后颅窝脑肿瘤的多模态磁共振成像诊断研究

目的:探讨多模态磁共振成像在后颅窝脑肿瘤中的诊断价值。方法:回顾性分析经病理证实的18例后颅窝脑肿瘤患者的MR平扫、扩散加权成像（DWI）、动态增强影像资料。结果:18例患者共有22个病灶，3例为多发病灶。所有病灶在T1WI呈低或稍低信号；T2WI上16个病灶呈稍高信号，3个呈等信号，3个呈混杂稍高信号；DWI上3例扩散受限呈高信号，12例扩散稍受限呈稍高信号，3例扩散不受限呈等信号。表观扩散系数（ADC）图上测得肿瘤实质与对照侧平均ADC值分别为(0.595±0.089)×10-3 mm2/s和(0.695±0.051)×10-3 mm2/s，两者差异有统计学意义(P=0.03)，rADC为0.875±0.119。结论:多模态磁共振成像有助于后颅窝脑肿瘤的明确诊断。

Multimodal magnetic resonance imaging diagnosis of posterior fossa brain tumor

Objective:To explore the diagnostic value of multimodality MR imaging in posterior fossa brain tumors.Methods:MR plain scan，diffusion-weighted imaging (DWI)，and dynamic contrast-enhanced image data of 18 patients with posterior fossa brain tumors confirmed pathologically were retrospectively analyzed.Results:A total of 22 lesions were found in 18 patients and 3 were multifocal.All lesions showed low or slightly low signal on T1WI.On T2WI，16 lesions showed slightly high signal，3 showed iso-signal，and 3 showed mixed hyperintensity signals.On DWI，diffusion-restricted hyperintensity was detected in 3 cases，and 12 cases were slightly diffused.Restricted slightly higher signal，3 cases were not limited to the proliferation of signals.The average ADC values of the tumor parenchyma and the control side measured on the apparent diffusion coefficient (ADC) were (0.595±0.089)×10-3 mm2/s and (0.695±0.051)×10-3 mm2/s，respectively.They were statistically significant (P=0.03)，rADC was 0.875±0.119.Conclusion:Multimodal magnetic resonance imaging is helpful for the definitive diagnosis of posterior fossa brain tumors.