前庭导水管扩大畸形的CT诊断

CT diagnosis of the large vestibular aqueduct malformation

目的评价横轴位高分辨率CT扫描对前庭导水管扩大畸形的诊断价值。方法分析16例前庭导水管畸形横轴位耳部扫描的高分辨率CT图像并与50例正常人进行对比分析。结果正常人前庭导水管表现为岩骨后缘小而浅的模糊骨切迹或者与后半规管平行的略低小细管状影。前庭导水管扩大大多表现为岩骨后缘深大三角形骨缺损影,少数为深长裂隙影,岩骨后缘骨缺损影边缘均清晰锐利,其内侧缘绝大部分与总脚或前庭直接相通,前庭导水管中段最大前后径大于1.5mm。结论CT轴位扫描对前庭导水管扩大畸形的诊断有重要价值。

Objective To assess the value of axial high resolution computed tomography（HRCT） scans in the diagnosis of the large vestibular aqueduct malformation. Methods Sixteen patients with the large vestibular aqueduct malformation and 50 controls with normal vestibular aqueduct underwent axial HRCT scans and then all CT images were comparatively analyzed. Results Axial CT images showed that the normal vestibular aqueducts in 50 controls were tiny - shoal vague bony impressiones on back edge of petrosal bone or fine - smal tubular shadows with lightly low density and were parallel to posterior semicircular canal, while the large vestibular aqueduct malformations in 16 patients were mostly deep - large triangular bony defect shadows on back edge of petrosal bone and few were deep - long gap shadows, the borders of bony defect shadows on back edge of petrosal bone were clear and sharp and the most of inside borders were directly passaging to vestibulus or commune erura. The maximal anterio - posterior path vestibular mid - segment aqueduct was longer than 1.5 cm. Conclusion Axial HRCT scans play important role in the diagnosis of the large vestibular aqueduct malformation.