Detecting Lesions after Traumatic Brain Injury Using Susceptibility Weighted Imaging: A Comparison with Fluid-Attenuated Inversion Recovery and Correlation with Clinical Outcome

The development and utilization of newer neuroimaging modalities provides the capability to more accurately detect the extent of pathology after TBI. The current study examined the ability of susceptibility-weighted imaging (SWI) to detect lesions after TBI as well as the relationship to subsequent clinical outcome. The performance of SWI was compared to that of fluid-attenuated inversion recovery (FLAIR). This study comprised 79 individuals with mild-to-severe TBI, 38 of whom completed neuropsychological tests of attention, working memory, processing speed, memory, and executive functions. SWI was found to quantify a greater lesion volume over the entire brain, specifically in frontal, central, limbic, subcortical gray, and parietal brain regions, than did FLAIR. Moreover, SWI was able to identify TBI-related lesions in almost one third of patients for whom FLAIR was unable to detect any lesions. Greater overall SWI volume, as well as frontal SWI volume, was found to relate to the severity of TBI. Conversely, no association was found between FLAIR lesion volume and injury severity. In addition, there was some evidence that higher lesion volume, for both SWI and FLAIR, were associated with poorer memory as well as processing speed impairment. This study suggests that SWI may provide additional sensitivity in the detection of lesions after TBI. Consequently, this imaging sequence may provide a more accurate representation of the severity of individuals' injuries and their subsequent neuropsychological outcomes.