title: Dual-energy digital radiography for the assessment of bone mineral density.
abstract: BACKGROUND
  Bone mineral density (BMD) is usually determined by dual-energy X-ray absorptiometry (DXA). Digital radiography (DR) has enabled the application of dual-energy techniques for separating bone and soft tissue, but it is not clear yet whether BMD information can reliably be obtained using DR.
  
  
  OBJECTIVE
  To determine the ability of dual-energy digital radiography (DEDR) to predict BMD as determined by DXA.
  
  
  METHODS
  Reindeer femora (n=15) were imaged in a water bath at a typical clinical imaging voltage of 79 kVp and additionally at 100 kVp on a DR system. BMD was determined in four segmented regions (femoral neck, trochanter, inter-trochanter, Ward's triangle) from these images using the DXA calculation principle. BMD results as determined by DEDR were compared with BMD values as determined by DXA.
  
  
  RESULTS
  Significant moderate to high linear correlations (0.66-0.76) were observed at the femoral neck, Ward's triangle, and trochanter between BMD values as determined by the two techniques. The coefficient of variation (CV(RMS)) ranged between 2.2 and 4.7% and 0.2 and 1.8% for DEDR and DXA analyses, respectively.
  
  
  CONCLUSIONS
  DXA-based BMD information can be obtained with moderate precision and accuracy using DEDR. In future, combining BMD measurements using DEDR with structural and geometrical information available on digital radiographs could enable a more comprehensive assessment of bone.
authors.affiliation: Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland. paivi.tahvanainen@oulu.fi
authors.forename: Päivi S
authors.initials: PS
authors.lastname: Tahvanainen
authors.forename: Eveliina
authors.initials: E
authors.lastname: Lammentausta
authors.forename: Pasi
authors.initials: P
authors.lastname: Pulkkinen
authors.forename: Osmo
authors.initials: O
authors.lastname: Tervonen
authors.forename: Timo
authors.initials: T
authors.lastname: Jämsä
authors.forename: Miika T
authors.initials: MT
authors.lastname: Nieminen
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D015519:Bone Density; D005269:Femur / Q000000981:diagnostic imaging*; D066298:In Vitro Techniques; D011856:Radiographic Image Enhancement; D012053:Reindeer; D015203:Reproducibility of Results