儿童后颅窝肿瘤的MRI诊断与鉴别诊断

目的：探讨磁共振成像（MRI）对儿童后颅窝肿瘤的诊断与鉴别诊断价值。方法：回顾性分析33例经手术病理证实的儿童后颅窝肿瘤的MRI和临床资料，其中星形细胞瘤13例、髓母细胞瘤11例、室管膜瘤5例、血管母细胞瘤1例、胚胎发育不良性神经上皮瘤2例、弥漫性大B细胞淋巴瘤1例。结果：肿瘤位于小脑半球7例，小脑蚓部16例，第四脑室4例，脑干6例。所有病灶均引起梗阻性脑积水。MRI能显示肿瘤的位置、大小、形态及信号特点，增强扫描对肿瘤的定性诊断有帮助。结论：儿童后颅窝肿瘤的MRI表现具有一定的特征性，MRI多参数、多平面成像，对儿童后颅窝肿瘤的定位和定性诊断具有重要的临床应用价值。

MRI diagnosis and differential diagnosis of posterior cranial fossa tumors in children

Objective： To evaluate the value of MR/in the diagnosis and diiYerential diagnosis of posterior cranial fossa tumors in children. Methods：MR images of 33 children with posterior cranial fossa tumors were retrospectively reviewed, including 13 cases of astrocytoma, 11 medulloblastoma, 5 ependymoma, 1 hemangioblastoma, 2 dysembryoplastic neuroepithelial tumor （DNT）, and 1 diffuse large B-cell lymphoma （DLBL）. Results： 16 cases of these were located in vermis, 7 cases in cerebellar hemisphere, 4 cases in fourth ventricle, and 6 cases in brain stem. There were hydrocephalus in all the patients on MRI. The location, size, shape, and signal intensity of the tumors could be well displayed on MRI, and the qualitative diagnosis could be improved by contrast-enhanced MRI. Conclusion： There are some characteristic findings on MRI of posterior cranial fossa tumors in children. MRI plays an important value in the diagnosis and differential diagnosis of posterior cranial fossa tumors in children.