婴幼儿神经系统遗传代谢病的脑MRI研究

目的探讨婴幼儿神经系统遗传代谢病的脑MRI表现。方法收集2014年1月—12月我院诊治的16例遗传代谢病病人临床及影像资料,并结合临床特点及实验室检查分析该组病人的脑MRI表现。结果 16例遗传代谢病病人中包括有机酸血症12例(甲基丙二酸血症8例,枫糖尿病4例),尿素循环障碍3例,异染性脑白质营养不良1例。12例有机酸血症中,7例基底节区信号异常,主要表现在T_1FLAIR上呈低信号,T_2FLAIR上呈稍高信号,DWI上呈明显高信号;4例脑干及2例小脑半球在DWI上呈明显高信号,2例脑萎缩,1例胼胝体在DWI上呈高信号,1例双侧半卵圆中心在T_1FLAIR上呈低信号、T_2FLAIR高信号、DWI高信号,1例脑室扩大。3例尿素循环障碍病人中2例脑室扩大,1例大脑皮质在DWI上呈弥漫性高信号。1例异染性脑白质营养不良表现为两侧侧脑室周围白质、半卵圆中心T_2FLAIR高信号。结论婴幼儿神经系统遗传代谢病脑MRI表现缺乏特异性,根据疾病类型不同MRI表现各异,其中有机酸血症患儿以基底节区受累为主。

Brain imaging characteristics of inherited metabolic diseases in infants and young children

Objebtive To explore the characteristics of brain MRI images in pediatric patients with inherited metabolic diseases. Methods Sixteen pediatric patients within herited metabolic diseases were recruited from January 2014 to December 2014. Their clinical features, laboratory examsand brain MRI were analyzed. Results There were twelve cases of organic academia,eight case of methylmalonicacademia,four cases of maple syrup urine disease. Three cases of urea cycle disorders, and 1 case of metachromatic leukodystrophy. Among the 12 patients with organic acidemia, basal ganglia showed hypointensity on T1 FLAIR, mild hyperintensity on T2 FLAIR, and intense hyperintensity on DWI (n=7); brainstem and cerebellum showed intense hyperintensity on DWI (n=4 and 2, respectively);corpus callosum showed hyperintensityon DWI in 1 case; brain atrophy in 2 cases; one case showed hypointensity on T1 FLAIR, hyperintensity on T2 FLAIR, and hyperintensity on DWI atbilateral centrum-semiovale;and ventricular enlargement in 1 case.Among the 3 patients with urea cycle disorders, ventricular enlargement was seen in 2 cases, cerebral cortex showed diffuse hypeninternsity on DWI in 1 case. The case with metachromatic leukodystrophy showed hyperintensity on T2 FLAIR at bilateral preventricular white matter and centrum-semiovale. Conclusion The brain MRI is lack of specificity in infants and young children with inherited metabolic diseases.Different disease types show varied MRI manifestations,and the organic acidemia in children mainly shows basal ganglia involvement.