1Department of Physics, University of Kuopio, Kuopio, Finland; 2Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; 3Diagnostic Imaging Centre, Kuopio University Hospital, Kuopio, Finland; 4Department of Medical Technology, University of Oulu, Oulu, Finland; 5Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
In the dGEMRIC method, full equilibrium of gadopentetate is required to quantify the proteoglycan content of articular cartilage. In this study, the diffusivity and kinetics of gadopentetate was studied by limiting equilibration only through the articular surface or deep cartilage. The distribution of gadopentetate in bovine cartilage samples was followed for 18 hours with repeated T1 mapping at 9.4 T. The results showed that full equilibration takes longer than previously assumed. Diffusion was faster through the articular surface. With equilibration through the articular surface, the superficial cartilage reached near-equilibrium relatively quickly, possibly allowing early visualization of superficial degenerative changes.