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基于扩散张量成像的盲人脑解剖网络的研究
Alternative TitleStudy of Brain Anatomical Network in Blind Subjects Based on Diffusion Tensor Imaging
李佳佳
Subtype工学硕士
Thesis Advisor蒋田仔
2011-05-31
Degree Grantor中国科学院研究生院
Place of Conferral中国科学院自动化研究所
Degree Discipline模式识别与智能系统
Keyword扩散张量成像 盲人 脑网络 白质完整性 Diffusion Tensor Imaging Blind Brain Network White Matter Integrity
Abstract不同失明年龄的盲人为我们提供了一个独特的模型来研究单感觉模态剥夺对大脑结构的影响。近期扩散磁共振成像对盲人的研究主要集中在失明年龄较早的群体,迄今为止,不同发育阶段失明盲人的脑解剖网络变化和脑白质改变仍未可知。本文的主要工作包括以下两个部分:第一部分,利用脑网络,研究不同失明年龄的盲人组的脑解剖网络变化,以及失明年龄和脑网络属性的直接关系;第二部分,利用基于白质骨架的统计方法,研究不同失明年龄的盲人组的脑白质扩散异常情况,以及失明年龄和白质扩散属性的直接关系。 在盲人脑解剖网络的研究中,我们利用扩散张量跟踪方法成功的构建了所有个体的二值脑解剖网络,并利用图论的方法计算了网络的拓扑属性。为了考察失明年龄对脑网络属性的影响,我们首先将97个盲人按照失明年龄的不同分为先天盲人、早期盲人、青春期盲人和晚期盲人。网络属性的组间比较发现,与正常对照相比,先天盲人和早期盲人在全局的网络属性上发生了显著变化。差异主要表现在连接度的降低、最短路径长度的增加和全局效率的降低,最为明显的区域集中于视皮层和额下回,而在晚期盲人中并没有发现类似结果。与组间比较的结果一致,在盲人组中,我们发现脑内连接度和全局效率与失明年龄成正相关。我们的结果一致表明,早期发育阶段的视觉经历对于形成一个完整、高效的网络具有重要的作用。 为了研究失明年龄对盲人脑白质完整性的影响,我们还利用基于白质骨架的统计方法,研究了不同分组之间(4组盲人和1组正常人)的脑白质扩散属性的差异。结果表明,组间差异主要分布在枕叶、颞叶和内囊后肢。在与视觉通路相关的枕叶和颞叶区域,所有盲人组脑白质完整性均显著低于正常人,这可能是由于视觉剥夺造成的脑白质发育不成熟或跨神经元变性,而在内囊后肢处,所有盲人脑白质的完整性升高,这可能是由于经历造成的脑白质可塑性变化。 本文利用扩散张量成像技术,对不同发育阶段失明的盲人进行了较为详细的分析,为理解不同时期失明盲人的脑结构变化提供了不同方面的证据。
Other AbstractBlindness at different onset age provides us an exceptional example to investigate how the unimodal sensory deprivation affects the structure of human brain. Recently diffusion magnetic resonance imaging studies about blindness mainly focused on early blind, no previous research has examined the alteration of white matter in the whole brain and anatomical network across different onset age of blindness. In this dissertation, we focused on the following two topics: the first one investigates the brain anatomical network of different groups of blind subjects based on diffusion tensor tractography (DTT), and studies the relation between onset age of blindness and network properties; the second one investigates the abnormal diffusion change of white matter in the blind groups using tract-based spatial statistics (TBSS) methods, and studies the relation between onset age of blindness and the attributes of the white matter. The main content of this paper is as follows: We successfully constructed the binary anatomical networks of all subjects using DTT, and calculated topological properties of the network using a graph theory approach. In order to determine the effect of the onset ages on the brain anatomical network, we divided the 97 blind subjects into congenital blind (CB), early blind (EB), adolescent blind (AB) and late blind (LB) subgroups. Compared with normal sighted subjects, CB and EB demonstrated a reduced degree of connectivity, an increased path length and a decreased global efficiency, especially in the inferior frontal gyrus and visual cortex. However, no such difference was found in LB. We also revealed significant correlation between onset age of blindness and the network properties. The results suggest that visual experience at early developmental period is critical to establish an intact, efficient anatomical network of the human brain. In order to evaluate the influence of blindness onset age on the white matter integrity of whole brain, we employed TBSS to explore the difference of white matter integrity in five groups (CB, EB, AB, LB and normal controls). Our finding revealed that significantly changed white matter integrity was mainly located in the occipital lobe, the temporal lobe and the posterior limb of internal capsule. Compare with normal sighted controls, the white matter integrity of all the blind groups reduced in the occipital and temporal lobe, which may be due to transneuronal degeneration and/or immaturity. However...
shelfnumXWLW1641
Other Identifier200828014628043
Language中文
Document Type学位论文
Identifierhttp://ir.ia.ac.cn/handle/173211/7559
Collection毕业生_硕士学位论文
Recommended Citation
GB/T 7714
李佳佳. 基于扩散张量成像的盲人脑解剖网络的研究[D]. 中国科学院自动化研究所. 中国科学院研究生院,2011.
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