title: Preliminary observations and clinical value of N-acetyl resonances in ovarian tumours using in-vivo proton MR spectroscopy at 3T.
abstract: OBJECTIVE
  To retrospectively evaluate the clinical significance of N-acetyl resonances at 2 ppm in in-vivo proton magnetic resonance (MR) spectroscopy for distinguishing mucinous and non-mucinous tumours in patients with ovarian masses.
  
  
  METHODS
  MR spectroscopy was performed in patients with pathologically diagnosed ovarian tumours at 3T-MR imaging. Single-voxel MR spectroscopy data were collected from a single square volume of interest that encompassed the ovarian masses. The metabolite resonance peak areas at 2 ppm were quantified relative to unsuppressed water using a software package (LCModel).
  
  
  RESULTS
  A total of 32 ovarian lesions in 32 patients were evaluated in this study. High metabolite peak at 2 ppm was observed in all nine mucinous tumours (9.71 +/- 7.46 mM), whereas low peak was observed in 14 of 23 non-mucinous tumours (3.12 +/- 1.42 mM) (p < 0.001). Using a cut off value of 4.45 mM for mucinous tumours had a sensitivity of 89%, specificity of 86%, PPV of 80%, and NPV of 92%.
  
  
  CONCLUSIONS
  Proton MR spectroscopy with quantitative evaluation of the metabolite at 2 ppm concentration, which may suggest the presence of mucinous material containing N-acetyl mucinous compounds, can provide helpful information in distinguishing mucinous and non-mucinous ovarian tumours. Key Points • MR spectroscopy helps distinguish mucinous from non-mucinous ovarian tumours. • High N-acetyl resonance at 2 ppm is observed in ovarian mucinous tumours. • Thus MR spectroscopy could improve management of these patients.
authors.affiliation: Department of Radiology, University of Tokushima, 3-18-15, Kuramoto-cho, Tokushima 7708503, Japan. mayumi@clin.med.tokushima-u.ac.jp
authors.forename: Mayumi
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsuzaki
authors.forename: Masafumi
authors.initials: M
authors.lastname: Harada
mesh_terms: D000107:Acetylation; D002288:Adenocarcinoma, Mucinous / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D018282:Cystadenocarcinoma, Mucinous / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D018291:Cystadenoma, Mucinous / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007725:Krukenberg Tumor / Q000175:diagnosis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D009077:Mucins / Q000378:metabolism*; D015588:Observer Variation; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D011237:Predictive Value of Tests; D011522:Protons; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D009077:Mucins; D011522:Protons