蜗神经发育异常影像学诊断

目的:探讨蜗神经发育异常的影像学表现。方法:回顾性分析17例影像诊断为蜗神经发育异常患者的CT及MRI表现,总结相关征象。17例患者均行MRI检查,常规行横轴面和冠状面SE T_1 WI,FSE T_2 WI,并采用三维快速平衡稳态(3D FIESTA)序列进行内耳成像;CT检查采用横轴面HRCT扫描。结果:MRI检查显示17例33耳蜗神经发育异常中,25耳蜗神经未显示,8耳显示细小。蜗神经未显示的25耳中,进行了HRCT检查的19耳均显示蜗神经孔异常改变.其中伴有内耳道狭窄18耳,骨迷路畸形15耳,前庭神经异常10耳,面神经细小2耳。蜗神经显示细小的8耳中,4耳伴有蜗神经孔异常改变,4耳内耳道呈壶腹状或喇叭状,5耳伴有内耳Mondini畸形。结论:HRCT显示蜗神经孔区异常改变可初步提示蜗神经发育异常。HRCT及MRI联合使用可较准确的显示蜗神经发育异常,对于临床人工耳蜗术前评价具有重要的指导意义。

Imaging Diagnosis of Cochlear Nerve Dysplasia

Objective:To analyze the imaging features of cochlear nerve dysplasia.Methods:The images of 17 cases with cochlear nerve dysplasia diagnosed by CT and MRI were retrospectively reviewed.All of the 17 patients had axial and coronal SE T_1 WI,FSE T_2 WI,3-Dimension FIESTA sequences for internal ear MR imaging.Axial plane high resolution CT (HRCT)was performed.Results:Of the 17 cases,there were 33 ears with cochlear nerve dysplasia,cochlear nerve was not assessed in 25 cases,and tiny cochlear nerve in 8 cases.In the 25 ears with cochlear nerve not assessed,all of the 19 ears which had HRCT showed abnormality of cochlear nerve forarnen,including internal auditory canal stenosis in 18 ears,bony labyrinth anomaly in 15 ears.vestibular nerve dysplasia in 10 ears and tiny facial nerve in 2 ears.Of the 8 ears with tiny co chlear nerves,cochlear nerve foramen abnormality was found in 4 ears,ampulla-like or trumpet-like internal auditory canal in 4 ears and associated with Mondini anomaly of inner ear in 5 ears.Conclusion:When abnormal change of cochlear foramen was showed by HRCT,cnchlear nerve dysplasia should he preliminary considered.Cochlear nerve dysplasia could he accu rately demonstrated by MRI in combination with HRCT which provided important value in the treatment planning for artifi- cial cochlear implantation.