title: Bone mineral density measurements of the proximal femur from routine contrast-enhanced MDCT data sets correlate with dual-energy X-ray absorptiometry.
abstract: OBJECTIVE
  To evaluate the utility of femoral bone mineral density (BMD) measurements in routine contrast-enhanced multi-detector computed tomography (ceMDCT) using dual-energy X-ray absorptiometry (DXA) as the reference standard.
  
  
  METHODS
  Forty-one patients (33 women, 8 men) underwent DXA measurement of the proximal femur. Subsequently, transverse sections of routine ceMDCT of these patients were used to measure BMD of the femoral head and femoral neck. The MDCT-to-DXA conversion equations for BMD and T-score were calculated using linear regression analysis. The conversion equations were applied to the MDCT data sets of 382 patients (120 women, 262 men) of whom 74 had osteoporotic fractures.
  
  
  RESULTS
  A correlation coefficient of r = 0.84 (P < 0.05) was calculated for BMD(MDCT) values of the femoral head and DXA T-scores of the total proximal femur using the conversion equation T-score = 0.021 × BMD(MDCT) - 5.90. The correlation coefficient for the femoral neck was r = 0.79 (P < 0.05) with the conversion equation T-score = 0.016 × BMD(MDCT) - 4.28. Accordingly, converted T-scores for the femoral neck in patients with versus those without osteoporotic fractures were significantly different (female, -1.83 versus -1.47; male, -1.86 versus -1.47; P < 0.05).
  
  
  CONCLUSIONS
  BMD measurements of the proximal femur were computed in routine contrast-enhanced MDCT and converted to DXA T-scores, which adequately differentiated patients with and without osteoporotic fractures.
authors.affiliation: Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria. michael.gruber@meduniwien.ac.at
authors.forename: M
authors.initials: M
authors.lastname: Gruber
authors.forename: J S
authors.initials: JS
authors.lastname: Bauer
authors.forename: M
authors.initials: M
authors.lastname: Dobritz
authors.forename: A J
authors.initials: AJ
authors.lastname: Beer
authors.forename: P
authors.initials: P
authors.lastname: Wolf
authors.forename: K
authors.initials: K
authors.lastname: Woertler
authors.forename: E J
authors.initials: EJ
authors.lastname: Rummeny
authors.forename: T
authors.initials: T
authors.lastname: Baum
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D000367:Age Factors; D000368:Aged; D015519:Bone Density / Q000502:physiology*; D015331:Cohort Studies; D003287:Contrast Media; D018450:Disease Progression; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000503:physiopathology; D005272:Femur Neck / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology; D011856:Radiographic Image Enhancement; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media