A novel fixel-based approach for resolving neonatal white matter microstructure from clinical diffusion MRI

Area of Science:

• Neuroimaging
• Developmental Neuroscience
• Medical Physics

Background:

• Preterm birth disrupts neonatal brain development, leading to neurodevelopmental disorders.
• Standard neuroimaging faces challenges in premature infants due to low data quality and immature brain structures.
• Understanding white matter development in neonates is crucial but mechanisms remain unclear.

Purpose of the Study:

• To develop and present an advanced diffusion magnetic resonance imaging (dMRI) method for examining white matter microstructure in premature neonates.
• To investigate the relationship between white matter microstructural metrics, postmenstrual age, and neonatal illness severity.
• To establish a practical framework for studying neonatal brain development in clinical settings.

Main Methods:

• Utilized a novel dMRI approach resolving multiple tissue compartments for detailed white matter fiber orientation and quantification.
• Employed automated segmentation algorithms to measure microstructural metrics across key brain tracts and subcortical regions.
• Analyzed data from a cohort of clinically-acquired premature neonates.

Main Results:

• Successfully segmented and reconstructed numerous white matter tracts in the neonatal brain.
• Demonstrated tract-specific developmental trajectories, with early-maturing pathways showing higher microstructural organization.
• Found modest, tissue-specific associations between neonatal illness severity and white matter microstructural properties.

Conclusions:

• Advanced microstructural dMRI can extract meaningful white matter measurements from clinical scans in premature infants.
• This method provides a practical framework for studying neonatal brain development in real-world hospital settings.
• The technique allows for non-invasive study of vulnerable populations at very young ages, prior to behavioral assessments.