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Reliability and Validity of an Ultrasound-Based Protocol for Measurement of Quadriceps Muscle Thickness in Children
Emil Rydell Högelin1,2, Kajsa Thulin1,3, Ferdinand von Walden4,5
1Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
Insights
Ultrasound (US) measurement of muscle thickness (MT) is a reliable and time-efficient alternative to MRI for assessing skeletal muscle size in children. This method shows high reproducibility and strong correlation with gold-standard muscle volume measurements.
Area of Science:
- Pediatric Physiology
- Biomedical Imaging
- Musculoskeletal Research
Background:
- Accurate skeletal muscle size assessment is crucial for understanding growth, aging, and disease impacts.
- Ultrasound (US) offers a cost-effective and accessible method for measuring muscle thickness (MT).
- Magnetic Resonance Imaging (MRI) is the gold standard for muscle volume (MV) but is less accessible.
Purpose of the Study:
- To evaluate a multisite ultrasonographic protocol for measuring quadriceps muscle thickness (MT) in children.
- To assess the reproducibility of US-based MT measurements.
- To determine the correlation between US-measured MT and MRI-derived muscle volume (MV) in pediatric populations.
Main Methods:
- 15 children (11 ± 1 years) underwent US measurements of the quadriceps femoris muscle heads after a 20-minute rest period.
- Two investigators performed US MT measurements at pre-defined sites.
- Muscle volume (MV) was subsequently quantified using MRI with manual contouring.
Main Results:
- Ultrasound measurement of MT demonstrated excellent intra-rater reliability (ICC = 0.985-0.998) and high inter-rater reliability (ICC = 0.868-0.964).
- US examinations were completed in under 15 minutes per investigator.
- A significant correlation was found between US-measured MT and MRI-derived MV for all quadriceps muscle heads (r = 0.789, p < 0.001).
Conclusions:
- Multisite ultrasound measurement of muscle thickness (MT) is a reproducible and valid method for assessing skeletal muscle size in children.
- US-based MT assessment is a practical and time-efficient alternative to MRI, particularly in resource-limited settings.
- This ultrasonographic protocol holds potential for broader clinical and scientific application in pediatric research and practice.
Abstract:
Introduction and aims: Accurate determination of skeletal muscle size is of great importance in multiple settings including resistance exercise, aging, disease, and disuse. Ultrasound (US) measurement of muscle thickness (MT) is a method of relatively high availability and low cost. The present study aims to evaluate a multisite ultrasonographic protocol for measurement of MT with respect to reproducibility and correlation to gold-standard measurements of muscle volume (MV) with magnetic resonance imaging (MRI) in children. Material and methods: 15 children completed the study (11 ± 1 year, 41 ± 8 kg, 137 ± 35 cm). Following 20 min supine rest, two investigators performed US MT measurements of all four heads of the m. quadriceps femoris, at pre-determined sites. Subsequently, MRI scanning was performed and MV was estimated by manual contouring of individual muscle heads. Results: Ultrasound measurement of MT had an intra-rater reliability of ICC = 0.985-0.998 (CI 95% = 0.972-0.998) and inter-rater reliability of ICC = 0.868-0.964 (CI 95% = 0.637-0.983). The US examinations took less than 15 min, per investigator. Muscle thickness of all individual quadriceps muscles correlated significantly with their corresponding MV as measured by MRI (overall r = 0.789, p < 0.001). Conclusion: The results of this study indicate that US measurement of MT using a multisite protocol is a competitive alternative to MRI scanning, especially with respect to availability and time consumption. Therefore, US MT could allow for wider clinical and scientific implementation.
