title: Fat fraction estimation of the vertebrae in females using the T2*-IDEAL technique in detection of reduced bone mineralization level: comparison with bone mineral densitometry.
abstract: OBJECTIVE
  The aim of this study was to use the T2*-iterative decomposition of water and fat with echo asymmetry and least squares estimation quantification (IDEAL) technique to estimate vertebral fat fraction (FF) and compare it with bone mineralization levels in females.
  
  
  METHODS
  Forty-five (mean age, 49.5 years) consecutive women who underwent magnetic resonance imaging and spinal dual-energy x-ray absorptiometry bone mineral density (BMD) examination constituted the study population. Depending on t scores derived from dual-energy x-ray absorptiometry, the vertebrae were classified into 3 groups (1, healthy; 2, osteopenia; and 3, osteoporosis). The Spearman ρ test was used to investigate the presence of correlation between FF and BMD. Analysis of covariance was performed to compare the differences among the groups. The FF cutoff value for the prediction of osteoporosis/osteopenia was evaluated with the receiver operating characteristic curve analysis.
  
  
  RESULTS
  We found a moderate negative correlation between BMD (grams per square centimeter) and FF (r = - 0.42), and it was statistically significant (P < 0.001). The FF mean of age-corrected group 1 (45.17%; SD, 1.3) was lower than that of groups 2 (51.77%; SD, 0.69) and 3 (50.82%; SD, 1.5), and the difference was statistically significant (P < 0.001, P = 0.021). The area under the receiver operating characteristic curve for FF was 0.80 (95% confidence interval, 0.72-0.86). The optimal cutoff point was obtained as 39%, and for this cutoff point, the sensitivity and the specificity were 93% and 60.3%, respectively.
  
  
  CONCLUSIONS
  The T2*-IDEAL technique can be used as an alternative technique in estimation of FF, and it is possible to detect reduced bone mineralization of the vertebrae by estimation of FF value with this technique.
authors.affiliation: From the *Department of Radiology, Hacettepe University School of Medicine, Ankara, Turkey; † Department of Radiology, Göztepe Teaching and Research Hospital, Istanbul, Turkey; ‡GE Healthcare, Istanbul, Turkey; and §Department of Biostatistics, Hacettepe University School of Medicine, Ankara, Turkey.
authors.forename: Fatma Bilge
authors.initials: FB
authors.lastname: Ergen
authors.forename: Gulsah
authors.initials: G
authors.lastname: Gulal
authors.forename: Adalet Elcin
authors.initials: AE
authors.lastname: Yildiz
authors.forename: Azim
authors.initials: A
authors.lastname: Celik
authors.forename: Jale
authors.initials: J
authors.lastname: Karakaya
authors.forename: Ustun
authors.initials: U
authors.lastname: Aydingoz
mesh_terms: D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000175:diagnosis*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis*; D013122:Spinal Diseases / Q000175:diagnosis*