Statistical Analysis

The statistical software MedCalc, version 11.1.1.0, was used for all statistical analyses. The normality of the data for each continuous parameter was assessed using the Kolmogorov–Smirnov test. Categorical and noncategorical clinical variables were compared between the two groups using Fisher’s exact test and the Mann–Whitney U-test, respectively. For the myelin content, the Mann–Whitney U-test was used to compare the average MVFs and total myelin volume at various locations between mTBI patients and controls. The Spearman rank correlation test was used to correlate the myelin volume parameters with the time interval between injury and MR imaging. For patients with an interval of 2 weeks or less between neuropsychological tests and MR images, the Spearman rank correlation test was also used to obtain correlations between myelin volume parameters and neuropsychological test scores. p values < 0.05 were considered statistically significant.