T₂ mapping of the articular cartilage as a biomarker for knee osteoarthritis

Abstract

Objective: Only few studies have investigated quantitative magnetic resonance imaging (MRI) T₂ mapping of knee cartilage in population-based cohorts. Our objective was to evaluate the association between T₂ relaxation times of different cartilage segments and the presence of knee MRI-based osteoarthritis (OA) and patient characteristics in a large population-based cohort. Design: In this cross-sectional study, we included 673 females (mean age: 59.8 years; standard deviation: 3.7) scanned with 1.5T-MRI from a sub-cohort of the Rotterdam Study. T₂ relaxation times were calculated in six femoral and tibial cartilage regions of interest. Associations between T₂ relaxation times, MRI Osteoarthritis Knee Score (MOAKS)-based tibiofemoral OA, and Knee injury and Osteoarthritis Outcome Score (KOOS)-based symptom status were evaluated using multivariate fixed effects regression analyses. Results: A total of 1332 knees were included, of which 237 (17.7%) had MRI-based OA. Patients with OA had higher T₂ relaxation times across all cartilage segments, and T₂ values positively correlated with BMI (r = 0.17–0.46), the strongest correlations being in the lateral compartment. Weak associations were found between T₂ relaxation times and age. After adjustments, T₂ values in the lateral weight-bearing femur (OR: 0.67; 95%CI: 0.56–0.79), lateral tibia (OR: 1.11; 95%CI: 1.00–1.24), lateral posterior femur (OR: 1.48; 95%CI: 1.28–1.72), and medial posterior femur (OR: 1.14; 95%CI: 1.01–1.30), were associated with the presence of OA. T₂ relaxation times were not associated with the KOOS-based symptom status. Conclusion: In this population-based cohort, T₂ values were associated with BMI. Additionally, T₂ values in the lateral cartilage subregions were associated with MRI-based OA.