Cerebral Blood Volume Measurements and Proton MR Spectroscopy in Grading of Oligodendroglial Tumors

AJR Am J Roentgenol. 2007 Jan;188(1):204-12. doi: 10.2214/AJR.05.1177.

Abstract

Objective: The purpose of this study was to determine whether perfusion-weighted imaging (PWI) and proton MR spectroscopy (MRS) are useful in differentiating high- and low-grade oligodendroglial tumors.

Materials and methods: PWI and MRS studies of 22 patients with histologically proven oligodendroglioma or oligoastrocytoma (13 low-grade and nine anaplastic tumors) were retrospectively reviewed. PWI of 14 subjects was performed with a dynamic contrast-enhanced susceptibility-weighted echo-planar technique. Intratumoral relative cerebral blood volume ratio was calculated and normalized to the same value in contralateral normal-appearing white matter. Multivoxel MRS was performed with a point-resolved spectroscopy sequence at a TE of 135 milliseconds in 20 patients and with the addition of a TE of 30 seconds in 17 patients. MRS data were expressed as intratumoral metabolite ratios (choline to creatine [Cho/Cr], choline to N-acetyl aspartate, N-acetyl aspartate to creatine, and myoinositol to creatine).

Results: Relative cerebral blood volume ratios were significantly different (p = 0.004) between low-grade (1.61 +/- 1.20) and high-grade tumors (5.45 +/- 1.96). The optimal relative cerebral blood volume ratio cutoff value in identification of anaplastic oligodendroglial tumors was 2.14. Analysis of MRS data showed significantly higher Cho/Cr ratios (p = 0.002) in high-grade than in low-grade tumors. A Cho/Cr ratio cutoff value of 2.33 had the highest accuracy in identification of high-grade tumors.

Conclusion: Relative cerebral blood volume measurement and MRS are helpful in differentiating low-grade from anaplastic oligodendroglial tumors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Blood Volume Determination / methods
  • Blood Volume*
  • Brain Neoplasms / blood supply
  • Brain Neoplasms / diagnosis*
  • Diagnosis, Computer-Assisted / methods*
  • Female
  • Humans
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Middle Aged
  • Oligodendroglioma / blood supply
  • Oligodendroglioma / diagnosis*
  • Protons*
  • Reproducibility of Results
  • Sensitivity and Specificity

Substances

  • Protons