title: Validation of quantitative bound- and pore-water imaging in cortical bone.
abstract: OBJECTIVE
  To implement and validate a previously proposed ultra-short echo time method for measuring collagen-bound- and pore-water concentrations in bone based on their T2 differences.
  
  
  METHODS
  Clinically compatible ultra-short echo time image sequences for quantitative T2 -based bound and pore-water imaging in bone were implemented and validated on a 3T human scanner and a 4.7T small bore system. Bound- and pore-water images were generating using T2 -selective adiabatic pulses. In both cases, the magnetization preparation was integrated into a three-dimensional ultra-short echo time acquisition, with 16 radial spokes acquired per preparation. Images were acquired from human cadaveric femoral mid-shafts from which isolated bone samples were subsequently extracted for nonimaging analysis using T2 spectroscopic measurements.
  
  
  RESULTS
  A strong correlation was found between imaging-derived concentrations of bound and pore water and those determined from the isolated bone samples.
  
  
  CONCLUSIONS
  These studies demonstrate the translation of the previously developed approaches for distinguishing bound and pore water from human cortical bone using practical human MRI constraints of gradient performance and radiofrequency power deposition.
authors.affiliation: Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA; Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Mary Kate
authors.initials: MK
authors.lastname: Manhard
authors.forename: R Adam
authors.initials: RA
authors.lastname: Horch
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Harkins
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Gochberg
authors.forename: Jeffry S
authors.initials: JS
authors.lastname: Nyman
authors.forename: Mark D
authors.initials: MD
authors.lastname: Does
mesh_terms: D002102:Cadaver; D005260:Female; D005269:Femur / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D019047:Phantoms, Imaging; D016062:Porosity; D014867:Water / Q000032:analysis
chemical_list: D014867:Water
keywords: adiabatic; bone; bound water; pore water; ultra-short echo time