Track-weighted imaging analysis of white matter microstructures in healthy children: Sex and hemispheric differences.
Track-weighted imaging analysis of white matter microstructures in healthy children: Sex and hemispheric differences.
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健康儿童白质微结构的轨迹加权成像分析：性别和半球差异。
DOI：
10.1117/12.2607490
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Ou,Xiawei
中科院分区：
文献类型：
--
作者：
Raja,Rajikha;Na,Xiaoxu;Glasier,Charles;Badger,Thomas;Akmyradov,Chary;Ou,Xiawei
先前的研究已经阐明了人类功能和行为中性别差异的结构基础。扩散加权磁共振成像（DW-MRI）是一种广泛应用于研究人脑白质结构组织的非侵入性成像技术。虽然许多报告 WM 结构性别差异的 DW-MRI 研究都是基于扩散张量成像 (DTI) 测量，但束特定的微观结构差异需要进一步研究。在本研究中，我们旨在基于新型轨迹加权成像 (TWI) 分析，调查健康 8 岁儿童白质微结构发育的性别差异和性别特异性半球差异。平均路径长度图 (APM) 是 TWI 对比度，其中利用穿过体素的纤维的平均长度。在这项研究中，我们采用了特定区域的 APM 测量来评估 WM 微观结构发育的性别差异。总共分析了 37 个 WM 束，包括 7 个连合束、9 个双侧关联束和 6 个双侧投射束。为每个区域生成了 APM 地图。使用 APM 地图的平均值进行按区域分组测试。使用基于一般线性模型的组比较来测试性别差异。年龄和总脑容量作为协变量纳入组分析中。对 15 个双侧束进行性别特异性半球差异。对左 > 右和右 > 左病例独立进行一个样本 t 检验，并根据年龄和大脑半球总体积控制 APM 测量。在校正了占束总数的多重比较后，P 值<0.05 被认为是显着的。男孩和女孩在 11 个 WM 束中的 APM 测量值显示出显着的性别差异，包括胼胝体头端体 (CC)、左下额枕束 (IFOF)、右侧扣带回、双侧第一和第二段上纵束 (SLF)、右侧中纵束 (MLF)、双侧额桥脑 (FPT) 和右顶枕脑桥束（POPT）。性别差异显示，与女孩相比，男孩这 11 个区域的 APM 值更高。在男孩和女孩的半球差异分析中，2个束、弓状束和视辐射显示左侧束的APM高于右侧； 5 个束、IFOF、MLF、SLF 第三段、FPT 和上丘脑辐射显示右侧束的 APM 高于左侧。这表明男孩和女孩在这 7 个束上具有相似的横向不对称性。此外，男孩的前丘脑放射（ATR）显示左束APM较高，右侧4个束、SLF第一段、POPT、下纵束和皮质脊髓束显示右侧APM较高。在女孩中，右半球的 SLF 第二段和钩束表现出较高的 APM。这些结果表明男孩和女孩之间 7 个束有不同的横向不对称性。总体而言，即使在控制了大脑总体积后，男孩在大多数神经束中都表现出较高的平均纤维长度。
Structural substrates of sex differences in human function and behavior have been elucidated in previous studies. Diffusion weighted magnetic resonance imaging (DW-MRI) is a widely used non-invasive imaging technique in studying human brain white matter structural organization. While many DW-MRI studies reporting sex differences in WM structure are based on diffusion tensor imaging (DTI) measures, tract specific microstructural differences require further investigation. In this study, we aim to investigate sex differences and sex-specific hemispheric differences in white matter microstructural development in healthy 8-year-old children based on novel track weighted imaging (TWI) analysis. Average pathlength map (APM) is a TWI contrast in which the average length of fibers passing through a voxel is utilized. In this study, we employed tract specific APM measures to evaluate sex differences in WM microstructural development. A total of 37 WM tracts were analyzed including 7 commissural tracts, 9 bilateral association tracts and 6 bilateral projection tracts. APM maps were generated for each tract. Tract-wise group tests were done using the mean values of APM maps. Sex differences were tested using general linear model based group comparisons. Age and total brain volume were included as covariates in the group analysis. Sex specific hemispheric differences were performed for the 15 bilateral tracts. One sample t-tests were done independently for left>right and right>left cases and the APM measures were controlled for age and total cerebral hemispheric volume. P-values<0.05 were considered significant after correcting for multiple comparisons accounting for the total number of tracts. Significant sex differences were revealed in APM measures between boys and girls in 11 WM tracts including rostral body of corpus callosum (CC), left inferior fronto-occipital fasciculus (IFOF), right cingulum, bilateral first and second segments of superior longitudinal fasciculus (SLF), right middle longitudinal fasciculus (MLF), bilateral fronto-pontine (FPT) and right parieto-occipital pontine tracts (POPT). The sex differences showed higher APM values for these 11 tracts in boys as compared to that of girls. In hemispheric differences analysis for both boys and girls, 2 tracts, arcuate fasciculus and optic radiation showed higher APM in left tracts as compared right; 5 tracts, IFOF, MLF, third segment of SLF, FPT and superior thalamic radiation showed higher APM in right tracts as compared to left. This indicates that boys and girls possess similar lateral asymmetries in these 7 tracts. Additionally, anterior thalamic radiation (ATR) showed higher APM in left tract and 4 tracts, first segment of SLF, POPT, inferior longitudinal fasciculus and cortico-spinal tract showed higher APM in right for boys. In girls, second segment of SLF and uncinate fasciculus showed higher APM in right hemisphere. These results indicate different lateral asymmetries between boys and girls for 7 tracts. Overall, boys showed higher average fiber length in most of the tracts, even after controlling for total brain volume.