Proper timing for the evaluation of neonatal brain white matter development: a diffusion tensor imaging study

Area of Science:

• Neuroscience
• Developmental Biology
• Medical Imaging

Background:

• Neonatal brain development, specifically white matter (WM) maturation, is crucial for assessing neurological status at birth.
• Understanding age-related changes in neonatal WM is essential for accurate interpretation of brain imaging and neurobehavioral assessments.

Purpose of the Study:

• To determine the optimal timing for assessing neonatal brain maturity by analyzing postnatal age-related changes in white matter (WM).
• To explore the biphasic pattern of neonatal brain white matter development.

Main Methods:

• Diffusion tensor imaging (DTI) and fractional anisotropy (FA) were used to study white matter (WM) development in 133 neonates (30-42 weeks gestational age).
• Tract-based spatial statistics (TBSS), LOESS, and piecewise linear-fitting analyzed the relationship between FA and postnatal age.
• FA values in key tracts (CST, OR, AR, thal-PSC) were correlated with neurobehavioral scores.

Main Results:

• Postnatal age (days 1-28) positively correlated with FA in major white matter (WM) tracts.
• A biphasic development pattern was observed: mild FA increase before day 14, followed by accelerated growth.
• FA and neurobehavioral correlations were significantly higher in days 15-28 compared to days 1-14.

Conclusions:

• Neonatal brain white matter (WM) development occurs in two distinct phases: a close-to-birth period (first 14 days) and an accelerated maturation phase.
• Evaluations of neonatal brain status should preferably be conducted within the first two postnatal weeks.
• Postnatal age-related effects are critical for comparing preterm and term neonates.