耳鼻咽喉科・頭頸部外科82巻11号

2010年10月発行

Current Article

内耳の炎症とMRI評価

著者： 曾根三千彦¹

所属機関： ¹名古屋大学大学院医学系研究科頭頸部・感覚器外科学耳鼻咽喉科

ページ範囲：P.741 - P.748

文献概要

Ⅰ　はじめに

　MRIを中心とした最近の画像検査の進歩により，今まで評価の困難であった内耳障害の病態把握が可能になってきた。以前は急性感音難聴症例に対する聴神経腫瘍の鑑別が主目的であったが，聴力像や眼振所見に一致してMRI上確認される迷路炎の報告^1）は画期的であった。急性感音難聴を主訴に当院を受診した366例についてMRI検査を施行した結果，内耳奇形や聴神経腫瘍以外に迷路炎5例や内耳出血4例が確認されている^2）。周囲からの炎症波及も含めて，内耳の炎症はさまざまな要因により生じる。中耳の炎症は主に正円窓経由で，頭蓋内の炎症は内耳道と蝸牛小管経由にて内耳へ傷害を及ぼし急性感音難聴や前庭症状を呈することが知られている。最近では臨床症状のみでは評価困難な迷路炎の病態をMRI所見から把握することが可能になり，その障害程度は治療方針の選択指針ともなりえる。本稿では内耳の炎症とMRI評価について，3T MRIによる3D fluid-attenuated inversion recovery（FLAIR）画像を主とした自験例を踏まえつつ解説したい。

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