[Phosphorus-31 MR spectroscopy of brain tumors]

Eleven normal volunteers and 17 subjects with brain tumors were studied by phosphorus-31 Magnetic Resonance (MR) spectroscopy. Measurements were performed by FROGS (Fast Rotating Gradient Spectroscopy) saturating nearly skin or muscle by Volume of Interest (VOI). This measurement took about 30 minutes for each case, including the imaging procedure, shimming and the measuring of spectroscopy. In phosphorus-31 MR spectroscopy, pH of the subjects with brain tumors showed a statistically significant elevation compared with that of the volunteers. In the subjects with benign tumors, only the elevation of pH was significant compared with that in volunteers. There was no other difference. This result suggests that benign tumors have an almost normal metabolic mechanism. Malignant brain tumors showed a decrease of PCr and an increase of Pi and PME. The increase of Pi indicates the increase of energy consumption. The increase of PME is connected with the acceleration of cell proliferation, there is a difference between malignant tumors and benign tumors. Phosphorus-31 spectroscopy has the potential to investigate the metabolism in vivo.