Variability of regional quadriceps echo intensity in active young men with and without subcutaneous fat correction

Quantifying echo intensity (EI), a proposed measure of muscle quality, is becoming increasingly popular. Additionally, much attention has been paid to regional differences in other ultrasonically evaluated measures of muscle morphology and architecture. However, the variability of regional (proximal, middle, distal) EI of the vastus lateralis, rectus femoris, and lateral and anterior vastus intermedius has yet to be determined. Twenty participants (40 limbs), were evaluated on 3 occasions, separated by 7 days. Intersession variability of EI with and without subcutaneous fat correction was quantified. Furthermore, the interchangeability of corrected EI across regions was evaluated. Variability of regional quadriceps EI was substantially lower with subcutaneous fat correction (intraclass correlation coefficient (ICC) = 0.81–0.98, coefficient of variation (CV) = 4.5%–16.8%, typical error of measure (TEM) = 0.13–0.49) versus raw values (ICC = 0.69–0.98, CV = 7.7%–42.7%, TEM = 0.14–0.68), especially when examining the vastus intermedius (ICC = 0.81–0.95, CV = 7.1%–16.8%, TEM = 0.23–0.49 vs. ICC = 0.69–0.92, CV = 22.9%–42.7%, TEM = 0.31–0.68). With the exception of the rectus femoris and vastus intermedius (p ≥ 0.143, effect size (ES) ≤ 0.18), corrected EI was greater for proximal and distal regions when compared with the midpoint (p ≤ 0.038, ES = 0.38–0.82). Researchers and practitioners should utilize subcutaneous fat thickness correction to confidently evaluate EI at all regions of the quadriceps. Regional EI cannot be used interchangeably for the vastus muscles, likely because of an increase in fibrous content towards the myotendinous junctions. Novelty Regional quadriceps echo intensity was reliable with and without correction for subcutaneous fat thickness. Intersession variability of regional quadriceps echo intensity was substantially improved following subcutaneous fat correction. Quadriceps echo intensity increased towards myotendinous junctions in the vastus muscles.

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EXAMINATION OF THE CONFOUNDING EFFECT OF SUBCUTANEOUS FAT ON MUSCLE ECHO INTENSITY UTILIZING EXOGENOUS FAT

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2020-0413 ◽

2020 ◽

Author(s):

Jonathan Neto Müller ◽

Fábio Juner Lanferdini ◽

Juliana Yasmin Passos Karam ◽

Heiliane de Brito Fontana

Keyword(s):

Tibialis Anterior Muscle ◽

Subcutaneous Fat ◽

Region Of Interest ◽

Muscle Quality ◽

Focus Position ◽

Echo Intensity ◽

Confounding Effect ◽

Muscle Region ◽

Subcutaneous Fat Thickness ◽

Fat Thickness

We aimed to provide an unbiased estimate of the confounding effect of subcutaneous fat thickness on ultrasound echo intensity (EI) measures of muscle quality. The effect of fat thickness on EI was verified for an approximate range of 0 to 3 cm of fat using exogeneous layers of pork fat over the human tibialis anterior muscle. Sonograms were obtained i) with focus constant across fat thickness conditions and ii) with focus position adjusted to the muscle region of interest (ROI) position for each fat thickness level. In agreement with our hypothesis, increasing fat between the probe and the ROI resulted in a decrease in EI. This overestimating effect of fat on muscle quality differs between sonograms with constant focus and sonograms with focus position adjusted to the vertical displacement in ROI position that occurs for different levels of fat thickness. Correcting equations to account for the overestimating effect of fat on muscle quality are provided for both focus conditions. This is the first study to systematically analyze the confounding effect of fat thickness as an independent factor and the provided equations can be used for improved accuracy in estimates of muscle quality in obese/overweight subjects/patients. NOVELTY • The independent confounding effect of subcutaneous fat thickness on US estimates of muscle quality was quantified • US estimates of muscle quality depend on whether focus is adjusted to the muscle region of interest or not • Equations for correcting muscle quality estimates are provided

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Age-, sex-, and region-specific differences in skeletal muscle size and quality

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2020-0114 ◽

2020 ◽

Vol 45 (11) ◽

pp. 1253-1260 ◽

Cited By ~ 3

Author(s):

Matt S. Stock ◽

Dustin J. Oranchuk ◽

Adam M. Burton ◽

David C. Phan

Keyword(s):

