目的探讨眼眶肌锥外间隙病变 MR影像特征及鉴别诊断。方法 回顾分析 67例经手术病理证实的眼眶肌锥外病变 MR表现。结果 眼眶肌锥外病灶共76个， 左眼27例、右眼31例、双眼9例，其中 淋巴增生性疾病24例，22例表现为沿眼 眶结构铸型生长T1WI等信号肿块，T2WI 等或稍高信号肿块，2例表现等T1等T2 信号软组织肿块；9例炎性病变表现等T1 等T2、稍高或稍低信号肿块；癌性病变3 例表现为稍长T1稍短T2或稍长T1稍长T2 信号肿块；脉管源性肿瘤5例表现为稍长 T1长T2信号肿块；良性实性及囊实性肿 块16例,大多表现为稍长T1稍短T2或混杂 T2信号肿块，囊性肿块4例表现为长T1长 T2信号，6例表现为短T1长T2信号，而其 中4例皮样囊肿可见特征性抑脂后信号减 低。结论 MR能清晰显示眼眶肌锥外间隙 病变的影像学特征，对于眼眶肌锥外占 位性病变的诊断、鉴别诊断和术前精确 定位具有重要价值。

Objective To explore the MR imaging characteristics and the clinical application value of lesions of orbits tumors in extraconal compartment. Methods Analyzed the MR imaging characteristics of 67 patients with orbits tumors in extraconal compartment retrospectively, all of them were confirmed by surgical pathology. Results Totally find out 78 lesions in orbital extraconal compartment, 27 cases in left eye and 31 cases in right eye, 9 case in bilateral. Lymphoproliferative diseases account for 24 cases, 22 of them growing along with the orbital structure and showed isointensity on T1WI and isointensity or hyperintensity on T2WI, and 2 cases showed isointensity on T1WI and T2WI. A total of 9 cases were inflammatory disease, and showed isointensity on T1WI and hypointensity or hyperintensity on T2WI. Three cases were cancer, and showed slight hypointensity on T1WI,slight hyperintensity on T2WI. Vascular tumor account for 5 cases, which showed hypointensity on T1WI and hyperintensity on T2WI. Benign tumor were 16 cases, which showed hypointensity on T1WI and hyperintensity on T2WI, 4 cases were cystic mass, showed hypointensity on T1WI and hyperintensity on T2WI, 6 cases showed hyperintensity on T1WI and T2WI, however 4 cases dermoid cyst showed characteristic signal decrease after fat suppression on T1WI and T2WI. Conclusion MR imaging can clearly show the characteristic of orbital tumors in extraconal compartment, and it's an important method in the differentiation, diagnosis and preoperative localization for orbital tumors in extraconal compartment.