臂丛区神经源性肿瘤的影像学诊断

Imaging diagnosis of neurogenic tumors of the brachial plexus

目的：分析臂丛区神经源性肿瘤的影像学表现，探讨臂丛区影像检查方法。材料和方法：报告６例臂丛区神经源性肿瘤，其中神经鞘瘤４例，神经纤维瘤２例，均经手术及病理证实。结果：Ｘ线平片可见肺尖区肿块３例，椎间孔扩大１例。ＣＴ检查：示肿块平均直径约４ｃｍ，呈梭形４例，呈哑铃形２例；平扫密度与肌肉ＣＴ值相近，增强扫描肿块密度高于肌肉、低于血管。ＭＲＩ检查：示Ｔ１加权像上肿瘤信号与肌肉相近３例，略低于肌肉信号２例；Ｔ２加权像均为高信号，其中３例信号接近脑脊液（均为神经鞘瘤）。１例行增强扫描，病变呈中等度强化。结论：根据病变的分布及上述影像学表现，臂丛神经源性肿瘤可于手术前做出诊断；

Purpose: To analyse the imaging characteristics of neurogenic tumors in the brachial plexus. Materials and methods: Six cases of neurogenic tumors of the brachial plexus were reported pathologically proved as schwannoma in 4 and neurofibroma in 2 cases. Results: The plain films demonstrated the mass at the apex of lung in 3 cases, enlargement of cervical intervertebral foramen in 1. CT scan revealed that the average diameter of the masses was 4cm, with spindle shape in 4, dumb bell shape in 2 cases. The averaged CT value was similar to that of muscle on plain scan. The density of the tumor was higher than that of muscle and lower than that of the vessels after contrast enhancement. On MRI T 1W image, the signal intensity of the tumor was similar to that of muscle in 3 cases and slightly lower in 2; On T 2W, the masses were all hyperintense. Three schwannomas presented high signal intensity similar to CSF. The lesion demonstrated moderate enhancement after contrast administration in 1 case. Conclusion: Based on the location of the mass and its imaging features, diagnosis of neurogenic tumor of the brachial plexus could possibly be established before ope ration. MRI imaging is the imaging modality of choice in displaying the anatomy and the lesion of brachial plexus.