Watkins L, MacKay J, Haddock B, et al. - This study was undertaken to investigate physiological mechanisms of [ ¹⁸ F]NaF uptake in subchondral bone of individuals with and without knee osteoarthritis (OA). Researchers enrolled 11 healthy volunteers and twenty OA individuals. They scanned both knees of all individuals simultaneously using a 3T hybrid PET/MRI system. This study’s findings revealed that in OA individuals, bone metabolism is altered, including bone regions with and without structural findings, compared to healthy individuals. Kinetic parameters of [ ¹⁸ F]NaF uptake in subchondral bone exhibit potential to quantitatively assess the role of bone physiology in OA initiation and progression. The outcomes illustrated that objective measures of bone metabolism from [ ¹⁸ F]NaF PET imaging can complement evaluations of structural abnormalities found on MRI.