title: Prediction of bone loss in elderly female subjects by MR perfusion imaging and spectroscopy.
abstract: OBJECTIVE
  To determine whether MR perfusion indices or marrow fat content at baseline can predict areal bone mineral density (BMDa) loss.
  
  
  METHODS
  Repeat dual x-ray absorptiometry (DXA) of the hip was performed in female subjects at 2 years (n = 52) and 4 years (n = 45) following baseline MR perfusion imaging and spectroscopy of the hip.
  
  
  RESULTS
  Percentage reduction in femoral neck BMDa at 4 years post-baseline was greater in subjects with below median acetabulum enhancement slope (E(slope)) (-5.6 ± 1.2 Vs -1.1 ± 1.2 (mean ± standard error) p = 0.014) or muscle maximum enhancement (E(max)) (-5.7 ± 1.2 Vs -0.23 ± 1.2, p = 0.009) after adjusting for baseline co-variables. Baseline MR parameters correlated with reduction in BMDa at 4 years (acetabulum E(slope) r = 0.517, p = 0.0003; muscle E(max) r = 0.306, p = 0.043) as well as traditionally applied clinical risk factors. Acetabulum E(slope), femoral neck E(max) and marrow fat content at baseline had sensitivities of 89%, 81% and 72% respectively at distinguishing between fast (>1%/annum) (n = 18) and slow (<1%/annum) (n = 27) BMD losers.
  
  
  CONCLUSIONS
  Elderly female subjects with reduced perfusion indices at baseline had increased femoral neck bone loss at 4 years. Selected perfusion indices and marrow fat content have a moderate to high sensitivity in discriminating between fast and slow bone losers.
authors.affiliation: Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong. griffith@cuhk.edu.hk
authors.forename: James F
authors.initials: JF
authors.lastname: Griffith
authors.forename: David K W
authors.initials: DK
authors.lastname: Yeung
authors.forename: Jason Chi Shun
authors.initials: JC
authors.lastname: Leung
authors.forename: Timothy C Y
authors.initials: TC
authors.lastname: Kwok
authors.forename: Ping C
authors.initials: PC
authors.lastname: Leung
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000502:physiology*; D003720:Densitometry / Q000379:methods*; D005260:Female; D005270:Femur Head / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity