基于MRI的阿尔茨海默氏病海马结构形态和功能研究

发布时间：2018-02-07 15:48

本文关键词： 阿尔茨海默病海马海马体积弥散张量成像磁敏感加权成像穹隆海马静脉　出处：《首都医科大学》2017年博士论文　论文类型：学位论文

【摘要】：海马(hippocampus)是神经系统中重要的组织器官,人类的高级神经活动记忆主要由海马参与完成,海马病变将导致认知和精神功能方面的障碍。穹隆主要由海马神经元轴突延伸组成的白质纤维束。我们利用MRI成像技术中的MPRAGE图像,DWI图像,DTI图像和SWI血管图像,分别对阿尔茨海默氏病(AD)患者海马弥散特点,海马穹隆纤维束整体完整性的显示,穹隆弥散特点,海马区域静脉血管显示特点进行了研究对比分析。首先利用DWI图像对AD患者的海马弥散特点和海马穹隆纤维束整体显示特点进行了研究。利用3TMRI扫描仪收集了25例AD患者和25例年龄、教育程度匹配的正常自愿者的DWI图像和MPRAGE图像,并将图像在西门子NEURO3D工作站进行后处理分析,记录和统计海马ADC值和FA值以及海马穹隆整体3D纤维束形态显示等级,然后将上述指标在AD组和正常自愿者组间进行对比分析。结果显示AD患者双侧海马穹隆纤维束等级、海马ADC值和FA值均显示显著性异常改变。相对于NC组,AD组左侧、右侧海马穹隆纤维束显示明显不完整,双侧海马ADC值升高,左侧海马FA值降低。内侧颞叶视觉评估量表(MTA)等级评分显示AD组明显高于NC组。两组内比较发现左右侧海马穹隆纤维束形态评分和左右侧海马ADC值,左右侧海马FA值对比并没有统计学差异。然后利用图像数据处理软件ExploreDTI软件包和FSL软件包对收集的17例AD,12例MCI和17例HC的DTI图像进行了进一步后处理和分析。对比发现AD患者穹隆FA值和穹隆长度指标相对于MCI组和HC组显著降低,而穹隆MD值显示升高。相对于HC组,MCI组穹隆MD值同样显示升高表现。同时我们收集16例AD患者和16例自愿者的高分辨率3DMPRAGE图像,SWI血管图像和DWI图像,然后在后处理工作站上分别测量获取两组研究对象海马体积及海马ADC值,并对海马区域静脉血管显示进行等级评估,并测量研究对象MMSE量表得分和MoCA量表得分。将指标进行组间对比分析和相关性分析发现相对于NC组,AD组海马体积、海马静脉血管显示等级、MMSE得分和MoCA得分显著降低,右侧海马ADC值升高。在AD组内,LHV与RHV,MMSE与MoCA,MMSE与Edu,MoCA与LADC,LADC与RADC显示正相关性,而LADC分别与MMSE得分、MoCA得分、Edu显示负相关性。在HC组内,LHvein与RHvein,LHvein与MoCA,RHvein与MoCA均显示显著正相关性。根据上述研究结果我们得出相对于HC,AD患者海马体积明显萎缩、海马组织表现出异常弥散特点、海马穹隆纤维束整体形态和海马穹隆纤维束组织弥散亦显示异常改变。AD海马区域静脉血管整体显示等级明显变小。AD显示的异常MMSE得分和MoCA得分与上述部分影像学评估指标具有相关性,但仍需要进一步探讨分析。海马体积、海马穹隆纤维束整体形态和穹隆弥散评估指标、海马区域静脉血管形态显示等级均可以作为辅助诊断和评估AD病情的影像学指标。
[Abstract]:Hippocampus (Hippocampus) is an important organ in the nervous system. Hippocampal lesions can lead to cognitive and mental dysfunction. The fornix is made up of white matter fibers, which are mainly composed of axonal extensions of hippocampal neurons. We use the MPRAGE images of the MRI imaging technique to make use of the DTI images and the SWI vascular images. The characteristics of hippocampal diffusion, the overall integrity of the fibrous tract of the hippocampal fornix, and the diffusive characteristics of the fornix were observed in patients with Alzheimer's disease (AD), respectively. The characteristics of hippocampal regional venous vessel display were compared and analyzed. Firstly, the characteristics of hippocampal diffusion and the whole display of hippocampal fornix fiber bundle in AD patients were studied by using DWI images. 25 cases were collected by 3T MRI scanner. Patients with AD and 25 patients with age, The DWI images and MPRAGE images of normal volunteers matched with educational level were analyzed by post-processing at Siemens NEURO3D workstation, and the ADC and FA values of hippocampus were recorded and counted, as well as the morphological grade of 3D fibrous tracts of hippocampal fornix. Then the above indexes were compared between AD group and normal volunteers group. The results showed that the grade of bilateral hippocampal fornix fibrous tract, hippocampal ADC value and FA value were significantly abnormal in AD patients, compared with the left side of AD group in NC group. The right hippocampal fornix fiber bundle was obviously incomplete, and the ADC value of bilateral hippocampus was increased. The left hippocampal FA value decreased, and the medial temporal lobe visual assessment scale score showed that AD group was significantly higher than NC group, the left and right hippocampal fornix fibrous tract morphology score and left and right hippocampal ADC value were found in the two groups. There was no statistical difference between left and right hippocampal FA values. Then, the DTI images of 17 cases of MCI and 17 cases of HC were further processed and analyzed by using the software package ExploreDTI and FSL. Compared with MCI group and HC group, the FA value and dome length index of AD patients were significantly lower than those of MCI group and HC group. Compared with HC group, the Dome MD value also showed an increase. At the same time, high resolution 3DMPRAGE images and DWI images were collected from 16 AD patients and 16 volunteers. Then the hippocampal volume and hippocampal ADC were measured on the postprocessing workstation. The scores of MMSE scale and MoCA scale were measured and compared with those of NC group, the scores of MMSE and MoCA were significantly lower than those of AD group. In AD group, there was a positive correlation between LHV and RHVMMSE, MMSE and MMSE, Eduardo MoCA, LADC, LADC and RADC. In HC group, LHvein, RHvein and MoCARHvein showed significant positive correlation with MoCA. According to the results, we found that the hippocampal volume of patients with AD was significantly smaller than that of patients with AD. The hippocampal tissue showed abnormal dispersion. The shape of the hippocampal fornix fiber bundle and the diffusion of the fibrous tract of the hippocampal fornix also showed abnormal changes. The grade of the whole display of venous vessels in the hippocampus of AD was obviously smaller. The abnormal MMSE scores and MoCA scores showed by AD were compared with some of the above imaging images. The assessment indicators are relevant, However, further analysis is needed. Hippocampal volume, global shape of hippocampal fornix fibrous tract and evaluation index of dome diffusion, and the grade of vascular morphology of hippocampal region can be used as imaging indexes to assist diagnosis and evaluation of AD.
【学位授予单位】：首都医科大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R749.16;R445.2

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