原发性中枢神经系统淋巴瘤与胶质瘤的DWI对比研究

目的:探讨DWI在原发性中枢神经系统淋巴瘤(PCNSL)与胶质瘤鉴别诊断中的价值。方法:回顾性分析24例经病理证实的PCNSL的MRI表现,另选取70例胶质瘤作对照(WHOⅠ～Ⅱ级31例为A组,Ⅲ～Ⅳ级39例为B组),观察及测量肿瘤的T1WI、T2WI、DWI信号、ADC值及强化方式等,并进行统计学分析。结果:PCNSL在T1WI上多呈低信号(23/24),T2WI上多呈高信号(23/24),DWI上多呈明显高信号(11/15),平均ADC值为(0.57±0.14)×10-3 mm2/s,低于对侧正常脑白质;A组及B组胶质瘤在T1WI上多呈低信号(51/70),T2WI上多呈高信号(61/70),DWI上多为低信号(29/70),平均ADC值分别为(1.63±0.48)×10-3和(1.37±0.54)×10-3 mm2/s,高于对侧正常脑白质,PCNSL组与胶质瘤组在DWI信号、ADC值上差异均具统计学意义(P均<0.05)。增强后PCNSL多呈明显均匀强化(21/24),呈"裂隙样"(16/21)或"团块样"(5/21)。A组胶质瘤强化多不明显,B组胶质瘤多呈不均匀明显强化,呈"花环样"。结论:DWI和ADC值对PCNSL与胶质瘤的鉴别诊断有一定价值,结合T1WI、T2WI及增强扫描等可提高诊断符合率。

Study on DWI for differentiation of primary central nervous system lymphoma and glioma

Objective：To assess the clinical value of MR diffusion-weighted imaging（DWI） in the differentiation between primary central nervous system lymphoma（PCNSL） and glioma.Methods：MR performances of 24 cases of PCNSL proved by pathology were retrospectively reviewed.70 cases of gliomas were taken as the control group（WHO Ⅰ~Ⅱgrade as group A,Ⅲ~Ⅳ grade as group B）.Statistical analysis was made of the T1WI,T2WI,DWI signals of the tumor and apparent diffusion coefficient（ADC） values.Results：The DWI and ADC values of primary central nervous system lymphoma（PCNSL） and glioma were quite different.PCNSL presented as hypointense on T1-weighted images（23/24） and hyperintense on T2-weighted image（23/24）,it presented as hyperintense on DWI（11/15）,the average ADC value was（0.57±0.14）×10-3mm2/s,which was lower than the normal white matter in the contralateral hemisphere;while glioma presented as hypointense on DWI,the average ADC values were（1.63±0.48）×10-3 and（1.37±0.54）×10-3mm2/s respectively in group A and group B,which were higher than the normal white matter in the contralateral hemisphere.Most PCNSL lesions showed dense homogenous enhancement（21/24）,it was ＂crack-like＂（16/21） or ＂mass-like＂（5/21）.while group A mostly showed no enhancement,group B mostly showed heterogeneous enhancement,it was ＂rosette-like＂.Conclusion：There is significant difference between PCNSL group and glioma groups in the performance of DWI and the values of ADC,the diagnostic accuracy of PCNSL can be improved by combining T1WI,T2WI and other enhanced MRI performances.