HRCT和增强MRI诊断面神经损伤

HRCT and contrast-enhanced MRI in diagnosis of facial nerve injuries

目的探讨HRCT、增强MR扫描诊断面神经损伤的价值。方法对18例面神经损伤患者行HRCT及增强MR扫描。在Philips EBW工作站行面神经管、面神经CPR,观察颞骨骨折部位、类型、面神经管、面神经受累及走行。采用GE AW 4.5工作站,与健侧相比,观察患侧面神经受累位置、粗细及信号变化。结果 18例中,纵行骨折8例、横行骨折5例、混合型骨折5例。HRCT轴位及CPR显示颞骨骨折18例,其中面神经骨管迷路段受累1例,膝状神经窝受累2例,鼓室段受累4例,膝状神经窝、鼓室段同时受累并发中耳腔积血2例,面神经管鼓室段与中耳腔积血关系密切3例,面神经管骨壁无明显骨折6例。增强MRI及CPR显示面神经损伤18例,其中内听道段受累12例,迷路段受累14例,膝状神经节受累18例,鼓室段受累16例,乳突段受累15例。患侧面神经内听道段、迷路段、膝状神经节、鼓室段、乳突段信号强度比值均高于健侧(P均<0.001)。结论 HRCT、增强MRI可评价不同节段面神经损伤,CPR可直观显示颞骨内面神经及骨管损伤。

Objective To explore the value of HRCT and contrast-enhanced MRI in diagosis of facial nerve injuries. Methods HRCT and contrast-enhanced MRI were performed in 18 cases of facial nerve injuries. CPR of the facial nerve and canal was performed on the Philips EBW workstation, and the temporal bone involved location, fracture type and involvement of facial nerve and canal and its course were observed. The involved location, size, signal variation of facial nerve were analyzed compared with contralateral side on the GE AW 4.5 workstation. Results Among 18 cases, 8 cases of longitudinal fractures, 5 cases of transverse fractures and 5 cases of mixed fractures were found. HRCT axial scan and CPR of facial canal revealed that 18 cases had temporal bone fractures, including 1 case of labyrinthine segment, 2 cases of geniculate fossa, 4 cases of tympanic segment, 2 cases of geniculate fossa, tympanic segment and hematoma of middle ear cavity, 3 cases of tympanic segment with adjacent hematoma of middle ear cavity and 6 cases without obvious fracture of facial canal. Contrast-enhanced MRI and CPR of facial nerve revealed facial nerve injuries in all 18 cases, including 12 cases of internal auditory meatus segment, 14 cases of labyrinthine segment, 18 cases of geniculate ganglion, 16 cases of tympanic segment and 15 cases of mastoid segment. Signal intensity ratio of affected internal auditory meatus segment, labyrinthine segment, geniculate ganglion, tympanic segment and mastoid segment were higher than those of contralateral side （all P〈0.001）. Conclusion HRCT and contrast-enhanced MRI can clearly reveal the involvement of different segment of traumatic facial nerve, HRCT CPR and MR CPR are helpful to visualiz the involvement of traumatic facial nerve and canal.