The current project will be designed following a prospective longitudinal study design. All MRI scanning will be performed on a 3 Tesla Philips Achieva MRI scanner located in Imaging Research Center (IRC) in the Cincinnati Children's Hospital Research Foundation (CCHRF). Sedation will not be used for any of the test visits. The entire MRI series, including anatomical imaging, DTI, resting state fMRI, SWI, HARDI, ASL and BOLD will be completed in 65 minutes or less (see Table 1 for detailed specifications). All functional and neurocognitive testing will be performed at the Cincinnati Children's Hospital Human Performance Laboratory.