Experimental study on the pathological basis of high signal intensity on T_1 weighted image after brain ischemia in rats
- VernacularTitle:脑缺血后T_1WI产生高信号的病理基础
- Author:
Yanshuang REN
;
Yunting ZHANG
;
Songling LIU
- Publication Type:Journal Article
- Keywords:
Brain ischemia;
Models, animal;
Magnetic resonance imaging;
Pathology
- From:
Chinese Journal of Radiology
2001;0(08):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To verify the pathol ogical basis of high signal intensity on T 1 weighted image after brain ischemia by using the rat model. Methods Fifty-six male Wistar rats, weighing 250 to 300 g, were used for the model of middle cerebral artery occlusion(MCAO). 46 rats model were counted in the results. They were divided into two groups randomly, experimental group (T 1, n =39) and control group (T 0, n =7). Experimental group was further divided into 4 subgroups: 15 minute's MCAO (T 1-a, n =13), 30 minute's MCAO (T 1-b, n =12), 60 minute's MCAO (T 1-c, n =7), and permanent MCAO (T 1-d, n =7). Intraluminal filament technique was used with the method modified by Zea-Longa. Follow-up MRI was applied to observe the time and the position of short T 1 signal. H & E staining and electronic microscope were applied to observe the pathological changes in the position of short T 1 signal. Results In T 0 group ( n = 7), no short T 1 signal was observed in bilateral cerebral hemispheres. In T 1-a subgroup ( n =13), short T 1 signal was observed in 7 rats at the 14 th day. In T 1-b subgroup ( n =12), short T 1 signal was observed in the ischemic side in 8 rats. All of the rats in T 1-c subgroup ( n =7) and T 1-d subgroup ( n =7) were observed to have short T 1 signal. The histological changes of short T 1 signal were hemorrhage, lipid-laden macrophage, denatured protein, and myelinolysis. Earlier short T 1 signal in cortical region was mainly related with hemorrhage, short T 1 signal in the basal ganglia appeared at a later stage, which was induced by lipid-laden macrophages. The occurrence of short T 1 signal was prominently different in the time of MCAO (? 2=29.328, P
