新生猪缺氧缺血性脑病模型脑部ADC图的分区研究

Subregion study of ADC maps in piglet model with acute severe hypoxic ischemic encephalopathy

目的:探讨急性期重度新生猪缺氧缺血性脑病(HIE)模型脑部磁共振ADC图的特点及其分区研究的方法与意义。方法:7日龄健康新生约克猪48只随机分为正常对照组(5只)和HIE组(43只),HIE组再按缺氧缺血后病情的变化分为病情稳定组(30只)和病情恶化组(13只)2个亚组。分别于缺氧缺血后24h内不同时间点采集HIE组2亚组ADC图,并对照相应临床和病理学资料,探讨HIE脑部ADC图特点及其分区研究的方法与意义。结果:HIE脑部ADC图病变呈年轮状、多中心分布,病变中心区主要分布在两侧矢状旁区、侧脑室旁白质与基底节区。本实验根据其ADC图的特点人为地将病变区到正常区等距划分为4个亚区,分别定义为"不可逆脑缺血区"(Ⅰ区)、"高度危险区"(Ⅱ区)、"次要危险区"(Ⅲ区)和"相对正常区"(Ⅳ区),根据不同的机体缺氧状态和并发症的严重程度,HIE2亚组各区均具有不同的特点及预后。结论:分析急性期HIE脑部ADC图各区特点能对HIE病情和预后作出比较客观的评价,具有很大的科研价值与临床应用潜力。

Objective： To study the subregion of MR apparent diffusion coefficient maps （ADC maps） in piglet model with acute severe hypoxic ischemic encephalopathy （HIE）, compared with clinical manifestation and pathology. Methods： Seven days old piglets（n=48） were divided into two groups randomly： group A （normal control group, n=5） and group B（HIE group, n=43, perform by bilateral common carotid artery occlusion and then inspirited 4% oxygen about 1 hour）. According to the clinical manifestation of experimental animal, group B were divided into two subset： group Bl（stable group, n=30） and group B2（aggra-vated group, n=13）. ADC maps were got at the time point of 0, 1, 3, 6, 12, 18 and 24 hours after hypoxic ischemic, and 4 regions of interest（ROI I-IV） were set from the minimum ADC values point to the consecutive normal ADC values area. The ADC values of 4 ROIs and the number of the focus were studied compared with clinical manifestation and pathology. Results： Multiple small patchy regions of hypointensity were found in the bilateral cerebrum by ADC maps, and most focuses were dis-tributed in subcortical white matter, basal ganglia, thalami and periventricular white matter. The evolvement patterns of ADC values in 4 ROls of two HIE groups were quite different, and markedly correlative with clinical manifestation and pathology. Conclusion： To analyze the evolvement patterns of ADC values in 4 ROIs of ADC maps could evaluate pathogenetic condition and prognosis of acute HIE.