Multiparametric MRI Assessment of Morpho-Functional Muscle Changes Following a 6-Month FES-Cycling Training Program: Pilot Study in People With a Complete Spinal Cord Injury

Spinal cord injuries (SCIs) lead to muscle deterioration and cardiovascular issues, reducing quality of life. Functional electrical stimulation (FES) combined with cycling (FES-cycling) may improve muscle function in SCI individuals. This study used multiparametric magnetic resonance imaging (MRI) to evaluate muscle health during and after a 6-month FES-cycling rehabilitation program in four male participants with chronic SCI. The MRI protocol included T1-weighted imaging for volume quantification, Dixon imaging for fat fraction, multi-echo spin echo for T2 relaxation times, and diffusion tensor imaging to assess diffusion parameters.

• 1
  Muscle volume increased by an average of 22.3% at 3 months and 36.7% at 6 months compared to baseline, remaining 23.2% higher one month post-training.
• 2
  Fat fraction decreased from 11.1% at baseline to 9.1% at 6 months, rebounding to 10.9% one month post-training, indicating reduced fat infiltration during training.
• 3
  Diffusion tensor imaging revealed subtle changes in muscle tissue microstructure, with a decrease in fractional anisotropy mainly associated with an increase of radial diffusivity.