CLASSIFICATION OF BRAIN-TUMORS BY EX-VIVO H-1-NMR SPECTROSCOPY

Ex vivo biopsy samples (n = 42) from human brain tumors and normal bra in have been examined by high-resolution proton magnetic resonance spe ctroscopy. Parameters from one-dimensional H-1 spectra, two-dimensiona l COSY spectra, and transverse relaxation time (T-2) data were used to classify the tumors according to the histopathological diagnoses. The ratio of the area between 3.4 and 3.1 ppm to that between 1.5 and 1.1 ppm distinguished glioblastomas from astrocytomas and normal brain, a nd appeared to be indicative of malignant potential. In support of the one-dimensional data, crosspeaks in the COSY spectra of brain specime ns classified glioblastomas and metastases into one group and the more benign tumors, meningiomas, astrocytomas, and normal brain into a sec ond group. The transverse relaxation of the resonance at 1.3 ppm was f itted by a model with two T-2 values. The longer T-2 value could be us ed to distinguish glioblastomas from normal brain, the latter having a much longer long T-2 value. Astrocytomas showed a continuum of T-2 va lues between glioblastomas and normal brain, with the grade of the ast rocytoma correlating roughly with the value of the long T-2 component.