成人髓母细胞瘤的CT、MR影像诊断

CT and MR Imaging of Medulloblastomas in Adults

目的 研究成人髓母细胞瘤的CT、MR影像表现 ,并与儿童髓母细胞瘤的影像表现进行对照。方法 回顾性分析了经手术、病理证实的成人髓母细胞瘤 4 1例。并与 13 5例 18岁以下儿童髓母细胞瘤进行了对照。结果 4 1例中 ,15例 (3 6 6% )发生在小脑半球 ,位于四脑室者 19例 (46 3 % ) ,位于小脑蚓部 7例 (17 1% )。 1例肿瘤最大径大于 5cm ,3 1例肿瘤大小为 3～ 5cm之间 ,9例肿瘤小于 3cm。 17例表现为圆形或椭圆形 ,2 4例为不规则半圆形。18例边缘略显模糊 ,2 3例边缘相对清楚。 2 9例肿瘤内或肿瘤边缘可见囊变、坏死灶。 1例在肿瘤内可见散在斑点样高密度钙化灶。 2 9例可见因肿瘤压迫四脑室而引起不同程度的梗阻性脑积水。静脉注入对比剂后 ,3例未见肿瘤增强 ,3 1例肿瘤表现为非均匀性圆形或类圆形增强 ,7例为均匀性圆形或类圆形增强。结论 成人髓母细胞瘤并非少见 ,其影像学表现具有一定特点 ,仔细分析发生部位以及影像征象 ,多数情况下可在术前作出影像学诊断。

Purpose To evaluate the role of CT and MR imaging in diagnosing medulloblastomas in adults. Methods MR and CT imaging of 41 adults with the medulloblastomas was reviewed retrospectively and compared the imaging findings with the features of 135 medulloblastomas in children. All cases were pathologically verified diagnosis of medulloblastoma. Results In this series of 41 medulloblastomas,15(36.6%) located in cerebellar hemispheres,19(46.3%) in the fourth ventricle and 7(17.1%) in vermis. The size of the tumor was larger than 5cm in one,through 3cm from 5cm in 31 and smaller than 3cm in 9. The shape of tumors was global in 17 cases and semiovali in 24. The cystic components or necrosis were intratumoral in 29 patients and calcification in one. Hydrocephalus was presented in 29 patients. Homogeneous enhancement was found in 7 cases and heterogeneous enhancement in 31. Three tumors did not enhanced. Conclusion The adult medulloblastoma had location and imaging characteristics. Therefore,it is possible to make preoperative diagnosis using CT or MR. [