先天性外耳道闭锁的CT分析

目的分析先天性外耳道闭锁及合并中耳畸形的ＣＴ征象。方法先天性外耳道闭锁病人１９例（２１只耳），男１６ 例，女 ３例，平均年龄 １４岁。选用显示骨算法重建行 ＣＴ扫描，层厚１～２ ｍｍ，横断面为常规切层方向。 ５例病人加做 冠状面扫描。结果①外耳道闭锁：骨性闭锁１９耳（９０．５％），膜性闭锁２耳（９．５％）。②中环发育畸形：中耳鼓室腔狭 小１２耳（５７．１％），听小骨畸形１２耳（５７．１％）。③乳突气化不良者１０耳（４７．６％），气化良好者１１耳（５２．４％）。④本组 病例内耳结构未见明显异常。⑤鼓骨畸形１３例（６１．９％），面神经管垂直段前移１０耳（４７．６％）。结论高分辨率ＣＴ横 断面及冠状面扫描可获得外耳、中耳及内耳的三维影像资料，明确外环道闭锁的程度及类型、鼓室及听小骨畸形的 情况、乳突气化及面神经管垂直段的位置以及内耳细微结构有无畸形等，有助于手术方式的选择，提高外耳边畸形 手术的成功率。

CT analysis of congenital atresia of the external auditory meatus

Objective To study the CT features of congenital atresia in the external auditory meatus. Methods Highresolution CT(HRCT) examination was performed in 19 cases (21 ears) of congenital atresia in the external auditory meatus diagnosed clinically or surgically. All the cases were diagnosed to be conduction deafness by pure tone hearing test. Results Bony atresia was found in 20 ears, membranous atresia in 1 ear, stenosis of the tympnum in 12 and malformations of the ossicles in 12 ears. Ten ears were found with anterior position of facial canal, 11 with well developed mastoid, and 10 with underdeveloped mastoid. Conclusion CT could definitely demonstrate congenital atresia in the external auditory meatus as well as malformation of the media and internal ear structure, which provide important information for surgery.