Validation of shear wave elastography in skeletal muscle

Area of Science:

• Biomechanics
• Biomedical Engineering
• Musculoskeletal Research

Background:

• Accurate quantification of skeletal muscle stiffness is vital for improving physical function and independence, especially after pathology.
• Shear wave elastography (SWE) is an ultrasound technique used to measure tissue mechanical properties.
• Validating SWE across a muscle's functional range is essential for its clinical application.

Purpose of the Study:

• To validate shear wave elastography (SWE) for measuring skeletal muscle stiffness across its functional range of motion.
• To compare SWE measurements with traditional materials testing (MTS) techniques under varying tensile loads.
• To evaluate the influence of ultrasound transducer orientation on SWE accuracy.

Main Methods:

• Tensile loading was applied to porcine brachialis whole-muscle specimens.
• Simultaneous SWE and materials testing system (MTS) measurements were recorded.
• Regression analysis and generalized linear models were used to correlate Young's modulus (MTS) and shear modulus (SWE).

Main Results:

• A significant correlation (regression coefficient = 0.1944) was found between MTS and SWE for parallel transducer orientation.
• Both parallel SWE and MTS demonstrated increased stiffness with increasing tensile load.
• Shear wave propagation was poor for 45° and perpendicular transducer orientations.

Conclusions:

• Shear wave elastography is a viable method for assessing skeletal muscle stiffness, particularly when the transducer is parallel to muscle fibers.
• This study establishes a foundation for further research into the spatial distribution of muscle stiffness.
• Optimizing transducer orientation is crucial for accurate SWE measurements in skeletal muscle.