Table 2.
Significant Differences in DTI Metrics between Control and TBI Groups at the Early and 12-Month MRI Time-Points Reported as t-Statistics
| |
|
cMild/mod |
Severe |
||
|---|---|---|---|---|---|
| Region | Early | 12-month | Early | 12-month | |
| FA | ALIC/basal ganglia | ns | -3.794 *** | -3.913 *** | -4.620 *** |
| Brainstem | ns | -2.917 ** | ns | -2.890 ** | |
| Corpus callosum | ns | ns | -4.375 *** | -4.581 *** | |
| Frontal white matter | ns | -3.073 ** | ns | -2.683 ** | |
| Occipital white matter | ns | -3.610 *** | -4.023 *** | -3.904 *** | |
| Parietal white matter | -3.606 *** | -4.414 *** | ns | -4.346 *** | |
| Temporal white matter | ns | ns | ns | ns | |
| ADC | ALIC/basal ganglia | ns | ns | ns | ns |
| Brainstem | ns | ns | ns | ns | |
| Cerebellum | ns | ns | ns | ns | |
| Frontal white matter | ns | ns | ns | 3.860 *** | |
| Occipital white matter | 2.737 ** | 5.025 *** | ns | 4.358 *** | |
| Parietal white matter | ns | 3.806 *** | ns | 4.394 *** | |
| Temporal white matter | ns | 3.268 ** | ns | 4.012 *** | |
| PLIC/thalamus | -2.018 * | ns | ns | ns | |
| AD | ALIC/basal ganglia | ns | ns | -3.013 ** | ns |
| Brainstem | ns | ns | -3.996 *** | ns | |
| Corpus callosum | ns | ns | -3.381 *** | ns | |
| Frontal white matter | ns | ns | ns | 3.717 *** | |
| Occipital white matter | ns | 3.250 ** | ns | ns | |
| Parietal white matter | ns | 2.645 ** | ns | 3.490 *** | |
| Temporal white matter | ns | 2.641 ** | ns | 3.723 *** | |
| PLIC/thalamus | ns | ns | ns | ns | |
| RD | ALIC/basal ganglia | ns | 3.195 ** | ns | 3.947 *** |
| Brainstem | ns | ns | ns | ns | |
| Cerebellum | ns | ns | ns | ns | |
| Corpus callosum | ns | ns | ns | 3.796 *** | |
| Frontal white matter | ns | 2.654 ** | ns | 3.772 *** | |
| Occipital white matter | ns | 5.230 *** | ns | 4.872 *** | |
| Parietal white matter | ns | 4.296 *** | ns | 4.635 *** | |
| Temporal white matter | ns | 3.136 *** | ns | 3.697 *** | |
A negative t statistic indicates an inverse linear relationship between the injury severity and the DTI metric.
Between-group comparisons at the early time point showed that only corpus callosum FA differed significantly between the groups (bold; t = -2.719; p = 0.02)
p < 0.01; ***p < 0.001.
DTI, diffusion tensor imaging; TBI, traumatic brain injury; MRI, magnetic resonance imaging; cMild/mod, complicated mild/moderate TBI; FA, fractional anisotropy; ALIC, anterior limb internal capsule; ns; ADC, apparent diffusion coefficient; AD, axial diffusivity; PLIC, posterior limb internal capsule; RD, radial diffusivity.