Exercise-related changes in knee articular structures detected using magnetic resonance imaging T1ρ and T2 mapping

Purpose

To evaluate the changes in various knee joint structures before and after physical activities using magnetic resonance imaging (MRI) T1ρ and T2 mapping.

Methods

MRI of the right knee was performed for 12 healthy volunteers before and after jumping rope, flexion and extension, and at rest. Different parts of articular cartilage, anterior and posterior cruciate ligaments, medial and lateral meniscus, gastrocnemius muscle and Hoffa’s fat pad were quantitatively assessed based on T1ρ and T2 values. A paired t-test was performed to determine whether the effects of various activities on different parts of the knee articular structures were statistically different.

Results

The T1ρ values for the lateral meniscus decreased, while both T1ρ and T2 values for the gastrocnemius muscle increased after jumping rope. No statistically significant differences were observed in the other parts of the meniscus, cruciate ligaments, and Hoffa’s fat pad. The T1ρ and T2 values for the weight-bearing cartilages of the femur and tibia were both reduced after jumping rope. However, no statistically significant differences were observed in the cartilage after flexion and extension or at rest.

Conclusions

MRI T1ρ and T2 mapping can be used to evaluate the changes in various joint structures before and after physical activities. These changes in knee tissue were hypothesized to reflect variations in tissue fluid, collagen fibers, and proteoglycan content. Further studies are required to investigate the influence of exercise on articular structures using MRI mapping techniques.