Purpose
To assess the transverse relaxation time T2 and diffusion coefficient D before and following exercise in the tibialis anterior muscle and determine whether T2 and D values were correlated.
Methods
Measurements of T2 and D were performed at 3 T within axial slices through the calf muscles of six healthy volunteers at 95 s intervals before and for 10–12 min after a dorsiflexion exercise to exhaustion.
Results
The mean ± standard deviation (SD) of T2 and D before exercise were 32 ± 1.55 ms and 1.52 ± 0.15 μm2/ms, and after exercise were 43 ± 2.5 ms and 1.72 ± 0.13 μm2/ms, respectively. The mean ± SD inter-individual recovery times of the % change in T2 and D after exercise were 7.9 ± 4.2 and 10.9 ± 7.0 min, respectively. The T2 and D values showed a significant correlation throughout the experiments (r 2 = 0.45).
Conclusions
The increase in T2 of skeletal muscle after exercise is correlated with the increase of the diffusion coefficient D and the recovery times appear similar, indicating that any model used to explain T2 increases with exercise must also account for increased diffusion coefficients.