Journal Article

Mapping the asynchrony of cortical maturation in the infant brain: A MRI multi-parametric clustering approach

Hertz-Pannier, L., Dubois, J., Adibpour, P., Poupon, C., Lebenberg, J., Mangin, J.-F., Thirion, B., Dehaene-Lambertz, G., Leroy, F.

2019

Overview

While the main neural networks are in place at term birth, intense changes in cortical microstructure occur during early infancy with the development of dendritic arborization, synaptogenesis and fiber myelination. These maturational processes are thought to relate to behavioral acquisitions and the development of cognitive abilities. Nevertheless, in vivo investigations of such relationships are still lacking in healthy infants. To bridge this gap, we aimed to study the cortical maturation using non-invasive Magnetic Resonance Imaging, over a largely unexplored period (1–5 post-natal months). In a first univariate step, we focused on different quantitative parameters: longitudinal relaxation time (T1), transverse relaxation time (T2), and axial diffusivity from diffusion tensor imaging (λ//) These individual maps, acquired with echo-planar imaging to limit the acquisition time, showed spatial distortions that were first corrected to reliably match the thin cortical ribbon identified on high-resolution T2-weighted images. Averaged maps were also computed over the infants group to summarize the parameter characteristics during early infancy. In a second step, we considered a multi-parametric approach that leverages parameters complementarity, avoids reliance on pre-defined regions of interest, and does not require spatial constraints. Our clustering strategy allowed us to group cortical voxels over all infants in 5 clusters with distinct microstructural T1 and λ// properties The cluster maps over individual cortical surfaces and over the group were in sound agreement with benchmark post mortem studies of sub-cortical white matter myelination, showing a progressive maturation of 1) primary sensori-motor areas, 2) adjacent unimodal associative cortices, and 3) higher-order associative regions. This study thus opens a consistent approach to study cortical maturation in vivo. [Display omitted] •The cortical maturation was studied in infants between 1 and 5 months of age.•Diffusion and relaxometry MRI were analyzed in univariate and multivariate manner.•Clustering analyses provided reliable results both at the subject and group levels.•Distinct maturation profiles were shown across regions of the infant cortex.

• Publisher: Elsevier Inc,Elsevier Limited,Elsevier
• Subject: Age / Anisotropy / Babies / Brain / Brain - diagnostic imaging / Brain - growth & development / Brain mapping / Brain Mapping - methods / Cluster Analysis / Clustering / Cognitive ability / Cognitive science / Complementarity / Cortex / Cortical maturation / Dendritic branching / Diffusion tensor imaging DTI / Engineering Sciences / Female / Human brain project (HBP) / Humans / Image Processing, Computer-Assisted / Infancy / Infant / Infants / Magnetic Resonance Imaging / Magnetic resonance imaging MRI / Male / Maturation / Myelination / Nerve Net - diagnostic imaging / Nerve Net - growth & development / Neural networks / Neuroimaging / Neuroscience / NMR / Nuclear magnetic resonance / Premature birth / Quantitative T1 and T2 mapping / Sensorimotor integration / Signal and Image processing / Standard deviation / Substantia alba / Synaptogenesis