原发性中枢神经系统淋巴瘤MRI表现

目的 探讨原发性中枢神经系统淋巴瘤(PCNSL)的典型和不典型MRI表现.方法 回顾性分析26例经病理证实的PCNSL术前MRI资料.分析其发生部位、信号特征、强化方式,瘤周水肿、室管膜播散以及胼胝体累及情况.结果 26例中7例为单发,19例为多发;其中基底节区、脑室旁白质、胼胝体区16例,半球凸面白质区7例.二者中同时伴室管膜下结节者13例;仅发生于脑室内者3例.累及胼胝体时,均可见典型"蝶翼征".常规平扫实性部分表现为T1Wl低信号,T2WI等或稍高信号,DWI呈明显高信号.ADC值降低明显.增强扫描24例实性部分表现为明显均匀强化,2例表现为边缘环状中度强化.脑室内病灶或室管膜下播散结节,均未见坏死区,增强均呈明显均匀强化.瘤周水肿因部位而异,基底节区、脑室旁白质、胼胝体区病灶水肿多呈轻度到中度,大部分以轻度为主;大脑半球凸面病灶水肿多较明显,呈中度到重度.结论 绝大多数PCNSL表现较典型,MRI检查有助于提高正确诊断率.

MRI features of primary central nervous system lymphomas

Objective To observe MRI features of primary central nervous system lymphoma(PCNSL).Methods MRI findings of 26 cases with pathologically-proved PCNSI.were analyzed retrospeetively,emphasizing on the location,signal feature,contrast-enhanced type,perilesional edema,ependymal seeding,and infiltration of corpus callosum.Results A- mong the 26 cases(7 of them were solitary,the others were multiple),16 of them were located in the corpus callosum,basal ganglia and periventricule region,7 cases in encephalic surface and white-gray matter junction region,and 3 in intraventri- cule,respectively,whereas ependymal seeding lesions could be observed in 13 cases.Typical"butterfly sign"was found in cases with involvement of corpus callosum.Solid portion displayed as hypointensity on T1WI and iso-hyperintensity on T2WI,and hyperintensity on DWI with low ADC.After the infusion of paramagnetic contrast material,intense homogene- ous enhancement in the solid portion was detected in 24 cases,while ring enhancement in the rest 2 cases.Intraventricular and ependymal seeding lesions appeared as homogeneous masses,enhanced intensively and homogeneously.Perilesional ede ma depended on the locations.There was mild to moderate edema in the corpus callosum,basal ganglia and periventricule re- gion lesions,while moderate to high in the encephalie surface and white-gray matter junction region lesions.Conclusion Most PCNSL have typical MRI appearance that will he helpful for the preoperative diagnosis.