Elli-Noora Salo1, 2, Timo Liimatainen3, Shalom Michaeli4, Silvia Mangia4, Jutta Ellermann4, Miika T. Nieminen1, 5, Mikko J. Nissi, 24
1Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; 2Department of Applied Physics, University of Eastern Finland, Kuopio, Finland; 3Department of Biotechnology and Molecular Medicine, A. I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland; 4Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States; 5Department of Medical Technology, University of Oulu, Oulu, Finland
T1ρ relaxation time has been proposed and demonstrated as a marker for articular cartilage degeneration. However, the sensitivity of T1ρ to different tissue constituents remains somewhat unclear. In this study, we investigated T1ρ relaxation dispersion at four clinically relevant spin-lock fields (γB1 = 125-1000 Hz) in proteoglycan- and collagen-specific enzymatic degradation models. The results suggest that the properties of the collagen network contribute significantly to T1ρ relaxation and dispersion in cartilage. Increasing spin-lock power altered the T1ρ sensitivity to the constituents, as well as the correlation with biomechanical properties.