原发性中枢神经系统弥漫性大B细胞淋巴瘤的多模态影像学特征分析

Multi-modality imaging features analysis of primary central nervous system diffuse large B-cell lymphoma

目的探讨原发性中枢神经系统弥漫性大B细胞淋巴瘤(PCNS-DLBCL)的影像学特征。方法回顾性分析经病理证实的23例PCNS-DLBCL患者的临床及影像学资料。结果13例患者为单发病灶,10例患者为多发病灶。病灶主要分布于胼胝体及侧脑室周围的脑深部,瘤周水肿多为轻中度;部分患者有轻中度占位效应。CT检查示病灶多为等/稍高密度影。MRI检查示病灶多为等/稍长T1WI、等/稍长T2WI信号影,FLAIR呈等/稍高信号,DWI多呈高信号;增强扫描大多数病灶呈团块状、结节状明显均匀强化,出现“握拳征”、“尖角征”、“裂隙征”、“蝴蝶征”、“卫星灶”及“硬环征”等特征性表现;磁共振波谱表现为Cho峰升高、NAA峰降低、Cr峰轻度降低,出现高耸的Lip峰及倒置Lac峰;PWI上肿瘤实质区为低灌注。18F-FDG-PET检查示病灶呈明显高摄取。多发病灶多局限于幕上,具区域性分布特点,密度、信号及强化表现较单发病灶多样。单发病灶患者MRI增强扫描出现“握拳征”、“裂隙征”、“蝴蝶征”的比率高于多发病灶患者。结论PCNS-DLBCL的多模态影像学表现具有一定的特征,合理应用多模态影像学检查有助于其早期诊断。

Objective To investigate the multi-modality imaging features of primary central nervous system diffuse large B-cell lymphoma(PCNS-DLBCL).Methods The clinical imaging data of 23 patients with PCNS-DLBCL confirmed by pathology were analyzed retrospectively.Results 13 cases were solitary,10 were multiple,mainly distributed in the brain around the corpus callosum and lateral ventricles.The peritumoral edema was mostly mild to moderate,and some cases showed mild to moderate space occupying effect.The lesions were mostly of equal/slightly high density on CT and equal/slightly long T1WI,equal/slightly long T2WI signal,FLAIR presented equal/slightly high signal on MRI.DWI showed hyperintense.Most of the lesions showed massive and nodular enhancement on contrast-enhanced scan.On contrast-enhanced MRI scan,the characteristics of“clench fist sign”,“sharp angle sign”,“fissure sign”,“butterfly sign”,“satellite focus”and“hard ring sign”can be seen.The 1H-MRS showed that Cho peak increased,NAA peak decreased,Cr peak decreased slightly,high Lip peak and inverted Lac peak,and the tumor parenchyma area on PWI was hypoperfusion.18F-FDG-PET examination showed that the lesions were obviously high metabolism.The multiple cases are mostly confined to the supratentorial and have regional distribution characteristics.The density,signal and enhancement manifestations were more diverse than those of single cases.The incidence of“clench fist sign”,“fissure sign”,and“butterfly sign”on contrast-enhanced MRI scan in solifary cases was higher than that in multiple cases.Conclusion The multi-modality imaging manifestations of PCNS-DLBCL have certain characteristics,which is helpful for its early and accurate diagnosis.