The Influence of Sonographer Experience on Skeletal Muscle Image Acquisition and Analysis

The amount of experience with ultrasonography may influence measurement outcomes while images are acquired or analyzed. The purpose of this study was to identify the interrater reliability of ultrasound image acquisition and image analysis between experienced and novice sonographers and image analysts, respectively. Following a brief hands-on training session (2 h), the experienced and novice sonographers and analysts independently performed image acquisition and analyses on the biceps brachii, vastus lateralis, and medial gastrocnemius in a sample of healthy participants (n = 17). Test–retest reliability statistics were computed for muscle thickness (transverse and sagittal planes), muscle cross-sectional area, echo intensity and subcutaneous adipose tissue thickness. The results show that image analysis experience generally has a greater impact on measurement outcomes than image acquisition experience. Interrater reliability for measurements of muscle size during image acquisition was generally good–excellent (ICC2,1: 0.82–0.98), but poor–moderate for echo intensity (ICC2,1: 0.43–0.77). For image analyses, interrater reliability for measurements of muscle size for the vastus lateralis and biceps brachii was poor–moderate (ICC2,1: 0.48–0.70), but excellent for echo intensity (ICC2,1: 0.90–0.98). Our findings have important implications for laboratories and clinics where members possess varying levels of ultrasound experience.

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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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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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Muscle Thickness and Echo Intensity by Ultrasonography and Cognitive and Physical Dimensions in Older Adults

Diagnostics ◽

10.3390/diagnostics11081471 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1471

Author(s):

Alvaro Mateos-Angulo ◽

Alejandro Galán-Mercant ◽

Antonio Ignacio Cuesta-Vargas

Keyword(s):

Older Adults ◽

Older People ◽

Physical Performance ◽

Functional Capacity ◽

Biceps Brachii ◽

Handgrip Strength ◽

Muscle Thickness ◽

Medial Gastrocnemius ◽

Echo Intensity ◽

Physical Dimensions

The purpose of the present study was to investigate the associations between muscle thickness and echo intensity with cognitive and physical dimensions like functional capacity measured in older people. This cross-sectional study involved 20 older adults (15 women and 5 men, mean age ± SD: 85 ± 7 years, body mass index: 25 ± 3 kg/m2) from a geriatric centre in Malaga (Spain). Anthropometric measurements, cognitive assessment with Pfeiffer Short Portable Mental Status Questionnaire and Motor Memory test, Physical Performance with Short Physical Performance Battery, and muscle strength were tested. Additionally, using B-mode ultrasonography, images of wrist flexors, biceps brachii, rectus femoris, vastus lateralis, medial gastrocnemius, and tibialis anterior were captured, and muscle thickness and echo intensity variables were extracted. An association between muscle parameters assessed by ultrasonography and cognitive and physical dimensions were found in older people. Echo intensity was the best predictor in a set of regression models with different muscle parameters and a battery of cognitive and physical tests in older people. Echo intensity adjusted by handgrip strength could be a low cost and ambulatory index and an indirect and reversible indicator of functional capacity.

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Effects of Rest Position on Morphology of the Vastus Lateralis and Its Relationship with Lower-Body Strength and Power

Journal of Functional Morphology and Kinesiology ◽

10.3390/jfmk4030064 ◽

2019 ◽

Vol 4 (3) ◽

pp. 64 ◽

Cited By ~ 3

Author(s):

Alyssa N. Varanoske ◽

Nicholas A. Coker ◽

Bri-Ana D.I. Johnson ◽

Tal Belity ◽

Gerald T. Mangine ◽

...

Keyword(s):

