胚胎发育不良性神经上皮瘤的MRI表现特征

目的 探讨胚胎发育不良性神经上皮瘤（DNT）的MRI表现特征。方法 对经手术病理证实的6例DNT的MRI材料进行回顾性分析，总结DNT的MRI表现特征。结果 6例患者的肿瘤均局限于皮层或以皮层为主，呈三角形假囊肿样，T1WI呈低信号，T2WI呈高信号；T2水抑制像上边缘和分隔呈高信号，其他部分呈等偏低信号；扩散加权像（DWI）上呈低或等偏低信号，表观扩散系数（ADC）图呈ADC值升高；MR波谱测定肿瘤胆碱（Cho）峰和肌酸（Cr）峰改变不明显，N-乙酰天门冬氨酸（NAA）较正常参照侧降低，但降低不明显；增强无强化；瘤体夹杂细条索状等信号分隔；无瘤周水肿，无占位效应；肿瘤邻近的颅骨内板发育不良。结论 胚胎发育不良性神经上皮瘤MRI表现较具特征性，有助于术前正确诊断。

MRI features of dysembryoplastic neuroepithelial tumor

Objective To better characterize and report the MR images of the dysembryoplastic neuroepithelial tumor(DNT) in a series of 6 cases.Methods Clinical,neuroradiologic,and pathologic features of all cases were retrospectively studied.Results All cases displayed a triangular cortical tumoral lesion that demonstrated neither perilesional edema nor mass effect on midline structures.On T_1WI the lesion appeared to be hypointense;T_2WI,hyperintense;and absence of contrast enhancement.On T_2 fluid attenuated inversion recovery-weighted images,the margin and the septa of the lesion appeared to be hyperintense.Thin septa of the lesion appeared to be isointense on T_1 and T_2WI.On diffuse-weighted images(DWI) the lesion appeared to be isointense to hypointense,while the apparent diffusion coefficient(ADC) value was high.On MR spectroscopy(MRS),Choline(Cho) and Creatine(Cr) were all near normal or diminished,and N-acetylaspartate(NAA) diminished a little.Deformation of the overlying skull was observed in all cases.Conclusion The typical neuroradiologic aspect of DNT may be helpful for the diagnosis of DNT preoperatively.