Examining intra- and inter-tester reliability of post-scan dual-energy X-ray absorptiometry regional body composition analysis in athletes
摘要
The purpose of this investigation was (i) to assess the intra- and inter-tester reliability of delineating regions of interest (ROIs) in Dual-energy X-ray Absorptiometry (DXA) for measuring regional fat mass (FM), lean soft tissue (LST), and bone mineral content (BMC) and (ii) to investigate the prevalence of inconsistencies between automatically defined ROIs and manufacturer guidelines. A secondary aim was to assess whether discrepancies in the delineation of ROIs by different testers could bias regional body composition changes over time.
MethodsDXA measurements were performed with a total body scan in 86 athletes (64.0% females) from 12 sports. Two independent testers conducted post-scan analysis following the manufacturer’s guidelines. Intra- and inter-tester reliability was evaluated using the intra-class correlation coefficient (ICC), mean differences, paired samples t-tests and Bland-Altman plots.
ResultsIntra- and inter-tester reliability was nearly perfect (ICC: 0.998-1.000) across all regions and components (FM, LST, and BMC). Mean differences were consistently <1% for all regions and components, except for left arm FM (1.4%; SD = 4.6%) in inter-tester reliability. Inconsistencies between automatically defined ROIs and manufacturer guidelines were frequent, with chest line corrections (which separate the arm from the trunk) required in 91.9% of scans. Inter-tester ICC for regional changes (n = 52) ranged from 0.668 to 0.981, with wider limits of agreement than cross-sectional estimates.
ConclusionDXA post-scan regional analysis can be performed with very high reliability and low measurement error, but manual review is essential. When monitoring changes over time, baseline and follow-up scans should be analyzed by the same evaluator.