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Updated: Dec 17, 2025
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Long-term development of white matter fibre density and morphology up to 13 years after preterm birth: A fixel-based
Claire E Kelly1, Deanne K Thompson2, Sila Genc3
1Victorian Infant Brain Study (VIBeS), Murdoch Children's Research Institute, Melbourne, Australia; Developmental Imaging, Murdoch Children's Research Institute, Melbourne, Australia.
Insights
Very preterm birth impacts white matter development in children, leading to altered axonal growth evident into adolescence. Perinatal factors further exacerbate these long-term brain development changes.
Area of Science:
- Neuroscience
- Developmental Biology
- Medical Imaging
Background:
- Infants born very preterm (VP) face risks of brain injury and altered development.
- Longitudinal studies on VP birth effects on childhood white matter are limited.
- Novel fixel-based analysis (FBA) allows detailed, sub-voxel white matter analysis.
Purpose of the Study:
- To investigate long-term effects of VP birth on white matter development.
- To examine the influence of perinatal risk factors on fibre development.
- To apply FBA for detailed analysis of white matter microstructure and macrostructure.
Main Methods:
- Acquired diffusion MRI from VP and full-term (FT) children at ages ~7 and ~13 years.
- Utilized FBA to analyze fibre density (FD), cross-section (FC), and combined (FDC) metrics.
- Compared VP and FT groups cross-sectionally and longitudinally, examining perinatal risk factors.
Main Results:
- VP children showed lower FD, FC, and FDC in major white matter tracts compared to FT children.
- Slower FDC development observed in VP children's corpus callosum and corticospinal tract.
- Lower gestational age, birth weight, and neonatal abnormalities correlated with reduced FBA metrics in VP children.
Conclusions:
- VP birth is linked to long-term, tract-specific alterations in axonal development.
- Perinatal risk factors significantly influence white matter development trajectories.
- FBA provides a sensitive method for assessing subtle white matter changes in VP individuals.
Background:
It is well documented that infants born very preterm (VP) are at risk of brain injury and altered brain development in the neonatal period, however there is a lack of long-term, longitudinal studies on the effects of VP birth on white matter development over childhood. Most previous studies were based on voxel-averaged, non-fibre-specific diffusion magnetic resonance imaging (MRI) measures, such as fractional anisotropy. In contrast, the novel diffusion MRI analysis framework, fixel-based analysis (FBA), enables whole-brain analysis of microstructural and macrostructural properties of individual fibre populations at a sub-voxel level. We applied FBA to investigate the long-term implications of VP birth and associated perinatal risk factors on fibre development in childhood and adolescence.
Methods:
Diffusion images were acquired for a cohort of VP (born <30 weeks' gestation) and full-term (FT, ≥37 weeks' gestation) children at two timepoints: mean (SD) 7.6 (0.2) years (n = 138 VP and 32 FT children) and 13.3 (0.4) years (n = 130 VP and 45 FT children). 103 VP and 21 FT children had images at both ages for longitudinal analysis. At every fixel (individual fibre population within an image voxel) across the white matter, we compared FBA metrics (fibre density (FD), cross-section (FC) and a combination of these properties (FDC)) between VP and FT groups cross-sectionally at each timepoint, and longitudinally between timepoints. We also examined associations between known perinatal risk factors and FBA metrics in the VP group.
Results:
Compared with FT children, VP children had lower FD, FC and FDC throughout the white matter, particularly in the corpus callosum, tapetum, inferior fronto-occipital fasciculus, fornix and cingulum at ages 7 and 13 years, as well as the corticospinal tract and anterior limb of the internal capsule at age 13 years. VP children also had slower FDC development in the corpus callosum and corticospinal tract between ages 7 and 13 years compared with FT children. Within VP children, earlier gestational age at birth, lower birth weight z-score, and neonatal brain abnormalities were associated with lower FD, FC and FDC throughout the white matter at both ages.
Conclusions:
VP birth and concomitant perinatal risk factors are associated with fibre tract-specific alterations to axonal development in childhood and adolescence.
