Graduate Program for Neuroscience Boston University Boston MA USA.
Department of Neurology Boston Children's Hospital Boston MA USA.
Brain Behav. 2018 Jan 18;8(2):e00834. doi: 10.1002/brb3.834. eCollection 2018 Feb.
Adolescents with d-transposition of the great arteries (d-TGA) who had the arterial switch operation in infancy have been found to have structural brain differences compared to healthy controls. We used cortical thickness measurements obtained from structural brain MRI to determine group differences in global brain organization using a graph theoretical approach.
Ninety-two d-TGA subjects and 49 controls were scanned using one of two identical 1.5-Tesla MRI systems. Mean cortical thickness was obtained from 34 regions per hemisphere using Freesurfer. A linear model was used for each brain region to adjust for subject age, sex, and scanning location. Structural connectivity for each group was inferred based on the presence of high inter-regional correlations of the linear model residuals, and binary connectivity matrices were created by thresholding over a range of correlation values for each group. Graph theory analysis was performed using packages in R. Permutation tests were performed to determine significance of between-group differences in global network measures.
Within-group connectivity patterns were qualitatively different between groups. At lower network densities, controls had significantly more long-range connections. The location and number of hub regions differed between groups: controls had a greater number of hubs at most network densities. The control network had a significant rightward asymmetry compared to the d-TGA group at all network densities.
Using graph theory analysis of cortical thickness correlations, we found differences in brain structural network organization among d-TGA adolescents compared to controls. These may be related to the white matter and gray matter differences previously found in this cohort, and in turn may be related to the cognitive deficits this cohort presents.
患有大动脉转位（d-TGA）的青少年在婴儿期接受动脉调转手术后，与健康对照组相比，其大脑结构存在差异。我们使用从结构脑 MRI 获得的皮质厚度测量值，通过图论方法确定大脑整体组织差异。
92 名 d-TGA 患者和 49 名对照者使用两种相同的 1.5T MRI 系统进行扫描。使用 Freesurfer 从每个半球的 34 个区域获得平均皮质厚度。线性模型用于每个脑区，以调整受试者年龄、性别和扫描位置。基于线性模型残差的高区域间相关性，推断每组的结构连接，通过为每组设定一系列相关值的阈值来创建二进制连接矩阵。使用 R 中的包进行图论分析。采用置换检验来确定组间全局网络指标差异的显著性。
组内连接模式在两组之间存在定性差异。在较低的网络密度下，对照组具有明显更多的长程连接。两组之间的枢纽区域的位置和数量存在差异：在大多数网络密度下，对照组的枢纽区域数量更多。与 d-TGA 组相比，对照组的网络在所有网络密度下都具有明显的右侧不对称性。
通过皮质厚度相关性的图论分析，我们发现 d-TGA 青少年的大脑结构网络组织与对照组存在差异。这些差异可能与该队列先前发现的白质和灰质差异有关，进而可能与该队列存在的认知缺陷有关。