Vastus Lateralis ◽

Morphological Characteristics ◽

Muscle Thickness ◽

Lower Body ◽

Echo Intensity ◽

Cross Sectional ◽

Performance Variables ◽

Body Strength ◽

And Performance ◽

Subcutaneous Adipose

Ultrasonography of the lower body typically encompasses supine rest due to fluid shifts affecting tissue size and composition. However, vastus lateralis (VL) examination is completed in the lateral recumbent position, and this positional change may influence morphology and its ability to predict function. This study aimed to examine the effect of position on VL morphology and its relationship with lower-body performance. Cross-sectional area (CSA), muscle thickness (MT), pennation angle (PA), echo intensity (UnCorEI), subcutaneous adipose tissue thickness (SFT), and echo intensity corrected for SFT (CorEI) were assessed in 31 resistance-trained males (23.0 ± 2.1 yrs; 1.79 ± 0.08 m; 87.4 ± 11.7 kg) immediately after transitioning from standing to supine (IP), after 15 min of standing (ST), and after 15 min of rest in three recumbent positions: supine (SUP), dominant lateral recumbent (DLR), non-dominant lateral recumbent (NDLR). Participants also completed unilateral vertical jumps, isometric/isokinetic tests, and a one-repetition maximum leg press. CSA, MT, PA, and SFT were greater in ST compared to NDLR, DLR, and SUP (p < 0.05). CSA, UnCorEI, and CorEI were different between recumbent positions; however no differences were observed for MT, PA, and SFT. Different magnitudes of relationships were observed between muscle morphological characteristics measured after rest in different positions and performance variables. Muscle morphology in IP generally appears to be the best predictor of performance for most variables, although utilizing the NDLR and DLR positions may provide comparable results, whereas morphology measured in ST and SUP provide weaker relationships with physical performance. IP also requires less time and fewer requirements on the technician and subject, thus researchers should consider this positioning for VL examination.

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Muscle fiber number in biceps brachii in bodybuilders and control subjects

Journal of Applied Physiology ◽

10.1152/jappl.1984.57.5.1399 ◽

1984 ◽

Vol 57 (5) ◽

pp. 1399-1403 ◽

Cited By ~ 52

Author(s):

J. D. MacDougall ◽

D. G. Sale ◽

S. E. Alway ◽

J. R. Sutton

Keyword(s):

Muscle Fiber ◽

Biceps Brachii ◽

Cross Sectional Area ◽

Muscle Size ◽

Sectional Area ◽

Cross Sectional ◽

Trained Subjects ◽

Fiber Area ◽

Muscle Cross Sectional Area

Muscle fiber numbers were estimated in vivo in biceps brachii in 5 elite male bodybuilders, 7 intermediate caliber bodybuilders, and 13 age-matched controls. Mean fiber area and collagen volume density were calculated from needle biopsies and muscle cross-sectional area by computerized tomographic scanning. Contralateral measurements in a subsample of seven subjects indicated the method for estimation of fiber numbers to have adequate reliability. There was a wide interindividual range for fiber numbers in biceps (172,085–418,884), but despite large differences in muscle size both bodybuilder groups possessed the same number of muscle fibers as the group of untrained controls. Although there was a high correlation between average cross-sectional fiber area and total muscle cross-sectional area within each group, many of the subjects with the largest muscles also tended to have a large number of fibers. Since there were equally well-trained subjects with fewer than normal fiber numbers, we interpret this finding to be due to genetic endowment rather than to training-induced hyperplasia. The proportion of muscle comprised of connective and other noncontractile tissue was the same for all subjects (approximately 13%), thus indicating greater absolute amounts of connective tissue in the trained subjects. We conclude that in humans, heavy resistance training directed toward achieving maximum size in skeletal muscle does not result in an increase in fiber numbers.

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Behaviour of Motor Units during Submaximal Isometric Contractions in Chronically Strength-Trained individuals

Journal of Applied Physiology ◽

10.1152/japplphysiol.00192.2021 ◽

2021 ◽

Author(s):

Andrea Casolo ◽

Alessandro Del Vecchio ◽

Thomas Grant Balshaw ◽

Sumiaki Maeo ◽

Marcel Bahia Lanza ◽

...

Keyword(s):

Prolonged Exposure ◽

Biceps Brachii ◽

Isometric Force ◽

Force Production ◽

Motor Units ◽

Surface Emg ◽

Muscle Size ◽

Training Experience ◽

Cross Sectional ◽

Neural Input

Neural and morphological adaptations combine to underpin the enhanced muscle strength following prolonged exposure to strength training, although their relative importance remains unclear. We investigated the contribution of motor unit (MU) behaviour and muscle size to submaximal force production in chronically strength-trained athletes (ST) vs. untrained controls (UT). Sixteen ST (age, 22.9±3.5 yr; training experience, 5.9±3.5 yr) and fourteen UT (age, 20.4±2.3 yr) performed maximal voluntary isometric force (MViF) and ramp contractions (at 15, 35, 50, 70%MViF) with elbow flexors, whilst high-density surface EMG (HDsEMG) was recorded from the biceps brachii (BB). Recruitment thresholds (RT) and discharge rates (DR) of MUs identified from the submaximal contractions were assessed. The neural drive-to-muscle gain was estimated from the relation between changes in force (ΔFORCE, i.e. muscle output) relative to changes in MU DR (ΔDR, i.e. neural input). BB maximum anatomical cross-sectional area (ACSAMAX) was also assessed by MRI. MViF (+64.8% vs. UT, P<0.001) and BB ACSAMAX (+71.9%, P<0.001) were higher in ST. Absolute MU RT was higher in ST (+62.6%, P<0.001), but occurred at similar normalized forces. MU DR did not differ between groups at the same normalized forces. The absolute slope of the ΔFORCE-ΔDR relationship was higher in ST (+66.9%, P=0.002), whereas it did not differ for normalized values. We observed similar MU behaviour between ST athletes and UT controls. The greater absolute force-generating capacity of ST for the same neural input, demonstrates that morphological, rather than neural, factors are the predominant mechanism for their enhanced force generation during submaximal efforts.

