FIGURE 1.

(a–d) Abnormal voxel calculations. (a) For each control subject, baseline images were subtracted from the corresponding follow up images. (b) At each voxel, abnormally high and abnormally low changes were respectively defined as +/− 2 SDs from the control population mean (pink regions under the distribution curve). (c) Postseason minus preseason change in diffusion images were created for each football subject. (d) Diffusion changes for each football subject were compared to that of the control population distribution. Abnormally high or low diffusion changes at each voxel were identified for each football subject. Abnormally high and low voxels for a low, medium, and high HIE subject are displayed in red on the Dartel template image. Note the graded differences in the number of abnormal voxels between subjects.