大鼠严重烧伤早期应激性脑损害磁共振成像的实验研究

发布时间：2018-03-21 20:02

本文选题：应激　切入点：脑损害　出处：《蚌埠医学院》2017年硕士论文　论文类型：学位论文

【摘要】：【背景与目的】:烧伤是国内外常见的一种意外创伤,虽然当今精湛的医疗技术水平已大大降低了烧伤患者的死亡率,但烧伤患者还极易出现持续而强烈的应激反应,从而导致一些系统相关的应激性损害。其中大脑作为产生感觉、控制运动及完成各种高级脑功能的高级神经中枢,应激反应引起的脑损害所带来的危害尤为突出。目前,关于严重烧伤早期应激性脑损害动物模型进行的研究较少。本研究在建立烧伤早期脑损害大鼠模型的基础上,应用磁共振T2加权成像(T2 weighted imaging,T2WI)、弥散加权成像(diffusion weighted imaging,DWI)及弥散张量成像(diffusion tensor imaging,DTI)技术,并结合病理学检查,检测在不同时间点(3h、6h、12h、18h、24h、48h、72h)严重烧伤早期应激性脑损害动物模型的脑组织特征,旨在阐明烧伤早期脑损害的影像学变化规律,并跟病理学结果进行对照分析研究。【材料与方法】:实验选取40只SD雄性大鼠(280±31.8g)进行实验,随机分为正常对照组和不同时间点(3h、6h、12h、18h、24h、48h、72h)烧伤模型组,共8组,每组5只。在大鼠清醒状态下,建立烧伤应激模型。分别于烧伤后不同时间点使用磁共振(德国SIEMENS Skyra 3.0T超导MR扫描仪)及大鼠脑专用线圈(上海辰光医疗科技有限公司),行T2WI序列、DWI序列及DTI序列扫描。采用SIEMENS公司提供的Syngo.via软件,观察T2WI、DWI、DTI序列的图像,并对其进行后处理,分别测量不同时间点大鼠脑不同部位(双侧对称顶叶皮层、额叶皮层、尾状核)的T2WI信号强度(signal intensity,SI)值、表观弥散系数(apparent diffusion coefficient,ADC)及各向异性指数(fractional anisotropy,FA)。各组大鼠行磁共振扫描后于麻醉状态下迅速取脑组织,对相应部位行病理学检查。然后对整体数据进行正态分布性检验证实为正态分布后,组间比较应用单因素方差分析,用SPSS22.0统计学软件对所测值行独立样本t检验,比较不同部位T2WI SI值、FA值和ADC值在不同时间点是否存在显著性差异,P0.05为差异有统计学意义,并对影像学与病理学结果进行对比分析。【结果】:1.同组不同部位T2WI SI值、FA值和ADC值在双侧大脑半球间均未见统计学差异。2.不同部位ADC值:烧伤组不同部位与对照组相比,烧伤后3小时组ADC值未见统计学差异,烧伤后6小时组额顶叶皮层ADC值较对照组降低,于24小时组达最低值,48小时组及72小时组ADC值有升高趋势,但仍低于正常对照组;尾状核ADC值于12小时组才发现有降低趋势,之后变化趋势与额顶叶皮层相似,差异有统计学意义。3.不同部位T2WI SI值:烧伤组不同部位与对照组相比,烧伤后各部位3小时到12小时组T2WI SI值未见明显差异,18小时组及24小时组有上升趋势,并达最大值,48小时及72小时组有下降趋势,但仍高于正常组,差异有统计学意义。4.不同部位FA值:烧伤组不同部位与对照组相比,烧伤后各组尾状核FA值未见明显统计学差异。烧伤后额顶叶皮层FA值于12小时组发现较对照组降低,24小时组达最低值,之后逐渐升高,但仍低于正常对照组,差异有统计学意义。5.HE染色:正常对照组除神经元和血管周围有些间隙之外,神经细胞形态正常,分布比较均匀,数量多而排列规整,胶质细胞无明显肿胀。烧伤组后6小时组细胞轻度肿胀,血管周围间隙轻度增宽,随烧伤后时间延长,各项病变不同程度增多及加重,偶可见局灶性的神经元崩解坏死,伤后24小时细胞水肿最明显,水肿以脑组织周边部位改变为著,48小时及72小时组细胞肿胀程度相对24小时组有所减轻。【结论】:磁共振DWI、DTI及T2WI技术并结合病理学检查可以用来评估大鼠严重烧伤应激性脑损害的动态变化过程,可为临床烧伤后早期应激性脑损害的早期诊断、干预和治疗提供理论依据和循证支持。
[Abstract]:Background and objective: [] burn is a common accident trauma at home and abroad, although the superb medical technology level has greatly reduced the mortality of burn patients, but also burn patients prone to stress lasting and strong, leading to stress damage of some related systems. The brain as a result of feeling. Senior neural control movement and complete all kinds of advanced brain function damage, brain damage caused by stress response is particularly prominent. At present, a severe burn on early brain injury animal model of stress is less. The research in the establishment of early brain injury in burn rat model based on the application of T2 weighted magnetic resonance imaging (T2 weighted imaging, T2WI), diffusion weighted imaging (diffusion weighted, imaging, DWI) and diffusion tensor imaging (diffusion tensor, imaging, DTI) technology, combined with pathological examination The investigation, detection at different time points (3H, 6h, 12h, 18h, 24h, 48h, 72h) early stress-induced brain injury in animal models of brain tissue characteristics of severe burns, to elucidate the early brain injury, burn the imaging changes and pathological results were compared. [materials and methods] experiment: a total of 40 SD male rats (280 + 31.8g) experiment, were randomly divided into normal control group and different time points (3H, 6h, 12h, 18h, 24h, 48h, 72h) burn group, a total of 8 groups, 5 rats in each group. The rats in the awake state, the establishment of burn stress model. To burn at different time points after using magnetic resonance (Skyra 3.0T superconducting MR Germany SIEMENS scanner) and rat brain coil (Shanghai Chenguang Medical Technology Co Ltd), T2WI sequence, DWI sequence and DTI sequence scanning. By using SIEMENS company's Syngo.via software, T2WI DWI, DTI observation, image sequence, and