title: Measurement of temperature dependent changes in bone marrow using a rapid chemical shift imaging technique.
abstract: OBJECTIVE
  To provide quantitative temperature monitoring for thermal therapies in bone marrow by measuring temperature-dependent signal changes in the bone marrow of ex vivo canine femurs heated with a 980-nm laser at 1.5T and 3.0T.
  
  
  METHODS
  Using a multi-gradient echo (≤ 16) acquisition and signal modeling with the Stieglitz-McBride algorithm, the temperature sensitivity coefficients (TSC, ppm/°C) of water and multiple lipid components' proton resonance frequency (PRF) values are measured at high spatiotemporal resolutions (1.6 × 1.6 × 4 mm(3) , ≤ 5 seconds). Responses in R(2) * and amplitudes of each peak were also measured as a function of temperature simultaneously.
  
  
  RESULTS
  Calibrations demonstrate that lipid signal may be used to compensate for B(0) errors to provide accurate temperature readings (<1.0°C). Over a temperature range of 17.2-57.2°C, the TSCs after correction to a bulk methylene reference are -0.87 × 10(-2) ± 4.7 × 10(-4) ppm/°C and -0.87 × 10(-2) ± 4.0 × 10(-4) ppm/°C for 1.5T and 3.0T, respectively.
  
  
  CONCLUSIONS
  Overall, we demonstrate that accurate and precise temperature measurements can be made in bone marrow. In addition, the relationship of R(2) * and signal amplitudes with respect to temperature are shown to differ significantly where conformal changes are predicted by Arrhenius rate model analysis.
authors.affiliation: Department of Imaging Physics, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Taylor
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Elliott
authors.forename: Ken-Pin
authors.initials: KP
authors.lastname: Hwang
authors.forename: Anil
authors.initials: A
authors.lastname: Shetty
authors.forename: John D
authors.initials: JD
authors.lastname: Hazle
authors.forename: R Jason
authors.initials: RJ
authors.lastname: Stafford
mesh_terms: D000465:Algorithms; D000818:Animals; D001853:Bone Marrow / Q000473:pathology*; D002138:Calibration; D004285:Dogs; D005269:Femur / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008055:Lipids / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015233:Models, Statistical; D011522:Protons; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D008055:Lipids; D011522:Protons; D014867:Water