四肢良性神经鞘瘤的MRI诊断

目的探讨四肢良性神经鞘瘤的MRI表现。方法回顾性分析42例经手术病理证实的四肢良性神经鞘瘤的MRI资料，FSE序列T1wI、T2wI及脂肪抑制序列PDWI，其中33例行增强扫描，分析、总结其MRI特征。结果42例均为单发，上肢18例，下肢24例。35例肿瘤信号不均匀，其中，13例肿瘤于T2WI上呈“靶征”改变；16例肿瘸中央呈中等T1、中等T2信号，其内可见多发裘变区，周围呈囊性长T1、长T2信号：6例肿瘤呈中等T1．中等T2实性肿块，伴有多发囊变，周围未见明显的囊性区，增强扫描，肿块实性部分明显强化，其内．囊变、坏死区及周围囊性区未见明显强化。7例肿瘤信号均匀，增强扫描呈明显均匀强化。26例肿瘤两端可见“神经出入征”，9例肿瘤一侧有神经伴行，38例肿瘤周围可见“脂肪包绕征”，33例肿瘤两端可见“脂肪彗星尾征”。结论MRI对四肢艮性神经鞘瘤的诊断具有重要应用价值。

MRI Diagnosis of Benign Neurilemoma of Extremities

Objective To explore the MRI manifestations of benign neurilemoma of extremities. Methods MRI data, FSE T~WI, T2WI and PDWI of 42 cases（33 cases were examined by enhanced scanning） with neurilemoma of extremities which were confirmed by surgery were analysed retrospectively. MRI features were analyzed and summarized. Results All 42 cases were solitary, including 18 cases in upper extremity and 24 cases in lower extremity. MRI showed heterogeneous signal intensity in 35 cases, and 13 cases of them showed ＂＇target sign＂ on T2WI. The centre of tumors of 16 cases showed is~intensity signal oll T~ and T,WI and multiple long Th long T,_ cystic lesions arouud the mass. 6 cases tumors showed isointensity T~ and T2 signal, and cystic lesions were found in the tumor but not around it. Solid mass exhibited intense enhancement, but cystic lesions and necrosis exhibited no enhancement. 7 cases exhibited uniform signal, which showed unilform enhancement. Nerve entering and exiting sign were founded in 26 cases; fat-encircling sign showed in 38 cases; 9 cases showed accompanying nerve in one side; fat comet tail sign showed in 33 cases. Conclusion MR imaging has important application value in the diagnosis of benign neurilemoma of extremities.