包膜期脑脓肿的高场强MRI影像特点  

High Field MRI Features of Brain Abscess During Capsule-Period

作　　者：黄远军[1] 韩永良[1] 周泽芳[1] 段莉[1] 张鸿志[1] 曹笃[2] HUANG Yuanjun;HAN Yongliang;ZHOU Zefang(Department of Neurology,The First Affiliated Hospital of Chongqing Medical University,Chongqing 400016,P.R.China)

机构地区：[1]重庆医科大学附属第一医院第一分院神经内科,400016 [2]重庆医科大学附属第一医院第一分院放射科,400016

出　　处：《临床放射学杂志》2021年第8期1460-1464,共5页Journal of Clinical Radiology

摘　　要：目的分析包膜期脑脓肿在高场强磁共振成像(MRI)的影像特点,提高临床医师对脑脓肿影像特点的认识。方法搜集2016年1月至2019年12月于本院经手术病理证实为包膜期脑脓肿的住院患者的高场强MRI资料,分析病灶数量、部位、形态、大小、边缘、信号特点及强化特征。结果共搜集到30例患者MRI资料,发现脓肿病灶34个,其中单发病灶27例,多发病灶3例;额叶、颞叶、顶叶、枕叶、小脑、基底节区病灶数分别为11、9、7、4、2、1个。感染来源依次为隐源性16例、血源性7例、耳源性、开颅术后各3例、外伤性1例。脑脓肿的平均大小为3.60 cm×2.86 cm×2.81 cm。所有病例均处于包膜期,脓肿轮廓清晰,均有包膜形成。14例形状为卵圆形,其他为不规则形。脓腔在T1WI呈低信号28例,高信号2例;除1例呈高低分隔信号外,其余29例T2WI全部呈高信号、扩散加权成像(DWI)呈高信号、表观扩散系数(ADC)值减低。脓肿壁在T2WI上全部呈现环形低信号,均可见不等高信号"靶环征"。增强扫描后脓肿壁全部呈闭环强化,脓腔无强化。所有脓肿周围见不同程度的水肿带,有明显的占位效应。结论脑脓肿大多数为单发,好发于额、颞叶,感染来源多为隐源性及血源性。高场强MRI检查简便易行,对包膜期脑脓肿的识别有很高的敏感性,尤其是在T2WI中的环形低信号,联合环形结构内的DWI高信号,可以更为敏感地识别出包膜期脑脓肿。Objective To investigate the imaging features of brain abscessduring capsule-period in high field MRI and to better understand the features of brain abscess.Methods Retrospective analysis was made on the high field MRI data of 30 hospitalized patients with brain abscessduring capsule-period confirmed by surgery and pathology from January 2015 to December 2019.The number,location,shape,size,edge,signal characteristics and enhancement characteristics of brain abscesses were analyzed.Results 34 abscess lesions were detected,27 cases were single and 3 cases were multiple.The lesions’number of frontal lobe,temporal lobe,parietal lobe,occipital lobe,cerebellum and basal ganglia were 11,9,7,4,2,1 respectively.Sources of infection:16 cases of cryptogenic,7 cases of blood-borne,3 cases of otogenic,3 cases of craniotomy and 1 case of traumatic brain injury.The average volume of brain abscess was 3.60 cm×2.86 cm×2.81 cm.All cases were in the capsule stage,and the abscess had a clear outline with capsule.14 cases were round in shape and others were irregular.Abscesses characteristics:28 cases with hypointensity and 2 cases with hyperintensityon T1WI;except one case showed heterogeneous intensityon T2WI&DWI,the others showed hyperintensityon T2WI&DWI with ADC value decreased.The wall of the abscess showed a ring-shaped low signal on T2WI,and the target signal sign was observed.Complete ring enhancement was visible in all lesions after enhancement but none enhancement withinthe abscess.All the abscesses had different degrees of edema with obvious occupying effect.Conclusion Most of the brain abscesses were single,usually in the frontal lobe and temporal lobe,and the source of infection was mostly cryptogenic and blood-borne.High field MRI was easy to perform and hadhigh sensitivity to the recognition of brain abscessduring capsule-period.The ring-shaped hypointensityon T2WI sequence,combined with the hyperintensity on DWI in the ring structure,could help sensitively identify brain abscesses during capsule-period.

关 键 词：脑脓肿 磁共振成像 扩散加权成像 

分 类 号：R445.2[医药卫生—影像医学与核医学] R742.7[医药卫生—诊断学]