It appears brain imaging exams performed on high school football players revealed changes in both the gray and white matters in their brains. This is correlated with exposure to head impacts, which may have a huge effect on their health, according to a study presented at the annual Radiological Society of North America meeting.

Elizabeth Davenport from the UT Southwestern Medical Center in Dallas, who led the analysis, said this was essential to understand the potential changes in the brain related to youth contact sports.

According to Science Daily, professional football players can suffer from a serious condition known as chronic traumatic encephalopathy or CTE. The analysis may help find out where the process starts and how to keep sports "healthy" for millions of children and adolescents.

According to a press release from the RSNA, the study involves 24 players from a football team in a school in North Carolina, each with a helmet with the Head Impact Telemetry System (HITS) during all their practices and games.

The helmets have six accelerometers or sensors that measure the magnitude, location, and direction of the hit. The data are then uploaded to a server or analysis.

Davenport said there are significant changes in the brains of the players after a single season. 

According to the Scientist, each player underwent pre- and post-season imaging which is composed of a specialized MRI scan to measure the brain's white matter integrity, and a magnetoencephalography scan which records and analyzes the magnetic fields produced by brain waves.

The MEG can be used to measure delta waves in the brain which is like a distress signal, as these represent slow wave activity that increases after brain injuries.

After calculation, the scientists were able to measure abnormalities observed on diffusion imaging (to measure the white matter in the brain) and abnormally increased delta wave activity. 

None of the 24 players were diagnosed with a concussion, but players with greater head impact exposure had the greatest change in diffusion imaging and MEG metrics.

Davenport explained much of the changes in the diffusion imaging metrics correlated to linear acceleration, like the impact of a car crash. Meanwhile, the MEG changes correlated to rotational impact like a punch. This means both metrics are needed to assess impact exposure because they are related to different biomechanical processes. 

Davenport also suggested having a larger population to study as it's difficult to know the long-term effects of the study for now. She added there are still no indications that off-season time will allow the brain to heal as well.