眶部丛状神经纤维瘤的MRI表现

目的探讨眶部丛状神经纤维瘤(PNF)的MRI特点。方法回顾性分析79例85侧眶部PNF的MRI表现。79例均接受眼眶MR检查,其中71例接受增强MR扫描。结果眶部PNF均表现为侵袭性生长,增强后不均匀强化。位于眼睑及眶周表浅部位的病变呈弥漫性生长并穿透筋膜和肌层,与肌肉相比,76侧T1WI呈等信号,T2WI呈不均匀略高信号,9侧病变T1WI呈低信号,T2WI呈高信号;3侧可见靶征。眶腔和(或)颞下窝等深层部位病变呈多发边界清楚的小结节或束状病变,主要沿神经干生长并压迫周围结构,77侧T1WI呈等或略低信号,T2WI呈不均匀略高信号,7侧病变T1WI呈低信号,T2WI呈高信号;34侧可见靶征。结论眶部PNF多呈侵袭性生长,MRI可清晰显示PNF累及范围,眼眶表浅部及深部病变有着不同的形态及信号特点。

MRI findings of the orbital plexiform neurofibroma

Objective To analyze MRI features of patients with orbital PNF. Methods MR images of 85 orbital PNF in 79 patients were analyzed retrospectively. All 79 patients underwent plain MR scanning, among whom 71 patients underwent contrast enhanced MR examination. Results The orbital tumors of 79 patients were invasive, which enhanced heterogeneously. Superficial PNF located subcutaneously, penetrating into fascial membrane and muscle of the orbit. Seventy-six orbits were isointense to mild hypointense in relation to muscle on T1WI and mild heterogeneous hyperintense on T2WI, 9 were hypointense on T1WI and hyperintense on T2WI, 3 had target sign. Deep PNF located in the orbital cavity and/or infrotemporal fossa, characterized by multinodular smoothly defined borders compressing adjacent structures, primarily along the course of major nerves. Seventy-seven orbits were isointense on T1WI and mildly heterogeneous hyperintense on T2WI, 7 were hypointense on T1WI and hyperintense on T2WI, 34 had target sign. Conclusion The orbital PNF exhibit features of invasive growth. MRI is useful to evaluate the distribution of orbital PNF. There are significant differences in morphology and signal intensity between the superficial and the deep portion PNF.