title: Quantitative assessment of trabecular bone micro-architecture of the wrist via 7 Tesla MRI: preliminary results.
abstract: OBJECTIVE
  The goal of this study was to determine the feasibility of performing quantitative 7 T magnetic resonance imaging (MRI) assessment of trabecular bone micro-architecture of the wrist, a common fracture site.
  
  
  METHODS
  The wrists of 4 healthy subjects (1 woman, 3 men, 28 ± 8.9 years) were scanned on a 7 T whole body MR scanner using a 3D fast low-angle shot (FLASH) sequence (TR/TE = 20/4.5 m s, 0.169 × 0.169 × 0.5 mm). Trabecular bone was segmented and divided into 4 or 8 angular subregions. Total bone volume (TBV), bone volume fraction (BVF), surface-curve ratio (SC), and erosion index (EI) were computed. Subjects were scanned twice to assess measurement reproducibility.
  
  
  RESULTS
  Group mean subregional values for TBV, BVF, SC, and EI (8 subregion analysis) were as follows: 8489 ± 3686, 0.27 ± 0.045, 9.61 ± 6.52; and 1.43 ± 1.25. Within each individual, there was subregional variation in TBV, SC, and EI (>5%), but not BVF (<5%). Intersubject variation (≥12%) existed for all parameters. Within-subject coefficients of variation were ≤10%.
  
  
  CONCLUSIONS
  This is the first study to perform quantitative 7T MRI assessment of trabecular bone micro-architecture of the wrist. This method could be utilized to study perturbations in bone structure in subjects with osteoporosis or other bone disorders.
authors.affiliation: Quantitative Multinuclear Musculoskeletal Imaging Group, Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, 660 First Avenue, 4th Floor, New York, NY 10016, USA. gregory.chang@nyumc.org
authors.forename: Gregory
authors.initials: G
authors.lastname: Chang
authors.forename: Ligong
authors.initials: L
authors.lastname: Wang
authors.forename: Guoyuan
authors.initials: G
authors.lastname: Liang
authors.forename: James S
authors.initials: JS
authors.lastname: Babb
authors.forename: Graham C
authors.initials: GC
authors.lastname: Wiggins
authors.forename: Punam K
authors.initials: PK
authors.lastname: Saha
authors.forename: Ravinder R
authors.initials: RR
authors.lastname: Regatte
mesh_terms: D000328:Adult; D015519:Bone Density; D002348:Carpal Bones / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008297:Male; D009929:Organ Size; D012015:Reference Standards; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods