Comparative evaluation of corpus callosum DTI metrics in acute mild and moderate traumatic brain injury: Its correlation with neuropsychometric tests

Primary objective: To look for differences in vulnerability of corpus callosum (CC) in patients of mild and moderate traumatic brain injury (TBI) in the acute stage using quantitative diffusion tensor imaging (DTI) and to correlate these with neuropsychometric tests (NPT) done at 6 months post-injury. Research design, methods and procedures: Conventional MRI, DTI and NPT were performed on 83 patients (moderate TBI, n = 57; mild TBI, n = 26) within 5-14 days after TBI. Thirty-three age- and sex-matched healthy controls were also included for comparison. Results: Significantly decreased fractional anisotropy (FA) in genu and splenium; significantly increased radial diffusivity (RD) values in genu, midbody and splenium with significant increase in mean diffusivity (MD) and a decrease in axial diffusivity (AD) only in genu, respectively, in patients with moderate TBI compared to healthy controls were observed. However, in moderate TBI, significantly decreased FA was found only in genu compared to mild TBI. Moderate TBI showed poor NPT scores compared to mild TBI, but this did not reach statistical significance. Conclusions: It is concluded that DTI abnormalities in the regions of CC were more in patients with moderate TBI compared to mild TBI and this was associated with relatively poor neuropsychological outcome 6 months post-injury.