Five patients, each with a brain abscess, were examined by means of 1H MR spectroscopic imaging in vivo. The aspirated pus was analyzed in vitro by means of 1D and 2D COSY 1H MRS. In addition to resonance lines from compounds (lactate, alanine and lipids) often found in the spectra from intracranial tumors, resonance lines were detected from a number of markers of infectious involvement (acetate, succinate, and various amino acids). These results suggest that 1H MRS in vivo might contribute in establishing noninvasively a differential diagnosis between brain abscess and tumor.

An in vivo study of intracerebral rat glioma using proton-localized NMR spectroscopy showed important modifications of the spectra in the tumor as compared with the contralateral brain. To carry out the assignment of the resonances of the glioma spectra, tumoral and normal rat brain tissues were studied in vivo, ex vivo, and in vitro by one-dimensional and two-dimensional proton spectroscopy. N-Acetylaspartate was found at an extremely low level in the glioma. The change of peak ratio total creatinel 3.2 ppm peak was found to be due to a simultaneous decrease of the total creatine content and an increase of the 3.2 ppm peak. The 3.2 ppm resonance in the glioma spectra has been shown to originate from choline, phosphocholine, glycerophosphocholine, taurine, inositol, and phosphoethanolamine. The increase of the 3.2 ppm peak in the glioma was found to result from the increase of taurine and phosphoethanolamine contents. The peak in the 1.3 ppm region of the glioma spectra was due to both lactate and mobile fatty acids. Moreover, two-dimensional spectroscopy of excised tissues and extracts showed the presence of hypotaurine only in the tumor.

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