后颅窝原发性中枢神经系统淋巴瘤MRI多模态表现  

Multimodality MRI manifestations of primary central nervous system lymphoma in the posterior fossa

作　　者：宋振强 张岚[2] SONG Zhenqiang;ZHANG Lan(Kaifeng People's Hospital,Kaifeng 475002,China;The First Affiliated Hospital of Henan University of Chinese Medicine,Zhengzhou 450000,China)

机构地区：[1]开封市人民医院,河南开封475002 [2]河南中医药大学第一附属医院,河南郑州450000

出　　处：《中国实用神经疾病杂志》2020年第2期125-129,共5页Chinese Journal of Practical Nervous Diseases

基　　金：河南省医学科技攻关项目(编号:201602030)。

摘　　要：目的总结后颅窝原发性中枢神经系统淋巴瘤(PCNSL)MRI多模态表现,提高对后颅窝PCNSL诊断的正确率。方法回顾性分析经病理证实的15例后颅窝PCNSL的MRI多模态影像学表现,包括MRI平扫和增强、弥散加权成像(DWI)和磁共振波谱成像(MRS)。结果15例PCNSL多发病灶者5例,单发病灶者10例均位于幕下。后颅窝病灶位于小脑半球和小脑蚓部、中脑、第四脑室、桥小脑角区等。T1WI上呈稍低或中等信号,T2WI上呈中等或稍高信号。所有病灶表现为明显强化,6个病灶呈现“尖角征”和“脐凹征”。后颅窝20个病灶中结节状强化12个,条纹状强化4个,斑片状强化3个,四脑室团块状不均匀强化1个。5例DWI呈均质高信号,2例DWI为不均匀高信号,3例DWI为中等信号;ADC呈低至等信号。后颅窝PCNSL的ADC值为(0.62±0.095)×10^-3 mm^2/s,与对侧脑实质ADC值比较有显著差异(P<0.05)。3例于MRS出现宽大耸立的Lip峰,2例Lip峰短小。结论后颅窝PCNSL的MRI多模态表现具有一定的特征性,但对于不典型的后颅窝PCNSL术前诊断仍非常困难。Objective To summarize the multimodality MRI manifestation of primary central nervous system lymphoma(PCNSL)in the posterior fossa in order to improve the correct diagnosis.Methods 15 patients of PCNSL in the posterior fossa confirmed by pathology were retrospectively analyzed,including plain and enhanced MRI features,DWI and MRS.Results There were multiple lesions of 5 cases and the solitary lesion of 10 cases in the posterior fossa.The locations of posterior fossa were cerebellum,cerebellar vermis,midbrain,the fourth ventricle,cerebellopontine angle.The lesions showed slightly low or iso-signal intensity on T1WI and iso-or high signal intensity on T2WI.All the lesions showed obvious enhancement,"cusp sign"and"notch sign"were seen in 6 lesions.There were nodular enhancement in 12 lesions,stripe enhancement in 4 lesions,patchy enhancement in 3 lesions and the fourth ventricular mass-like heterogeneous enhancement in 1 lesion of 20 lesions in the posterior fossa.The tumors showed homogeneous hyperintensity on DWI in 5 cases,inhomogeneous hyperintensity on DWI in 2 cases,intermediate signal intensity on DWI in 3 cases and iso-signal or hypointensity on ADC map.The ADC value of tumors was(0.62±0.095)×10^-3mm^2/s,which was statistically significant compared with contralateral normal parenchyma(P<0.05).There was an increased Lip peak in 3 cases and short Lip peak in 2 cases on MRS.Conclusion Multimodality MRI Manifestations of PCNSL in the posterior fossa has some certain characteristics,but preoperative diagnosis for atypicl PCNSL in the posterior fossa is still very difficult.

关 键 词：后颅窝 原发性中枢神经系统淋巴瘤 磁共振成像 多模态 早期诊断 

分 类 号：R733[医药卫生—肿瘤]