title: [Usefulness of Cho/Cr ratio in proton MR spectroscopy for differentiating residual/recurrent glioma from non-neoplastic lesions].
abstract: OBJECTIVE
  We evaluated the clinical usefulness of the Cho/Cr ratio of proton MR spectroscopy(1H-MRS) to differentiate residual/recurrent glioma from non-neoplastic lesions.
  
  
  METHODS
  20 cases of glioma were involved in this study(astrocytoma grade I-II: 7, oligodendroglioma: 1, astrocytoma grade III: 2, glioblastoma: 10). Seven of the patients underwent surgical resection only, 4 underwent surgical resection and radiotherapy(40-60 Gy), and 9 underwent surgical resection and radiotherapy with concurrent chemotherapy(14-60 Gy). 1H-MRS was performed on a 1.5 Tesla clinical MR unit using a 3D-chemical shift imaging sequence(1500 msec/270 msec/1 (TR/TE/excitations), and the Cho/Cr ratio was calculated in the voxel where neoplastic lesion was most suspected on MRI. The presence of lactate + lipid peak was also evaluated. All spectra were obtained after the contrast enhanced study.
  
  
  RESULTS
  Cho/Cr ratios were significantly higher in cases of residual/recurrent tumors(mean +/- SD = 1.70 +/- 0.96) than in non-neoplastic lesions(mean +/- SD = 1.04 +/- 1.16) (Mann-Whitney U-test p = 0.047). If a Cho/Cr ratio of more than 1.5 was used as a marker of tumor presence, its sensitivity was 64%, specificity 83%, and accuracy 70%. One false-positive case that of radiation necrosis whose spectrum showed a high Cho/Cr ratio with markedly elevated lactate + lipid peak.
  
  
  CONCLUSIONS
  The Cho/Cr ratio of 1H-MRS provides additional information to MRI in differentiating residual/recurrent gliomas from non-neoplastic lesions.
authors.affiliation: Department of Radiology, Hyogo College of Medicine.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Ando
authors.forename: Reiichi
authors.initials: R
authors.lastname: Ishikura
authors.forename: Yuki
authors.initials: Y
authors.lastname: Nagami
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Morikawa
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takada
authors.forename: Jota
authors.initials: J
authors.lastname: Ikeda
authors.forename: Norio
authors.initials: N
authors.lastname: Nakao
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Norio
authors.initials: N
authors.lastname: Arita
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D002794:Choline / Q000032:analysis*; D003401:Creatine / Q000032:analysis*; D005260:Female; D005910:Glioma / Q000175:diagnosis*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D018365:Neoplasm, Residual; D012680:Sensitivity and Specificity
chemical_list: D003401:Creatine; D002794:Choline