注意缺陷多动障碍患儿脑结构和功能磁共振成像研究

目的使用三维高分辨结构磁共振和静息态功能磁共振成像技术研究注意缺陷多动障碍(attention deficit/hyperactivity disorder,ADHD)儿童的脑部改变,探讨其脑功能改变是否具有结构基础。材料与方法对10例ADHD患儿及10例正常对照组儿童进行全脑扫描,获取高分辨T1加权图像,得到每个被试的灰质及白质体积参数图;获取静息态功能图像,得到低频振幅(amplitude of low frequency fluctuation,ALFF)参数图。采用基于体素的分析方法比较两组被试参数图之间的差别。结果与正常对照组相比,ADHD患儿双侧额中回、中央前回、前扣带皮质、壳核,左侧眶额皮质、尾状核及右侧小脑的灰质体积减小;双侧前额叶白质、胼胝体前部和后部及左侧眶额白质体积减小。在前扣带回、前额叶、尾状核等区域,ADHD患儿存在显著的ALFF的升高,提示自发功能活动更加活跃。结论 ADHD儿童在脑部功能和结构两方面均有异常,且存在相互关联,揭示该疾病的病理机制。

A study of brain structural and functional magnetic resonance imaging in children with attention deifcit hyperactivity disorder

Objective:To investigate the structural and functional brain changes in ADHD children using MRI.Materials and Methods:Ten ADHD children and 10 matched healthy controls underwent whole brain MRI scans on a GE 1.5 T scanner. High resolution 3-dimensional T1 weighted images and resting-state functional MRI were acquired. From MRI data, parametric maps (the volume maps of gray/white matter tissues and ALFF) were computed in standard toolkits, and group comparisons were performed in SPM8 using a voxel-based approach.Results:Compared with healthy controls, children with ADHD showed decrease of gray matter volumes in the bilateral mid-frontal cortex, precentral cortex, anterior cingulate cortex, putamen, and left orbitofrontal cortex and right caudate and cerebellum, decrease of white matter volumes in the bilateral prefrontal gyrus, anterior and posterior of corpus callosum and left orbitofrontal gyrus, and increased ALFF in bilateral anterior cingulate cortex, right mid- and superior-frontal cortex.Conclusion:ADHD is associated with both structural and functional deifcits in brain development. High resolution 3D T1WI and rs-fMRI provides complementary neuropathological information underlying ADHD.