title: Noninvasive evaluation of cerebral glioma grade by using diffusion-weighted imaging-guided single-voxel proton magnetic resonance spectroscopy.
abstract: OBJECTIVE
  To investigate the usefulness of diffusion-weighted imaging (DWI)-guided, single-voxel proton magnetic resonance spectroscopy (SVS) for preoperative evaluation of cerebral glioma grade.
  
  
  METHODS
  For SVS, placement of volume-of-interest was guided by the minimal apparent diffusion  coefficient value obtained from DWI. Spectral data for N-acetylaspartate (NAA), choline (Cho), and phosphocreatine (Cr) were analysed in 33 patients with primary gliomas.
  
  
  RESULTS
  Cho/Cr and Cho/NAA ratios were significantly higher in high-grade than in low-grade gliomas; NAA/Cr ratios  were significantly lower in high-grade than in low-grade gliomas. Receiver operating characteristic curve analysis demonstrated a threshold value of 2.01 for Cho/Cr for sensitivity, specificity, positive predictive and negative predictive values of 86.36%, 90.00%, 95.00% and 75.00%, respectively.  Threshold values of 2.49 and 0.97 were obtained for Cho/NAA and NAA/Cr, respectively. Despite no significant difference in diagnostic accuracy between the metabolite ratios, diagnostic accuracy using the Cho/Cr ratio was slightly better than that of Cho/NAA or NAA/Cr.
  
  
  CONCLUSIONS
  DWI-guided  SVS has potential value for the preoperative prediction of glioma grade.
authors.affiliation: Department of Radiology, Qilu Hospital of Shandong University, Jinan, China.
authors.forename: Z-L
authors.initials: ZL
authors.lastname: Liu
authors.forename: Q
authors.initials: Q
authors.lastname: Zhou
authors.forename: Q-S
authors.initials: QS
authors.lastname: Zeng
authors.forename: C-F
authors.initials: CF
authors.lastname: Li
authors.forename: K
authors.initials: K
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000473:pathology; D001932:Brain Neoplasms / Q000473:pathology*; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000473:pathology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011522:Protons; D015173:Supratentorial Neoplasms / Q000473:pathology; D013702:Temporal Lobe / Q000473:pathology; D055815:Young Adult
chemical_list: D011522:Protons