多层螺旋CT容积扫描在先天性外中耳畸形面神经管影像测量中的对照研究

Evaluation of facial nerve canal in congenital abnormalities of external and middle ear based on volume scanning of multi-slice CT

目的 探讨MSCT容积扫描在评估先天性外中耳畸形面神经管各段影像中的临床价值。方法回顾性分析2008年7月—2014年10月东南大学医学院附属南京同仁医院收治的先天性外中耳畸形患者（病变组）和无颞骨病变患者（对照组）MSCT资料各18例（26耳），两组均常规采用多平面重建（MPR）和面神经管曲面重建（CPR）。在MPR图像斜矢状面、斜横断面测量面神经管各段长度、宽度、前后膝角度进行测量，并比较两组差异。在MPR和CPR图像上观察面神经管是否遮盖前庭窗。结果病变组面神经管迷路段、鼓室段、乳突段长度分别为（3．38±0．44）mm、（10．07±1．23）mm、（9．25±2．44）mm，第1膝及第Ⅱ膝角度分别为65．10。±9．14°、103．52°±8．79°。对照组面神经管迷路段、鼓室段、乳突段长度分别为（3．72±0．30）mm、（11．4±0．55）mm、（9．92±1．67）mm，第1膝及第Ⅱ膝角度分别为65．62°±6．30°、112．10°±5．84°。病变组面神经管迷路段长度、鼓室段长度、第Ⅱ膝角度与对照组比较，差异均有统计学意义（P值均〈0．01）；面神经管乳突段长度、第1膝角度测量两组之间比较，差异均无统计学意义（P值均〉0．05）。MPR与CPR显示面神经管遮窗的发生率均为46．15％（12／26），差异无统计学意义（X2=0．000，P〉0．05）。结论MSCT及后处理技术能够准确测量先天性外中耳畸形患者面神经管各段长度及角度，并对面神经管病变进行准确评估，对临床诊疗有重要意义。

Objective To analyze the CT findings of each segment of facial nerve canal in congenital abnormalities of external and middle ear （ CAEM ） and evaluate the clinical value of multi-slice CT （MSCT）. Methods The clinical data of 18 patients（26 eras） with CAEM（lesion group） and 18 patients （26 eras） of temporal bone without abnormality （ control group） wer retrospectivelye analyzed. Both groups received muhiplanar reconstruction （MPR） and curved planar reformation （CPR） in the Affiliated Nanjing Tongren Hospital of Southeast University Medical College from July 2008 to October 2014. The length and included angle of the facial nerve canal structures were measured in MPR images and the appearances of the facial nerve canal in two groups were compared. Fenestra vestibule was observed if it was overspreaded by the facial nerve canal on MPR and CPR imaging. Results The measurements of facial nerve canal in lesion group were as follows ： the length of tympanic segment/labyrinth/mastoid segment were （3.38±0.44） mm, （10.07±1.23） mm,（9.25 ±2.44）mm, the angle of I and ]] were65.10°± 9.14°and 103.52° ± 8.79°, respectively. The measurements of facial nerve canal in matched group were as follows： the length of tympanic segment/labyrinth/ mastoid segment were （3.72±0.30） mm, （11.4±0.55） mm,（9.92±1.67） mm, the angle of Ⅰ and Ⅱ were 65.62°±6.30and 112.10°±5.84°, respectively. There were significant differences in the length of tympanic segment/labyrinth segment and included angle of Ⅱ between the CAEM and normal groups （all P values 〈0.01 ） ; There was no significant difference in the length of mastoid segment and included angle of I between the two groups （ all P values 〉 0.05 ）. The incidence rate of fenestra vestibule overspreaded by the facial nerve canal on MPR and CPR images was 46.15% （12/26）. There was no significant difference between the two groups. Conclusions The anatomical structure of facial nerve canal in CAEM patients can be demonstrated by MSCT and reconstruction technique, which provides the accurate information to the clinical diagnosis and treatment.