Abstract #0051

T1rho Dispersion in Constituent-Specific Degradation Models of Articular Cartilage with Correlation to Biomechanical Properties

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

T_1ρ relaxation time has been proposed and demonstrated as a marker for articular cartilage degeneration. However, the sensitivity of T_1ρ to different tissue constituents remains somewhat unclear. In this study, we investigated T_1ρ 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 T_1ρ relaxation and dispersion in cartilage. Increasing spin-lock power altered the T_1ρ sensitivity to the constituents, as well as the correlation with biomechanical properties.