MRI-derived T2 relaxation times and cartilage morphometry of the tibio-femoral joint in subjects with and without osteoarthritis during a 1-year follow-up

Abstract

Objective: To assess differences in magnetic resonance imaging (MRI)-based compositional (T2) and morphometric (volume and thickness) parameters of the tibio-femoral joint cartilage in subjects with and without osteoarthritis (OA) and compare these with clinical assessment tools during a 1-year follow-up.

Method: Three Tesla MRI of the knee joint was performed in eight female patients (body mass index [BMI]>30) with early OA and 10 age-matched female controls (BMI<30) at baseline (BL) and after 3, 6 and 12 months. Cartilage T2 maps, volume and average thickness were calculated in five compartments (medial/lateral femoral condyle, medial/lateral tibia and trochlea). These data were correlated with changes in clinical parameters and joint space width determined in standardized knee radiographs using a mixed random effects model.

Results: At BL, T2 was significantly higher (P<0.05) across the cartilage in patients (45.68+/-5.17ms) compared to controls (41.75+/-4.33ms). Patients had significantly (P<0.05) less cartilage volume and less average cartilage thickness in the tibia than controls (2.10+/-0.53cm(3) vs 2.91+/-0.49cm(3) and 1.59+/-0.24mm vs 1.90+/-0.29mm, respectively). A significant change in clinical parameters of OA, cartilage T2 values or a decrease of volume and average thickness could not be demonstrated within both groups.

Conclusion: Significant differences between the groups indicate that both T2 and morphometric parameters may be useful in quantifying early OA related changes. In a 12-month follow-up, however, no significant alterations of the studied parameters were found, which may be due to the length of the observation interval.