Influence of the physical pressure of an ultrasound probe on shear-wave elastography measurements of the gastrocnemius muscle in a paediatric population: a non-interventional cohort study

Abstract

PurposeThe aim of our study is to evaluate the impact of ultrasound probe mechanical pressure on the stiffness of the gastrocnemius muscle in a healthy paediatric population. As far as we know, there has been no previous qualitative in vivo study on the impact of probe pressure on muscle shear-wave elastography results with objective evaluation of compression in the paediatric population.Material and methodsIn this cohort study, a group of 22 children (mean age 8.99 years, SD 2.74, 11 males) underwent elastography of the gastrocnemius muscle of the dominant leg. A custom-made, 3-dimensional printed probe cover was used to measure the mechanical pressure of the probe on tissues.ResultsThe obtained results were related to the age, sex, BMI, and calf circumference of the subjects. We observed a significant difference in the stiffness parameter at a pressure of 1 N, with a further increase if force was increased (<i>p</i> < 0.001). A significant, very weak positive correlation of age and stiffness was observed (<i>p</i> < 0.001, <i>r<sup>2</sup></i> = 0.022). There was no significant correlation of stiffness, BMI, and calf circumference.ConclusionsThe use of compression during muscle elastography in children causes a significant bias in results, regardless of age, sex, BMI, or calf size.