Lewis D S, Rollwitz W L, Bertrand H A, Masoro E J
J Appl Physiol (1985). 1986 Mar;60(3):836-40. doi: 10.1152/jappl.1986.60.3.836.
A nuclear magnetic resonance (NMR) method is described for quantitatively measuring total body water (TBW) and for estimating the fat content of baboons. The hydrogen associated with water was measured as the amplitude of the free-induction decay voltage following a series of 90 degree radio frequency pulses at the Lamour frequency for hydrogen with a pulse length of 14 microseconds and a peak measuring time of 50 microseconds. TBW was calculated by multiplying the peak amplitude (volts) by the experimentally determined constant for a water standard (g water/V). This NMR method yielded TBW contents similar to those obtained in the same baboons by direct gravimetric procedures. In contrast, the widely used 3H2O-dilution method usually and variably overestimated body water. By providing an accurate measure of body water, this NMR procedure provides a rapid, noninvasive, reasonably accurate way of estimating body fat content.
描述了一种核磁共振（NMR）方法，用于定量测量狒狒的全身水（TBW）并估计其脂肪含量。与水相关的氢是在拉莫尔频率下，通过一系列90度射频脉冲后自由感应衰减电压的幅度来测量的，氢的脉冲长度为14微秒，峰值测量时间为50微秒。TBW是通过将峰值幅度（伏特）乘以水标准品的实验测定常数（克水/体积）来计算的。这种NMR方法得到的TBW含量与通过直接重量法在相同狒狒中获得的结果相似。相比之下，广泛使用的3H2O稀释法通常会高估身体水分，且变化不定。通过提供准确的身体水分测量，这种NMR程序提供了一种快速、无创、相当准确的估计身体脂肪含量的方法。
