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Abstract
In skeletal muscle sonography high echogenicities have proved to be of diagnostic value. The following study examines whether these echointensities are caused mainly by interstitial fat or fibrosis. Consequently, the echogenicities of 86 muscles, their diameters, and the thickness of subcutaneous fat layers superficial to these muscles were measured and compared for content of fat and connective tissue, which were assessed by morphometry and biochemical testing in the corresponding muscle biopsy samples. The results indicate that fat replacement constitutes the main cause of increased muscle echogenicity, whereas intramuscular fibrosis did not significantly affect the muscles' echogenicity.
... These measurements have both been shown to be valid when compared to CT [4] and MRI [5] scans, and reliable [6] amongst different clinicians. Muscle thickness has been shown to increase following resistance training [7], concentric [2], eccentric [8] and isometric [9] contractions, however it is not conclusive as others have shown size not to increase following resistance training [10]. However, since these studies have used single images to measure muscle thickness, it has not been determined if panoramic images [9] are better at measuring muscle size changes than single US images. ...
... The darker the pixels of the muscle the more structural and contractual proteins commonly referred to as quality muscle [12] The whiter the pixels, the more fibrous the tissue [13,14], intramuscular adiposity [15,16], glycogen stored [17] and water content [18]. Furthermore, EI is being used as an indicator of muscle damage [19] as it has shown to increase with both concentric [7], eccentric [20], isometric [9] exercise as well as plyometric training [21]. Most of the research evaluating EI as a marker of muscle damage is a result of resistance exercises, yet EI has not shown to change with endurance resistance type exercise [20]. ...
... It is theorized that immediate EI changes may be a result of increased blood and water content rather than muscle damage [1]. However, a study by Radaelli et al [7] found that there were no changes in EI following 4 sets of 10 repetitions at 80% max of the elbow flexors. They did find that 24 hours following the bout of exercise EI did increase. ...
Time Course Changes in Muscle Size and Echo Intensity Following Resistance Training
... Tongue-strengthening exercise [31] and expiratory muscle strength training (EMST) [32] increased the geniohyoid muscle area. Ultrasonography can also evaluate the quality of muscles indicated by intensity [33] because noncontractile tissues, such as fat tissues, show high intensity indicated as brightness in ultrasound images [34]. In previous reports, the ultrasonographic geniohyoid muscle intensity in elder people was greater than that in younger people [24], and the tongue muscle thickness was negatively related to intensity [35]. ...
... To date, studies have focused on assessing swallowing rehabilitation, muscle strength, and muscle area. The evaluation of muscle intensity is necessary because increased muscle area may reflect increased fat tissue, not muscle fibers [33]. ...
Insufficient suprahyoid muscle strength with poor opening of the upper esophageal sphincter can cause dysphagia. This study investigated whether an exercise of the suprahyoid muscle, named forehead exercise for suprahyoid muscles (FESM, “Enge-Odeko-Taiso” in Japanese), improves the geniohyoid muscle area and intensity using ultrasonography. Sixty-four participants (15 men and 49 women, 82.8 ± 6.0 years) living independently with no symptoms of swallowing difficulties were enrolled. The participants were divided into the FESM and the control group. The FESM is an isometric exercise involving repetitions of looking into the navel as if the chin is pulled back with little neck motion using a hand pushed against the forehead for resistance. This exercise is performed five times in 10 courses a day (total 50 times) for 8 weeks. Participants in the control group did not conduct any exercises. Body mass index, hand grip strength, gait speed, calf circumference, Mini Nutritional Assessment short-form, eating assessment tool, repetitive saliva swallowing test (RSST), and Food Intake LEVEL Scale scores were examined. The ultrasonographic geniohyoid muscle area, intensity, and RSST were investigated before and after the program. In the FESM group, the geniohyoid muscle area increased from 2.24 to 2.52 cm² (P < 0.05), intensity decreased from 34.6 to 32.0 (P < 0.05), and the median RSST increased from 5 to 6 (P < 0.05) significantly. Conversely, no significant differences were observed in the control group. The FESM was effective to increase the area and decrease the intensity of the geniohyoid muscle and may improve swallowing function.
... an indicator used to estimate muscle quality [4]. Previous studies have shown that EI is associated with the level of adipose tissue within the muscle, as determined by histochemical and chemical shift analyses [5,6]. It is well known that a higher muscle EI leads to lower muscle strength, especially in older individuals [7,8]. ...
