颞下窝原发肿瘤的CT及MR表现

目的：探讨颞下窝原发肿瘤CT及MRI表现。方法回顾性分析20例经病理证实的颞下窝原发肿瘤的CT及MR资料。结果颞下窝肿瘤形态多不规则。神经鞘瘤多边界清楚（5/6），MR T1WI为等信号，T2WI为高信号肿物伴线状分隔样低信号，2例通过卵圆孔伸入中颅窝呈哑铃状生长。恶性外周神经鞘膜肿瘤边界多不清楚（4/5），MR T1WI为等信号，T2WI为不均匀高信号，病变可侵犯邻近肌肉及骨质。横纹肌肉瘤MR T1WI为等信号，T2WI为高信号。孤立性纤维性肿瘤边界清楚，MR T1 WI等信号，T2 WI为混杂略高信号，增强后较明显强化。腺样囊性癌边界不清，沿神经浸润生长。侵袭性多形性腺瘤MR T1 WI为等、低信号，T2 WI为高信号，侵犯邻近肌肉。淋巴瘤形态不规则，边界清楚，MR T1WI为低信号，T2WI为中高信号，轻度强化，内有线样血管影穿行。结论熟悉颞下窝原发肿瘤CT及MRI表现，有助于提高该部位病变诊断及鉴别诊断水平。

Computed tomography and magnetic resonance imaging appearance of tumor originating from the infratemporal fossa

Objective To analyze the computed tomography （CT） and magnetic resonance imaging （MRI） appearance of tumor originating from the infratemporal fossa （ITF） .Methods 20 patients with tumor originating in the ITF confirmed by histopathological examination ,CT and MR appearance were analyzed retrospectively .Results All the tumors originating from the ITF showed irregular shape .5 neurilemmomas had well-defined border （5/6） .On MR imaging ,the tumors were isointense compared to muscle on T1WI while hyperintense with hypointense septum on T2WI .2 tumors extentded to middle cranial fossa through foramen ovale and showed dumbbell-shaped .4 malignant peripheral nerve sheath tumors had ill-defined border（4/5） .The tumors were isointense on T1 WI while hyperintense on T2 WI .The tumors invaded adjacent muscle and bone .Rhabdomyosarcoma showed isointense on T1WI while hyperintense on T2WI .Solitary fibrous tumor was isointense on T1 WI while slight hyperintense on T2 WI and showed marked enhancement .Adenoid cystic carcinoma grow along the nerve with infiltration .Aggressive pleomorphic adenoma showed iso-or hypointense on T1 WI while heterogeneous hyperintense on T2WI ,invaded the adjacent muscles .Lymphoma had irregular shape and well-defined border .On MR imaging ,the tumor showed hypointense on T1WI while mild hyperintense on T2WI and slight enhancement .The enhanced vessel could be seen in the tumor .Conclusion The tumors originating from the ITF had their own characteristics .To know well about the characteristics can contribute the diagnosis and differential diagnosis of the lesions originating from the ITF .