Comparison of Two DXA Systems, Hologic Horizon W and GE Lunar Prodigy, for Assessing Body Composition in Healthy Korean Adults

Abstract

Background: Dual-energy X-ray absorptiometry (DXA) is the most widely used method for evaluating muscle masses. The aim of this study was to investigate the agreement between muscle mass values assessed by two different DXA systems.Methods: Forty healthy participants (20 men, 20 women; age range, 23 to 71 years) were enrolled. Total and regional body compositional values for fat and lean masses were measured consecutively with two DXA machines, Hologic Horizon and GE Lunar Prodigy. Appendicular lean mass (ALM) was calculated as the sum of the lean mass of four limbs.Results: In both sexes, the ALM values measured by the GE Lunar Prodigy (24.8±4.3 kg in men, 15.8±2.9 kg in women) were significantly higher than those assessed by Hologic Horizon (23.0±4.0 kg in men, 14.8±3.2 kg in women). Furthermore, BMI values or body fat (%), either extremely higher or lower levels, contributed greater differences between two systems. Bland-Altman analyses revealed a significant bias between ALM values assessed by the two systems. Linear regression analyses were performed to develop equations to adjust for systematic differences (men: Horizon ALM [kg]=0.915×Lunar Prodigy ALM [kg]+0.322, R2=0.956; women: Horizon ALM [kg]=1.066×Lunar Prodigy ALM [kg]–2.064, R2=0.952).Conclusion: Although measurements of body composition including muscle mass by the two DXA systems correlated strongly, significant differences were observed. Calibration equations should enable mutual conversion between different DXA systems.

Total and regional appendicular skeletal muscle mass prediction from dual-energy X-ray absorptiometry body composition models

“…To explore the magnitude of potential DXA scanner differences, we compared Hologic Discovery and GE Lunar iDXA estimates of ALM in our laboratory (Supplementary Fig. 3 ), similar to the study reported by Park et al 14 that compared Hologic Horizon and GE Lunar Prodigy scanners. Although ALM measured by both DXA systems in our laboratory were highly correlated (n = 45; R 2 , 0.99), average scanner differences (X ± SD; 0.54 ± 0.58 kg; p < 0.001) and significant bias (p < 0.05) were present.…”

“…Although ALM measured by both DXA systems in our laboratory were highly correlated (n = 45; R 2 , 0.99), average scanner differences (X ± SD; 0.54 ± 0.58 kg; p < 0.001) and significant bias (p < 0.05) were present. Park et al 14 found between-scanner ALM differences of 1.79 ± 0.92 kg (p < 0.001). These kinds of between DXA and MRI system measurement differences are likely part of the reason why we found small mean differences and bias between our SM predictions and those of Kim et al 8 …”

“…Moreover, we similarly found strong correlations but absolute differences and bias when applying Zhao and Sagayama’s models 10 , 11 to the Kiel dataset (data not shown). These kinds of SM prediction variation can be anticipated due to between-sample, DXA system 14 , MRI scanner, and image segmentation method differences (Table 4 ). To explore the magnitude of potential DXA scanner differences, we compared Hologic Discovery and GE Lunar iDXA estimates of ALM in our laboratory (Supplementary Fig.…”

Cross-Calibration of iDXA and pQCT Scanners at Rural and Urban Research Sites in The Gambia, West Africa

“…Importantly, participants were representative of the populations usually imaged at these two research facilities meaning that the corrections should be applicable in our context. While studies have been published detailing the cross-calibration of different modalities in hospital or research settings, to date these have been from high income settings [4,8,13,14,[19][20][21][22][23][24][25][26]. To the best of our knowledge, this represents the first such study in sub-Saharan Africa, where research sites with dedicated bone imaging facilities are few, and hospitals have limited access to standard clinical modalities such as DXA.…”

Estimation of Absolute and Relative Body Fat Content Using Noninvasive Surrogates: Can DXA Be Bypassed?

“…For one of the studies, 41 DXA scanning instrumentation was manufactured by Hologic, Inc. For the other 2 studies, 42,43 Lunar scanning instrumentation from GE HealthCare was used. Because the 2 instrument sources do not yield identical results, [44][45][46] quantitative readings obtained from the Lunar instrument were converted to the equivalent Hologic readings based on studies in which DXA scanning was performed on the same individuals using both Lunar and Hologic instrumentation. 44 Using the regression coefficients generated from the above analysis of the NHANES 2003-2006 group, the independent anthropometric variables in the ELS subjects were used to calculate PTBF for the individual ELS participants.…”