Including diffusion tensor imaging in return-to-play protocols improves athletes' outcomes
The addition of diffusion tensor imaging in return to play (RTP) protocols for athletes has significant potential for injury prevention, authors of a new paper suggest.
Determining whether an athlete is physically ready to return to play following a muscle injury can be difficult. These assessments are typically subjective based on patients' self-reported symptoms and mobility, and although the use of imaging is growing in these areas, many questions challenge its utility in RTP protocols.
“Determining the return to play (RTP) prognosis following hamstring injury remains difficult. There is conflicting evidence for the use of conventional MRI to accurately determine the RTP time following a hamstring injury,” Milo J.K. Mokkenstorm, with the department of orthopedic surgery and sports medicine at Amsterdam University Medical Center, and colleagues noted.
Diffusion tensor imaging (DTI) is a quantitative technique that allows for better visualization of micro-trauma to the muscles. The authors suggest its use could enable providers to make more informed decisions about athletes’ readiness to re-enter competition.
To test the utility of the method, the team recently conducted a prospective analysis on a group of over 100 athletes with hamstring injuries. Each athlete underwent a 3 T MRI scan of the upper legs, including DTI acquisition within 7 days after injury. Researchers compared of six different DTI parameters—the relative difference between legs, including the first, second and third eigenvalues, mean diffusivity, radial diffusivity and fractional anisotropy—to the athletes’ RTP to determine if specific imaging findings correlated with their readiness.
The median RTP time for the group was 37 days post-hamstring injury. The group found numerous associations between the DTI parameters and RTP times, with the parameters explaining between 5 and 15% of variance in RTP. All six parameters were found to be associated with RTP, though the first eigenvalue was the only factor that was not an independent predictor.
“Our findings showed that increased diffusivity parameters were associated with prolonged RTP time. This association was strongest in the DTI parameters that included information about the physiological barriers in the radial axes (second eigenvalue, third eigenvalue, radial diffusivity and mean diffusivity). The diffusivity in these axes is limited by physiological barriers that limit the diffusion along the perpendicular axis of the muscle fiber tract,” the authors explained. “In skeletal muscle, this may reflect the fiber integrity of the muscle along its short axis, indicate the integrity of the sarcolemma, endomysium or perimysium.”
The group noted that larger increases in diffusivity parameters could indicate greater integrity loss in the muscle, suggesting that more time is needed to recover. They added that future studies should include DTI techniques to standard RTP imaging protocols to determine whether the combination of the two could further improve predictive value.
The study is available here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.