Exercise-related leg muscle signal changes: assessment using diffusion-weighted MRI

Area of Science:

• Musculoskeletal imaging
• Physiology
• Sports medicine

Background:

• Magnetic resonance imaging (MRI) is crucial for assessing muscle physiology.
• Diffusion-weighted imaging (DWI) offers insights into tissue microstructure.
• Understanding exercise-induced muscle changes is vital for sports science and clinical applications.

Purpose of the Study:

• To detect physiologic changes in leg muscles using MRI DWI after repetitive plantar flexion exercises in asymptomatic individuals.
• To evaluate both visual and quantitative DWI parameters for detecting these changes.
• To establish the detectability of exercise-induced muscle alterations in healthy subjects.

Main Methods:

• Prospective monocentric study involving 20 healthy subjects.
• Diffusion-weighted imaging (DWI) performed at rest and post-exercise (5 and 10 minutes).
• Analysis included visual semiquantitative evaluation and quantitative apparent diffusion coefficient (ADC) and fractional anisotropy (FA) in five leg compartments.

Main Results:

• Significant signal changes were observed in fibular and gastrocnemius muscles post-exercise.
• Quantitative analysis showed increased ADC and decreased FA in these muscles.
• Visual assessment confirmed exercise-induced changes, primarily in fibular and gastrocnemius muscles.

Conclusions:

• Repetitive plantar flexion exercises induce detectable physiologic changes in leg muscles.
• DWI, both visually and quantitatively, can identify these exercise-induced muscle alterations.
• Findings are applicable to asymptomatic, active individuals and may inform sports-related assessments.