颞骨内面神经病变的影像学表现

目的总结分析面神经病变的影像学检查方法和表现，提高诊断准确性。资料与方法回顾性分析31例经手术病理或临床跟踪随访证实的面神经病变的CT和MRI表现，31例行MR扫描，其中28例行平扫和增强扫描，3例仅行平扫；19例行CT扫描。结果（1）面神经损伤13例，8例行CT扫描，6例显示面神经管骨折，2例表现正常；13例MRI扫描均表现为面神经增粗，其中10例增强扫描显示面神经明显强化。（2）面神经炎14例，7例行CT扫描，1例因岩尖胆脂瘤致面神经管迷路段、前膝部、鼓室段前部骨质破坏，6例面神经管未见异常；14例MRI增强扫描显示面神经节段性异常强化。（3）面神经鞘瘤4例，CT表现为受累面神经管骨质破坏和软组织肿块；MRI表现为面神经节段性增粗，呈长T1、长T2信号，信号不均匀，增强后不均匀强化。经统计学处理，MRI显示颞骨内面神经病变明显优于CT（P＜0．01）。结论HRCT可显示面神经管的异常，MRI尤其是MR增强扫描可显示面神经病变的形态、部位、范围及强化表现，有助于病变的诊断和鉴别诊断。

Imaging Findings of Facial Nerve Diseases within the Temporal Bone

Objective To analyze imaging methods and imaging findings of facial nerve diseases so as to improve the diagnostic accuracy of facial nerve diseases.Materials and Methods CT and MRI findings of 31 patients with facial nerve diseases proved by surgery and pathology or follow up findings were analyzed retrospectively.MRI was performed in all 31 patients and high resolution CT(HRCT)was performed in 19 patients.Results Injury of the facial nerve was found in 13 cases,which displayed enlargement of the facial nerve on MR imaging and enhancement of the facial nerve in 10 cases after contrast administration.However,of 13 cases,HRCT performed in 8 cases showed fractures of the facial canal in 6 and no abnormality in 2.Facial neuritis was observed in 14 cases showing abnormally focal enhancement of the facial nerve on post contrast T1-weighted image,of which bony destruction of labyrinthine segment,anterior genu and anterior tympanic segment resulting from cholesteatoma of the petrous apex was found in only 1 case on CT.4 patients with schwannomas of the facial nerve manifested as bony destruction of the facial canal and soft tissue mass on CT,and enlargement of the facial nerve and enhancement after contrast administration on MR imaging.MR imaging was superior to HRCT in demonstrating facial nerve diseases.Conclusion HRCT could show bony changes of the facial canal,and MR imaging,especially post-contrast T1WI,could accurately display shape,location,extension of facial nerve diseases,which could contribute to diagnosis and differential diagnosis of facial nerve diseases.