Susceptibility-weighted imaging detects small lesions in TBIs

Susceptibility-weighted imaging (SWI) enhances and detects small lesions in mild traumatic brain injuries (TBIs), revealing a hypointensity burden metric with statistically significant changes in male patients over time, according to a study published online by the Journal of Neurology on Feb. 4.

The increasing prevalence of sports-related concussions requires advanced imaging for the enhancement and detection of mild TBIs, often referred to as “invisible injuries.” Though SWI is normally used to identify larger cerebral microbleeds (CMBs) that result from severe TBIs, lead author Karl G. Helmer, PhD, of the Massachusetts General Hospital in Boston, and colleagues investigated the modality’s utility in observing smaller lesions in mild TBIs.

The researchers strove to detect changes in the number of low-intensity clusters that occurred in response to concussion, investigate the initial clusters’ burden in each sex, examine how the clusters correlate with previous concussions, and determine how they change over time when no further concussion is reported.

Comprised of 45 adult male and female hockey players, the study obtained images before and after a season using SWI. Eleven participants also underwent imaging at 72 hours, two weeks, and two months after concussion. A hypointensity burden index was created at the beginning of the season, end of the season, and at postconcussion time points.

Results revealed a statistically significant increase in the hypointensity burden relative to the beginning of the season for the male subjects with concussions at the 2-week postconcussion time point. A smaller, nonsignificant rise in the burden for female subjects with concussions was also observed in the same time period.

There were no significant changes in burden for nonconcussed subjects of either sex between the beginning and end of season time points. However, there was a statistically significant difference in the burden between male and female subjects in the nonconcussed group at both the time points, with males demonstrating a higher hypointensity burden.

It is important to note that not all of the concussed players completed imaging at every postconcussion point due to fear of being unable to play. The researchers also did not image the nonconcussed participants at one more points during the season, which may have been beneficial to the study.

“Data acquired using this method could be used for the monitoring of players throughout their careers and could lead to improved diagnoses and return-to-play guidelines,” wrote the authors.