Advanced In-Vivo 3D Quantitative Magnetization Transfer Imaging of Cartilage Extracellular Matrix of the Whole Knee Joint

Motivation: Quantitative magnetization transfer (qMT) provides biomarkers to assess articular cartilage extracellular matrix. Currently, qMT techniques are limited to small cartilage region coverage. Goal(s): Characterize the knee cartilage extracellular matrix using novel qMT imaging technique BTS (Bloch-Siegert and magnetization Transfer Simultaneously). Approach: A new BTS protocol was implemented to image the knee and investigate remodeling of the BTS model to estimate full set of bias-free T1, f, kF and additional T2R for characterizing the whole knee cartilage extracellular matrix. Results: Spatial variation reflecting the regional dependence of qMT parameters and depth dependence between the deep and superficial layers of cartilage was observed. Impact: BTS showed spatial variation and regional features of qMT parameters in a healthy model, presenting great potential in providing 3D relaxometry and qMT imaging biomarkers to characterize whole knee cartilage extracellular matrix, which requires further investigation using groupwise analysis.