Tissue characterization of glioma by proton magnetic resonance spectroscopy and perfusion-weighted magnetic resonance imaging: glioma grading and histological correlation

Background and Purpose Our intent was to clarify the usefulness of proton magnetic resonance spectroscopy (MRS) and perfusion-weighted magnetic resonance imaging (PW-MRI) in the grading of glioma. Methods Twenty-three consecutive patients with gliomas were investigated by both proton MRS and PW-MRI. For quantitative analysis, the metabolite data of the gliomas were estimated using the LCModel software. Receiver operating characteristic (ROC) curve analyses were also performed to assess which metabolite parameter was optimal for discrimination of glioma grade. From the PW-MRI data, the value of blood volume was measured on the parametric map corresponding to the location of MRS analysis. We then compared tumor blood volume with the amount of choline (Cho). Results The mean Cho/creatine (Cre) ratio was useful to discriminate between Grades II and III, and the mean lactate (Lac)/Cre ratio was found to be significantly different between Grades III and IV. ROC curve analysis showed that measurements involving Cho were superior indices for grading glioma compared with blood volume information. Furthermore, the correlation between tumor blood volume and the amount of choline was statistically significant. Conclusion MRS may provide valuable information for glioma grading.