内耳畸形的CT及MRI表现及其临床意义

CT and MRI manifestations and clinical significance of the inner ear malformation

目的探讨内耳畸形的影像学表现及其在临床方面的应用。方法对2007年1月至2008年2月耳鼻喉科听力学检查后确诊为SNHL的47例患者进行CT和MRI扫描,并对其伴发的内耳畸形影像学表现进行回顾性分析。结果 MRI显示蜗神经发育不良32例(42耳),其中17耳伴不同程度的蜗神经信号缺如和内听道狭窄,25耳蜗神经缺如或变细但内听道宽度正常;CT显示内耳道狭窄17耳,蜗神经孔狭窄22耳,骨性封闭11耳。MRI诊断蜗神经发育不良明显优于CT。CT和MRI在诊断内耳其它结构发育不良方面诊断率一致,其中耳蜗畸形46耳,其中有3耳伴中耳畸形,2耳Michel畸形,共腔畸形2耳,Mondini畸形25耳;前庭畸形56耳;半规管畸形60耳;前庭导水管扩大4耳。结论虽然CT和MRI检查都能诊断先天性SNHL的患者是否伴有内耳畸形,但MRI能够判断内耳膜迷路及听神经发育的异常程度,已成为电子人工耳蜗植入术的术前必要检查。

Objective To investigate the CT and MRI manifestations and clinical significance of the in- ner ear malformation. Methods CT and MRI examinations were performed on 47 patients diagnosed with SNHL by audiological test from January, 2007 to Feburary, 2008 followed by a retrospective analysis on the imaging manifestations of inner ear malformations. Results Forty - two ears with abnormal vestibular nerve were detected by MRI, in which 17 ears were companied with absence of cochlear nerves and nar- row inner ear auditory and 25 ears with absence or thinness of cochlear nerves and normal inner ear au- ditory. Seventeen ears with stenotic internal auditory canal, 22 ears with stenotic cochlear nerve forami- na and 11 ears with resie cochlear nerve foramina were examined by CT. MRI in the diagnosis of cochle- ar nerve dysplasia was better than CT. Furthermore, CT in the diagnosis of other inner ear malformations was consistent with MRI. Of the other inner ear malformations, 46 ears with cochlear malformation con- taining 3 ears with outer and middle ear formation, 2 ears with Michel deformity, 25 ears with mondini deformity and 2 ears with common cavity deformity; 56 ears with vestibule malformation; 60 ears with semicircular canal deformity; 4 ears with large vestibule aqueduct were found. Conclusion CT and MRI examinations could help diagnose SNHL patients with inner ear malformations and MRI examination can judge the abnormal development of labyrinth and nerves of inner ear and be used as a necessary pre - operative examination for electronic cochlear implantation.