背景:基于扩散MRI(dMRI)的纤维束成像是研究发育中大脑白质的有用工具。然而,由于子宫内dMRI的运动伪影和低分辨率,其在胎儿大脑中的应用受到限制,导致可靠性降低,这在以前的研究中几乎没有研究过。
目的:确定胎儿大脑中可追踪的纤维,并评估可重复性是否随胎龄(GA)而变化以及在大脑区域之间变化。
方法:前瞻性队列研究。
方法:共44例健康胎儿,GA在25至37(31±6)之间。
■3-T,弥散加权回波平面成像序列(每个受试者在同一疗程内进行2-5次重复dMRI扫描)。
结果:我们用约束的球形反卷积模型拟合了dMRI,并在八根纤维上进行了纤维束成像。我们提取了体积,分数各向异性,和每根纤维的纤维计数,并评估这些指标在每个受试者重复扫描之间的再现性。数据分为两个基于年龄的亚组(≤30周,N=28,并且>30周,N=16)用于进一步测试。
方法:通过方差分析和双样本t检验比较纤维之间的再现性。多重比较被错误发现率校正(5%被接受)。
结果:前丘脑辐射的可重复性,下纵束(ILF),call体(GCC),随着GA的提高,call体(BCC)显着降低(相关系数=0.525-0.823),早期GA(≤30周)和晚期GA(>30周)组胎儿之间的组间比较证实。皮质脊髓束,下额枕骨束,和GCC显示纤维计数的高再现性(加权骰子平均值=0.846vs.0.814),而BCC和ILF在两个年龄组中的重现性最低。
结论:研究表明,胎儿脑纤维束造影的可靠性取决于GA,并且在不同纤维之间有所不同。
方法:2技术效果:阶段2。
BACKGROUND: Tractography based on diffusion MRI (dMRI) is a useful tool to study white matter of the developing brain. However, its application in fetal brains is limited due to motion artifacts and low resolution of in utero dMRI, leading to reduced reliability, which was scarcely investigated in previous studies.
OBJECTIVE: To identify reliably traceable fibers in fetal brains and assess whether reproducibility varies with gestational age (GA) and varies between brain regions.
METHODS: Prospective cohort study.
METHODS: A total of 44 healthy fetuses with GAs between 25 and 37 (31 ± 6).
UNASSIGNED: 3-T, diffusion-weighted echo-planar imaging sequence (2-5 repeated dMRI scans within the same session per subject).
RESULTS: We fitted dMRI with constrained spherical deconvolution model and conducted
tractography on eight fibers. We extracted volume, fractional anisotropy, and fiber count for each fiber and assessed the reproducibility of these metrics between repeated scans within each subject. Data were divided into two age-based subgroups (≤30 weeks, N = 28, and >30 weeks, N = 16) for further tests.
METHODS: The reproducibility were compared between fibers by analysis of variance and two-sample t tests. Multiple comparisons were corrected by the false discovery rate (5% was accepted).
RESULTS: The reproducibility of the anterior thalamic radiation, inferior longitudinal fasciculus (ILF), genu of the corpus callosum (GCC), and body of the corpus callosum (BCC) significantly decreased with advancing GA (correlation coefficient = 0.525-0.823), as confirmed by group comparisons between fetuses in early GA (≤30 weeks) and late GA (>30 weeks) groups. Corticospinal tract, inferior fronto-occipital fasciculus, and GCC showed high reproducibility for fiber count (weighted dice average = 0.846 vs. 0.814), while BCC and ILF exhibited the lowest reproducibility in both age groups.
CONCLUSIONS: The study indicates that the reliability of fetal brain
tractography depends on GA and varies among different fibers.
METHODS: 2 TECHNICAL EFFICACY: Stage 2.