内听道狭窄合并耳蜗神经管狭窄的影像学表现

目的 研究内听道(IAC)狭窄合并耳蜗神经管(CNC)狭窄的影像学特点.资料与方法 回顾性分析23例内听道狭窄(30个内听道)合并耳蜗神经管狭窄的高分辨CT及其中5例MRI表现,并通过CT测量相应耳蜗神经管与内听道宽度,同时与颞骨CT显示中耳炎对照组(30例60个内听道)的相应测量值进行比较.结果 CT显示病变组耳蜗神经管和内听道均有不同程度狭窄,平均耳蜗神经管宽度为(0.72±0.38) mm,平均内听道宽度为(231±0.46) mm,两者呈正相关(.=0.552,P＜0.01),即二者宽度具有一致性.中耳炎对照组平均耳蜗神经管宽度为(2.02±0.20) mm,平均轴位内听道宽度为(4.62±0.63) mm.病变组与中耳炎对照组内听道宽度与耳蜗神经管宽度比较,差异均有统计学意义(t=-17.898,P＜0.01;t=-21.351,P＜0.01).内听道薄层MRI可以显示耳蜗神经管狭窄及耳蜗神经发育不良征象.结论 内听道狭窄常合并耳蜗神经管狭窄,后者会引起耳蜗神经发育异常,进而导致感音神经性耳聋.

Imaging Features of Inner Acoustic Canal Stenosis Combined with Cochlear Nerve Canal Stenosis

Purpose To describe the imaging features of inner acoustic canal (IAC) stenosis combined with cochlear nerve canal (CNC) stenosis.Materials and MethodsHigh-resolution CT images of 23 patients (30 IAC) with IAC stenosis were retrospectively analyzed. The width of CNC and IAC was measured and compared with control group (30 patients with otitis media). Five patients undertook MRI examination simultaneously.Results CT displayed variable stenosis of CNCs and IACs in the study group. The mean width of CNC was (0.72±0.38) mm, and that of IAC was (2.31±0.46) mm. It showed significant correlation between two groups (r = 0.552, P <0.01). The mean width of CNC in the control grouop was (2.02±0.20)mm, and that of IAC was (4.62±0.63) mm. The width of the CNC and IAC was significantly smaller in study group than in control group (t=-17.898, P < 0.01; t =-21.351, P < 0.01). Thin-sliced MRI displayed stenosis of CNC and dysplasia of cochlear nerve. Conclusion The IAC stenosis often combines with CNC stenosis, which may caused dysplasia of cochlear nerve and corresponding sorineural hearing loss.