Zili David Chu
Traumatic brain injuries (TBIs) and concussions are major causes of morbidity and disability in the United States and throughout the world. Disruption of white matter integrity is thought to contribute to persistent difficulties in cognitive, memory, and executive functions as well as emotional and somatic complaints. Up to now, a limited number of imaging techniques have been shown to be sensitive to these changes in the acute phase following mild TBI (MTBI), including MR DTI. In the acute phase of MTBI, finding affected regions is challenging. In our exploratory work, we used the voxel-based linear regression method to investigate whole-brain integrity and identified common regions affected following MTBI.
Our long-term goal is to find regions of interest commonly affected by TBI, and also to build normative databases for different healthy age groups. A comparison z-score map of an individual patient against the obtained values in a normative database can be a useful indicator to reveal the degree of injury in the acute phase, and provides additional information to help physicians make early decisions regarding treatments.
This was a preliminary study with a relatively small sample size. There remains significant interest in the application of DTI findings to uncover pathology at the individual patient level. Because of challenges related to building large normative datasets, including scanner comparability between vendors, protocol differences, and analytic techniques, there is a long way to go before DTI can provide an indicator for clinical diagnosis leading to early intervention. However, changes in the acute phase in our findings will help physicians better understand the impact of these injuries on patients, at least in a qualitative way. In addition, DTI could provide an objective tool to assist in the diagnosis of MTBI, which is currently based upon subjective clinical assessment and patient report.