苯中毒性脑病的MRI表现

MRI analysis of benzene toxic encephalopathy

目的:探讨苯中毒性脑病的MRI影像学特征及动态变化特点。方法:回顾性分析2009年3月至2016年11月温州市4家三甲医院收治的35例经确诊苯中毒性脑病患者的MRI影像及临床资料,分析其MRI表现特征。结果:患者表现为急性或慢性起病,有明确苯剂接触史,临床表现为中枢神经受损改变,大部分患者血常规白细胞下降,部分患者脑电图异常,腰穿脑脊液压力增高。MRI扫描35例均累及白质区皮层下弓形纤维,呈"葵花瓣"或"火焰"状改变,33例累及两侧小脑齿状核,病变区呈"蝶翼"样改变,28例累及外囊,病变区呈条状异常信号,边缘光整,16例累及豆状核。病变区T1WI低信号,T2WI、FLAIR高信号,DWI高信号,26例ADC呈高信号或等信号,9例ADC值减低呈低信号。1例磁共振波谱成像(MRS)示Cho、Cr峰略升高,2例MRS无异常;MRI增强、SWI、MRA扫描均无明显异常改变。结论:苯中毒性脑病的MRI表现具一定特征性,结合病史,可提示诊断并全面评估脑内病变的累及范围与程度,对临床及时治疗具有重要的价值。

Objective： To study the dynamic MRI characteristics of benzene toxic encephalopathy. Methods： Complete imaging and clinical data of 35 cases with benzene toxic encephalopathy were collected from 4 hospitals of Wenzhou between March 2009 and November 2016. The imaging characteristics of benzene toxic encephalopathy were retrospectively analyzed. Results： All patients had a definite history of benzene exposure, acute or chronic onset. The clinical manifestations included the damage of central nerve system, the decline of routine blood leucocytes, the abnormality of EEG and the rise of cerebrospinal fluid pressure in lumbar puncture, et al. The arc zone of subcortical white matter fiber was invaded in 35 cases of benzene toxic encephalopathy on MRI scan, demonstrating a sign of ＂kwai petals＂ or ＂flame＂ shape. ＂Butterfly＂ change on both dentate nuclei of cerebellum was seen in 33 cases. The number of external capsule and lentiform nucleus was involved in 28 cases and 16 cases. All lesions demonstrated low signal on T1 WI, high signal on T2 WI, FLAIR and DWI. High or isosignal on ADC images appeared in 26 cases and low signal in 9 cases. In 3 cases of MRS examination, the peak of Cho and Cr slightly elevated in 1 case, and no abnormality in 2 cases. No obvious changes appeared on MRI contrast enhancement, SWI and MRA. Conclusion： MRI manifestations of benzene toxic encephalopathy have some characteristics. Combined with the history, MRI can reduce the misdiagnosis of the disease and provide reference for clinical diagnosis and treatment.