Change in knee cartilage T2 at MR imaging after running: a feasibility study.

All participants provided informed consent to participate in this study, which was approved by the institutional review board of Milton S. Hershey Medical Center. The purpose of the study was to determine the feasibility of cartilage T2 mapping in the evaluation of response of femoral and tibial cartilage to running exercise. Quantitative magnetic resonance (MR) T2 maps of weight-bearing femoral and tibial articular cartilage were obtained in seven young healthy men before and immediately after 30 minutes of running by using a 3.0-T MR imager. There was no statistically significant change in T2 profiles of tibial cartilage. There was a statistically significant decrease in T2 of the superficial 40% of weight-bearing femoral cartilage after exercise. These in vivo observations agree well with published ex vivo results and support the hypothesis that cartilage compression results in greater anisotropy of superficial collagen fibers.