title: Long-term performance in vitro and in vivo of dual-energy X-ray absorptiometry.
abstract: Dual-energy X-ray absorptiometry (DXA) is actually considered as one of the most appropriate techniques for measuring bone mineral content (BMC) and bone mineral density (BMD). An anthropomorphic phantom and a 25-year-old girl were repeatedly measured, 160 times and 50 times respectively, over an 18-month period to investigate performance in vitro and in vivo of a commercial DXA equipment (HOLOGIC QDR 1000). DXA is a highly accurate technique, the BMC and BMD determinations only overestimated the exact value of the phantom by 0.20% and 0.51% respectively. In vivo long-term (18 months) reproducibility of BMD of the spine is characterized by an interassay coefficient of variation (CVt) of 0.8% while, for the different regions of interest of the hip, BMD CVt varies from 1.1% (total zone) to 5.3% (Ward's triangle). In the subject tested, BMD sensitivity for changes of 2.2% at the lumbar spine and 3% at the hip were recorded.
authors.affiliation: Centre Universitaire d'Investigation du Métabolisme Osseux et du Cartilage Articulaire, University of Liège, Belgium.
authors.forename: J Y
authors.initials: JY
authors.lastname: Reginster
authors.forename: R
authors.initials: R
authors.lastname: Deroisy
authors.forename: B
authors.initials: B
authors.lastname: Zegels
authors.forename: I
authors.initials: I
authors.lastname: Jupsin
authors.forename: A
authors.initials: A
authors.lastname: Albert
authors.forename: P
authors.initials: P
authors.lastname: Franchimont
mesh_terms: D015502:Absorptiometry, Photon / Q000295:instrumentation / Q000379:methods; D000328:Adult; D015519:Bone Density; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008961:Models, Structural; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity