聴神経鞘腫「術後」のMRI所見—特に内耳道内で観察される「神経浮腫」について

Postoperative' MR Findings in Acoustic Neuromas: Nerve edema within the internal auditory canal

I．はじめに

　聴神経鞘腫のMRIによる術前診断に関しては，すでに多くの報告があり，その有用性はすでに確立している^3-5,7,8）．しかし聴神経鞘腫「術後」のMRI所見については充分な検討がなされていない．本研究では聴神経鞘腫の術前，術後のMRI所見を比較検討し，特に術後内耳道内で観察される所見について詳細な検討を行い二，三の知見を得たので報告する．

Postoperative MR findings of eleven acoustic neuro-mas were analyzed.

MRI's were able to clearly visualize residual tumor around the 7th and 8th cranial nerves that were left to preserve cranial nerve function, although conventional X ray CT scans often failed to detect it due to artifacts in the parapetrous area. The facial nerves preserved during operations were also visualized from their brain-stem portion to the internal auditory meatus. These findings indicate that MRI is excellent in delineating soft tissue in the CP angle that would be overlooked by conventional X ray CT scan.