Comparison of MRI and DXA for Measurement of Visceral Adipose Tissue in Adolescent Females

Abstract

Increased adiposity is associated with metabolic complications, but it may be depot-specific fat that is more relevant than generalized obesity in the assessment of related metabolic disorders. For example, excess visceral adipose tissue (VAT) has been identified as a risk factor for type-2 diabetes and other health complications. Magnetic resonance imaging (MRI) and computed tomography are accurate methods for assessment of VAT, but the procedures are expensive, lengthy and not widely available. Measurement of VAT by dual energy X-ray absorptiometry (DXA) is a practical alternative because of the lower cost, short testing time and minimal radiation exposure for the participant, but limited data are available. The aim of this study was to determine if DXA-derived VAT measurements could serve as accurate surrogate measurements of VAT as compared to MRI in late-adolescent females. VAT was measured by 3T MRI (General Electric 16-channel fixed-site Signa HDx 3.0 Tesla magnet) and DXA (Discovery A; APEX software, version 3.3; Hologic Inc., Waltham, MA) in 24 females ages 18 to 19 years. Pearson correlations were conducted to examine the relationships between DXA-derived VAT and MRI-derived VAT. The Bland-Altman analysis was used to assess agreement between the two methods. The participants’ mean (± SD) BMI was 27.0 ± 5.6 kg/m2, BMI for age percentile, 72.8 ± 25.7% and waist circumference, 88.4 ± 14.5 cm. DXA derived VAT and MRI VAT were strongly correlated (r = 0.893, p <.001). Additionally, MRI and DXA derived VAT were highly correlated with waist circumference (r = 0.826, p <.001; r = 0.910, p<.001, respectively). The Bland-Altman analysis revealed the bias of the sample, +20.14 cm2 and the 95% limits of agreement, −21.66 to 61.94 cm2 (Figure 1). Our data show that DXA can be used in place of MRI to measure VAT in late adolescent females, however, as the average VAT increases, there is less agreement between the two methods. Support or Funding Information National Institute of Food and Agriculture, HATCH project GEO00647 Figure 1Open in figure viewerPowerPoint Bland-Altman plots and linear regression estimate, with 95% prediction bands, between VAT measured by MRI (MRI-VAT) and VAT measured by DXA (DXA-VAT). VAT, visceral adipose tissue; MRI, magnetic resonance imaging; DXA dual-energy X-ray absorptiometry.