室管膜下室管膜瘤的影像学诊断(附三例分析)

Imaging diagnosis of subependymoma (analysis of three cases)

目的 探讨室管膜下室管膜瘤的CT及MRI特征。方法 经手术病理证实的室管膜下室管膜瘤 3例 ,回顾分析其CT及MRI表现。结果 室管膜下室管膜瘤的特征表现为 :(1)幕上肿瘤位于侧脑室内孟氏孔附近 ,CT平扫呈等密度或低密度 ,很少显示钙化及坏死 ;(2 )MRT1WI示肿瘤呈等、低信号 ,其内可见多数微囊状更低信号区 ,肿瘤飘浮于侧脑室中 ;T2 WI示肿瘤呈均匀高信号 ;(3)CT、MR增强扫描 ,病灶未见强化征象。结论 幕上室管膜下室管膜瘤的CT及MRI表现很有特征性 ,影像学检查对其定位及定性诊断极有帮助。

Objective To study the CT and MR imaging features of subependymoma. Methods The CT and MR findings of 3 cases of subependymomas pathologically proved were analyzed and correlated with operative and pathologic reports. Results CT and MR appearances of subependymoma were as follows: (1) Subependymoma were rare and benign intraventricular tumors, which were often isodense or hypodense on unenhanced CT; Calcification and necrosis were not common.(2) They were isointense to hypointense relative to normal white matter in T 1 weighted image and hyperintense in PD and T 2 weighted image on MR, with microcystic structures and clear margins in the lateral ventricle. (3) No enhancement was found in all tumors both on enhanced CT and MR examinations. Conclusion The CT and MR appearances of lateral ventricular subependymomas possess unique features which are very helpful in diagnosis of subependymoma.