Fig. 3.

Number of abnormal regions of fractional anisotropy in concussive blast TBI and combat-deployed controls at 5-year outcome. To account for the potential heterogeneity of brain injury, the total number of abnormal regions of FA were summed for each participant. Abnormality was defined as a value that was > 2 standard deviations below the mean of the control value for that region. To compute this summation for control participants, a “leave one out” approach was employed and the mean and standard deviation by region were rederived for each control omitting their scan data. The graph summarizes the percent of participants by group with abnormal regions.