Quantitative Susceptibility Mapping with Source Separation in Normal Brain Development of Newborns.

Area of Science:

• Neuroimaging
• Biophysics
• Developmental Neuroscience

Background:

• Quantitative susceptibility mapping (QSM) is crucial for assessing brain tissue composition, including myelination and iron deposition.
• Challenges exist in neonate brain analysis due to opposing susceptibility signals (myelin: negative, iron: positive) within the same voxel.
• Susceptibility source separation is a novel approach to address these challenges in the developing brain.

Purpose of the Study:

• To measure positive and negative magnetic susceptibility sources in the healthy neonate brain using QSM with susceptibility source separation.
• To characterize regional variations and age-related changes in susceptibility in key brain structures.
• To evaluate the potential of this technique for identifying early signs of abnormal myelination or iron levels.

Main Methods:

• Sixty-nine healthy neonates underwent MRI with gradient-echo imaging for QSM.
• Susceptibility source separation was performed using R2* data and linear modeling.
• Mean susceptibility values were calculated for various brain regions (GM, WM, deep GM nuclei, lobes) after atlas-based normalization.

Main Results:

• Sixty-five neonates were analyzed, showing distinct susceptibility patterns in different brain regions.
• White matter (WM) had lower positive and higher negative susceptibility than gray matter (GM).
• Regional differences were observed in the thalamus, putamen, globus pallidus, and brain lobes, with some correlating with neonate age.

Conclusions:

• The study highlights regional and temporal variations in neonatal brain susceptibility, linked to myelination and iron deposition.
• QSM with source separation shows promise for the early detection of myelination delays or iron deficiency in infants.
• This technique offers valuable insights into normal brain development and potential deviations.