小年龄段孤独症谱系障碍与社会交流障碍相关白质纤维束的DTI研究

发布时间：2018-01-04 07:42

本文关键词：小年龄段孤独症谱系障碍与社会交流障碍相关白质纤维束的DTI研究　出处：《重庆医科大学》2014年硕士论文　论文类型：学位论文

【摘要】：目的：通过弥散张量成像（DTI）和各向异性分数（FA）、平均扩散系数（ADC）的测量，研究小年龄段的孤独症谱系障碍(ASD）与社会交流障碍相关的脑白质纤维微结构特点，探讨ASD脑白质微结构随年龄的变化趋势。材料与方法： ASD组16例，年龄1.5岁～5.6岁，平均（3.21.4）岁，男14例，女2例；对照组10例，年龄1.5～5.7岁，平均（3.41.4）岁，男7例，女3例。使用单次激发平面回波DTI序列成像，在全盲状态下采用机器自带的后处理FuncTool软件进行DTI分析，得到FA图、ADC图和颜色编码图。按照约翰霍普金斯大学提出的白质纤维束示踪图集定位纤维束，选择与ASD交流障碍相关的纤维束作为感兴趣区(ROI），，包括胼胝体膝部、体部及压部、双侧扣带束、双侧钩束、双侧下额枕束、双侧下纵束。每个区域画制2-3个ROI，每个ROI面积35mm2～45mm2，求得平均FA、ADC。ASD组与正常对照组之间FA及ADC的比较采用独立样本t检验，P0.05认为有统计学意义。ASD组和正常对照组的FA、ADC与年龄的关系采用线性回归分析。结果：ASD胼胝体压部（P=0.030）及右侧扣带束(P=0.037)FA较正常对照组的FA显著增高，胼胝体压部（P=0.015）及左侧扣带束ADC（P=0.026）较正常对照组的ADC显著减少。ASD组及对照组大部分白质纤维束FA随年龄的升高而增加，ADC随年龄的递增而下降。与正常对照组相比，ASD组FA值（ADC值）随年龄升高（降低）的幅度在部分脑区较低，而在部分脑区较高。结论：（1）DTI能够准确定位并评估白质纤维束的完整性，是研究ASD神经解剖基础的理想手段。（2）小年龄段ASD白质纤维束的FA较正常对照组高，ADC较正常对照组低，推测ASD早期部分脑区可能存在过度髓鞘化现象。（3）小年龄段ASD大部分脑区FA值随年龄增长而增长，但仅少数脑区FA值随年龄增长的幅度低于对照组，提示ASD不同脑区白质纤维髓鞘化异常的出现并不同步。
[Abstract]:Objective: by using diffusion tensor imaging (DTI) and fractional anisotropy (FA), average diffusion coefficient (ADC) measurements, autism spectrum disorders of small age (ASD) of cerebral white matter fiber associated with social communication disorders micro structure characteristics of ASD whitematter microstructure change with age.
Materials and methods: 16 cases of ASD group, aged 1.5 to 5.6 years old, the average age (3.21.4), male 14 cases, female 2 cases; 10 cases in the control group, aged 1.5 to 5.7 years old, the average age (3.41.4), male 7 cases, female 3 cases. Using single shot echo planar imaging sequence DTI in the blind state, using its own FuncTool postprocessing software for DTI analysis, FA diagram, ADC diagram and color encoding. According to the diagram presented by Johns Hopkins University white matter tractography atlas orientation of fiber bundles, selection associated with ASD communication obstacles in the fiber bundle as regions of interest (ROI), including the corpus callosum. Knee, body and splenium, bilateral cingulum, bilateral uncinate fasciculus, bilateral inferior fronto occipital fasciculus, bilateral inferior longitudinal fasciculus. 2-3 ROI of each region painting system, each ROI area of 35mm2 ~ 45mm2, the average FA, compared with FA and ADC between ADC.ASD group and normal control group, independent samples t test P0.05 was considered statistically significant.A The relationship between FA, ADC and age in the SD group and the normal control group was analyzed by linear regression.
Results: ASD splenium of corpus callosum (P=0.030) and right cingulate fasciculus (P=0.037 FA) compared with the normal control group, FA increased significantly, the splenium of the corpus callosum (P=0.015) and the left cingulum bundle ADC (P=0.026) compared with the normal control group, ADC was significantly reduced in.ASD group and control group the majority of white matter fibers FA increase with age increased, ADC decreased with increasing age. Compared with the normal control group, ASD group, FA value (ADC value) with the age increase (decrease) in the range of brain regions is relatively low, but in some brain regions is higher.
Conclusion: (1) DTI can accurately locate and assess the integrity of white matter fiber, is an ideal method for the research of ASD neural anatomy. (2) the small age ASD white matter fiber FA was higher than normal control group, ADC lower than the normal control group, presumably ASD early brain regions are over myelination phenomenon. (3) the small age ASD most brain areas and the value of FA increase with the increase of age, but only a few areas of the brain FA values increase with age significantly lower than the control group, suggesting that ASD in different regions of the brain white matter myelination abnormalities are not synchronized.

【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R445.2;R749.94

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