What CTE Looks Like in Brain Imaging and Scans
In MRI and PET scans, CTE often shows up as abnormal tau protein buildup around small blood vessels in the brain's sulci, especially in the frontal and temporal lobes. Researchers from the Boston University CTE Center and the VA Boston Healthcare System have used specialized MRI techniques to detect these changes in both living athletes and former military personnel, with findings published in peer-reviewed journals and reported by Forbes and other outlets. Diffusion tensor imaging can reveal disruptions in white matter tracts that correspond to cognitive and behavioral symptoms, and these imaging patterns are now being compared across large cohorts to refine diagnostic criteria.
Radiologists and neuropathologists use standardized scales to grade the severity of CTE-related brain atrophy and tau deposition, and these scales help distinguish CTE from other neurodegenerative conditions like Alzheimer's disease. The Concussion Legacy Foundation and its partners have compiled imaging data from former NFL players and contact-sport athletes, contributing to a growing public dataset that links specific scan findings to clinical outcomes. These imaging signatures are also being explored as potential biomarkers for early detection, with studies involving former athletes from the NFL, NHL, and soccer communities.
How CTE Appears in Brain Tissue and Pathology
Under a microscope, CTE is defined by dense clusters of hyperphosphorylated tau protein in neurons and astrocytes, forming unique patterns that differ from other tauopathies. The brain tissue of individuals diagnosed with CTE often shows atrophy of the frontal cortex, enlargement of the ventricles, and thinning of the corpus callosum, with the most severe changes concentrated in the depths of cortical folds. The VA-BU-CLF Brain Bank, one of the largest brain donation programs in the world, has analyzed thousands of cases and shares data with researchers at institutions like the National Institute of Neurological Disorders and Stroke.
Pathologists grade CTE severity using a four-stage system based on the distribution and density of tau aggregates, ranging from isolated clusters in the sulci to widespread tau pathology across the cerebral cortex. Recent studies have linked higher stages of CTE to longer careers in contact sports and to specific symptoms such as memory loss, impulsivity, and depression. The findings from these autopsies are often cross-referenced with in vivo imaging data to improve the accuracy of diagnosis during life, and organizations like the Concussion Legacy Foundation maintain updated summaries of this research on their website.
What Recent Studies and Institutions Say About CTE Brain Findings
In 2024, researchers from the Boston University CTE Center and collaborating institutions published studies that used advanced imaging and fluid biomarkers to identify CTE-related changes in living former athletes, with results covered by Forbes and medical news outlets. These studies aim to develop diagnostic protocols that do not require autopsy, and they include data from former NFL players, boxers, and military veterans who participated in longitudinal research programs.
The National Institute of Neurological Disorders and Stroke and the Department of Veterans Affairs continue to fund large-scale investigations into CTE pathology, and their findings are shared through public databases and peer-reviewed journals. The Concussion Legacy Foundation also partners with universities and sports leagues to collect brain donations and imaging data, with the goal of creating a comprehensive atlas of CTE-related brain changes that can be used by researchers worldwide.