Layers-Based Analysis of Knee Articular Cartilage: Comparing T1ρ Imaging Against Quantitative Susceptibility Mapping at 3 Tesla

The vertical microstructural organization of articular cartilage varies in its arrangement of collagen fibers, as well as the relative proteoglycan content. Knee osteoarthritis (OA) involves an inflammatory degenerative process that leads to depth-wise degeneration of the cartilaginous matrix. While quantitative MR protocols have emerged to evaluate proteoglycan content (T1ρ) and microstructural integrity (Quantitative Susceptibility Mapping; QSM), advances in layer-based analyses (e.g., superficial vs. deep) are warranted to identify the progression of diseased cartilage. We demonstrate the integrated utilization of QSM and T1ρ for characterizing depth-specific microstructural arrangement of articular cartilage, including differences in tissue organization and composition, respectively.