Data-driven imaging marker for cerebral consequences of Post-Acute Sequelae of COVID19 - prospective validation and [18F]FEPPA PET correlation

Motivation: Recognizing neurological symptoms in Post-Acute Sequelae of COVID-19 (PASC), this study investigates neuroinflammatory markers to develop reliable neuroimaging diagnostics. Goal(s): To validate CoreFA, a data-driven imaging marker, for detecting white matter changes and to explore its correlation with [18F]FEPPA PET neuroinflammatory markers. Approach: Diffusion MRI-derived fractional anisotropy (FA) was assessed in white matter tracts to derive CoreFA. CoreFA was validated in a prospective cohort and examined for association with neuroinflammation via FEPPA PET. Results: CoreFA demonstrated high diagnostic accuracy (AUC = 0.81 for initial group; AUC = 0.77 for prospective cohort). [18F]FEPPA PET scans confirmed neuroinflammation in regions with reduced FA. Impact: The strong correlation between CoreFA and neuroinflammatory markers from PET imaging provides a potential biomarker for assessing PASC-related brain changes.