18F-sodium fluoride ([18F]NaF) is a well-established bone-seeking agent for the detection of bone metastases. There have been numerous attempts to apply qualitative and semi-quantitative [18F]NaF PET/CT to common benign osseous and arthritic conditions. In Kinetic [18F]-Fluoride of the Knee in Normal Volunteers, Haddock and colleagues investigate parametric values for [18F]NaF 50-minute list-mode uptake in specific bone regions in 12 normal knees using simultaneous PET/MR localization. The image-derived input function was determined from the popliteal artery. Using a Hawkins model, Patlak analysis was performed to obtain Ki (Ki pat) values and nonlinear regression analysis to obtain Ki NLR, K1, k3/(k2 + k3), and blood volume. Comparisons for the measured kinetic parameters, SUV, and SUVmax were made between subchondral, cortical, and trabecular bone and between regional subsections of subchondral bone. Cortical bone had the highest [18F]NaF uptake, differing significantly in all measured parameters when compared with trabecular bone and significantly higher SUVmax and K1 than subchondral bone. Subchondral bone had significantly higher SUV, SUVmax, and Ki than trabecular bone tissue. Regional differences were observed in K1 and k3/(k2 + k3) values. They concluded that quantitative [18F]NaF PET/MRI is sensitive to variations in bone vascularization and knee joint metabolism.