MR image-guided P-31 MR spectroscopy in the evaluation of brain tumor treatment.

Magnetic resonance (MR) image-guided phosphorus-31 MR spectra have been obtained from in situ brain tumors. The volumes of interest used for spectroscopy were defined from hydrogen-1 MR images. Direct comparisons were possible between normal and abnormal tissue, since P-31 spectra from different parts of the brain could be measured in a single examination. P-31 MR spectra of the tumors often showed abnormally high concentrations of phosphomonoesters and low concentrations of phosphocreatines. The effects of pharmacotherapy and radiation therapy were studied in three patients; in each of these cases changes were observed in the P-31 spectra of the tumor. The correlation between MR imaging and P-31 MR spectroscopy was essential for the interpretations of these results.