Objectives The aim was to systematically compare T2 relaxation times of the knee and ankle cartilage within subjects at 7T. Methods Ten healthy volunteers were examined by 7 Tesla MR using a three-dimensional triple-echo steady state sequence (3D-TESS). The differences between seven cartilage compartments (patella, femur, proximal tibia, and distal tibia and talus in both medial and lateral facet) were analyzed by ANOVA. Results The results showed statistically significantly higher T2 (mean ± standard deviation, in milliseconds) values in patellar (25.8 ± 1.2) and femoral (24.9 ± 1.3) cartilage compared to the tibial (19.2 ± 1) and talar (18.1 ± 0.6 ms) cartilage. The cartilages of the medial and lateral facet in the ankle joint were not significantly different (p > 0.05). Conclusions This is the first study to systematically compare within-subject T2 values in the knee and ankle non-invasively, in vivo. Our results are in agreement with the previous findings demonstrating different biochemical and biomechanical properties between the knee and ankle cartilage.
- T2 mapping