Validation of Ultrasound-Based Muscle Elastic Modulus Estimation in a Healthy Human Volunteer Model

Area of Science:

• Biomedical Engineering
• Musculoskeletal Ultrasound
• Diagnostic Imaging

Background:

• Accurate measurement of muscle compartment pressure is crucial for diagnosing acute compartment syndrome.
• Current gold-standard methods are invasive and costly.
• Ultrasound (US) offers a potential non-invasive alternative through compression sonography.

Purpose of the Study:

• To assess the reliability and validity of elastic modulus estimation (EME) using compression sonography across multiple muscle locations.
• To establish the correlation between EME and compartment pressure in simulated physiological and injury states.
• To evaluate the inter- and intra-rater reliability of this technique.

Main Methods:

• A phantom model was used to calibrate EME measurements against known pressures.
• Ten healthy subjects underwent ultrasound scans of the forearm, arm, lower leg, and thigh.
• Scans were performed in both relaxed and flexed (simulating elevated pressure) muscle states by two investigators.
• EME was calculated using probe force and tissue displacement data.

Main Results:

• The phantom model showed EME > 170.0 kPa corresponded to pressures > 20 mmHg.
• Flexed muscle states consistently yielded higher EME values than relaxed states across all locations (P < .001).
• Good inter- and intra-rater reliability was observed for EME measurements (ICC = 0.67 and 0.63, respectively).

Conclusions:

• Compression sonography for EME demonstrates good reliability in multiple muscle sites.
• The technique effectively differentiates between relaxed and elevated muscle pressure states.
• This ultrasound-based method presents a promising, low-cost approach for aiding in the detection of elevated compartment pressures.