title: Bone age assessment by dual-energy X-ray absorptiometry in children: an alternative for X-ray?
abstract: OBJECTIVE
  The aim of the study was to validate dual-energy X-ray absorptiometry (DXA) as a method to assess bone age in children.
  
  
  METHODS
  Paired dual-energy X-ray absorptiometry (DXA) scans and X-rays of the left hand were performed in 95 children who attended the paediatric endocrinology outpatient clinic of University Hospital Rotterdam, the Netherlands. We compared bone age assessments by DXA scan with those performed by X-ray. Bone age assessment was performed by two blinded observers according to the reference method of Greulich and Pyle. Intra-observer and interobserver reproducibility were investigated using the intraclass correlation coefficient (ICC), and agreement was tested using Bland and Altman plots.
  
  
  RESULTS
  The intra-observer ICCs for both observers were 0.997 and 0.991 for X-ray and 0.993 and 0.987 for DXA assessments. The interobserver ICC was 0.993 and 0.991 for X-ray and DXA assessments, respectively. The mean difference between bone age assessed by X-ray and DXA was 0.11 years. The limits of agreement ranged from -0.82 to 1.05 years, which means that 95% of all differences between the methods were covered by this range.
  
  
  CONCLUSIONS
  Results of bone age assessment by DXA scan are similar to those obtained by X-ray. The DXA method seems to be an alternative for assessing bone age in a paediatric hospital-based population.
authors.affiliation: The Generation R Study Group, Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands.
authors.forename: D H M
authors.initials: DH
authors.lastname: Heppe
authors.forename: H R
authors.initials: HR
authors.lastname: Taal
authors.forename: G D S
authors.initials: GD
authors.lastname: Ernst
authors.forename: E L T
authors.initials: EL
authors.lastname: Van Den Akker
authors.forename: M M H
authors.initials: MM
authors.lastname: Lequin
authors.forename: A C S
authors.initials: AC
authors.lastname: Hokken-Koelega
authors.forename: J J M
authors.initials: JJ
authors.lastname: Geelhoed
authors.forename: V W V
authors.initials: VW
authors.lastname: Jaddoe
mesh_terms: D015502:Absorptiometry, Photon / Q000706:statistics & numerical data*; D000293:Adolescent; D000365:Age Determination by Skeleton / Q000379:methods*; D000367:Age Factors; D015519:Bone Density / Q000502:physiology; D001846:Bone Development / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006225:Hand / Q000000981:diagnostic imaging*; D050276:Hand Bones / Q000000981:diagnostic imaging / Q000254:growth & development; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results