迷路炎的影像学

Radiological examinations and diagnosis of labyrinthitis

目的探讨迷路炎的影像学检查方法及其诊断价值。方法观察27例31耳临床提示为迷路炎同时存在异常影像学表现的病例的高分辨率CT(high resolution CT,HRCT)及MRI图像,总结其内耳在HRCT及MRI图像上的不同改变。结果进行了HRCT扫描的22耳中,内耳1个或多个结构表现为密度增高者6耳,密度增高且发生变形者8耳,单纯变形者1耳,内耳迷路内腔局部或完全硬化消失者7耳。在22耳中除上述改变外亦有内耳骨质缺损者4耳。进行了HRCT及MRI检查的9耳中,7耳在HRCT上可见内耳不同程度的异常改变,2耳内耳未见异常改变。MRI图像上9耳均可见内耳迷路内腔1个或多个结构T2WI信号减低或消失。行增强扫描的6耳中,4耳可见明显强化,2耳未见强化。31耳中,耳蜗受累30耳,其中仅基底周受累5耳,中顶周受累2耳,耳蜗各周均受累23耳;半规管受累26耳;前庭受累20耳;前庭窗受累18耳;蜗窗受累19耳。结论HRCT可以较好显示骨迷路迷路炎的异常改变,MRI对于显示迷路内腔有重要价值,二者在迷路炎的影像检查与诊断中的作用是互补的,对迷路炎的临床诊断起着重要的辅助作用。

OBJECTIVE To investigate the radiological findings of labyrinthitis and evaluate the diagnosis value of HRCT and MRI. METHODS The HRCT and MR images of 27 cases （ 31 ears） with labyrinthitis, suggested by clinical examinations and abnormal changes on images coexisting, were studied. RESULTS In the 22 ears which underwent HRCT examinations, 6 ears showed increase of the density of one or more structures of inner ear, 8 ears showed increase of the density of structure as well as change of the shape of the inner ear, 1 ear showed change of the shape only. Labyrinth inner cavity appeared local or total sclerosis and disappearance in 7 ears. Among the 22 ears, there was bony incompleteness in 4 besides the changes mentioned above. In the 9 ears which accepted HRCT and MR scanning, 7 ears showed abnormal changes of different degree in the inner ear on HRCT images and the other 2 appeared normal. On MR images, all 9 ears showed decrease or disappearance of the signal of T2Wl in one or more structures of membranous labyrinth. Among the 6 ears which performed contrast scanning, markedly enhancement was seen in 4 and no enhancement in 2 ears. Of all the 31 ears, cochlea was involved in 30, of which only basal turn involved in 5, upper and second turns in 2 and all turns in 23, semicircular canal involved in 26, vestibule in 20, oval window in 18 and round window in 19. CONCLUSION HRCT can demonstrate the abnormal changes of bony labyrinth, and MRI is helpful to detect the changes of labyrinth inner cavity. They have important value in the detection and diagnosis of labyrinthitis.