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.