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Age-Related Differences in Hip Flexion Maximal and Rapid Strength and Rectus Femoris Muscle Size and Composition

Journal of Applied Biomechanics ◽

10.1123/jab.2020-0383 ◽

2021 ◽

pp. 1-9

Author(s):

Ahalee C. Farrow ◽

Ty B. Palmer

Keyword(s):

Young Men ◽

Rectus Femoris ◽

Peak Torque ◽

Cross Sectional Area ◽

Muscle Size ◽

Sectional Area ◽

Echo Intensity ◽

Cross Sectional ◽

Age Related ◽

Hip Flexion

This study aimed to examine the effects of age on hip flexion maximal and rapid strength and rectus femoris (RF) muscle size and composition in men. Fifteen young (25 [3] y) and 15 older (73 [4] y) men performed isometric hip flexion contractions to examine peak torque and absolute and normalized rate of torque development (RTD) at time intervals of 0 to 100 and 100 to 200 milliseconds. Ultrasonography was used to examine RF muscle cross-sectional area and echo intensity. Peak torque, absolute RTD at 0 to 100 milliseconds, and absolute and normalized RTD at 100 to 200 milliseconds were significantly lower (P = .004–.045) in the old compared with the young men. The older men exhibited lower cross-sectional area (P = .015) and higher echo intensity (P = .007) than the young men. Moreover, there were positive relationships between cross-sectional area and absolute RTD at 0 to 100 milliseconds (r = .400) and absolute RTD at 100 to 200 milliseconds (r = .450) and negative relationships between echo intensity and absolute RTD at 100 to 200 milliseconds (r = −.457) and normalized RTD at 100 to 200 milliseconds (r = −.373). These findings indicate that hip flexion maximal and rapid strength and RF muscle size and composition decrease in old age. The relationships observed between ultrasound-derived RF parameters and measurements of RTD suggest that these age-related declines in muscle size and composition may be relevant to hip flexion rapid torque production.

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The Association of Multiple Gene Variants with Ageing Skeletal Muscle Phenotypes in Elderly Women

Genes ◽

10.3390/genes11121459 ◽

2020 ◽

Vol 11 (12) ◽

pp. 1459

Author(s):

Praval Khanal ◽

Lingxiao He ◽

Adam J. Herbert ◽

Georgina K. Stebbings ◽

Gladys L. Onambele-Pearson ◽

...

Keyword(s):

Skeletal Muscle ◽

Elderly Women ◽

Biceps Brachii ◽

Vastus Lateralis ◽

Elbow Flexion ◽

Knee Extension ◽

Nucleotide Polymorphisms ◽

Cross Sectional ◽

Caucasian Women ◽

Fto Rs9939609

There is a scarcity of studies that have investigated the role of multiple single nucleotide polymorphisms (SNPs) on a range of muscle phenotypes in an elderly population. The present study investigated the possible association of 24 SNPs with skeletal muscle phenotypes in 307 elderly Caucasian women (aged 60–91 years, 66.3 ± 11.3 kg). Skeletal muscle phenotypes included biceps brachii thickness, vastus lateralis cross-sectional areas, maximal hand grip strength, isometric knee extension and elbow flexion torque. Genotyping for 24 SNPs, chosen on their skeletal muscle structural or functional links, was conducted on DNA extracted from blood or saliva. Of the 24 SNPs, 10 were associated with at least one skeletal muscle phenotype. HIF1A rs11549465 was associated with three skeletal muscle phenotypes and PTK2 rs7460 and ACVR1B rs10783485 were each associated with two phenotypes. PTK2 rs7843014, COL1A1 rs1800012, CNTF rs1800169, NOS3 rs1799983, MSTN rs1805086, TRHR rs7832552 and FTO rs9939609 were each associated with one. Elderly women possessing favourable genotypes were 3.6–13.2% stronger and had 4.6–14.7% larger muscle than those with less favourable genotypes. These associations, together with future work involving a broader range of SNPs, may help identify individuals at particular risk of an age-associated loss of independence.

