NONINVASIVE CHARACTERIZATION OF BRAIN-TUMOR BY IN-VIVO PROTON MAGNETIC-RESONANCE SPECTROSCOPY

We studied the feasibility of characterizing brain tumor tissue by loc alized proton magnetic resonance spectroscopy (H-1-MRS), Twenty-six ne wly diagnosed tumors were examined by in-vivo H-1-MRS. The NAA (N-acet ylaspartate)/Cho (choline) ratio of Grade 2 astrocytoma was higher tha n 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 H-1-MRS can be used to differentiate Grade 2 from Grade 4 in most cases of ast rocytoma based on the NAA/Cho ratio, though a few cases will overlap, Meningioma can be distinguished easily from glioma, and the results of our study suggest that ependymoma shows a characteristic pattern on H -1-MRS, different from those of other brain tumors.