title: Bone mineral disorders in children: evaluation with dual x-ray absorptiometry.
abstract: OBJECTIVE
  To evaluate the utility of dual x-ray absorptiometry (DXA) in children with bone mineral disorders.
  
  
  METHODS
  In phase 1, radial DXA was compared with single-energy photon absorptiometry (SPA) (n = 117). In phase 2, radial and lumbar bone mineral density (BMD) measured with DXA and second metacarpal cortical thickness were compared (254 examinations, 224 children).
  
  
  RESULTS
  For radial BMD, DXA and SPA correlated well (r = .956) and SPA-equivalent values could be calculated from DXA measurements (mean residual error = 0.024 g/cm2). After controlling for age, sex, weight, and height, partial correlations were very small for lumbar BMD with radial BMD (r = .186) and lumbar BMD with cortical thickness (r = .158), and slightly better for radial BMD with cortical thickness (r = .544). Z scores also correlated poorly with no meaningful correlation for lumbar BMD with radial BMD (r = .07)
  
  
  CONCLUSIONS
  In children with bone mineral disorders, radial DXA and SPA measurements correlate well. However, lumbar BMD, radial BMD, and cortical thickness correlate poorly and lumbar BMD frequently does not identify abnormality in patients with abnormal radial BMD. Lumbar BMD alone is not adequate for evaluation of bone mineral status in these patients.
authors.affiliation: Department of Radiology, Northwestern University Medical School, Chicago, IL 60614, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Shore
authors.forename: C B
authors.initials: CB
authors.lastname: Langman
authors.forename: J M
authors.initials: JM
authors.lastname: Donovan
authors.forename: J J
authors.initials: JJ
authors.lastname: Conway
authors.forename: A K
authors.initials: AK
authors.lastname: Poznanski
mesh_terms: D015502:Absorptiometry, Photon; D018488:Bone Demineralization, Pathologic / Q000000981:diagnostic imaging*; D015519:Bone Density; D002648:Child; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D008663:Metacarpus / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D011884:Radius / Q000000981:diagnostic imaging