脑实质间变性室管膜瘤的MRI表现

Magnetic resonance imaging findings of parenchymal anaplastic ependymoma

目的:探讨MRI对脑实质间变性室管膜瘤的诊断价值。方法:15例经手术病理证实的脑实质间变性室管膜瘤行T1WI、T2WI、DWI及增强检查,分析其形态及信号特点。结果:肿瘤主要位于幕上额、顶叶,5例位于额叶,3例位于额顶叶,2例位于顶叶;幕下3例,均位于小脑半球。本组形态分3型,囊实性7例,囊结节性4例,实性4例。囊实性肿瘤中囊性部分与实性部分比例相差不大;囊结节性肿瘤囊相对较大;实性肿瘤呈不规则分叶状。囊实性、囊结节性肿瘤边界较清,多无水肿。实质性边界不清或欠清,多有轻中度瘤周水肿。3型中的实性成分T1WI呈稍低或低信号,T2WI呈等或稍高信号,DWI呈等或混杂信号。增强扫描:实性部分明显不均匀强化,囊壁部分明显强化,部分无强化。结论:各型脑实质间变性室管膜瘤MRI表现有一定的特点,结合发病年龄、临床病史对其诊断及鉴别诊断有较高的临床价值。

Objective：To explore the value of MRI in the diagnosis of parenchymal anaplastic ependymoma. Methods： Fifteen cases with histologically proved parenchymal anaplastic ependymoma had accepted T1WI,T2WI,DWI and enhanced examination. Their morphology and signal characteristics were analyzed. Results：Tumors were mainly located in frontal and parietal lobes. The MRI features of parenchymal anaplastic ependymoma in the present cases consisted of three patterns： cystic-solid mass （n=7）,cyst with nodule （n=4） and solid mass （n=4）. Proportion of cyst and solid part in cystic-solid mass was approximate. In cyst with nodule mass,the cyst was relative large. Solid mass manifested irregular lobulation. Per- itumoral edema was absent or slight in cystic-solid and cyst with nodule type with well-defined margin,while peritumoral e- dema was slight or intermediate in solid mass with unclear border. The solid part of the three types of tumors showed slight hypointense or hypointense on T1 WI,isointense or slight hyperintense on T2 WI and isointense or heterogeneous intense on DWI. There was remarkable enhancement in the solid part and a part of cystic wall,while no enhancement in other parts of cystic wall. Conclusion： Different types of parenchymal anaplastic ependymoma have their own MRI characteristic manifesta- tions, which can be helpful, combined with age and history,in the diagnosis and differential diagnosis of parenchymal ana- plastic ependymoma.