软组织良性神经鞘肿瘤的磁共振成像表现

摘要

Objective To analyze and summarize the MRI manifestations of benign nerve sheath tumors ( NSTs) in soft tissue,and to improve MRI diagnostic accuracy before operation. Method MRI manifestations of 42 benign NSTs in soft tissue proved by histological results were retrospectively reviewed. They included 27 schwannomas,15 neurofibromas. Result There are significant difference between schwannoma and neurofibroma in the size(5cm) of tumors, margin, shape,capsule,split fat sign,the relationship to peripheral nerves. The split fat sign was found in 30 of 42 tumors,and the target sign was pointed out in 23 of 42 tumors,and the sign of contiguity with peripheral nerves presented in 17 of 42 tumors, and 5 of 52 tumors showed fascicular sign. The presence of two or more of the four features suggestion to schwannoma with sensitivity of 82% and specificity of 73. 0%. Conclusion The tumors of size(5cm),shape, capsule,split fat sign and the relationship to peripheral nerves contributed to differential diagno-sis between schwannoma and neurofibroma. Split fat sign,target sign, sign of contiguity with peripheral nerves and fascicular sign were characteristic signs of NSTs in soft tissue, The presence of two or more of the four features sug-gested schwannoma.%目的：分析和总结软组织良性神经鞘肿瘤( nerve sheath tumors,NSTs)的磁共振成像( nucler mag-netic resonance imaging,MRI)表现,提高该病术前MRI诊断的准确性。方法回顾性分析42例经手术病理证实的软组织良性NSTs的MRI表现,其中神经鞘瘤27例和神经纤维瘤15例。结果神经鞘瘤和神经纤维瘤在肿瘤大小5cm分界、边界、形态、包膜、脂肪分离征、肿块与神经关系的差异有显著性(P<0.05)。42例病例中,出现脂肪分离征30例,靶征23例,与神经相连征象17例,束状征5例。具有2种或以上上述征象诊断神经鞘瘤的灵敏度和特异度分别为82%和73%。结论肿瘤大小5cm分界,形态、包膜、脂肪分离征及与神经相连的MRI征象有助于软组织神经鞘瘤和神经纤维瘤的鉴别；脂肪分离征、靶征、与神经相连征象、束状征是软组织NSTs的特征性MRI征象,具有2种或以上上述征象提示神经鞘瘤的诊断。