Diffusion Tensor Imaging in Acute, Chronic, and Remote Mild Traumatic Brain Injury: A Systematic Review of Cross-Sectional and Longitudinal Studies.

Mild traumatic brain injury (mTBI) is a global health concern that remains difficult to clinically evaluate due to variable diagnostic criteria and a lack of objective biomarkers. Diffusion tensor imaging (DTI) has been shown to be a sensitive measure of microstructural injury caused by head injury that cannot be visualized by conventional neuroimaging, which may potentially aid in the diagnosis and prognosis of mTBI. This review seeks to evaluate the available literature concerning the role of DTI in evaluating microstructural alterations in white matter (WM) associated with mTBI. An initial systematic search from PubMed, CENTRAL, Embase, MEDLINE, Web of Science, and Scopus yielded 1507 articles published between 2007 and 2024. A total of 79 studies met the full eligibility criteria for inclusion in this qualitative synthesis. The majority of studies demonstrated DTI abnormalities in the setting of acute, chronic, and remote mTBI, predominantly in the WM tracts of the corpus callosum, corona radiata, internal capsule, and longitudinal fasciculus. Many studies identified associations between DTI parameters and clinical measures of mTBI, such as cognitive performance, executive functioning, and comorbidities, including post-concussion syndrome and post-traumatic stress disorder. Overall, the weight of evidence in this review supports the cautious integration of DTI in the clinical assessment of mTBI. The observed discrepancies reported in the literature on DTI may be explained by significant variability in study design, analytical technique, and measured clinical outcomes. Further research that implements consistent methodology is crucial to fully realize the use of DTI as an imaging biomarker of mTBI.