Effect of collagen cross-linking on quantitative MRI parameters of articular cartilage (original) (raw)

2016, Osteoarthritis and Cartilage

Objective: To investigate the sensitivity of quantitative magnetic resonance imaging (MRI) parameters to increase of collagen cross-linking in articular cartilage, a factor possibly contributing to the aging-related development of osteoarthritis (OA). The issue has not been widely studied although collagen cross-links may significantly affect the evaluation of cartilage imaging outcome. Design: Osteochondral samples (n ¼ 14) were prepared from seven bovine patellae. To induce crosslinking, seven samples were incubated in threose while the other seven served as non-treated controls. The specimens were scanned at 9.4 T for T 1 , T 1Gd (dGEMRIC), T 2 , adiabatic and continuous wave (CW) T 1r , adiabatic T 2r and T 1sat relaxation times. Specimens from adjacent tissue were identically treated and used for reference to determine biomechanical properties, collagen, proteoglycan and crosslink contents, fixed charge density (FCD), collagen fibril anisotropy and water concentration of cartilage. Results: In the threose-treated sample group, cross-links (pentosidine, lysyl pyridinoline (LP)), FCD and equilibrium modulus were significantly (P < 0.05) higher as compared to the non-treated group. Threose treatment resulted in significantly greater T 1Gd relaxation time constant (þ26%, P < 0.05), although proteoglycan content was not altered. Adiabatic and CWT 1r were also significantly increased (þ16%, þ28%, P < 0.05) while pre-contrast T 1 was significantly decreased (À10%, P < 0.05) in the threose group. T 2 , T 2r and T 1sat did not change significantly. Conclusion: Threose treatment induced collagen cross-linking and changes in the properties of articular cartilage, which were detected by T 1 , T 1Gd and T 1r relaxation time constants. Cross-linking should be considered especially when interpreting the outcome of contrast-enhanced MRI in aging populations.