More than myelin: Probing white matter differences in prematurity with quantitative T1 and diffusion MRI.
More than myelin: Probing white matter differences in prematurity with quantitative T1 and diffusion MRI.
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不仅仅是髓磷脂：利用定量 T1 和扩散 MRI 探测早产儿白质差异。
DOI：
10.1016/j.nicl.2019.101756
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Feldman,HeidiM
中科院分区：
文献类型：
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作者：
Travis,KatherineE;Castro,MariaRH;Berman,Shai;Dodson,CoryK;Mezer,AvivA;Ben-Shachar,Michal;Feldman,HeidiM
目的我们将扩散 MRI (dMRI) 与定量 T1 (qT1) 松弛测量法结合起来，对早产和足月学龄儿童样本进行分析，以确定早产组胼胝体内各向异性分数 (FA) 的减少是否可以通过髓鞘质含量减少来解释，如 qT1 扫描中的 R1 (1/T1) 所示。方法 8 岁早产儿童（n=29；GA） 22-32 周）和足月 (n=24) 接受 dMRI 和 qT1 扫描。根据皮质投影区（枕叶、颞叶、运动和前额叶），在个体原生空间中将胼胝体的四个细分部分进行分割。沿每个分区的束轨迹对分数各向异性 (FA) 和 R1 进行量化，并在两个出生组之间进行比较。结果与对照组相比，早产儿在 4 个分析的胼胝体分区（颞叶、运动和前额段）中的 3 个中表现出 FA 显着降低，而在 4 个胼胝体分区（颞叶和运动节段）中仅 2 个中的 R1 显着降低。在术语组中，FA 和 RD 与胼胝体颞叶区域内的 R1 显着相关，但与胼胝体前额分区无关；仅在早产儿组中，RD 与前分区中的 R1 相关。结论 以 R1 为索引的髓鞘质含量导致早产儿和足月儿之间白质的部分差异，但不是全部差异。其他因素，例如轴突直径和方向一致性，可能导致胼胝体前额段的 FA 差异，而 R1 无法很好地解释这一差异。
ObjectiveWe combined diffusion MRI (dMRI) with quantitative T1 (qT1) relaxometry in a sample of school-aged children born preterm and full term to determine whether reduced fractional anisotropy (FA) within the corpus callosum of the preterm group could be explained by a reduction in myelin content, as indexed by R1 (1/T1) from qT1 scans.Methods8-year-old children born preterm (n= 29; GA 22–32 weeks) and full term (n= 24) underwent dMRI and qT1 scans. Four subdivisions of the corpus callosum were segmented in individual native space according to cortical projection zones (occipital, temporal, motor and anterior-frontal). Fractional anisotropy (FA) and R1 were quantified along the tract trajectory of each subdivision and compared across two birth groups.ResultsCompared to controls, preterm children demonstrated significantly decreased FA in 3 of 4 analyzed corpus callosum subdivisions (temporal, motor, and anterior frontal segments) and decreased R1 in only 2 of 4 corpus callosum subdivisions (temporal and motor segments). FA and RD were significantly associated with R1 within temporal but not anterior frontal subdivisions of the corpus callosum in the term group; RD correlated with R1 in the anterior subdivision in the preterm group only.ConclusionsMyelin content, as indexed by R1, drives some but not all of the differences in white matter between preterm and term born children. Other factors, such as axonal diameter and directional coherence, likely contributed to FA differences in the anterior frontal segment of the corpus callosum that were not well explained by R1.