Assessment of EchoMRI-AH versus dual-energy X-ray absorptiometry by iDXA to measure human body composition

Eur J Clin Nutr. 2017 Apr;71(4):558-560. doi: 10.1038/ejcn.2016.236. Epub 2016 Nov 30.


Comparison of percent fat mass across different body composition analysis devices is important given variation in technology accuracy and precision, as well as the growing need for cross-validation of devices often applied across longitudinal studies. We compared EchoMRI-AH and Lunar iDXA quantification of percent body fat (PBF) in 84 adults (43M, 41F), with the mean age 39.7±15.9 years and body mass index (BMI) 26.2±5.3 kg/m2. PBF correlated strongly between devices (r>0.95, P<0.0001). A prediction equation was derived in half of the subjects, and the other half were used to cross-validate the proposed equation (EchoMRI-AH PBF=[(0.94 × iDXA PBF)+(0.14 × Age)+(3.3 × Female)-8.83). The mean PBF difference (predicted-measured) in the validation group was not different from 0 (diff=0.27%, 95% confidence interval: -0.42-0.96, P=0.430). Bland-Altman plots showed a bias with higher measured PBF on EchoMRI-AH versus iDXA in all 84 subjects (β=0.13, P<0.0001). The proposed prediction equation was valid in our cross-validation sample, and it has the potential to be applied across multicenter studies.

Publication types

  • Comparative Study
  • Validation Study

MeSH terms

  • Absorptiometry, Photon / methods
  • Absorptiometry, Photon / statistics & numerical data*
  • Adult
  • Body Composition*
  • Body Mass Index
  • Confidence Intervals
  • Female
  • Healthy Volunteers
  • Humans
  • Magnetic Resonance Imaging / methods
  • Magnetic Resonance Imaging / statistics & numerical data*
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Reproducibility of Results
  • Whole Body Imaging / methods
  • Whole Body Imaging / statistics & numerical data*