了相对于 D（2）O 和 4-C 的准确性，适用于婴儿。我们的结果表明，经过适当数学调整的儿科 QMR 为评估婴儿和体重达 50 公斤的儿童的 FM 提供了一种快速、精确的方法。
