Regional Variation in Human Thalamic Maturation Revealed by Diffusion Tensor Imaging of Premature Newborns
deIpolyi A, Berman J, Mukherjee P, Henry R, Vigneron D, Barkovich A, Veeraraghavan S
University of California, San Francisco
Diffusion tensor imaging (DTI) has revealed regional heterogeneity in preterm neocortical maturation. We examined whether this is also true of thalamic nuclei that are reciprocally interconnected with different cortical areas. We found that, throughout the thalamus, mean diffusivity and all three eigenvalues correlated negatively with age, whereas in most regions, anisotropy correlated positively with age. First-order thalamic relay nuclei projecting to primary sensorimotor cortex have lower diffusivity and eigenvalues, but higher anisotropy, than higher-order thalamic nuclei projecting to neocortical association areas. Our data support the hypothesis that the thalamus exhibits a hierarchical pattern of maturation analogous to the preterm neocortex.