摘要
背景:放射性脑损伤是近些年关注和研究的热点,尤其是动物实验研究,国内外研究显示,磁共振成像检查放射性脑损伤动物模型尚无统一扫描参数,文章通过行家兔颅脑磁共振成像,确定磁共振扫描各序列参数。目的:建立新西兰兔放射性脑损伤动物模型,并利用LOOP7线圈获取兔颅脑磁共振(MR)图像,为深入研究放射性脑损伤早期磁共振诊断提供基础。方法:使用LOOP7线圈分别行T2加权成像、弥散张量成像、磁共振波谱分析及磁敏感加权成像的多次扫描,确定每个序列的最佳扫描参数。建立放射性脑损伤兔模型,于右半脑分别接受40,80,120 Gy的6 MV X射线单次大剂量照射,观察实验兔的日常表现和动态的颅脑磁共振征象,当磁共振检测出现异常或随访20周后取脑组织行病理学检查。结果与结论:40 Gy组仅1例发生硬膜下出血,其他未见异常;80 Gy组T2WI均可见异常信号,病理证实为散在神经元变性和中性粒细胞浸润;120 Gy组磁共振检查均可见随时间逐渐扩大的异常信号影,病理证实为放射性脑病。结果证实,通过放射治疗系统制定放疗计划,制作放射性脑损伤兔模型,能很好的模拟放射性脑损伤的发生过程,且该模型能适用于临床常规LOOP7线圈的磁共振检查。
BACKGROUND： Radiation-induced brain injury has recently become an increasing area of research, in particular in animal experimental studies. Domestic and international researches show that there have been no uniform scanning parameters used for examination of animal models of radiation-induced brain injury by magnetic resonance imaging. In this study, we performed magnetic resonance imaging in rabbits to determine related sequence parameters. OBJECTIVE： To establish the New Zealand rabbit models of radiation-induced brain injury, and obtain the brain magnetic resonance images of rabbits using LOOP7 coil, so as to provide experimental evidence for diagnosis of radiation-induced brain injury by magenetic resonance imaging. METHODS： Each of T2-weighted imaging, diffusion tensor imaging, magnetic resonance spectroscopy and magnetic susceptibility-weighted imaging were performed several times through the use of LOOP7 coil, to determine the optimal scanning parameters for each sequence. Rabbit models of radiation-induced brain injury were established and then their right hemispheres were irradiated using 6 MV X-rays at a single dose of 40, 80 and 120 Gy. The daily performance and dynamic magnetic resonance signs of rabbits were observed. The brain tissue was taken for pathological examination once abnormal magnetic resonance findings were observed or after 20 weeks of follow-up. RESULTS AND CONCLUSION： Only one rabbit model in the 40 Gy group had subdural hemorrhage. In the 80 Gy group, abnormal T2-weight imaging signals were observed in all rabbit models, which were pathologically confirmed as scattered degenerated neurons and infiltrated neutrophils. The abnormal signals that gradually expanded over time were seen in rabbits from the 120 Gy group by magnetic resonance imaging and werepathologically confirmed as radiation-induced brain injury loci. The results confirm that establishing rat models of radiation-induced brain injury using radiation therapy system can better simulate the pathological process of ra
出处
《中国组织工程研究》
CAS
北大核心
2015年第27期4299-4303,共5页
Chinese Journal of Tissue Engineering Research
