High-grade Gliomas and Solitary Metastases: Differentiation by Using Perfusion and Proton Spectroscopic MR Imaging

Radiology. 2002 Mar;222(3):715-21. doi: 10.1148/radiol.2223010558.

Abstract

Purpose: To determine whether perfusion-weighted and proton spectroscopic MR imaging can be used to differentiate high-grade primary gliomas and solitary metastases on the basis of differences in vascularity and metabolite levels in the peritumoral region.

Materials and methods: Fifty-one patients with a solitary brain tumor (33 gliomas, 18 metastases) underwent conventional, contrast material--enhanced perfusion-weighted, and proton spectroscopic MR imaging before surgical resection or stereotactic biopsy. Of the 33 patients with gliomas, 22 underwent perfusion-weighted MR imaging; nine, spectroscopic MR imaging; and two underwent both. Of the 18 patients with metastases, 12 underwent perfusion-weighted MR imaging, and six, spectroscopic MR imaging. The peritumoral region was defined as the area in the white matter immediately adjacent to the enhancing (hyperintense on T2-weighted images, but not enhancing on postcontrast T1-weighted images) portion of the tumor. Relative cerebral blood volumes in these regions were calculated from perfusion-weighted MR data. Spectra from the enhancing tumor, the peritumoral region, and normal brain were obtained from the two-dimensional spectroscopic MR acquisition. The Student t test was used to determine if there was a statistically significant difference in relative cerebral blood volume and metabolic ratios between high-grade gliomas and metastases.

Results: The measured relative cerebral blood volumes in the peritumoral region in high-grade gliomas and metastases were 1.31 +/- 0.97 (mean +/- SD) and 0.39 +/- 0.19, respectively. The difference was statistically significant (P <.001). Spectroscopic imaging demonstrated elevated choline levels (choline-to-creatine ratio was 2.28 +/- 1.24) in the peritumoral region of gliomas but not in metastases (choline-to-creatine ratio was 0.76 +/- 0.23). The difference was statistically significant (P =.001).

Conclusion: Although conventional MR imaging characteristics of solitary metastases and primary high-grade gliomas may sometimes be similar, perfusion-weighted and spectroscopic MR imaging enable distinction between the two.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Aspartic Acid / analogs & derivatives*
  • Aspartic Acid / analysis
  • Blood Volume
  • Brain / pathology*
  • Brain Chemistry
  • Brain Neoplasms / blood supply
  • Brain Neoplasms / chemistry
  • Brain Neoplasms / diagnosis*
  • Brain Neoplasms / pathology
  • Cerebrovascular Circulation
  • Choline / analysis
  • Contrast Media
  • Creatine / analysis
  • Diagnosis, Differential
  • Female
  • Glioma / blood supply
  • Glioma / chemistry
  • Glioma / diagnosis*
  • Glioma / secondary*
  • Humans
  • Magnetic Resonance Imaging*
  • Magnetic Resonance Spectroscopy*
  • Male
  • Middle Aged

Substances

  • Contrast Media
  • Aspartic Acid
  • N-acetylaspartate
  • Creatine
  • Choline