title: Noninvasive evaluation of malignancy of brain tumors with proton MR spectroscopy.
abstract: OBJECTIVE
  To test clinical proton MR spectroscopy as a noninvasive method for predicting tumor malignancy.
  
  
  METHODS
  Water-suppressed single-voxel point resolved spectroscopy in the frontal white matter of 17 healthy volunteers and 25 patients with brain tumors yielded spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cre), and lactate. These peak intensities were semiquantitated as a ratio to that of the external reference. The validity of the semiquantitation was first evaluated through phantom and volunteer experiments.
  
  
  RESULTS
  The variation in measurements of the designated region in the volunteers was less than 10%. Normal ranges of NAA/reference, Cho/reference, and Cre/reference were 3.59 +/- 0.68, 1.96 +/- 0.66, and 1.53 +/- 0.64 (mean +/- SD), respectively. In 17 gliomas, the Cho/reference value in high-grade gliomas was significantly higher than in low-grade gliomas. Levels of NAA/reference were also significantly different in low-grade and high-grade malignancy. In eight meningiomas (four newly diagnosed and four recurrent), the level of Cho/reference was significantly higher in recurrent meningiomas than in normal white matter or in newly diagnosed meningiomas.
  
  
  CONCLUSIONS
  Higher grades of brain tumors in this study were associated with higher Cho/reference and lower NAA/reference values. These results suggest that clinical proton MR spectroscopy may help predict tumor malignancy.
authors.affiliation: Department of Neurosurgery, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Shimizu
authors.forename: T
authors.initials: T
authors.lastname: Kumabe
authors.forename: T
authors.initials: T
authors.lastname: Tominaga
authors.forename: T
authors.initials: T
authors.lastname: Kayama
authors.forename: K
authors.initials: K
authors.lastname: Hara
authors.forename: Y
authors.initials: Y
authors.lastname: Ono
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: N
authors.initials: N
authors.lastname: Arai
authors.forename: S
authors.initials: S
authors.lastname: Fujiwara
authors.forename: T
authors.initials: T
authors.lastname: Yoshimoto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000503:physiopathology; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005910:Glioma / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008579:Meningioma / Q000175:diagnosis / Q000503:physiopathology; D008875:Middle Aged; D019047:Phantoms, Imaging; D010725:Phosphocreatine / Q000378:metabolism; D011522:Protons; D012016:Reference Values; D015203:Reproducibility of Results
chemical_list: D007773:Lactates; D011522:Protons; D010725:Phosphocreatine; D001224:Aspartic Acid; D019344:Lactic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline