Studying how the brain develops and becomes functional is a prerequisite to understand the complexity of developmental pathologies. Thanks to Magnetic Resonance Imaging (MRI), it is now possible to image the baby’s brain non-invasively, and to provide subtle correlations between its anatomical development and the early acquisition of cognitive functions.
But imaging the immature brain implies several constraints at the levels of data acquisition and post-processing, because the baby may move, the examination length must then remain short, and because the size of cerebral structures and the image contrast are very different in comparison with the adult brain. Dedicated methodologies must then be applied to provide valid and instructive information on the development of cortical and white matter networks.
In this presentation, I will describe two recent MRI studies which evaluated the setting up of cortical morphology and connectivity under an original perspective. The first study has focused on the cortical folding patterns (formation of gyri and sulci), in preterm newborns from six to eight months of gestational age, by using T2-weighted conventional MRI. The second study has mapped the organization and maturation of major white matter fiber bundles (commissural, projection, association and limbic fascicles), in one- to four-months-old healthy infants, with diffusion tensor imaging (DTI) and tractography.
Both MRI studies have highlighted spatio-temporal differences in the maturation of brain regions, as well as early anatomical asymmetries between cerebral hemispheres. They have also emphasized the relationships between the structural development of the brain and the infant’s psycho-motor acquisitions after birth.