胼胝体肿瘤的影像学诊断

Tumors of the corpus callosum:imaging diagnosis

目的 探讨发生于胼胝体的不同类型肿瘤的影像学表现.方法 回顾性分析25例发生于胼胝体的不同类型的肿瘤.分析各种肿瘤在不同影像学检查方法下的表现特点.结果 低级别星形细胞瘤1例,间变性星形细胞瘤2例,胶质母细胞瘤7例,少突胶质细胞瘤1例,间变性少突星形细胞瘤1例,少突一星形细胞瘤1例,原发恶性淋巴瘤10例,转移瘤1例,脂肪瘤1例.肿瘤最大直径7 cm,最小0.5 cm.肿瘤实性部分T1WI为等或低信号,T2WI为等或稍高信号,部分肿瘤伴囊变坏死.脂肪瘤CT平扫为低密度,CT值-85 HU.增强扫描星形细胞瘤呈不均匀、环状或蝶翼状强化,恶性淋巴瘤呈明显实性或环状强化,胶质母细胞瘤和淋巴瘤多向脑室或邻近脑质浸润.结论 胼胝体肿瘤的影像学表现具有特征性,可为手术切除肿瘤提供指导作用.

Objective To study the imaging features of tumors in the corpus callosum. Methods Different imaging data of 25 tumors in the corpus callosum were retrospectively analyzed. Results Of the 25 cases, 2 cases were anaplastic astrocytomas,7 cases were glioblastomas,10 cases were malignant lymphomas, 1 case for each in the following tumors: low grade astrocytoma, oligodendroglioma, anaplastic oligodendroglioma, oligoastrocytoma, lipoma, and metastatic tumor. The lesion's size varied from 7 cm to 0.5 cm. These lesions were usually isoor hypointense on T1-weighted images and hyper-intense on T2-weighted images with focal necrosis, and showed ring-like or 'butterfly sign' enhancement after administration of contract medium. Lipoma showed hypodensity on CT with attenuation value of -85 HU. Glioblastomas and malignant lymphomas usually infiltrated into cerebral ventricles and brain parenchyma. Conclusions Tumors of the corpus callosum have characteristic imaging features. MRI exam before surgery is helpful for the surgical excision.