Concussion is a highly prevalent condition in adolescence, but it remains a clinical diagnosis that largely relies on subjective patient symptom-report as there are currently no reliable objective biomarkers for diagnosis. This study will ask adolescents with and without a concussion to undergo neuroimaging and neuropsychological testing to better understand the biological basis of brain pathology and to assess the predictive value of the brain imaging biomarkers with respect to clinical outcomes in adolescents with concussion. IRB 16-013207