儿童先天性感音神经性聋的影像学评估

Evaluation of Imaging in Children with Congenital Sensorineural Hearing Loss

目的:研究先天性感音神经性聋(SNHL)患儿的颞骨影像,分析内耳畸形的发生率及其类型,了解内耳畸形与耳蜗神经发育的关系,探讨部分患者是否仅行CT检查即可而无需进行MRI检查。方法:回顾性分析101例临床拟诊先天性SNHL的儿童颞骨CT和MRI影像资料,观察其内耳、蜗神经的结构。101例中,95例为重度或极重度双侧性SNHL,6例为单侧性SNHL。结果:196例患耳中,内耳畸形66耳:耳蜗不发育3耳;耳蜗发育不良5耳;不完全分隔I型7耳,不完全分隔II型10耳;前庭导水管扩大24耳;蜗神经不发育或发育不良19耳。10耳内听道狭窄均伴有蜗神经畸形。单侧性聋的6例患者中,均有蜗神经畸形。130例CT示内耳正常者,MRI也示蜗神经正常。结论:影像学诊断先天性重度或极重度双侧性SNHL内耳畸形发生率(31.6%)较单侧性SNHL者(100%)低,较为常见的畸形是前庭导水管扩大和耳蜗畸形,内耳畸形严重程度与蜗神经发育异常的发生率有一定相关性;对于双侧性耳聋者,CT诊断有严重内耳畸形者必须行MRI扫描,以排除蜗神经发育畸形;CT示耳蜗结构正常且内听道无狭窄者可无需行MRI扫描;单侧性耳聋者必须同时行CT和MRI扫描。

Objective：To investigate CT and MRI findings of temporal bone and analyze the prevalence and classifica- tion of inner ear abnormalities in children with congenital sensorineural hearing loss （SNHL）. To find out the relationship between inner ear abnormality and cochlear nerve, and discuss whether a portion of patients can be examined only with CT. Methods： 101 children with SNHL were examined with HRCT and MR scan, 95 of them had bilateral severe or profound bearing loss,6 had unilateral hearing loss. Results： Of the 196 ears,abnormalites of the inner ear were found in 66 ears. 3 were found to be cochlear aplasia; 3 cochlear dysplasia; 7 IP-I malformation ; 10 IP-II malformation; 28 large vestibular aque- duct;19 cochlear nerve aplasia or dysplasia; 10 internal auditory canal narrowing all accompanied with cochlear nerve dyspla- sia. All of the 6 children having ears with unilateral SNHL had cochlear nerve aplasia or dysplasia. 130 had normal inner ear both on HRCT and MR. Conclusion：Children having ears with bilateral severe or pro^ound SNHL had less inner ear abnor- malities than children with unilateral SNHL （31. 6% vs 100%）. The most common abnormalities were abnormal cochlea and large vestibular aqueduct. The abnormalities of inner ear have a definite relation to the malformation of cochlear nerve. Children with severe abnormalities of inner ear on HRCT must he examined with MR to exclude malformations of cochlear nerve. Children with normal cochlear on CT having no IAC stenosis can dispense with MR scan. Children having unilateral SNHL must be examined with both HRCT and MR scan.