title: Cross calibration of two dual-energy X-ray densitometers and comparison of visceral adipose tissue measurements by iDXA and MRI.
abstract: Compare total percentage body fat (pfat) measurements between two densitometers and visceral adipose tissue (VAT) estimates between iDXA and magnetic resonance imaging (MRI) from the same defined abdominal region.
  
  
  
  Participants [N = 93 (50 men, 43 women), BMI: 19.1-57.6 kg/m2] underwent dual-energy X-ray absorptiometry (DXA) scans on two DXA systems (GE Healthcare Lunar iDXA and Lunar Prodigy), and a subgroup underwent abdominal MRI imaging for quantification of VAT.
  
  
  
  Pfat correlated strongly between both machines (r2= 0.98, P < 1.0E-14). Bland-Altman plots showed a bias with higher measured pfat on iDXA versus Prodigy in leaner subjects and the opposite in more overweight subjects. The R2for regression of MRI on iDXA VAT values was 0.948. Bland-Altman bias was +104.1 cm3with 95% limits of agreement of -681.9 to 890.0 cm3. For both DXA methods, and iDXA versus MRI determined VAT, comparison using rank regression demonstrated no order bias.
  
  
  
  The total pfat measured by both machines was strongly and linearly associated, allowing for conversion (equations are provided) of iDXA for assessment of longitudinal body fat changes. Despite a bias of abdominal VAT measures of iDXA versus MRI, the high rank correlation makes iDXA a good alternative to the more complicated and time-consuming MRI for use in larger cross-sectional and longitudinal studies.
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, Arizona, USA.|Department of Diagnostic and Interventional Radiology, University of Leipzig, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Reinhardt
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, Arizona, USA.
authors.forename: Paolo
authors.identifier: 0000-0003-2774-9161
authors.initials: P
authors.lastname: Piaggi
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, Arizona, USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: DeMers
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, Arizona, USA.
authors.forename: Cathy
authors.initials: C
authors.lastname: Trinidad
authors.affiliation: Obesity and Diabetes Clinical Research Section, Phoenix Epidemiology and Clinical Research Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, Arizona, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Krakoff
mesh_terms: D050153:Abdominal Fat / Q000000981:diagnostic imaging*; D015502:Absorptiometry, Photon / Q000295:instrumentation* / Q000379:methods*; D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000293:Adolescent; D000328:Adult; D001823:Body Composition; D002138:Calibration; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D050177:Overweight; D053246:Receptor Activator of Nuclear Factor-kappa B; D014965:X-Rays; D055815:Young Adult
chemical_list: D053246:Receptor Activator of Nuclear Factor-kappa B; C505686:TNFRSF11A protein, human