title: In Vivo Quantitative MR Imaging of Bound and Pore Water in Cortical Bone.
abstract: OBJECTIVE
  To translate and evaluate an in vivo magnetic resonance (MR) imaging protocol for quantitative mapping of collagen-bound and pore water concentrations in cortical bone that involves relaxation-selective ultrashort echo time (UTE) methods.
  
  
  METHODS
  All HIPAA-compliant studies were performed with institutional review board approval and written informed consent. UTE imaging sequences were implemented on a clinical 3.0-T MR imaging unit and were used for in vivo imaging of bound and pore water in cortical bone. Images of the lower leg and wrist were acquired in five volunteers each (lower leg: two men and three women aged 24, 24, 49, 30, and 26 years; wrist: two men and three women aged 31, 23, 25, 24, and 26 years) to generate bound and pore water concentration maps of the tibia and radius. Each volunteer was imaged three times, and the standard error of the measurements at the region-of-interest (ROI) level was computed as the standard deviation across studies, pooled across volunteers and ROIs.
  
  
  RESULTS
  Quantitative bound and pore water maps in the tibia and radius, acquired in 8-14 minutes, had per-voxel signal-to-noise ratios of 18 (bound water) and 14 (pore water) and inter-study standard errors of approximately 2 mol (1)H per liter of bone at the ROI level.
  
  
  CONCLUSIONS
  The results of this study demonstrate the feasibility of quantitatively mapping bound and pore water in vivo in human cortical bone with practical human MR imaging constraints.
authors.affiliation: From the Departments of Biomedical Engineering (M.K.H., M.D.D.), Radiology (R.A.H., D.F.G.), and Orthopedic Surgery and Rehabilitation (J.S.N.), Vanderbilt University, 1161 21st Ave S, AA-1105 MCN, Nashville, TN 37232-2310.
authors.forename: Mary Kate
authors.initials: MK
authors.lastname: Manhard
authors.affiliation: From the Departments of Biomedical Engineering (M.K.H., M.D.D.), Radiology (R.A.H., D.F.G.), and Orthopedic Surgery and Rehabilitation (J.S.N.), Vanderbilt University, 1161 21st Ave S, AA-1105 MCN, Nashville, TN 37232-2310.
authors.forename: R Adam
authors.initials: RA
authors.lastname: Horch
authors.affiliation: From the Departments of Biomedical Engineering (M.K.H., M.D.D.), Radiology (R.A.H., D.F.G.), and Orthopedic Surgery and Rehabilitation (J.S.N.), Vanderbilt University, 1161 21st Ave S, AA-1105 MCN, Nashville, TN 37232-2310.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Gochberg
authors.affiliation: From the Departments of Biomedical Engineering (M.K.H., M.D.D.), Radiology (R.A.H., D.F.G.), and Orthopedic Surgery and Rehabilitation (J.S.N.), Vanderbilt University, 1161 21st Ave S, AA-1105 MCN, Nashville, TN 37232-2310.
authors.forename: Jeffry S
authors.initials: JS
authors.lastname: Nyman
authors.affiliation: From the Departments of Biomedical Engineering (M.K.H., M.D.D.), Radiology (R.A.H., D.F.G.), and Orthopedic Surgery and Rehabilitation (J.S.N.), Vanderbilt University, 1161 21st Ave S, AA-1105 MCN, Nashville, TN 37232-2310.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Does
mesh_terms: D000328:Adult; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000737:chemistry; D003094:Collagen / Q000737:chemistry; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D014867:Water / Q000032:analysis; D055815:Young Adult
chemical_list: D014867:Water; D003094:Collagen