Charting Brain Development in Graphs, Diagrams, and Figures from Childhood, Adolescence, to Early Adulthood: Neuroimaging Implications for Neuropsychology

The role of magnetic resonance (MR) neuroimaging in studying brain development in the first three decades of life is reviewed, in terms of its relevance to pediatric neuropsychology. This review places an emphasis on displaying development neuroimaging findings in various types of growth plots, diagrams and figures. MR imaging (MRI) methods can be divided into both structural and functional approaches for brain development quantification. Since MRI methods can readily separate brain parenchyma into white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF) spaces, depending on the anatomical region or region of interest (ROI), MRI quantification is typically in the form of volume, surface area, shape, and/or thickness. Diffusion tensor imaging (DTI) permits the computation of various quantitative metrics, especially sensitive to WM integrity, including the extraction and assessment of WM tracts. Functional MRI (fMRI) techniques provide physiological metrics that examine maturation through connectivity profiles. Regardless of the MRI method used for image quantification, dynamic changes of the brain occur throughout the first three decades of life, dominated by GM reductions associated with cellular pruning and WM increases, reflecting myelination and connectivity. From a neuroimaging perspective, when quantitative metrics show stabilization, this may be an indication of a neuroimaging-derived “brain age” metric. Future directions and the importance of understanding brain development and neuroimaging findings in the context of neural networks and their maturation as applied to pediatric neuropsychology are discussed.