中枢性原始神经外胚层肿瘤的影像表现与鉴别诊断

目的：探讨中枢性原始神经外胚层肿瘤(cPNET)的CT、MRI表现及鉴别诊断。方法回顾性分析经病理证实的15例cPNET患者的CT、MRI影像资料,总结其影像特征及鉴别诊断。结果本组cPNET病例平均年龄(8.82±2.53)岁,男女比例为9︰6。肿瘤均位于幕上,体积较大(平均直径约6.3 cm),多伴有小灶性或大片状坏死囊变(12/15),瘤周无水肿或轻度水肿。CT平扫肿瘤呈等、稍高或稍低密度,增强扫描较均匀或不均匀强化。MRI 平扫肿瘤实性成分 T1 WI 呈等或稍低信号,T2 WI 呈等或稍高信号, DWI大部分病例(12例)呈高信号,FLAIR呈等信号(9例)或稍高信号；增强扫描实性成分呈较均匀或小蜂窝状、不规则明显强化,坏死囊变成分未见强化。结论 cPNET具有一定特点,包括发病年龄较小、肿瘤大但界限较清且瘤周水肿轻或不明显、实性成分在DWI序列呈高信号、FLAIR序列呈等信号等。

Imaging findings and differential diagnosis of central nervous system primitive neuroectodermal tumors

Objective To investigate the CT,MRI features and differential diagnosis of central nervous system primitive neuroec-todermal tumors (cPNET).Methods The CT and MRI findings of 1 5 cases with cPNET proved by pathology were analyzed retro-spectively,and we summarized the imaging features and differential diagnosis.Results For this group,the average age was (8.82± 2.53)and the male to female ratio was 9 ︰6.All lesions located in supratentorial region,which had relatively large volume (average diameter of 6.3 cm),cystic necrosis (12/15),and no or mild peritumoral edema.cPNET showed isodensity,slight hyperdensity or slight hypodensity on CT plain scan,and demonstrated uniform or inhomogeneous enhancement.On MRI plain scan,solid part showed isointensity or slight hypointensity signal on T1 WI,isointensity or slight hyperintensity signal on T2 WI,hyperintensity sig-nal on DWI(12/15),isointensity(9/15)or slightly hyperintensity signal on FLAIR,and showed obvious uniform,honeycombed or irregular enhancement after enhanced scan,no enhancement in cystic necrosis.Conclusion cPNET have certain characteristics,inclu-ding the lower onset age,relatively large volume with well-defined edge and no or mild peritumoral edema,hyperintensity signal on DWI,isointensity signal on FLAIR.