title: 3 Tesla MRI detects deterioration in proximal femur microarchitecture and strength in long-term glucocorticoid users compared with controls.
abstract: BACKGROUND
  Glucocorticoid-induced osteoporosis (GIO) is the most common secondary form of osteoporosis, and glucocorticoid users are at increased risk for fracture compared with nonusers. There is no established relationship between bone mineral density (BMD) and fracture risk in GIO. We used 3 Tesla (T) MRI to investigate how proximal femur microarchitecture is altered in subjects with GIO.
  
  
  METHODS
  This study had institutional review board approval. We recruited 6 subjects with long-term (> 1 year) glucocorticoid use (median age = 52.5 (39.2-58.7) years) and 6 controls (median age = 65.5 [62-75.5] years). For the nondominant hip, all subjects underwent dual-energy x-ray absorptiometry (DXA) to assess BMD and 3T magnetic resonance imaging (MRI, 3D FLASH) to assess metrics of bone microarchitecture and strength.
  
  
  RESULTS
  Compared with controls, glucocorticoid users demonstrated lower femoral neck trabecular number (-50.3%, 1.12 [0.84-1.54] mm(-1) versus 2.27 [1.88-2.73] mm(-1) , P = 0.02), plate-to-rod ratio (-20.1%, 1.48 [1.39-1.71] versus 1.86 [1.76-2.20], P = 0.03), and elastic modulus (-64.8% to -74.8%, 1.54 [1.22-3.19] GPa to 2.31 [1.87-4.44] GPa versus 6.15 [5.00-7.09] GPa to 6.59 [5.58-7.31] GPa, P < 0.05), and higher femoral neck trabecular separation (+192%, 0.705 [0.462-1.00] mm versus 0.241 [0.194-0.327] mm, P = 0.02). There were no differences in femoral neck trabecular thickness (-2.7%, 0.193 [0.184-0.217] mm versus 0.199 [0.179-0.210] mm, P = 0.94) or femoral neck BMD T-scores (+20.7%, -2.1 [-2.8 to -1.4] versus -2.6 [-3.3 to -2.5], P = 0.24) between groups.
  
  
  CONCLUSIONS
  The 3T MRI can potentially detect detrimental changes in proximal femur microarchitecture and strength in long-term glucocorticoid users.
authors.affiliation: Department of Radiology, Center for Biomedical Imaging, NYU Langone Medical Center, New York, New York, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Chang
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Chamith S
authors.initials: CS
authors.lastname: Rajapakse
authors.affiliation: Department of Radiology, Center for Biomedical Imaging, NYU Langone Medical Center, New York, New York, USA.
authors.forename: Ravinder R
authors.initials: RR
authors.lastname: Regatte
authors.affiliation: Department of Radiology, Center for Biomedical Imaging, NYU Langone Medical Center, New York, New York, USA.
authors.forename: James
authors.initials: J
authors.lastname: Babb
authors.affiliation: Divison of Rheumatology, Hospital for Joint Diseases, NYU Langone Medical Center, New York, New York, USA.
authors.forename: Amit
authors.initials: A
authors.lastname: Saxena
authors.affiliation: Divison of Rheumatology, Hospital for Joint Diseases, NYU Langone Medical Center, New York, New York, USA.
authors.forename: H Michael
authors.initials: HM
authors.lastname: Belmont
authors.affiliation: Osteoporosis Center, Hospital for Joint Diseases, NYU Langone Medical Center, New York, New York, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Honig
mesh_terms: D000368:Aged; D015519:Bone Density / Q000187:drug effects; D005260:Female; D005272:Femur Neck / Q000187:drug effects* / Q000473:pathology*; D005938:Glucocorticoids / Q000009:adverse effects*; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000139:chemically induced* / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D005938:Glucocorticoids
keywords: MRI; glucocorticoids; hip; microarchitecture; osteoporosis