title: 30-Second bound and pore water concentration mapping of cortical bone using 2D UTE with optimized half-pulses.
abstract: MRI of cortical bone has the potential to offer new information about fracture risk. Current methods are typically performed with 3D acquisitions, which suffer from long scan times and are generally limited to extremities. This work proposes using 2D UTE with half pulses for quantitatively mapping bound and pore water in cortical bone.
  
  
  
  Half-pulse 2D UTE methods were implemented on a 3T Philips Achieva scanner using an optimized slice-select gradient waveform, with preparation pulses to selectively image bound or pore water. The 2D methods were quantitatively compared with previously implemented 3D methods in the tibia in five volunteers.
  
  
  
  The mean difference between bound and pore water concentration acquired from 3D and 2D sequences was 0.6 and 0.9 mol1H/Lbone(3 and 12%, respectively). While 2D pore water methods tended to slightly overestimate concentrations relative to 3D methods, differences were less than scan-rescan uncertainty and expected differences between healthy and fracture-prone bones.
  
  
  
  Quantitative bound and pore water concentration mapping in cortical bone can be accelerated by 2 orders of magnitude using 2D protocols with optimized half-pulse excitation. Magn Reson Med 77:945-950, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.|Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.
authors.forename: Mary Kate
authors.initials: MK
authors.lastname: Manhard
authors.affiliation: Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.|Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Harkins
authors.affiliation: Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.|Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.|Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Gochberg
authors.affiliation: Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.|Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.|Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, USA.|Orthopaedic Surgery and Rehabilitation, Vanderbilt University, Nashville, Tennessee, USA.|Center for Bone Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Jeffry S
authors.initials: JS
authors.lastname: Nyman
authors.affiliation: Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.|Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA.|Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.|Electrical Engineering, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Does
mesh_terms: D000465:Algorithms; D001834:Body Water / Q000737:chemistry / Q000378:metabolism*; D000071538:Cortical Bone / Q000033:anatomy & histology* / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D016062:Porosity; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
keywords: MRI; bound water; cortical bone; pore water; ultrashort echo time