Vastus Lateralis ◽

Subcutaneous Fat ◽

Rectus Femoris ◽

Older Men ◽

Muscle Size ◽

Cross Sectional ◽

Proximal Site ◽

Younger Men ◽

Subcutaneous Fat Thickness ◽

Fat Thickness

Ultrasonography-derived cross-sectional area (CSA) and echo intensity (EI) are increasingly utilized by investigators to study muscle size and quality, respectively. We sought to examine age, sex, and region (proximal, middle, distal) differences in vastus lateralis and rectus femoris CSA and EI, and determine whether correction for subcutaneous fat thickness influences the magnitude of EI differences. Fifteen younger men (mean age = 23 years), 15 younger women (aged 21 years), 11 older men (aged 74 years), and 15 older women (aged 70 years) participated. Clear differences were observed among age, sex, and region for vastus lateralis CSA (p ≤ 0.013, d = 0.38–0.73), whereas rectus femoris CSA was only different between younger and older participants at the proximal region (p = 0.017, d = 0.65). Uncorrected EI was greatest at the distal region of both muscles (p < 0.001, d = 0.59–1.38), with only the younger men having significantly lower EI values than the other groups (p ≤ 0.043, d = 0.37–0.63). Subcutaneous fat correction resulted in a marked increase in the magnitude of sex-specific EI differences (p ≤ 0.032, d ≥ 0.42). Additionally, subcutaneous fat correction increased the uniformity of EI throughout the thigh. These findings highlight considerable region-specific differences in muscle size and quality among younger and older men and women and highlight the need to correct for subcutaneous fat thickness when examining EI. Novelty Rectus femoris CSA is similar between younger and older adults except at the most proximal site evaluated. Age- and sex-specific differences in uncorrected EI are nonuniform across the thigh. Correction for subcutaneous fat thickness substantially increased EI in women, resulting in greater sex differences.

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The influence of subcutaneous fat on the relationship between body composition and ultrasound-derived muscle quality

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2016-0238 ◽

2016 ◽

Vol 41 (10) ◽

pp. 1104-1107 ◽

Cited By ~ 11

Author(s):

Eric D. Ryan ◽

Nicholas W. Shea ◽

Gena R. Gerstner ◽

Timothy J. Barnette ◽

Andrew J. Tweedell ◽

...

Keyword(s):

Body Composition ◽

Subcutaneous Fat ◽

Muscle Quality ◽

Echo Intensity ◽

Subcutaneous Fat Thickness ◽

Fat Thickness ◽

Total Fat ◽

The Relationship

Ultrasound echo intensity (EI) values are a popular assessment of muscle quality. The relationship between EI and total (%fat) and regional (%fatlimb) body composition was examined in 40 men, prior to and after accounting for subcutaneous fat thickness. Uncorrected EI values suggest that muscle quality improves (r = –0.329 to –0.224; P = 0.038–0.165) with greater %fat and %fatlimb. However, corrected EI values indicated that muscle quality decreases (r = 0.711 to 0.798; P < 0.001) with greater %fat and %fatlimb.

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Subcutaneous Thigh Fat Assessment: A Comparison of Skinfold Calipers and Ultrasound Imaging

Journal of Athletic Training ◽

10.4085/1062-6050-46.1.50 ◽

2011 ◽

Vol 46 (1) ◽

pp. 50-54 ◽

Cited By ~ 20

Author(s):

Noelle M. Selkow ◽

Brian G. Pietrosimone ◽

Susan A. Saliba

Keyword(s):

