In vivo proton spectroscopy of meningioma after preoperative embolization.

The time course of proton spectra of meningioma after embolization has been followed using a localized PRESS experiment with 135 ms of echo time. The most conspicuous findings were the observation of transient lactate signal within 24 h after blocking of the capillary bed. After that time large aliphatic signals from necrosis were observed, whereas other metabolite signals vanished. It was demonstrated, that tumor necrosis as shown by proton spectroscopy is complete within 4 days. This finding is significant for the timing of surgery, which can be performed after this period.