title: Differences between glioblastomas and primary central nervous system lymphomas in 1H-magnetic resonance spectroscopy.
abstract: OBJECTIVE
  The present study aimed to distinguish between glioblastomas and primary central nervous system lymphomas (PCNSLs) using (1)H-magnetic resonance spectroscopy (MRS), especially glutamate (Glu)/creatine (Cr) and Glu/Glu+glutamine (Gln) ratios.
  
  
  METHODS
  A total of 46 patients (31 cases diagnosed with glioblastoma, 15 with PCNSL) were examined by in vivo single-voxel proton (1)H-MRS with a 3-T MR imaging system. Differences in absolute concentration of Cr, choline/Cr, lipid (1.3 ppm)/Cr, Glu+Gln/Cr, Glu/Cr, and Glu/Glu+Gln ratios among groups were evaluated with Mann-Whitney U tests.
  
  
  RESULTS
  PCNSLs [3.408 ± 1.194 (standard deviation)] showed significantly higher Glu/Cr ratios as compared to glioblastomas (2.220 ± 0.942; P = 0.003) [Glu/Cr cutoff ratio of 2.509 showed a sensitivity of 88 % (7/8) and a specificity of 92 % (22/24)], while glioblastomas (0.539 ± 0.098) showed significantly lower Glu/Glu+Gln ratios as compared to PCNSLs (0.728 ± 0.147; P < 0.001) [Glu/Glu+Gln cutoff ratio of 0.558 showed a sensitivity of 69 % (18/26) and a specificity of 100 % (13/13)]. And PCNSLs (1.101 ± 0.387) showed significantly higher Cho/Cr ratios as compared to glioblastomas (0.850 ± 0.465; P = 0.026).
  
  
  CONCLUSIONS
  Glu/Cr, Glu/Glu+Gln, and Cho/Cr ratios may be useful in distinguishing between glioblastomas and PCNSLs.
authors.affiliation: Department of Radiology, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8641, Japan, aburano@arrow.ocn.ne.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Aburano
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Ueda
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Yoshie
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsui
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Nakada
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Gabata
mesh_terms: D001932:Brain Neoplasms / Q000175:diagnosis*; D016543:Central Nervous System Neoplasms / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis*; D006801:Humans; D008223:Lymphoma / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male