the For postprocessing, were measured in rats at different time points in different parts of the brain (bilateral parietal cortex, frontal cortex, caudate nucleus) of the signal intensity of T2WI (signal intensity SI) values, apparent diffusion coefficient (apparent diffusion, coefficient, ADC) and anisotropy index (fractional anisotropy, FA). The rats underwent after MRI scan under anesthesia quickly take brain tissue for pathological examination on the corresponding parts. Then the data of normal distribution test confirmed normal distribution after analysis and comparison between groups using one-way ANOVA, independent samples t test value of the measured by SPSS22.0 statistical software, comparison of different parts the T2WI SI value at different time points there is a significant difference between the FA value and ADC value of P0.05, the difference was statistically significant, and the imaging results were compared with pathology. [results]: 1. groups with different parts of the T2WI SI The value of FA and ADC values in the bilateral cerebral hemisphere showed no significant difference between different parts of.2. ADC value in different parts of the burn group compared with the control group, 3 hours group ADC there was no significant difference in value after burn, burn after 6 hours group of frontoparietal cortex ADC values were lower than the control group, 24 hour group was the lowest 48 hours and 72 hours, group group ADC value increased, but still lower than the normal control group; caudate nucleus ADC value in 12 hours group was found to have decreased after the change trend is similar to the parietal cortex, there was a significant difference between the different parts of.3. T2WI SI: burn injury group compared with the control group in different parts and each part of 3 hours to 12 hours after burn group T2WI SI there was no obvious difference, 18 hours group and 24 hours group has a rising trend, and reached the maximum value, 48 hours and 72 hours were decreased, but still higher than the normal group, the difference has statistical significance in different parts of.4. FA Value: different parts of the burn group compared with the control group, each group of caudate nucleus FA no significant difference after burn after burn. The parietal cortex FA value in 12 hours group were lower than the control group, 24 hour group reached the minimum value, then gradually increase, but still lower than the normal control group, the difference was statistically significant.5.HE staining: normal control group except some clearance around neurons and blood vessels, nerve cell morphology of normal distribution is more uniform, the number and arrangement of regular, glial cells had no obvious swelling. The burn group 6 hours after the cells were slightly swollen, perivascular space widened slightly, with prolonged time after burn, the lesions of different degrees of increase. And even worse, visible focal necrotic neurons, 24 hours after injury were the most obvious edema, edema in the peripheral area of brain changes for 48 hours and 72 hours, 24 hours group cell swelling degree Group has been reduced. [Conclusion]: magnetic resonance DWI, the dynamic process of DTI and T2WI technology combined with pathological examination can be used to evaluate the severe burn stress of brain damage in rats, early diagnosis for early clinical stress brain damage after burn injury, intervention and treatment and provide a theoretical basis and evidence-based support.

【学位授予单位】：蚌埠医学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R644;R445.2

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