Purpose: To evaluate the sensitivity of quantitative MRI techniques (T1 , T1,Gd , T2 , continous wave (CW) T1ρ dispersion, adiabatic T1ρ , adiabatic T2ρ , RAFF and inversion-prepared magnetization transfer (MT)) for assessment of human articular cartilage with varying degrees of natural degeneration.
Methods: Osteochondral samples (n = 14) were obtained from the tibial plateaus of patients undergoing total knee replacement. MRI of the specimens was performed at 9.4T and the relaxation time maps were evaluated in the cartilage zones. For reference, quantitative histology, OARSI grading and biomechanical measurements were performed and correlated with MRI findings.
Results: All MRI parameters, except T1,Gd , showed statistically significant differences in tangential and full-thickness regions of interest (ROIs) between early and advanced osteoarthritis (OA) groups, as classified by OARSI grading. CW-T1ρ showed significant dispersion in all ROIs and featured classical laminar structure of cartilage with spin-lock powers below 1000 Hz. Adiabatic T1ρ , T2ρ , CW-T1ρ, MT, and RAFF correlated strongly with OARSI grade and biomechanical parameters.
Conclusion: MRI parameters were able to differentiate between early and advanced OA. Furthermore, rotating frame methods, namely adiabatic T1ρ , adiabatic T2ρ , CW-T1ρ , and RAFF, as well as MT experiment correlated strongly with biomechanical parameters and OARSI grade, suggesting high sensitivity of the parameters for cartilage degeneration. Magn Reson Med 74:249-259, 2015. © 2014 Wiley Periodicals, Inc.
Keywords: cartilage; human; osteoarthritis; quantitative MRI; rotating frame relaxation.
© 2014 Wiley Periodicals, Inc.