Ultrasound Imaging ◽

Vastus Lateralis ◽

Subcutaneous Fat ◽

Rectus Femoris ◽

Random Order ◽

Measurement Tool ◽

Strong Correlations ◽

Limits Of Agreement ◽

Fat Thickness ◽

Mean Differences

Abstract Context: Skinfold calipers (SC) typically are used to determine subcutaneous fat thicknesses. Identifying the exact separation of muscle and fat can complicate measurements. Ultrasound imaging (USI) might provide a better technique for analyzing subcutaneous fat thicknesses. Objective: To compare measurements from SC and USI in assessing subcutaneous thigh fat thickness. Design: Descriptive laboratory study. Setting: Laboratory. Patients and Other Participants: Twenty healthy adults (13 men, 7 women; age = 26.9 ± 5.4 years, height = 173.9 ± 7.3 cm, mass = 77.4 ± 16.1 kg) participated. Intervention(s): Participants were seated in 90° of knee flexion and 85° of trunk extension. A standardized template was used to identify measurement sites over the vastus medialis obliquus (VMO), distal rectus femoris (dRF), proximal rectus femoris (pRF), and vastus lateralis (VL). Three measurements at each of the 4 sites were made in random order and were averaged for each measurement tool by the same investigator. Main Outcome Measure(s): Fat thickness was measured in millimeters with SC and USI. Measurements at each site were compared using Pearson product moment correlations and Bland-Altman plots. Results: Strong correlations between measures were found at the VMO (r = .90, P < .001), dRF (r = .93, P < .001), pRF (r = .93, P < .001), and VL (r = .91, P < .001). Mean differences between measures ranged from 1.7 ± 2.4 mm (dRF) to 3.7 ± 2.6 mm (pRF), indicating that the SC resulted in larger thicknesses compared with USI. Limits of agreement, as illustrated by the Bland-Altman plots, were fairly wide at each site: from −3.38 mm to 7.74 mm at the VMO, from −3.04 mm to 6.52 mm at the dRF, from −1.53 mm to 8.87 mm at the pRF, and from −3.73 mm to 8.15 mm at the VL. All plots except for the VL demonstrated increasing overestimation via the SC as fat thicknesses increased. Conclusions: We found strong correlations between the SC and USI; however, the large limits of agreement and increasing mean differences with larger fat thicknesses were a concern in terms of using this tool. When measuring subcutaneous fat thickness of the thigh, SC tended to overestimate thickness in individuals with higher fat values.

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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 ◽

10.15557/jou.2021.0002 ◽

2021 ◽

Vol 21 (84) ◽

pp. e7-e11

Author(s):

Eric J. Sobolewski ◽

◽

Leah D. Wein ◽

Jacquelyn M. Crow ◽

Kaitlyn M. Carpenter ◽

...

Keyword(s):

Vastus Lateralis ◽

Measurement Techniques ◽

Subcutaneous Fat ◽

Cross Sectional Area ◽

Muscle Quality ◽

Ultrasound Images ◽

Sectional Area ◽

Echo Intensity ◽

Cross Sectional ◽

Rater Reliability

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.

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Declines in skeletal muscle quality vs. size following two weeks of knee joint immobilization

PeerJ ◽

10.7717/peerj.8224 ◽

2020 ◽

Vol 8 ◽

pp. e8224 ◽

Cited By ~ 3

Author(s):

Rob J. MacLennan ◽

Michael Sahebi ◽

Nathan Becker ◽

Ethan Davis ◽

Jeanette M. Garcia ◽

...

Keyword(s):

Skeletal Muscle ◽

Knee Joint ◽

Vastus Lateralis ◽

Rectus Femoris ◽

Cross Sectional Area ◽

Muscle Quality ◽

Muscle Size ◽

Sectional Area ◽

Echo Intensity ◽

Cross Sectional

Background Disuse of a muscle group, which occurs during bedrest, spaceflight, and limb immobilization, results in atrophy. It is unclear, however, if the magnitude of decline in skeletal muscle quality is similar to that for muscle size. The purpose of this study was to examine the effects of two weeks of knee joint immobilization on vastus lateralis and rectus femoris echo intensity and cross-sectional area. Methods Thirteen females (mean ± SD age = 21 ± 2 years) underwent two weeks of left knee joint immobilization via ambulating on crutches and use of a brace. B-mode ultrasonography was utilized to obtain transverse plane images of the immobilized and control vastus lateralis and rectus femoris at pretest and following immobilization. Effect size statistics and two-way repeated measures analyses of variance were used to interpret the data. Results No meaningful changes were demonstrated for the control limb and the rectus femoris of the immobilized limb. Analyses showed a large increase in vastus lateralis echo intensity (i.e., decreased muscle quality) for the immobilized limb (p = .006, Cohen’s d = .918). For vastus lateralis cross-sectional area, no time × limb interaction was observed (p = .103), but the effect size was moderate (d = .570). There was a significant association between the increase in vastus lateralis echo intensity and the decrease in cross-sectional area (r = − .649, p = .016). Conclusion In female participants, two weeks of knee joint immobilization resulted in greater deterioration of muscle quality than muscle size. Echo intensity appears to be an attractive clinical tool for monitoring muscle quality during disuse.

