摘要
目的：明确急性脑缺血扩散张量成像（DTI）平均扩散系数（DCav）、各向同性图像（Iso）、部分各向异性（FA）、相对各向异性（RA）、各向异性指数（AI）值的动态变化。方法：清洁级健康雄性SD大鼠12只，分成4组：A组脑缺血1h（3只），B组脑缺血1.5h（3只），C组脑缺血3h（3只），D组脑缺血6h（3只）。按照时间点行脑MR检查，测量病变及对侧相应区域Iso信号、DCav、FA、RA、AI值，并于24h行脑TTC染色。结果：脑缺血各观察时间点患侧脑皮质和纹状体等皮质下结构显示DCav值降低为对侧的51%～67％，Iso显示明确的患侧异常高信号。在脑缺血1h和1.5h FA和RA图无明显变化，虽然患侧FA、RA测量值偏高，但与对侧不具备统计学差异，AI图显示患侧信号降低，测量计算两侧比值分别为0.50和0.46。脑缺血3h时患侧FA、RA值降低，与对侧差别有显著意义，此种现象持续至6h，AI图表现为病变信号进一步降低，两侧比值分别为0.18和0.06。结论：急性脑缺血不同MR DTI参数随时间变化各异。
Abstract
Objective: To explicit the dynamic changes of average diffusion coefficient(DCav), Isotropic image(Iso), fractional anisotropy(FA), relative anisotropy(RA), anisotropy index(AI) value in acute cerebral ischemia. Materials and Methods: Twelve male SD rats were divided into four groups randomly: group A: cerebral ischemia 1h(3 rats), group B: cerebral ischemia 1.5h(3 rats), group C: cerebral ischemia 3h(3 rats), group D: cerebral ischemia 6h(3 rats). MRI in the prescriptive time and the cerebral TTC stain in 24h were performed. The values of Iso signal, DCav, FA, RA, and AI in the lesion and control region were measured. Results: The DCav value of left cortical and striatal area were lowered grading 51%～67％ and the isotropic image showed hyperintensity significently in all times. After cerebral ischemia 1h and 1.5h, the FA and RA value in left hemisphere increased slightly, but had no significance with contralateral region. The AI image showed hypointensity in left hemisphere, the ratio of AI value between lesion and contralateral region were 0.50 and 0.46. In 3h and 6h, the FA and RA value of left hemisphere dropped. The AI values were lowered with the ratio of 0.18 and 0.06 between two sides. Conclusions: The MR DTI parameters changes were luxuriant in acute cerebral ischemia.
关键词
脑缺血 /
动物实验 /
磁共振成像
Key words
brain ischemia /
animal experimentation /
magnetic resonance imaging
杨艳梅;冯晓源;倪建明;姚振威;蒋胜洪;于同刚.
3.0T磁共振DTI诊断急性脑缺血的实验研究[J]. 中国临床医学影像杂志. 2007, 18(3): 157-159
YANG Yan-mei;FENG Xiao-yuan;NI Jian-ming;YAO Zhen-wei;JIANG Sheng-hong;YU Tong-gang.
Experimental study of acute cerebral ischemia by 3.0T MR DTI[J]. Journal of China Clinic Medical Imaging. 2007, 18(3): 157-159
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