Non-Gaussian diffusion metrics in development
Diffusion MRI techniques, such as diffusion tensor imaging (DTI) and, more recently, non-Gaussian techniques, such as diffusion kurtosis imaging (DKI), have made it possible to obtain valuable information relating to in vivo microstructural tissue changes and neuronal circuitry during brain development.
Patterns of cerebral maturation and decline render non-monotonic lifespan age trajectories of DTI/DKI metrics. Cognitive changes in early maturation are associated with changes in brain integrity and circuitry. Until now, only a very few studies of non-Gaussian diffusion have reported findings in relation to brain development based on DKI.
The purpose of this work is to compare the sensitivity of DTI, DKI, and other non-Gaussian methods to age-related microstructural changes along specific fibres in a group of children and in a (reference) group of middle-aged adults. We aim to explore which specific brain regions continue to develop throughout late childhood into the adulthood, as revealed by more advanced metrics. For between-group analysis, whole brain Tract-Based Spatial Statistics (TBSS) will be used, along with atlas based averaging over 20 anatomically defined regions.
Our findings thus far suggest a high sensitivity of non-Gasussian diffusion metrics as a biomarker of microstructural development and regional heterogeneity, as well as of the heterochronicity of various white matter tract groups, such as association, projection and commissural fibres, beyond pre-adolescence.
Literature
- Grinberg, F., Maximov, II, Farrher, E., et al. Diffusion kurtosis metrics as biomarkers of microstructural development: A comparative study of a group of children and a group of adults. Neuroimage, 2017, 144:12-22 (see also references therein).
- Paydar, A., Fieremans, E., Nwankwo, et al. Diffusional kurtosis imaging of the developing brain. AJNR Am J Neuroradiol, 2014, 35: 808-814.
- Lebel, C., Gee, M., Camicioli, R., et al. Diffusion tensor imaging of white matter tract evolution over the lifespan. Neuroimage, 2012, 60:340-352.
- Kochunov, P., Williamson, D.E., Lancaster, J., et al. Fractional anisotropy of water diffusion in cerebral white matter across the lifespan. Neurobiol Aging, 2012, 33: 9-20.
- Hasan, K.M., Kamali, A., Abid, H., et al. Quantification of the spatiotemporal microstructural organization of the human brain association, projection and commissural pathways across the lifespan using diffusion tensor tractography. Brain Struct Funct, 2010, 214:361-373.