正常成人脑区水平胼胝体纤维分支概率图谱的构建及连接模式分析

Construction of cortical level fiber branches probability maps for corpus callosum and analysis of their connectivity pattern in normal adults

目的基于扩散谱成像(DSI)技术,利用广义Q空间采样(GQI)重建技术构建正常成人脑区水平的胼胝体纤维分支概率图谱,并研究胼胝体纤维分支在脑区之间的连接模式。方法随机选取人类脑连接组计划(HCP)数据库(https://www.humanconnectome.org)的100名健康成年人的影像资料,男女各50名,平均年龄(25.1±2.3)岁。对DSI数据进行标准化处理后,利用GQI重建技术以胼胝体为种子点进行确定性纤维示踪,基于自动解剖标记图谱(AAL)提取双侧大脑半球间任意2个脑区之间胼胝体纤维束分支,构建脑区水平胼胝体纤维分支概率图谱。采用Bonferroni校正的配对t检验,比较各脑区同源连接及异源连接强度的差异。结果构建的胼胝体纤维分支概率图谱(https://gitee.com/yaojia01/CC)共包括156条胼胝体纤维束分支,主要分布于额、顶、枕叶共50个(25对)脑区中。同源连接18条,异源连接138条;其中双侧的尾状核、前扣带皮质、中扣带皮质、额下回岛盖部、顶下小叶、缘上回只有异源连接。50个脑区中有48个脑区的同源连接少于异源连接(P<0.05,Bonferroni校正),另外2个脑区中,右侧直回脑区的同源连接多于异源连接(P<0.05,Bonferroni校正),而右侧旁中央小叶的同源连接和异源连接差异无统计学意义(P>0.05)。结论根据构建的正常成人脑区水平胼胝体纤维分支概率图谱发现各脑区的胼胝体纤维连接以异源连接为主。

Objective By using generalized Q-space sampling(GQI)reconstruction based on diffusion spectroscopy imaging(DSI)technology,to construct probability map of corpus callosum fiber branches at cortical level of normal adult brain,and to study the connection pattern of corpus callosum fiber branches between brain regions.Methods The imaging data of 100 healthy adults(50 males and 50 females,25.1±2.3 years old)were randomly selected from the human brain connection group project(HCP)database(https://www.humanconnectome.org).After standard pretreatment of DSI data,deterministic fiber tracing was performed using corpus callosum as seed point using GQI reconstruction technique,and the branches of corpus callosum fiber tracts between any two brain regions between bilateral cerebral hemispheres were extracted based on automatic anatomical marker atlas(AAL),and the probability map of corpus callosum fiber branches at cortex-level was constructed.Bonferroni corrected paired t test was used to compare the strength of homologous connections and heterologous connections in different brain regions.Results Branches of corpus callosum fiber probability map(https://gitee.com/yaojia01/CC)was constructed,which included 156 corpus callosum fiber bundle branches,mainly distributed in50 brain regions(25 pairs)of frontal,parietal and occipital lobes.There were 18 homologous connections and 138 heterologous connections.The caudate nucleus,anterior cingulate cortex,middle cingulate cortex,inferior frontal gyrus,inferior parietal lobule and superior marginal gyrus only showed heterologous connections.In 48 of the 50 brain regions,the homologous connections were significantly less than the heterologous connections(P<0.05,Bonferroni correction).In the other 2 brain regions,the homologous connections in the right straight gyrus were more than heterologous connections(P<0.05,Bonferroni correction),and there was no significant difference between homologous connections and heterologous connections in the right paracentral lobule(P>0.05).Conclusion The branches probability atlas of corpus callosum fibers at the level of normal adult brain regions was constructed and it was found that the connections of corpus callosum fibers in each brain region were mainly heterologous connections.