High-Grade Cerebral Glioma Characterization: Usefulness of MR Spectroscopy and Perfusion Imaging Associated Evaluation.

The aim of our study was to evaluate if both spectroscopy and perfusion magnetic resonance (MR) imaging are necessary to differentiate high grade gliomas from low grade tumour, or if only one of these techniques is sufficient. Sixty-five patients with cerebral glioma were retrospectively evaluated. All patients were studied both with spectroscopy and perfusion imaging. In 43 cases histological examination showed a high grade glioma while a low grade glioma was found in 22 patients. For every patient spectroscopic maximum Cho/NAA ratio and lactate presence was established maximum relative CBV value was evaluated by perfusion MR. Both for Cho/NAA and rCBV threshold values were obtained by means of ROC curves. Then diagnostic sensitivity and specificity for high grade gliomas identification was evaluated for spectroscopic data only (Cho/NAA and lactate presence that was considered a high grade glioma marker), for perfusional data only (rCBV) and finally for both spectroscopic and perfusional data together. Sensitivity was significantly highest evaluating both spectroscopic and perfusional data together (89.7%) in comparison with spectroscopy (74.4%) or perfusion (79.4%) alone. Instead specificity was slightly lower with all data (91.7%) in comparison with spectroscopy (95.8%) and perfusion (95.8%) alone. In conclusion, to characterize high grade gliomas it is more useful to evaluate spectroscopic and perfusional data together with respect only one of these techniques alone.