侧脑室内室管膜下瘤的MRI诊断

MRI Diagnosis of Lateral Ventricular Subependymomas

目的 研究侧脑室内室管膜下瘤的MRI表现 ,以提高对该病的神经放射学认识。资料与方法 搜集 8例经手术病理证实的侧脑室内室管膜下瘤 ,男 5例 ,女 3例 ,发病年龄 16～ 4 7岁 ,平均 32 .9岁。着重分析肿瘤的好发年龄、部位 ,MRI信号特点 ,肿瘤增强情况。结果 左侧脑室内 4例 ,右侧脑室内 3例 ,双侧脑室内 1例 ,除 1例位于双侧脑室体部及三角区外 ,其余病例皆发生于侧脑室室间孔附近 ,肿瘤漂浮在侧脑室中。肿瘤最大直径 4cm ,最小 1cm。T2 WI肿瘤呈均匀高信号 ;T1WI肿瘤呈等、低信号 ,肿瘤内部可见小囊状低信号区。增强扫描 ,肿瘤无强化或有轻微强化。结论 室管膜下瘤的MRI表现具有特征性 。

Objective To delineate MRI features of subependymomas of lateral ventricle, to make a further neuroradiologic understanding of the disease.Materials and Methods Eight patients (5 males and 3 females with a mean age of 32.9 years) with pathologically proved subependymomas were collected. MRI manifestations, especially the site, signal and enhancement feature of the lesion, were observed and analyzed.Results Of 8 cases, the tumor developed in the left lateral ventricle in 4, in the right lateral ventricle in 3 and in both lateral ventricles in one. The lesions were located adjacent to the foramen of Monro except in one case whose lesion was located in both ventricles. The lesion's size varied from 1cm to 4cm. On MRI, the tumors showed homogeneous high-signal on T 2WI, and iso-/low-signal on T 1WI with small cystic low-signal areas within the tumor. On enhanced scans, the tumor showed no enhancement or only slight enhancement.Conclusion Lateral ventricular subependymoma has characteristic MRI features. MR exam before surgery is helpful for making a correct diagnosis.