Clustering the infant brain tissues based on microstructural properties and maturation assessment using multi-parametric MRI

Microstructural and physiological changes are intense in the developing brain, thus considerably modifying parameters quantified by MRI (relaxation times, anisotropy and diffusivities). The latest advances in EPI enabled to non-invasively measure these parameters in infants in a reasonable acquisition time to follow brain maturation. To take advantage of the parameters complementarity, we first proposed to correct EPI distortions by a registration approach never applied on infants' data. We then clustered brain regions according to their different microstructural properties and maturation, without spatial priors. Results were in agreement with post-mortem studies : maturation proceeds from center to periphery; first maturing regions included primary regions, but also the amygdala and the medial cingular region. The most delayed regions were observed in superior frontal and parietal lobes. In future analyses, we will propose new partitions of the whole brain and of specific functional regions based on maturation patterns returned by this approach.