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Unique Characteristics of Quadriceps Muscle Morphology and Function in Older Tennis Players

Journal of Aging and Physical Activity ◽

10.1123/japa.2021-0074 ◽

2021 ◽

pp. 1-8

Author(s):

Akito Yoshiko ◽

Moroe Beppu ◽

Naoki Chosa ◽

Kohei Watanabe

Keyword(s):

Vastus Lateralis ◽

Muscle Thickness ◽

Peak Torque ◽

Quadriceps Muscle ◽

Knee Extension ◽

Muscle Quality ◽

Muscle Size ◽

Echo Intensity ◽

Tennis Players ◽

Vastus Intermedius

We investigated the quadriceps muscle size and quantitative characteristics in older tennis players. Thirty-eight senior tennis players (70.8 ± 5.3 years) and 38 controls (71.6 ± 5.1 years) were included. To measure the muscle size and quality, we measured muscle thickness in the rectus femoris (RF), vastus lateralis, and vastus intermedius, and muscle echo intensity in the RF and vastus lateralis using B-mode transverse ultrasound, respectively. We measured knee extension peak torque for muscle function. Muscle thickness in the RF, vastus lateralis, and vastus intermedius were significantly larger in tennis players than in controls. Tennis players had a lower echo intensity in RF and a higher knee extension peak torque compared to controls. Stepwise multiple linear regression analysis implied that echo intensity and muscle thickness were predictors of knee extension peak torque. Higher muscle quality contributes to a higher knee extension peak torque in tennis players. Playing tennis may prevent age-related muscle atrophy and maintain muscle quality in older individuals.

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Echo Intensity Versus Muscle Function Correlations in Older Adults are Influenced by Subcutaneous Fat Thickness

Ultrasound in Medicine & Biology ◽

10.1016/j.ultrasmedbio.2018.04.009 ◽

2018 ◽

Vol 44 (8) ◽

pp. 1597-1605 ◽

Cited By ~ 15

Author(s):

Matt S. Stock ◽

Morgan Whitson ◽

Adam M. Burton ◽

Nicole T. Dawson ◽

Eric J. Sobolewski ◽

...

Keyword(s):

Older Adults ◽

Muscle Function ◽

Subcutaneous Fat ◽

Echo Intensity ◽

Subcutaneous Fat Thickness ◽

Fat Thickness

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Muscle Quality, Measured by Ultrasound-Derived Corrected Echo Intensity, Does not Affect Changes in Cross-sectional Area of the Vastus Lateralis Following Recumbent Rest

Journal of Diagnostic Medical Sonography ◽

10.1177/8756479320967277 ◽

2020 ◽

pp. 875647932096727

Author(s):

Alyssa N. Varanoske ◽

Nicholas A. Coker ◽

Bri-Ana D. I. Johnson ◽

Tal Belity ◽

Adam J. Wells

Keyword(s):

Vastus Lateralis ◽

Subcutaneous Fat ◽

Morphological Characteristics ◽

Time Frame ◽

Cross Sectional Area ◽

Muscle Quality ◽

Muscle Size ◽

Sectional Area ◽

Echo Intensity ◽

Cross Sectional

Objective: Recumbent rest elicits a decrease in muscle size of the lower extremity, but the extent of decrease may be related to differences in muscle quality. This could have implications for ultrasound-derived measures of muscle size, particularly in individuals with a large proportion of intramuscular contractile elements. The research objective was to determine whether decreases in muscle size following recumbent rest are related to ultrasound-derived corrected echo intensity in resistance-trained males. Methods: Cross-sectional area (CSA), echo intensity (EI), subcutaneous fat thickness (SFT), and EI corrected for SFT (EICor) of the vastus lateralis (VL) were measured via ultrasonography in 30 resistance-trained males. Measures were obtained immediately following recumbency (T0) and 15 minutes after recumbency (T15). The association between EICor and percentage change in CSA (%ΔCSA) from T0 to T15 was examined. Comparisons of morphological characteristics were examined between a subset of participants with the lowest (LO; n = 10; <33rd percentile) and highest (HI; n = 10; >66th percentile) EICor. Results: EICor was not correlated with %ΔCSA ( P = .151), and the decrease in CSA from T0 to T15 did not differ between the LO and HI groups. Conclusions: Muscle quality (EICor) is not related to the decrease in CSA of the VL following recumbent rest among resistance-trained, young males. The time frame of muscle CSA acquisition should not differ based solely on differences in muscle quality.

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