title: Changes in trabecular microarchitecture in postmenopausal women on bisphosphonate therapy.
abstract: OBJECTIVE
  In addition to bone mineral density (BMD), trabecular microstructure contributes to skeletal strength. Our goal was to examine changes in trabecular microstructure in women on therapy.
  
  
  METHODS
  We followed 10 postmenopausal women receiving a bisphosphonate, risedronate (35 mg once weekly), over 12 months and examined trabecular microarchitecture with high resolution wrist MR images (hr-MRI). MRI parameters included bone volume/total volume (BV/TV), surface density (representing plates), curve density (representing rods), surface-to-curve ratio and erosion index (depicting deterioration). We assessed BMD of the spine, hip and radius and markers of bone turnover.
  
  
  RESULTS
  Women had been receiving bisphosphonate therapy for 43+/-9 months (mean+/-SD) prior to the first MRI. Indices of hr-MRI demonstrated improvement in surface-to-curve ratio (13.0%) and a decrease in erosion index (12.1%) consistent with less deterioration (both p<0.05). BMD of the spine, hip and radius and markers of bone turnover remained stable. Parameters of hr-MRI were associated with 1/3 distal radius BMD (correlation coefficient 0.71 to 0.86, p<0.05).
  
  
  CONCLUSIONS
  We conclude that hr-MRI of the radius demonstrates improvements in trabecular microstructure not appreciated by conventional BMD and provides additional information on parameters that contribute to structural integrity in patients on antiresorptive therapy.
authors.affiliation: University of Pittsburgh, Department of Medicine, Pittsburgh, PA 15213, USA. greenspans@dom.pitt.edu
authors.forename: Susan L
authors.initials: SL
authors.lastname: Greenspan
authors.forename: Subashan
authors.initials: S
authors.lastname: Perera
authors.forename: Robert
authors.initials: R
authors.lastname: Recker
authors.forename: Julie M
authors.initials: JM
authors.lastname: Wagner
authors.forename: Parmatma
authors.initials: P
authors.lastname: Greeley
authors.forename: Bryon R
authors.initials: BR
authors.lastname: Gomberg
authors.forename: Pamela
authors.initials: P
authors.lastname: Seaman
authors.forename: Michael
authors.initials: M
authors.lastname: Kleerekoper
mesh_terms: D000368:Aged; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D001842:Bone and Bones / Q000187:drug effects* / Q000648:ultrastructure*; D004164:Diphosphonates / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D010024:Osteoporosis / Q000188:drug therapy*; D018579:Patient Selection; D010865:Pilot Projects; D017698:Postmenopause
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates