摘要
目的 探讨严重烧伤早期脑水肿MRI表现与病理改变的相关性。方法 2 6只犬随机分为对照组 (6只 )和致伤组 (伤后 6、12、18和 2 4h ,各组分别为 5只 ) ,采用体表烧伤法将致伤组犬制成 5 0 %总烧伤面积 (TBSA)Ⅲ度创面 ,并于伤后 6h静脉输注 5 %葡萄糖液 ,以建立严重烧伤脑水肿模型。应用MRI与病理 (巨检、光学显微镜、电子显微镜 )对比分析法对各致伤组犬进行了动态观察。结果 MRI形态改变显示的最早时间为伤后 12h ,以弥漫性脑肿胀为其表现特征。与对照组比较 ,当T1WI信号强度比值 (SIR)下降达 10 39%(t=2 2 6 1,P <0 0 5 )前 ,MRI难以发现 ;伤后 2 4hT2 WISIR增高 8 2 9%(t=3 6 95 ,P <0 0 5 ) ,脑灰、白质分界模糊 ,以致部分消失。病理学观察烧伤 6h以后毛细血管内皮细胞及血管周围星形胶质细胞终足肿胀 ;神经细胞出现空泡状现象 ;毛细血管内皮细胞、神经细胞及轴突呈不同程度的缺血性改变。随着观察时间的延长 ,这种改变逐渐明显 ,以伤后 2 4h表现最为显著。结论 严重烧伤早期脑水肿模型兼有血管源性和细胞毒性脑水肿的MRI及病理组织学特征。
Objective To investigate the correlation between MRI features and pathology in brain edema at the early stage of severe burn (50% TBSA Ⅲ grade) in dogs. Methods Twenty-six dogs were randomized into control and wounded groups. The manifestation of the dogs in control group was compared with those of 6 h, 12 h, 18 h, and 24 h groups postburn concerning MRI and pathological observation (gross appearance, light microscopy and electron microscopy). Results The earliest changes of cerebral morphology were found at 12 h after burn, which showed cerebral swelling with MRI characteristics. The decrease of SIR on T 1WI was not observed until it was above 10%. Signal of T 2WI increased for 8.29% at 24 h after burn. It was difficult to distinguish the gray matter from the white matter at the boundary line, which could not be seen later. Histological changes of brain edema were observed as early as 6 h after burn, accompanied by swelling of endothelial cells and peri-vascular astrocytes, vacuolation took place in neurons at 12 h after burn. In addition, ischemic necrosis of capillary endothelium, neurons, and axons appeared in various degrees. These changes became more marked with elapse of time and the most obvious consequences were revealed at 24 h after burn. Conclusion The model of the brain edema after severe burn had the feature of both vasogenic edema and cytotoxic edema on MRI and pathology.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2002年第1期32-35,共4页
Chinese Journal of Radiology
关键词
脑水肿
磁共振成像
病理学
烧伤
对比分析
Brain edema
Magnetic resonance imaging
Animals, laboratory
Pathology, clinical
