Prevalence of potentially clinically significant MRI findings in athletes with and without sport-related concussion.

Previous studies have shown that mild traumatic brain injury (mTBI) can cause abnormalities in clinically relevant MRI sequences. No large-scale study, however, has prospectively assessed this in athletes with sport-related concussion (SRC). The goal of the current study was to characterize and compare the prevalence of acute, trauma-related MRI findings and clinically significant, non-specific MRI findings in athletes with and without SRC. College and high-school athletes were prospectively enrolled and participated in scanning sessions between January 2015 through August 2017. Concussed contact sport athletes (n=138, 14 F, 19.51.6 years) completed up to four scanning sessions following SRC. Non-concussed contact (n=135, 15 F, 19.71.6) and non-contact athletes (n=96, 15 F, 20.01.7) completed similar scanning sessions and served as controls. Board certified neuroradiologists, blinded to SRC status, reviewed T1-weighted, T2-weighted Fluid Attenuated Inversion Recovery (FLAIR), T2*-weighted, and T2-weighted images for acute (i.e., injury-related) or non-acute findings that prompted recommendation for clinical follow-up. Concussed athletes were more likely to have MRI findings relative to contact (30.4% vs. 15.6%, OR=2.32, p=0.01) and non-contact control athletes (19.8%, OR=2.11, p=0.04). Female athletes were more likely to have MRI findings than males (43.2% vs. 19.4%, OR=2.62, p=0.01). One athlete with SRC had an acute, injury-related finding; group differences were largely driven by increased rate of non-specific white matter hyperintensities in concussed athletes. This prospective, large-scale study demonstrates that <1% of SRCs are associated with acute injury findings on qualitative structural MRI, providing empirical support for clinical guidelines that do not recommend use of MRI following SRC.