An innovative solution to reduce muscle deformation during ultrasonography data collection

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Musculoskeletal Ultrasound

Background:

• 3D freehand ultrasound captures volumetric data, but probe pressure can deform muscles, affecting morphological feature accuracy.
• Accurate muscle volume estimation is crucial for diagnosing and monitoring conditions like cerebral palsy.
• Existing ultrasound methods are susceptible to deformation errors caused by inconsistent probe force.

Purpose of the Study:

• To evaluate the effectiveness of a novel device, Portico, in minimizing muscle deformation during 3D ultrasound.
• To assess the impact of Portico on the accuracy of medial gastrocnemius (MG) muscle volume estimation.
• To compare the reliability of muscle volume measurements using Portico versus the conventional probe-on-skin (PoS) approach.

Main Methods:

• Twenty medial gastrocnemius (MG) muscles (10 typically developing, 10 spastic cerebral palsy) were scanned using three methods: water tank reference, probe-on-skin (PoS), and Portico.
• Data from PoS and Portico were registered to water tank measurements to quantify deformation.
• Muscle volume was calculated using Py3DFreeHandUS software and MeVisLab, with minimal detectable change (MDC) determined.

Main Results:

• The Portico device reduced muscle deformation by 46% compared to the PoS approach.
• Lower MDCs for MG volume were observed with the Portico in both typically developing and spastic cerebral palsy groups.
• Despite reduced deformation, the Portico did not achieve statistically superior MG volume estimation reliability over PoS.

Conclusions:

• The Portico device shows promise in reducing ultrasound-induced muscle deformation.
• Further optimization of the Portico, such as improving gel pad fit and geometry variety, may enhance its performance.
• While reducing deformation, the Portico's current iteration requires further development for statistically significant improvements in muscle volume estimation accuracy.