扩散加权成像在小儿髓母细胞瘤诊断中的价值

Diffusion weighted MR imaging in the diagnosis of medulloblastoma in children

目的:探讨磁共振扩散加权成像在小儿髓母细胞瘤诊断中的应用价值。方法:17例经手术病理证实的小儿颅后窝肿瘤,其中髓母细胞瘤8例,毛细胞星形细胞瘤5例,室管膜瘤4例,回顾性分析其扩散加权成像及ADC图像。结果:小儿髓母细胞瘤好发于小脑蚓部(7例),发生于小脑半球1例,肿瘤实质T1WI呈稍低信号,T2WI呈高信号,增强扫描有中度～明显强化。肿瘤实质DWI呈高信号,ADC值为(0.60±0.07)×10-3mm2/s;毛细胞星形细胞瘤肿瘤实质DWI呈低信号,ADC值为(1.28±0.28)×10-3mm2/s;室管膜瘤DWI呈等信号或稍低信号,ADC值为(0.89±0.11)×10-3mm2/s;正常脑白质的ADC值为(0.78±0.05)×10-3mm2/s。结论:DWI对小儿髓母细胞瘤的诊断和鉴别诊断有重要价值。

Objective：To assess the value of diffusion weighted MR imaging（DWI） in the diagnosis of pediatric medulloblastoma.Methods：17 pediatric patients with surgery and pathology proven tumors within posterior cranial fossa were studied,there were medulloblastoma（8 cases）,pilocytic astrocytoma（5 cases）,ependymoma（4 cases）.The DWI signal intensity and ADC values were analyzed restropectively.Results：Pediatric medulloblastoma mostly located at vermis of cerebellum（7 cases）,1 tumor located within cerebellum hemisphere.Slight hypointensity on T1WI and hyperintensity on T2WI with moderate to marked enhancement after Gd-DTPA injection were showed in the solid component of medulloblastoma,as well as high signal intensity on DWI and the ADC value was（0.60±0.07）×10^-3mm^2/s.For pilocytic astrocytoma,low signal intensity was assessed on DWI and the ADC value was（1.28±0.28）×10^-3mm^2/s;ependymoma showed iso-/slightly hypointense signal on DWI and the ADC value was（0.89±0.11）×10^-3mm^2/s.The ADC value of normal white matter was（0.78±0.05）×10^-3mm^2/s.Conclusion：DWI play an important role in the diagnosis and differential diagnosis of medulloblastoma in children.