Quantitative Magnetic Resonance Spectroscopy and T2 Mapping for Evaluating Knee Subchondral Bone and Cartilage Changes in Chronic Kidney Disease

Objective To investigate water and lipid composition changes in knee subchondral bone marrow and cartilage in chronic kidney disease (CKD) patients compared with age- and sex-matched healthy controls using magnetic resonance spectroscopy (MRS) and T2 mapping. Design This IRB-approved case-control study included 20 CKD patients (12 men, 8 women) and 20 age- and sex-matched healthy controls (10 men, 10 women). MRS and T2 measurements were performed on regions of interest in the knee subchondral bone and cartilage. Water content, lipid composition, fat content, and the unsaturation index (UI) were quantified using LCModel. Differences between groups were assessed using independent samples T -tests. Results The CKD group showed a significantly higher lipid UI compared with controls ( P = 0.035). In subgroup analysis, women with CKD had significantly higher water content (4.7 ppm), lower fat content, and higher lipid UI than female controls ( P = 0.023, 0.048, and 0.018, respectively). No significant differences were observed between men with CKD and male controls (all P > 0.4). Among CKD patients, men had significantly lower lipid composition (5.3 ppm) and lipid UI compared with women ( P = 0.026 and 0.012, respectively). T2 values were significantly elevated in CKD patients ( P = 0.016 for men; P = 0.031 for women). Conclusions Quantitative MRS and T2 mapping are feasible tools for assessing CKD-related changes in the knee joint. Increased unsaturated lipid content and water in subchondral bone may contribute to early degenerative changes.