Wistar大鼠癫痫模型的多模态功能磁共振成像与病理组织学对照研究

Control study on multimode function magnetic resonance imaging of wistar rat epilepsy model and its relationship with histopathology

目的通过对比研究分析Wistar大鼠癫痫模型的多模态功能MRI与其病理组织学间的关系.材料与方法 Wistar大鼠分为正常对照组(n=30)及癫痫模型组(n=30),癫痫模型组大鼠建立癫痫模型.分别于致病后3 d、1周、3周、5周和8周取雌雄各3只,行常规MRI、扩散峰度成像及三维磁化强度预备梯度回波等多序列脑部扫描,分别在脑灰质(gray matter,GM)和脑白质(white matter,WM)区域内选取双侧对称的感兴趣区(region of interest,ROI),检测各向异性分数(fractional anisotropy,FA)、平均扩散系数(mean diffusivity,MD)、平均扩散峰度(mean kurtosis,MK).取大鼠脑部组织,进行HE染色分析,分析大鼠MRI参数与其病理学结果间的关系.结果随着致病时间延长,癫痫模型组GM及WM区域FA及MD逐渐降低,而MK逐渐升高(P<0.05);且相同致病时间点癫痫模型组GM及WM区域FA及MD低于正常对照组,MK高于正常对照组(P<0.05).癫痫模型组大鼠致病时间与脑部FA、MD呈负相关,与MK呈正相关(P<0.05).随着致病时间延长,癫痫模型组脑部组织残存正常神经元数量逐渐降低,且在相同致病时间点癫痫模型组残存正常神经元数量少于正常对照组(P<0.05).致病后不同时间点,癫痫模型组大鼠残存正常神经元数量与其脑部FA及MD均呈正相关,与MK呈负相关(P<0.05).结论癫痫模型大鼠的多模态功能MRI检测结果与其脑组织病理学检测结果显著相关,多模态功能MRI可作为临床诊断癫痫及评估其疾病严重程度的影像学方法之一.

Objective: To analyze the relationship between multimode function magnetic resonance imaging (MRI) of Wistar rat epilepsy model and histopathology by comparative study. Materials and Methods: Wistar rats were divided into normal control group (n=30) and epilepsy model group (n=30). Epileptic model group established epilepsy model. Three males and three females were taken at 3 days, 1 week, 3 weeks, 5 weeks, and 8 weeks after the disease, and routine MRI, diffusion kurtosis imaging (DKI) and three-dimensional magnetization preparatory gradient echo (3D-MPRAGE) were performed. Multi-sequence brain scans, selecting bilateral symmetric regions of interest (ROI) in the gray matter (GM) and white matter (WM) regions, detecting anisotropy fraction (FA), mean diffusion coefficient (MD), and average diffusion kurtosis (MK). After the end of scan, the rat brain tissues were taken out to conduct pathological HE staining analysis. Rat brain tissue was taken for HE staining analysis to analyze the relationship between MRI parameters and pathological findings in rats. Results: With the extension of attack time, FA and MD in GM and WM areas of epilepsy model group were gradually decreased, while MK was gradually increased (P<0.05). At the same attack time points, FA and MD in GM and WM areas of epilepsy model group were lower than those of normal control group, while MK was higher than that in normal control group (P<0.05). The pathogenic time of rats in the epilepsy model group was negatively correlated with FA and MD in the brain, and positively correlated with MK (P<0.05). With the extension of attack time, the number of residual normal neurons in brain tissues of epilepsy model group were gradually decreased. At the same attack time points, number of residual normal neurons in epilepsy model group was lower than that in normal control group (P<0.05). At different time points after attack, number of residual normal neurons in epilepsy model group was positively correlated with FA and MD, while negatively correlated with MK (P<0.05). Conclusions: The test results of multimode function MRI in epilepsy model rats are significantly correlated with test results of brain histopathology. Msultimode function MRI can be applied as one of imaging methods for clinical diagnosis of epilepsy and assessment of disease severity.