Table 3.
Brain Locations of Lower Macromolecular Proton Fraction in Blast-mTBI Veterans (n=27) vs. Nonblast Veterans (n=16)
| Structurea | Tissueb | Coordinates (mm)c | Z-scored | % Reductione |
|---|---|---|---|---|
| R external capsule | WM | (−30, −1, 0) | 4.4 | 10.5 |
| R internal capsule, anterior limb | WM | (−17, 17, 9) | 4.0 | 12.3 |
| R superior longitudinal fasciculus | WM | (−44, −6, 27) | 4.1 | 16.3 |
| R superior frontal gyrus | GM | (−24, 59, 22) | 4.6 | 35.8 |
| WM | (−17, −13, 45) | 4.4 | 7.2 | |
| GM/WM | (−17, 8, 58) | 4.0 | 27.0 | |
| GM/WM | (−6, 32, 27) | 4.0 | 17.6 | |
| GM | (−24, 66, 7) | 4.0 | 36.4 | |
| R middle frontal gyrus | WM | (−39, 1, 47) | 4.4 | 19.6 |
| GM | (−46, 50, −2) | 4.1 | 28.1 | |
| GM/WM | (−37, 48, −4) | 4.3 | 16.7 | |
| L inferior frontal gyrus | GM/WM | (42, 5, 20) | 4.3 | 24.3 |
| R medial orbital gyrus | GM | (−26, 37, −16) | 4.2 | 30.5 |
| GM | (−21, 5, −11) | 4.1 | 18.4 | |
| R precentral gyrus | WM | (−19, −17, 45) | 4.4 | 8.1 |
| GM | (−46, −13, 43) | 4.1 | 19.6 | |
| R anterior cingulate gyrus | GM | (−3, 41, 18) | 4.5 | 23.6 |
| L subcallosal gyrus | GM | (15, 3, −14) | 4.3 | 32.5 |
| L superior parietal lobule | WM | (15, −62, 32) | 4.0 | 15.6 |
| R precuneus | WM | (−21, −58, 38) | 4.2 | 16.8 |
| L lingual gyrus | GM | (12, −91, −11) | 4.2 | 20.2 |
Assigned with reference to Talairach and Tournoux30 and John's Hopkins University71 brain atlases. R, right; L, left.
GM, gray matter; WM, white matter; GM/WM, gray matter/white matter border region.
Talairach atlas coordinates of significant between-group differences in MPF by whole brain voxel-wise analyses. For x-axis, positive values are left of midline and negative values are right of midline. For z-axis, positive values are superior to plane of line connecting anterior and posterior commissures. For y-axis, positive and negative values are anterior versus posterior (respectively) of the anterior commissure.
Z-score resulting from probability integral transformation of t-statistic for between-group comparison at voxel coordinates given in column 3.
Percent reduction (blast-mTBI vs. nonblast veterans) in mean MPF values for 4.5 mm diameter volumes-of-interest centered on Talairach atlas coordinates of significant (i.e., Z ≥4.0) voxel-wise between group differences.