外中耳先天畸形的HRCT研究

目的 研究外中耳先天畸形的高分辨CT（HRCT）表现，为临床诊断和治疗提供准确信息。资料与方法 对临床诊断的外、中耳先天畸形35例行HRCT扫描，单纯横断位扫描5例，横断位加冠状位扫描30例。结果 （1）外耳畸形32例共42耳，其中外耳道骨性闭锁30耳，显示闭锁板为完全性26耳，不完全性4耳。膜性闭锁5耳。双侧分别为不同类型闭锁1例。外耳道狭窄7耳，其中狭窄合并对侧闭锁1例。合并畸形中，面神经管垂直段明显前移22耳，下颌髁状突明显后上移25耳，乙状窦前移4耳，均见于骨性外耳道闭锁。伴发的中耳畸形主要为小鼓室及不同程度的听骨发育不全或缺如。合并内耳发育不全1例。（2）单纯性中耳畸形3例共6耳，均表现为听小骨异常。合并小鼓室1例，耳咽管和鼓室窦畸形扩大1例。结论 HRCT能准确显示外中耳先天畸形的类型、程度以及合并畸形，为临床治疗方案的正确制定提供重要的参考依据。

Evaluation of the Congenital Deformities of the External and Middle Ear with High Resolution CT

Objective To discuss HRCT features of the congenital deformities of external and middle ear so as to provide accurate information for the diagnosis and treatment.Materials and Methods 35 cases with congenital deformities of external and middle ear diagnosed clinically were performed with HRCT. Axial scans were performed in 5 cases, axial and coronal scans were taken in 30 cases.Results (1) 42 ears of 32 cases with external ear abnormalities were found, these abnormalities included bony external auditory canal atresia in 30 ears, membranous atresia in 5 ears, and external auditory canal stenosis in 7 ears. 1 case with different atresia patterns respectively at two sides and another case with stenosis associated contralateral atresia were found. Atresia plates, which were complete in 26 ears and incomplete in 4 ears, were demonstrated. In bony atresia, associated deformities which included anterior located descending segment of the facial nerve canal in 22 ears, posterior and superior oriented mandibular condyle in 25 ears and anterior located sigmoid sinus in 4 ears were found. In the patients with external ear deformities, small tympanic cavity and dysplasia or absence of auditory ossicles were manly associated with middle ear abnormalities. 1 case with concomitant inner ear dysplasia was confirmed. (2) 6 ears of 3 cases with isolated middle ear deformities were demonstrated. Auditory ossicles abnormalities presented in all these ears. Small tympanic cavity and enlarged eustachian tube and tympanic sinus were found in 1 case respectively.Conclusion HRCT can demonstrate patterns, severity and associated changes of congenital deformities of external and middle ear accurately, which has already become a indispensable imaging modality for microscopical operation of otology.