<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>
<bold>Introduction:</bold> The use of ultrasound images for analyzing muscle quality and size is continuing to grow in the literature. However, many of these manuscripts fail to properly describe their measurement techniques and steps involved in analyzing ultrasound images. <bold>Aim of this study:</bold> To evaluate the intra- and inter-rater reliability of the steps involved when analyzing ultrasound images to measure cross-sectional area and echo intensity. <bold>Material and methods:</bold> Twenty ultrasound images of the rectus femoris and vastus lateralis images were blinded and replicated, and then analyzed by experienced raters. The raters then were asked to analyze the images using open-source software for scaling measurements, subcutaneous fat thickness, cross-sectional area, and echo intensity. Matched image values for each measurement where compared for intra- and inter-rater reliability. <bold>Results:</bold> Intra-rater reliability ranged from fair (ICC<sub>3,1</sub> = 0.32) to high (0.98), with echo intensity values being the least reliable (>0.55), and scaling and depth measurements being the most reliable (&lt;0.85). Inter-rater reliability ranged from good (0.77) to high (0.97). Conclusion: Ultrasound-derived measures of cross-sectional area and echo intensity can be measured reliably, with echo intensity being the most difficult to replicate. However, reliability measures are unique to the rater and study and, therefore, should be clearly reported in every paper.</p>
</abstract>

Introduction: The use of ultrasound images for analyzing muscle quality and size is continuing to grow in the literature. However, many of these manuscripts fail to properly describe their measurement techniques and steps involved in analyzing ultrasound images. Aim of this study: To evaluate the intra- and inter-rater reliability of the steps involved when analyzing ultrasound images to measure cross-sectional area and echo intensity. Material and methods: Twenty ultrasound images of the rectus femoris and vastus lateralis images were blinded and replicated, and then analyzed by experienced raters. The raters then were asked to analyze the images using open-source software for scaling measurements, subcutaneous fat thickness, cross-sectional area, and echo intensity. Matched image values for each measurement where compared for intra- and inter-rater reliability. Results: Intra-rater reliability ranged from fair (ICC3,1 = 0.32) to high (0.98), with echo intensity values being the least reliable (>0.55), and scaling and depth measurements being the most reliable (<0.85). Inter-rater reliability ranged from good (0.77) to high (0.97). Conclusion: Ultrasound-derived measures of cross-sectional area and echo intensity can be measured reliably, with echo intensity being the most difficult to replicate. However, reliability measures are unique to the rater and study and, therefore, should be clearly reported in every paper.

Intra-rater and inter-rater reliability of the process of obtaining cross-sectional area and echo intensity measurements of muscles from ultrasound images

Journal of Ultrasonography

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Introduction: The use of ultrasound images for analyzing muscle quality and size is continuing to grow in the literature. However, many of these manuscripts...

	Scale		Depth		Rectus femoris				Vastus lateralis
Variable	(pixels/cm)		(cm)		CSA (cm²)		El (AU)		CSA (cm²)		El (AU)
RATER	1	2	1	2	1	2	1	2	1	2	1	2
Average	41.5	41.4	0.82	0.77	6.29	6.21	10.04	10.02	21.78	21.66	12.04	11.91
CV%	2.51	1.89	10.97	10.12	11.66	6.72	6.11	9.93	6.01	5.54	6.95	5.61
P value	0.45	0.42	0.86	0.52	0.47	0.25	0.40	0.36	0.13	0.07	0.32	0.22
ICC _3,1	0.85	0.88	0.96	0.98	0.74	0.67	0.36	0.32	0.85	0.88	0.55	0.47
SEM	1.69	1.60	0.05	0.04	0.68	0.77	1.00	1.05	1.44	1.38	0.71	0.72
SEM (%)	4.07	3.86	6.10	5.19	10.81	12.40	9.96	10.48	6.61	6.37	5.90	6.05
MD	4.68	4.43	0.14	0.11	1.88	2.15	2.79	2.92	4.00	3.83	1.97	2.00

	Scale	Depth	Rectus Femoris		Vastus Lateralis
Variable	(pixels/cm)	(cm)	CSA (cm²)	El (AU)	CSA (cm²)	El (AU)
Average	41.54	0.79	6.30	10.00	21.72	11.98
cv %	2.01	7.59	7.82	3.91	3.36	2.95
P value	0.68	0.4	0.12	0.21	0.98	0.45
ICC _3,1	0.87	0.97	0.87	0.77	0.92	0.91
SEM	1.62	0.04	0.47	0.56	1.11	0.28
SEM (%)	3.90	5.06	7.46	5.60	5.11	2.34
MD	4.49	0.13	1.30	1.56	3.06	0.78

Intra-rater and inter-rater reliability of the process of obtaining cross-sectional area and echo intensity measurements of muscles from ultrasound images

Article Category: research-article

Published Online: Mar 08, 2021

Page range: 7 - 11

Received: Sep 22, 2020

Accepted: Jan 16, 2021

DOI: https://doi.org/10.15557/jou.2021.0002

Keywords
muscle quality, muscle size, ultrasonography, echogenicity

© 2021 Polish Ultrasound Society. Published by Medical Communications Sp. z o.o.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1.

Intra-rater reliability statistics ultrasound derived measurements of the leg extensor muscles

Inter-rater reliability statistics ultrasound derived measurements of the leg extensor muscles

Intra-rater and inter-rater reliability of the process of obtaining cross-sectional area and echo intensity measurements of muscles from ultrasound images

Article Category: research-article

Published Online: Mar 08, 2021

Page range: 7 - 11

Received: Sep 22, 2020

Accepted: Jan 16, 2021

DOI: https://doi.org/10.15557/jou.2021.0002

Keywordsmuscle quality, muscle size, ultrasonography, echogenicity

© 2021 Polish Ultrasound Society. Published by Medical Communications Sp. z o.o.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1.

Intra-rater reliability statistics ultrasound derived measurements of the leg extensor muscles

Inter-rater reliability statistics ultrasound derived measurements of the leg extensor muscles

Keywords
muscle quality, muscle size, ultrasonography, echogenicity