鞍旁肿瘤及肿瘤样病变的MRI表现

MRI findings of parasellar tumors and tumor-like lesions

目的探讨鞍旁肿瘤及肿瘤样病变的MRI表现,以提高认识及诊断正确性。方法搜集41例病理证实鞍旁病变的术前MRI并对其进行回顾性分析,分析内容包括病变部位、形态、最大径、信号特点及增强表现等。结果 41例鞍旁病变中,脑膜瘤24例,信号均匀(22/24)或不均匀(2/24),增强扫描常可见脑膜尾征(18/24),6例包绕颈内动脉,11例侵入鞍内生长;神经鞘瘤5例,其中三叉神经鞘瘤2例,肿瘤内囊变多见(2/5);海绵状血管瘤4例,增强后均呈不均匀渐进性强化(4/4);表皮样囊肿3例,DWI序列上均呈高信号,而增强后无强化;颗粒细胞瘤1例,信号不均匀,内见多发小囊变,并见液平影;淋巴瘤1例,信号均匀,增强后亦呈均匀强化;黑色素瘤1例,T1WI高信号,T2WI呈低信号;脊索瘤1例,鞍旁肿块伴有右侧斜坡骨质信号异常;转移瘤1例,为转移性神经内分泌癌,增强后呈不均匀强化。结论鞍旁肿瘤及肿瘤样病变常有其典型的MRI表现,MRI很大程度上可于术前作出准确诊断。

Objective To investigate the MRI features of parasellar tumors and tumor-like lesions and to improve the accuracy of diagnosis. Methods The MRI images of 41 cases with pathologically proved parasellar masses were collected and analyzed retrospectively, including the location, shape, maximum diameter, signal and enhanced patterns, and so on. Results Among 41 cases with parasellar masses, there were 24 of meningiomas, 5 of schwannomas, 4 of cavernous hemangiomas, 3 of epidermoid cysts, 1 of granulosa cell tumor, 1 of lymphoma, 1 of melanoma, 1 of chordoma and 1 of metastatic tumor. The signal of parasellar meningiomas were homogeneous （22/24） or heterogeneous （2/24） with dural tail sign （18/24） in the enhanced scan. The masses wrapped the internal carotid artery in 6 cases and extended to inner sella in 11 cases. Among schwannomas, trigeminal neurinoma was common and intratumoral cystic change was found frequently（2/5）. All 4 cases of cavernous hemangiomas were performed inhomogeneous progressive enhancement. Epidermoid cysts were demonstrated hyperintensity on DWI and no enhancement. Granulosa cell tumor showed multiple cystic regions with fluid level. Lymphoma had homogeneous signal intensity with evenly enhanced. Melanoma showed hyperintensity on T 1WI and hypointensity on T 2WI. Chordoma displayed parasellar mass with abnormal signal on clivus. Metastatic tumor showed parasellar mass with uneven enhancement. Conclusion Parasellar tumors and tumor-like lesions usually have typical MRI findings, which can be helpful in the diagnosis preoperatively.