title: Overdiagnosis of osteoporosis in children due to misinterpretation of dual-energy x-ray absorptiometry (DEXA).
abstract: OBJECTIVE
  Dual-energy x-ray absorptiometry (DEXA) is increasingly used to evaluate children for osteoporosis. However, the interpretation of pediatric DEXA is complicated by growth and development. Because most DEXA scans are performed on adults, we hypothesized that physicians who interpret DEXA may not be aware of these pediatric issues, potentially leading to misdiagnosis.
  
  
  METHODS
  Children (n=34, aged 4-17 years) diagnosed with low bone mineral density (BMD) based on a DEXA scan were referred for possible inclusion in a childhood osteoporosis protocol. The referral DEXA scans were analyzed for accuracy.
  
  
  RESULTS
  Thirty (88%) of the scans had at least one error in interpretation. The most frequent error (62%) was use of T-score (SD score compared with young adults) to diagnose osteoporosis, which is inappropriate for children. Other errors included use of a reference database that does not consider gender or ethnic differences (21%), incorrect bone map (21%), inattention to short stature (15%), and other measurement or statistical error (12%). After correcting for these errors, 53% had normal BMD, whereas only 26% retained the diagnosis of low BMD. The remaining 21% could not be given a definitive diagnosis.
  
  
  CONCLUSIONS
  In children, the diagnosis of osteoporosis is often due to misinterpretation of a DEXA scan.
authors.affiliation: Unit on Growth and Development, Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-1862, USA. gafnir@mail.nih.gov
authors.forename: Rachel I
authors.initials: RI
authors.lastname: Gafni
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Baron
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D000293:Adolescent; D001827:Body Height / Q000502:physiology; D015519:Bone Density / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D019992:Databases as Topic; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008297:Male; D010024:Osteoporosis / Q000175:diagnosis* / Q000503:physiopathology; D012016:Reference Values; D014481:United States