Electrical Pathways Through the Intricate Network of Skeletal Muscle Fibres: Insights From MRI-Validated Numerical...

Area of Science:

• Biophysics
• Biomedical Engineering
• Anatomy

Background:

• Skeletal muscles possess inherent anisotropy due to their organized fiber structure, impacting electrical and mechanical properties.
• Understanding muscle anisotropy is vital for applications like electrical stimulation and pulsed field ablation (PFA).

Purpose of the Study:

• To develop and validate a numerical model explaining the origins of skeletal muscle anisotropy at the tissue level.
• To investigate the persistence of muscle anisotropy post-mortem for potential ex vivo applications.

Main Methods:

• A microscale numerical model of skeletal muscle fiber geometry was created.
• Current density imaging (CDI), a magnetic resonance technique, was used to experimentally validate the model's predictions.

Main Results:

• The numerical model successfully identified the origins of bulk tissue anisotropy.
• CDI measurements confirmed that muscle fiber properties and organization drive anisotropy.
• Observed anisotropy persisted for up to 48 hours post-mortem, indicating a stable structural basis.

Conclusions:

• Integrating CDI with advanced modeling offers a robust method for studying and utilizing skeletal muscle anisotropy.
• The validated model is relevant for electrical treatments and suggests ex vivo tissues can serve as in vivo models, reducing animal testing.