正常大鼠脑组织放射性损伤的病理及影像学对照研究  

Pathological and radiological-control study of brain tissue radiation injury in normal rats： a comparative study

作　　者：舒兵[1] 李少武[1] 叶成坤[1,2] 鲍恩萌[1] 孙异临[1] 高德智[1] 刘阿力[1] 

机构地区：[1]首都医科大学北京市神经外科研究所伽玛刀中心,100050 [2]徐州医学院附属医院神经外科

出　　处：《中华神经外科杂志》2015年第8期835-840,共6页Chinese Journal of Neurosurgery

基　　金：国家自然科学基金（11276270）

摘　　要：目的 研究伽玛射线照射正常大鼠脑组织早期放射性损伤的影像学表现及病理变化.方法 将成年SD大鼠70只随机分为照射组和对照组,利用自制大鼠立体定位头架,应用100 Gy剂量伽玛射线照射大鼠右侧脑组织,在照射后第1、2、3、4、5、6、7周各观察时间点接受7.0T头颅MRI、弥散张量成像（DTI）检查,统计分析表观扩散系数（ADC）值、部分各向异性（FA）值,同时获取大鼠脑组织标本行病理学观察.结果 （1） DTI检查结果：照射组较对照组rADC值、rFA值从第4周开始差异具有统计学意义（比值分别为,第4周：1.27±0.06：0.98±0.04、0.75 ±0.05：1.04±0.05;第5周：1.52±0.08：0.98 ±0.03、0.64 ±0.08：1.04 ±.0.05;第6周：1.35 ±0.09：1.00 ±0.02、0.63±0.03：1.04 ±0.05;第7周：1.37 ±0.10：0.99 ±0.05、0.58 ±0.04：1.04 ±0.03.均P＜0.01）. （2）照射后脑组织病理改变包括2个阶段：早期微血管周围水肿,血脑屏障结构完整;后期靶区病灶改变显著,包括神经元和神经胶质细胞数量减少,微血管扩张变形,血脑屏障结构破坏明显,髓鞘崩解.结论 大鼠脑组织放射性改变早期主要是血管性水肿,后期出现神经元、神经胶质细胞、微血管的损伤及脱髓鞘改变,且这种显著改变与DTI检测结果相一致,揭示了DTI在放射损伤研究中的价值.Objective To study the imaging findings and pathologic changes of early radiation injury of normal brain tissue in rats with gamma ray irradiation.Methods Seventy adult SD rats were randomly divided into either a radiation group or a control group.Using the self-made rat stereotactic head frame,the right side of rat brain tissue was irradiated by 100 Gy doses.Each observation time point received 7.0 T head MRI and diffusion tensor imaging （DTI） at 1,2,3,4,5,6,and 7 weeks after radiation.The values of apparent diffusion coefficient （ADC） and fractional anisotropy （FA） were statistically analyzed.Brain tissue samples were obtained for pathological observation at the same time.Results （1） The findings of DTI：There were significant differences in rADC values and rFA values from the 4th week between the radiation group and the control group （the ratios at the 4th,5th,6th,and 7th weeks were 1.27 ± 0.06 vs.0.98 ±0.04 and 0.75 ±0.05 vs.1.04 ±0.05,1.52 ±0.08 vs.0.98 ±0.03 and 0.64 ± 0.08 vs.1.04 ±0.05,1.35 ±0.09 vs.1.00 ±0.02 and0.63 ±0.03 vs.1.04 ±0.05,and 1.37 ±0.10 vs.0.99 ± 0.05 and 0.58 ± 0.04 vs.1.04 ± 0.03,respectively;all P 〈 0.01）.（2） The pathological changes of brain tissue after radiation included two stages：Early microvascular peripheral edema and the structural integrity of blood-brain barrier structure;late target lesions changed significantly,including the decreased number of neurons and glial cells,vasodilatation and deformation,obviously damaged blood-brain barrier structure,and myelin disintegration.Conclusions Early change of rat brain tissue radioactivity is mainly vasogenic edema.The changes of neurons,glial cells,microvascular damage,and demyelination appear in late stage,and these significant changes are consistent with the findings of DTI,indicating the value of DTI in the studies of radiation damage.

关 键 词：放射外科手术 伽玛刀 脑损伤 放射性 磁共振扩散张量成像 大鼠 

分 类 号：R818[医药卫生—放射医学]