Preoperative grading of gliomas by using metabolite quantification with high-spatial-resolution proton MR spectroscopic imaging

Radiology. 2006 Mar;238(3):958-69. doi: 10.1148/radiol.2382041896. Epub 2006 Jan 19.


Purpose: To evaluate proton magnetic resonance (MR) spectroscopic imaging with high spatial resolution for preoperative grading of suspected World Health Organization grades II and III gliomas.

Materials and methods: Institutional ethics committee approval and informed consent were obtained for control subjects but were not required for the retrospective component involving patients. Twenty-six patients (10 women, 16 men; mean age, 37.5 years) suspected of having gliomas and 26 age- and sex-matched control subjects underwent proton MR spectroscopy. Absolute metabolite concentrations for choline-containing compounds (Cho), creatine (Cr), and N-acetylaspartate (NAA)-N-acetylaspartylglutamate (total NAA [tNAA]) were calculated by using a user-independent spectral fit program. Metabolic maps of Cho/tNAA ratios were calculated, segmented, and used for MR spectroszpcopy-guided stereotactic brain biopsy. Two-sided paired Student t tests were used to test for statistical significance.

Results: Significantly lower Cho levels (P = .002) and higher tNAA levels (P = .010) were found in grade II tumors (n = 9) compared with grade III tumors (n = 17). The average Cho/tNAA ratio over the voxels in the tumor center showed a distinct difference (P < .001) between grade II and III gliomas at a threshold of 0.8 (with ratios <0.8 for grade II). The maximum Cr concentration in the tumor showed a clear-cut threshold between grade III oligodendrogliomas and oligoastrocytomas (Cr level, <7 mmol/L) and grade III astrocytomas (Cr level, >7 mmol/L; P = .020). Comparison between the histopathologic findings from the MR spectroscopy-guided biopsy samples (76 biopsies from 26 patients) and molar metabolite values in corresponding voxels located at the biopsy sampling points showed a negative linear correlation for tNAA (r = -0.905) and a positive exponential correlation for Cho (r = 0.769) and Cho/tNAA (r = 0.885).

Conclusion: Proton MR spectroscopic imaging with high spatial resolution allows preoperative grading of gliomas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aspartic Acid / analogs & derivatives
  • Aspartic Acid / metabolism
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology*
  • Case-Control Studies
  • Choline / metabolism
  • Creatine / metabolism
  • Female
  • Glioma / metabolism
  • Glioma / pathology*
  • Humans
  • Linear Models
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Retrospective Studies


  • Aspartic Acid
  • N-acetylaspartate
  • Creatine
  • Choline