颅内表皮样囊肿MRI诊断的序列选择及应用价值

The MR Sequences Selection and Its Diagnostic Value of the Intracranial Epidermoid Cyst

目的探讨MR各种扫描序列对颅内表皮样囊肿的诊断价值。资料与方法49例经手术及病理证实的颅内表皮样囊肿,均行T1WI、T2WI、液体衰减反转恢复序列(FLAIR)、扩散加权成像(DWI)及增强扫描。9例T1WI呈高信号者加扫脂肪抑制像。结果49例肿瘤中不规则形36例,圆形或类椭圆形13例。在T2WI上,38例呈高信号,另11例为高信号中夹杂斑片状等信号;肿瘤在T1WI上信号多变,其中40例为低信号,余9例为高低混杂信号(6例)或高信号(3例),经脂肪抑制后,其中3例部分高信号衰减;FLAIR为中等及低混杂信号;所有患者DWI均为高信号;增强后34例无强化,15例边缘弧线形强化。结论颅内表皮样囊肿在MR各序列上均有特征性表现。DWI扫描有助于鉴别诊断。MRI多方位、多序列扫描的综合应用,能术前准确诊断,使选择最佳手术方式和入路成为可能。

Objective To discuss the MR Sequences and its diagnostic value of the intracranial epidermoid cyst.Materials and Methods 49 cases with histologically proven intracranial epidermoid tumors were performed with MRI scan of pre- and post-contrast、Flair、DWI, and fat-suppression T1WI were included in 9 cases with hyperintensity in the tumor.Results 36 cases were presented as irregular shape, 13 cases were round or oval shape. 38 cases were hyperintensity on T_2WI, the others were hyperintensity with patch isointensity. The manifestation of T_1WI was variable:40 cases were exhibited hypointensity; 3 cases were hyperintensity and 6 cases with heterogenous intensity. 15 cases had rim enhancement in post-contrast scan, the others were no enhancement. In the 9 cases of T_1WI fat suppression, the signal intensity were decreased in 3 cases with moderate or heterogenous intensity on FLAIR.Conclusion The intracranial epidermoid tumors have typical MRI characteristics. DWI is helpful to differential diagnosis. Combination of Multi-axial and multi-sequence scan, MRI can make accurate diagnosis before surgery, which is useful for clinical evaluation and prediction of the best surgery mode and route.