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Validation of a Quantitative Magnetic Resonance Method for Measuring Human Body Composition
Author(s) -
Napolitano Antonella,
Miller Sam R.,
Murgatroyd Peter R.,
Coward W. Andrew,
Wright Antony,
Finer Nick,
Bruin Tjerk W.,
Bullmore Edward T.,
Nunez Derek J.
Publication year - 2008
Publication title -
obesity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.438
H-Index - 199
eISSN - 1930-739X
pISSN - 1930-7381
DOI - 10.1038/oby.2007.29
Subject(s) - lean body mass , fat mass , zoology , fat body , chemistry , body mass index , body weight , medicine , endocrinology , biology , biochemistry , gene
Objective: To evaluate a novel quantitative magnetic resonance (QMR) methodology (EchoMRI‐AH, Echo Medical Systems) for measurement of whole‐body fat and lean mass in humans. Methods and Procedures: We have studied (i) the in vitro accuracy and precision by measuring 18 kg Canola oil with and without 9 kg water (ii) the accuracy and precision of measures of simulated fat mass changes in human subjects ( n = 10) and (iii) QMR fat and lean mass measurements compared to those obtained using the established 4‐compartment (4‐C) model method ( n = 30). Results: (i) QMR represented 18 kg of oil at 40°C as 17.1 kg fat and 1 kg lean while at 30°C 15.8 kg fat and 4.7 kg lean were reported. The s.d. of repeated estimates was 0.13 kg for fat and 0.23 kg for lean mass. Adding 9 kg of water reduced the fat estimates, increased misrepresentation of fat as lean, and degraded the precision. (ii) the simulated change in the fat mass of human volunteers was accurately represented, independently of added water. (iii) compared to the 4‐C model, QMR underestimated fat and over‐estimated lean mass. The extent of difference increased with body mass. The s.d. of repeated measurements increased with adiposity, from 0.25 kg (fat) and 0.51 kg (lean) with BMI <25 kg/m 2 to 0.43 kg and 0.81 kg respectively with BMI >30 kg/m 2 . Discussion: EchoMRI‐AH prototype showed shortcomings in absolute accuracy and specificity of fat mass measures, but detected simulated body composition change accurately and with precision roughly three times better than current best measures. This methodology should reduce the study duration and cohort number needed to evaluate anti‐obesity interventions.