小脑髓母细胞瘤的MRI影像特征及鉴别诊断

目的:探讨小脑髓母细胞瘤的MRI表现及鉴别诊断。方法:回顾性分析21例经手术病理证实的小脑髓母细胞瘤的MRI资料,所有病例均行MRI平扫及增强扫描,5例行FLAIR序列及弥散加权成像(DWI)。结果:21例髓母细胞瘤中,19例位于小脑蚓部(占90%),2例位于小脑半球(占10%)。发病年龄5～41岁,15岁以下11例(占52%)。肿瘤平均大小约33mm,18例病灶边界较清楚,3例病灶周边模糊。圆形或类圆形11例,不规则形3例,边缘分叶5例。16例病灶内可见囊变、坏死。MRI扫描,T1WI呈稍低、等信号,T2WI呈等、稍高信号,FLAIR序列呈等、稍高信号,DWI序列病灶实性成分呈高信号,表面扩散系数(ADC)图呈略低信号。增强扫描大部分病灶不同程度强化。12例病灶周边见不规则水肿。结论:小脑髓母细胞瘤具有典型好发部位及特征性MRI影像表现,早期诊断有助于临床治疗及提高患者生存质量。

MRI imaging features and differential diagnosis of cerebellar medulloblastoma

Objective： To study MRI features and differential diagnosis of cerebellar medulloblastoma. Methods： A retrospective analysis of 21 cases of medulloblastoma was performed,confirmed by surgery and pathology. All cases were examined with plain and enhanced MRI,5 cases with FLAIR sequence and diffusion weighted imaging （DWI）. Results： Among these 21 cases with medulloblastoma, 19 patients＇ lesions were located at the midline of cerebellum （90%）, and other 2 cases＇ lesions were in the cerebellar hemisphere （10%）. The age ranged from 5 to 41 years,with 11 cases of bellow＇IS years old （52%）. The average tumor size was about 33 ram. 18 cases of lesion boundary more clearly,3 cases of lesions in peripheral blur. Round or oval in 11 eases,3 cases of irregular shape, the edge of leaf five cases. 16 cases with visible cystic degeneration. MRI displayed low or e qual-intensity signals on T1WI and slightly higher-intensity signals on T2 WI. The solid portion of the tumor gave slightly higher signals on DWI and slightly lower signals on the apparent diffusion coefficient map. The solid masses were enhanced at different extension. 12 cases the perifocal see irregular edema. Conclusion： Cerebellar medulloblastoma has a typical predilection in loea tion and characteristic MRI imaging findings. Early diagnosis and clinical treatment can improve patient life quality.