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Automated Confocal Laser Scanning Microscopy and Semiautomated Image Processing for Analysis of Biofilms

Applied and Environmental Microbiology ◽

10.1128/aem.64.11.4115-4127.1998 ◽

1998 ◽

Vol 64 (11) ◽

pp. 4115-4127 ◽

Cited By ~ 105

Author(s):

Martin Kuehn ◽

Martina Hausner ◽

Hans-Joachim Bungartz ◽

Michael Wagner ◽

Peter A. Wilderer ◽

...

Keyword(s):

Image Analysis ◽

Laser Scanning ◽

Fluorescent Protein ◽

Image Acquisition ◽

Three Dimensional ◽

Laser Scanning Microscopy ◽

Three Dimensions ◽

Confocal Laser ◽

Cross Sectional ◽

In Situ Conditions

ABSTRACT The purpose of this study was to develop and apply a quantitative optical method suitable for routine measurements of biofilm structures under in situ conditions. A computer program was designed to perform automated investigations of biofilms by using image acquisition and image analysis techniques. To obtain a representative profile of a growing biofilm, a nondestructive procedure was created to study and quantify undisturbed microbial populations within the physical environment of a glass flow cell. Key components of the computer-controlled processing described in this paper are the on-line collection of confocal two-dimensional (2D) cross-sectional images from a preset 3D domain of interest followed by the off-line analysis of these 2D images. With the quantitative extraction of information contained in each image, a three-dimensional reconstruction of the principal biological events can be achieved. The program is convenient to handle and was generated to determine biovolumes and thus facilitate the examination of dynamic processes within biofilms. In the present study, Pseudomonas fluorescens or a green fluorescent protein-expressing Escherichia coli strain, EC12, was inoculated into glass flow cells and the respective monoculture biofilms were analyzed in three dimensions. In this paper we describe a method for the routine measurements of biofilms by using automated image acquisition and semiautomated image analysis.

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ACTN3 genotype is associated with increases in muscle strength in response to resistance training in women

Journal of Applied Physiology ◽

10.1152/japplphysiol.01139.2004 ◽

2005 ◽

Vol 99 (1) ◽

pp. 154-163 ◽

Cited By ~ 174

Author(s):

Priscilla M. Clarkson ◽

Joseph M. Devaney ◽

Heather Gordish-Dressman ◽

Paul D. Thompson ◽

Monica J. Hubal ◽

...

Keyword(s):

Resistance Training ◽

Body Mass ◽

Biceps Brachii ◽

Elbow Flexor ◽

Muscle Performance ◽

Muscle Size ◽

P Value ◽

Ratio Test ◽

Cross Sectional ◽

Resistance Training Program

The α-actinin 3 (ACTN3) gene encodes a protein of the Z disk of myofibers, and a polymorphism of ACTN3 results in complete loss of the protein. The ACTN3 genotype (R577X) has been found to be associated with performance in Australian elite athletes (Yang N, MacArthur DG, Gulbin JP, Hahn AG, Beggs AH, Easteal S, and North K. Am J Hum Genet 73: 627–631, 2003). We studied associations between ACTN3 genotype and muscle size [cross-sectional area of the biceps brachii via magnetic resonance imaging (MRI)] and elbow flexor isometric (MVC) and dynamic [1-repetition maximum (1-RM)] strength in a large group of men ( N = 247) and women ( N = 355) enrolled in a 12-wk standardized elbow flexor/extensor resistance training program of the nondominant arm at one of eight study centers. We found no association between ACTN3 R577X genotype and muscle phenotype in men. However, women homozygous for the ACTN3 577X allele (XX) had lower baseline MVC compared with heterozygotes ( P < 0.05) when adjusted for body mass and age. Women homozygous for the mutant allele (577X) demonstrated greater absolute and relative 1-RM gains compared with the homozygous wild type (RR) after resistance training when adjusted for body mass and age ( P < 0.05). There was a trend for a dose-response with genotype such that gains were greatest for XX and least for RR. Significant associations were validated in at least one ethnic subpopulation (Caucasians, Asians) and were independent of training volume. About 2% of baseline MVC and of 1-RM strength gain after training were attributable to ACTN3 genotype (likelihood-ratio test P value, P = 0.01), suggesting that ACTN3 is one of many genes contributing to genetic variation in muscle performance and adaptation to exercise.

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