Use of diffusion tensor imaging to examine subacute white matter injury progression in moderate to severe traumatic brain injury.

Abstract

To demonstrate subacute progression of white matter (WM) injury (4.5mo-2.5y postinjury) in patients with traumatic brain injury using diffusion-tensor imaging. Prospective, repeated-measures, within-subjects design. Inpatient neurorehabilitation program and teaching hospital MRI department. Brain-injured adults (N=13) with a mean Glasgow Coma Scale score of 7.67+/-4.16. Not applicable. Fractional anisotropy (FA) values were measured at 4.5 and 29 months postinjury in right and left frontal and temporal deep WM tracts and the anterior and posterior corpus callosum. FA significantly decreased in frontal and temporal tracts: right frontal (.38+/-.06 to .30+/-.06; P<.005), left frontal (.37+/-.06 to .32+/-.06; P<.05), right temporal (.28+/-.05 to .22+/-.018; P<.005), and left temporal (.28+/-.05 to .24+/-.02; P<.05). No significant changes were in the corpus callosum. Preliminary results demonstrate progression of WM damage as evidenced by interval changes in diffusion anisotropy. Future research should examine the relationship between decreased FA and long-term clinical outcome.