不完全分割型III型内耳奇形の新たな画像所見と文献レビュー

New Imaging Findings of Incomplete Partition Type III Inner Ear Malformation and Literature Review.

• R Hong
• Q Du
• Y Pan

抄録

不完全分割型III型は、Xリンク型難聴とも呼ばれ、まれな遺伝性内耳奇形である。内耳道の球根状拡張やスカル間隔隔を有するモジュラスの欠如などの特徴的なCT所見はよく知られている。本シリーズでは、19例の前庭管と半円管の異常を報告し、そのCT所見とMR画像所見を網羅的に解説する。不完全分割III型の内耳奇形は両側性で基本的に左右対称であり、内耳管、眼底神経管、蝸牛、前庭、半円管、前庭水管、眼球カプセル、丸窓、楕円窓、スタペスに関与していた。嚢胞性の外観を有する不規則な前庭も特徴的な画像所見であり、我々の患者の約90％に見られ、半円管の嚢胞性の外観は半数近くの症例に見られた。

Incomplete partition type III, also referred to as X-linked deafness, is a rare genetic inner ear malformation. Its characteristic CT findings, including bulbous dilation of the internal auditory canal and absence of the modiolus with the interscalar septa present, have been well-recognized. In this series of 19 cases, we report the abnormalities of the vestibule and semicircular canals and provide a comprehensive description of their CT and MR imaging findings. The inner ear malformations in incomplete partition type III were bilateral and basically symmetric, with involvement of the internal auditory canal, nerve canals in the fundus, cochlea, vestibule, semicircular canals, vestibular aqueduct, otic capsule, round window, oval window, and stapes. An irregular vestibule with a cystic appearance is also a distinctive imaging feature, which could be seen in about 90% of our patients, with a cystic appearance of the semicircular canals present in nearly half of the cases.

© 2020 by American Journal of Neuroradiology.