脑实质表皮样囊肿的磁共振成像表现及鉴别诊断

目的探讨脑实质表皮样囊肿的磁共振成像(MRI)特点及鉴别诊断。方法回顾性分析8例脑实质表皮样囊肿及12例脑脓肿的MRI表现,包括常规序列、DWI序列及增强扫描,并比较表皮样囊肿、脓肿及正常脑脊液的ADC值。结果①脑实质表皮样囊肿常规表现为均匀长T1、T2信号或混杂T1、T2信号,FLAIR信号不均匀降低,DWI为均匀或不均匀高信号,ADC图呈混杂信号,增强扫描7例无强化、1例边缘强化,所有病灶均无瘤周水肿;②3者ADC值差异有统计学意义,脑脓肿最低为(0.76±0.12)×10^-3mm²/s,脑脊液最高为(2.98±0.16)×10^-3mm²/s,表皮样囊肿为(1.18±0.09)×10^-3mm²/s。结论常规MRI序列结合DWI序列可以准确的诊断脑实质表皮样囊肿。

MRI manifestations and differential diagnosis of intraparenchymal epidermoid cysts

Objective To investigate the MRI features and differential diagnosis of intraparenchymal epidermoid cysts(IEC).Methods The MRI findings of 8 cases with intraparenchymal epidermoid cysts and 12 cases with brain abscesses were analyzed retrospectively,including conventional sequences,DWI sequences and enhanced scans,and ADC values of IEC,brain abscess(BA)and cerebrospinal fluid(CSF)were compared.Results①IEC usually showed homogeneous long T1,T2 signals or mixed T1,T2 signals,FLAIR signals were unevenly reduced,and DWI was homogeneous or uneven high signal,ADC images show mixed signals.7 cases′enhanced scans have no enhancement,1 has edge enhancement and without peritumoral edema;②The differences of ADC values among the three groups were statistically significant,the lowest BA was(0.76±0.12)×10^-3mm²/s,the highest CSF was(2.98±0.16)×10^-3mm²/s,and IEC was(1.18±0.09)×10^-3mm²/s.Conclusion Conventional MRI sequence combined with DWI sequence can accurately diagnoze IEC.