Non‐invasive Characterization of Brain Tumor by in‐vivo Proton Magnetic Resonance Spectroscopy

We studied the feasibility of characterizing brain tumor tissue by localized proton magnetic resonance spectroscopy ((1)H‐MRS), Twenty‐six newly diagnosed tumors were examined by in‐vivo, (1)H‐MRS. The NAA (N‐acetylaspartate)/Cho (choline) ratio of Grade 2 astrocytoma was higher than that of Grade 4. The Cho/Cr (creatine and phosphocreatine) ratio of meningioma was considerably higher than that of glioma of all grades. We have experienced only two cases of ependymoma and the Cho/Cr ratios of both were lower than that of glioma. It seems likely that (1)H‐MRS can be used to differentiate Grade 2 from Grade 4 in most cases of astrocytoma based on the NAA/Cho ratio, though a few cases will overlap. Meningioma can be distingulshed easily from glioma, and the results of our study suggest that ependymoma shows a characteristic pattern on (1)H‐MRS, different from those of other brain tumors.