颅内曲霉菌病的影像学特点分析

Imaging characteristics of central nervous system aspergillosis

目的探讨中枢神经系统曲霉菌病(CNSAG)的影像学表现。方法分析解放军总医院第一医学中心于2013—2019年收治的5例CNSAG患者的头颅影像学改变,总结其影像学特征。结果5例患者中男性4例,女性1例,年龄20~59岁。5例中病变主要发生于海绵窦2例,脑实质3例。脑实质病变均表现长T1、长T2信号,海绵窦病变表现为等或短T1、等或长T2信号。所有病例的头颅磁共振成像(MRI)均表现为多发环形强化,可形成沿着病灶外周排列形成锯齿或花边样和聚集在一起形成"蜂巢样"强化特征。病灶外周强化程度更明显,病情加重后强化范围增大。环形强化灶内可见高弥散加权成像(DWI)信号,为化脓性感染MRI特征,可见强化环边缘高DWI信号。磁敏感加权成像可见出血低信号,波谱无特征性改变,中心区灌注减低。病灶CT可正常或见等密度占位,病灶出现明显水肿或并发梗死表现为低密度影,出血表现为高密度影。结论影像学可明确CNSAG的不同部位病灶,其MRI表现为混杂信号,可呈环形强化;CT正常或见等密度占位,或呈不规则低密度影,可发现出血征象。

Objective To explore the imaging manifestations of central nervous system aspergillosis(CNSAG).Methods The cranial imaging changes of five CNSAG patients admitted to the First Medical Center of People′s Liberation Army General Hospital from 2013 to 2019 were analyzed and their imaging characteristics were summarized.Results There were four males and one female with the minimum age of 20 years old and maximum age of 59 years old.Among the five cases,two cases mainly occurred in the cavernous sinus and three cases in the cerebral parenchyma.Long T1-weighted and long T2-weighted signals were observed in all the lesions of the cerebral parenchyma,while equal or short T1-weighted,equal or long T2-weighted signals were observed in the lesions of the cavernous sinus.Magnetic resonance imaging(MRI)of the brain of all cases showed multiple ring enhancement,which could form serrate or lace-like arrangement along the periphery of the lesion and gather together to form"honeycomb"enhancement characteristics.The degree of peripheral enhancement was more obvious,and the scope of enhancement increased after the disease was aggravated.High diffusion weighted imaging(DWI)signal can be seen in the ring enhanced focus,which is the MRI feature of abscess,and high DWI signal can be seen at the edge of the enhanced ring.Susceptibility weighted imaging showed low bleeding signal,no characteristic changes in the spectrum,and decreased perfusion in the central area.Computer tomography scan showed normal or equal density mass lesions,obvious edema or complicated infarction showed irregular low-density shadow,and bleeding showed high-density shadow.Conclusion MRI showed mixed signal and circular enhancement,computer tomography showed normal or isodense mass lesions,or irregular low-density shadow,and bleeding signs could be found in CNSAG.