title: A feasibility study of quantitative molecular characterization of musculoskeletal lesions by proton MR spectroscopy at 3 T.
abstract: OBJECTIVE
  The purpose of this study is to establish the feasibility and potential value of measuring the concentration of choline-containing compounds by proton MR spectroscopy (MRS) in musculoskeletal lesions at 3 T.
  
  
  METHODS
  Thirty-three subjects with 34 musculoskeletal lesions (four histologically proven malignant, 13 histologically proven benign or proven benign by follow-up analysis, and 17 posttreatment fibrosis with documented stability for 6-36 months) underwent single-voxel 3-T MRS studies. In each case, both water-suppressed and water-unsuppressed scans were obtained. The quality of the scans was recorded as excellent, adequate, or nondiagnostic, and the choline concentration was measured using water as the internal reference. The choline concentrations of benign and malignant lesions were compared using the Mann-Whitney test.
  
  
  RESULTS
  Spectral quality was excellent in 26 cases, adequate in four cases, and nondiagnostic in four cases. For malignant lesions (three sarcomas), the choline concentrations were 1.5, 2.9, and 3.8 mmol/kg, respectively. For five benign lesions (two neurofibromas, two schwannomas, and one enchondroma), the choline concentrations were 0.11, 0.28, 0.13, 0.8, and 1.2 mmol/kg, respectively. For seven benign lesions (two hematomas, two bone cysts, one lipoma, one giant cell tumor, and one pigmented villonodular synovitis), the spectra showed negligible choline content. For three posttreatment fibrosis cases, the choline concentration range was 0.2-0.4 mmol/kg. For the remaining 12 posttreatment fibrosis cases, the spectra showed negligible choline content. Average choline concentrations were different for malignant and benign lesions (2.7 vs 0.5 mmol/kg; p = 0.01).
  
  
  CONCLUSIONS
  The measurement of choline concentration within musculoskeletal lesions by MRS is feasible using an internal water-referencing method at 3 T and has potential for characterizing lesions for malignancy.
authors.affiliation: The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA. lfayad1@jhmi.edu <lfayad1@jhmi.edu>
authors.forename: Laura M
authors.initials: LM
authors.lastname: Fayad
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Nouha
authors.initials: N
authors.lastname: Salibi
authors.forename: Peter B
authors.initials: PB
authors.lastname: Barker
authors.forename: Michael A
authors.initials: MA
authors.lastname: Jacobs
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Machado
authors.forename: Kristy L
authors.initials: KL
authors.lastname: Weber
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
mesh_terms: D000328:Adult; D000465:Algorithms; D015415:Biomarkers / Q000032:analysis; D002794:Choline / Q000032:analysis*; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019042:Muscle Neoplasms / Q000175:diagnosis* / Q000473:pathology; D009140:Musculoskeletal Diseases / Q000175:diagnosis* / Q000473:pathology; D011237:Predictive Value of Tests; D011522:Protons; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D003287:Contrast Media; D011522:Protons; D002794:Choline