title: Bone marrow fat quantification of osteoporotic vertebral compression fractures: comparison of multi-voxel proton MR spectroscopy and chemical-shift gradient-echo MR imaging.
abstract: BACKGROUND
  Only a few studies have used in/opposed phase method for a quantitative evaluation of fat fraction in the spine.
  
  
  OBJECTIVE
  To compare multivoxel proton MR spectroscopy and chemical-shift gradient-echo MR imaging for bone marrow fat quantification in vertebral compression fractures (VCF).
  
  
  METHODS
  Vertebral marrow fat quantification in fifteen patients was measured at 3.0-T. Multi-voxel proton spectroscopy (MRS) and in/opposed-phase MR imaging using a fat map build with a triple-echo gradient-echo sequence was used. All the patients had benign vertebral collapse. Bone marrow fat content was evaluated by both techniques in compressed (acute or chronic) and in non-compressed vertebrae.
  
  
  RESULTS
  The percentage of fat fraction measured by the triple-echo sequence was well correlated with those calculated by MRS (r(2) = 0.85; P < 10(-4)). There was a significant decrease of fat fraction in acute VCF versus both chronic VCF (P < 10(-9)) and non-fractured vertebrae (P < 10(-7)). There was no significant difference in fat fraction evaluated by both techniques between non-fractured vertebrae and chronic VCF.
  
  
  CONCLUSIONS
  We have validated the in/opposed phase method compared with MRS for vertebral bone marrow fat quantification. The fat mapping using a triple-echo gradient-echo sequence allows distinguishing acute and chronic benign VCF.
authors.affiliation: Department of Radiology, University Hospital, Dijon, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Régis-Arnaud
authors.forename: Boris
authors.initials: B
authors.lastname: Guiu
authors.forename: Paul-Michael
authors.initials: PM
authors.lastname: Walker
authors.forename: Denis
authors.initials: D
authors.lastname: Krausé
authors.forename: Frédéric
authors.initials: F
authors.lastname: Ricolfi
authors.forename: Douraied
authors.initials: D
authors.lastname: Ben Salem
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000737:chemistry*; D002908:Chronic Disease; D005260:Female; D050815:Fractures, Compression / Q000378:metabolism*; D006801:Humans; D008055:Lipids / Q000032:analysis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000378:metabolism*; D016103:Spinal Fractures / Q000378:metabolism*
chemical_list: D008055:Lipids