Joint position affects muscle proton diffusion: Evaluation with a 3-T MR system.

Area of Science:

• Biomedical Engineering
• Musculoskeletal Imaging
• Diffusion Tensor Imaging

Background:

• Muscle diffusion characteristics are crucial for understanding muscle physiology.
• Joint position can alter muscle architecture and mechanical properties.

Purpose of the Study:

• To investigate the effect of ankle joint position on calf muscle diffusion parameters.
• To compare diffusion tensor imaging (DTI) metrics across different ankle angles.

Main Methods:

• Diffusion tensor imaging (DTI) was used to assess calf muscles.
• Muscle proton diffusion, fractional anisotropy (FA), and eigenvalues (λ1, λ2, λ3) were measured.
• Measurements were taken at three ankle positions: plantar flexion, intermediate, and dorsiflexion.

Main Results:

• In the tibialis anterior, FA and λ1 decreased, while λ2 and λ3 increased with increasing joint angle (p < 0.01).
• The gastrocnemius and soleus showed opposite changes in these diffusion parameters (p < 0.05).

Conclusions:

• Ankle joint position demonstrably influences muscle proton diffusion and DTI metrics.
• Different calf muscles exhibit distinct responses to changes in joint angle.