Study Design: We propose a prospective, observational study of 80 active duty military personnel who have sustained blast-related TBI. Initial scans will be performed within 4 days of injury at LRMC. Follow-up will occur monthly by telephone and in person at Washington University 6-12 months after injury. Clinical information on TBI outcomes collected will include global outcome assessments, neuropsychological testing for memory, attention and executive function deficits, motor performance measures, and clinician administered rating scales for depression and post-traumatic stress disorder. Controls will include 1) an additional group of 20 active duty military personnel with other injuries, but who have not had TBI, and 2) age, gender and education-based norms for standardized test and assessment results. Repeat DTI, resting-state fMRI, and conventional MRI will be performed to track the evolution of the injuries. Analysis approaches will include prespecified hypotheses based on known brain anatomical-clinical correlations and several exploratory approaches, as the structural bases for many post-traumatic neurological and neuropsychological deficits are not well understood. Non-parametric correlational statistical methods and rigorous correction for multiple comparisons will be employed. Expert collaborators and logistics coordinators will be or have already been recruited. Confidentiality and privacy will be tightly controlled.