Proton magnetic resonance spectroscopy in the distinction of high-grade cerebral gliomas from single metastatic brain tumors

Acta Radiol. 2010 Apr;51(3):316-25. doi: 10.3109/02841850903482901.


Background: Brain metastases and primary high-grade gliomas, including glioblastomas multiforme (GBM) and anaplastic astrocytomas (AA), may be indistinguishable by conventional magnetic resonance (MR) imaging. Identification of these tumors may have therapeutic consequences.

Purpose: To assess the value of MR spectroscopy (MRS) using short and intermediate echo time (TE) in differentiating solitary brain metastases and high-grade gliomas on the basis of differences in metabolite ratios in the intratumoral and peritumoral region.

Material and methods: We performed MR imaging and MRS in 73 patients with histologically verified intraaxial brain tumors: 53 patients with high-grade gliomas (34 GBM and 19 AA) and 20 patients with metastatic brain tumors. The metabolite ratios of Cho/Cr, Cho/NAA, and NAA/Cr at intermediate TE and the presence of lipids at short TE were assessed from spectral maps in the tumoral core, peritumoral edema, and contralateral normal-appearing white matter. The differences in the metabolite ratios between high-grade gliomas/GBM/AA and metastases were analyzed statistically. Cutoff values of Cho/Cr, Cho/NAA, and NAA/Cr ratios in the peritumoral edema, as well as Cho/Cr and NAA/Cr ratios in the tumoral core for distinguishing high-grade gliomas/GBM/AA from metastases were determined by receiver operating characteristic (ROC) curve analysis.

Results: Significant differences were noted in the peritumoral Cho/Cr, Cho/NAA, and NAA/ Cr ratios between high-grade gliomas/GBM/AA and metastases. ROC analysis demonstrated a cutoff value of 1.24 for peritumoral Cho/Cr ratio to provide sensitivity, specificity, positive (PPV), and negative predictive values (NPV) of 100%, 88.9%, 80.0%, and 100%, respectively, for discrimination between high-grade gliomas and metastases. By using a cutoff value of 1.11 for peritumoral Cho/NAA ratio, the sensitivity was 100%, the specificity was 91.1%, the PPV was 83.3%, and the NPV was 100%.

Conclusion: The results of this study demonstrate that MRS can differentiate high-grade gliomas from metastases, especially with peritumoral measurements, supporting the hypothesis that MRS can detect infiltration of tumor cells in the peritumoral edema.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Aspartic Acid / analogs & derivatives
  • Aspartic Acid / metabolism
  • Biomarkers / metabolism
  • Brain Neoplasms / metabolism*
  • Brain Neoplasms / pathology
  • Brain Neoplasms / secondary*
  • Choline / metabolism
  • Contrast Media
  • Creatine / metabolism
  • Diagnosis, Differential
  • Female
  • Gadolinium DTPA
  • Glioma / metabolism*
  • Glioma / pathology
  • Glioma / secondary*
  • Humans
  • Image Enhancement / methods
  • Lipid Metabolism
  • Magnetic Resonance Imaging / methods
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prospective Studies
  • ROC Curve
  • Reproducibility of Results
  • Sensitivity and Specificity


  • Biomarkers
  • Contrast Media
  • Aspartic Acid
  • N-acetylaspartate
  • Gadolinium DTPA
  • Creatine
  • Choline