... The difference between normalization and un-normalization data was greater than that of other muscles, suggesting that the difference in EI of the BF between the groups was affected by the difference in subcutaneous fat thickness. Higher muscle EI shows a higher concentration of adipose tissue and/or connective tissue within skeletal muscle [5,6], which leads to lower muscle strength and physical function [7,8]. Furthermore, many longitudinal and cross-sectional studies have proven the effect of exercise and physical activity on EI, especially in older individuals [10,26]. ...
This study aimed to investigate the effect of daily exercise on skeletal muscle function, size, and quality in young women. Twenty-six young women participated in this study, categorized into daily exercise and non-exercise groups. The exercise group had performed exercise or training three times a week for more than six months. Knee extension and flexion, plantar flexion, and dorsiflexion peak torques were measured for muscle function. B-mode ultrasound images were taken from the thigh and calf, and muscle thickness and echo intensity were measured in the vastus lateralis and medial gastrocnemius. Shear modulus at different joint angles of the knee (0° [full extended], 40°, and 90°) and ankle (40 °plantarflexion, 0° [neutral], and 10 °dorsiflexion) was measured from the vastus lateralis and medial gastrocnemius to determine muscle stiffness. Peak torque and echo intensity did not significantly differ between the exercise and non-exercise groups. Shear modulus in the medial gastrocnemius at 10° dorsiflexion was significantly lower in the exercise group compared with the non-exercise group (34.2 ± 7.7 vs. 46.5 ± 13.1 kPa, P < 0.05). These results suggest that daily exercise and training could affect muscle stiffness, but do not lead to an increase in muscle function.
... Both approaches can assess muscle thickness, intramuscular fat infiltration, and other biochemical indices of muscle quality since muscle and fat are clearly distinguished [56,58]. Variations in echo intensity (EI) are associated with increased intramuscular fiber and fat tissue [59][60][61][62][63][64]. Researchers who employed computeraided gray scale analysis to determine muscle quality say the EI increases intramuscular adipose and fibrous tissue. ...
... Researchers who employed computeraided gray scale analysis to determine muscle quality say the EI increases intramuscular adipose and fibrous tissue. In recent years, pixel/voxel threshold distinctions between muscle and other tissues have been established semiautomatically [60][61][62][63][64]. In addition to frailty, quantitative MRI data may identify variations in muscle function across age groups [65][66][67][68][69]. Using automated subcutaneous fat and muscle segmentation, multiparametric MRI has recently shown promise in measuring subcutaneous adipose tissue (SAT) and intermuscular adipose tissue (IMAT) [70]. ...
Sarcopenia is characterized by loss of muscle mass, altered muscle composition, fat and fibrous tissue infiltration, and abnormal innervation, especially in older individuals with immune-mediated rheumatic diseases (IMRDs). Several techniques for measuring muscle mass, strength, and performance have emerged in recent decades. The portable dynamometer and gait speed represent the most frequently used tools for the evaluation of muscle strength and physical efficiency, respectively. Aside from dual-energy, X-ray, absorptiometry, and bioelectrical impedance analysis, ultrasound (US) and magnetic resonance imaging (MRI) techniques appear to have a potential role in evaluating muscle mass and composition. US and MRI have been shown to accurately identify sarcopenic biomarkers such as inflammation (edema), fatty infiltration (myosteatosis), alterations in muscle fibers, and muscular atrophy in patients with IMRDs. US is a low-cost, easy-to-use, and safe imaging method for assessing muscle mass, quality, architecture, and biomechanical function. This review summarizes the evidence for using US and MRI to assess sarcopenia.
... This method enables the identification of fat infiltration in muscle, as demonstrated using magnetic resonance spectroscopy (MRS) (Fig. 1) and muscle biopsy. 16 Furthermore, in our previous study, 17 leg muscle echo-intensity measured during ultrasonographic imaging and extra-myocellular lipid content measured during MRS (both of which reflect myosteatosis and atrophy) positively correlated with urinary concentrations of titin-N fragment, a biomarker of skeletal muscle deterioration and functional decline. 18 In the present retrospective study, we investigated the importance of poor muscle quality (namely, a larger amount of non-contractile tissue, including intramuscular fat) as reflected by the presence of greater muscle echo-intensity on ultrasonography, as a risk factor for advanced liver fibrosis in patients with NAFLD. ...
Background: Muscle–liver crosstalk plays an important role in the development and progression of non-alcoholic fatty liver disease (NAFLD). The measurement of muscle echo-intensity during ultrasonography is a real-time, non-invasive method of assessing muscle quality. In this retrospective study, we investigated the significance of poor muscle quality (namely, a greater mass of non-contractile tissue, including intramuscular fat) as a risk factor for advanced liver fibrosis and considered whether it may represent a useful tool for the diagnosis of advanced liver fibrosis.
Methods: We analyzed data from 307 patients with NAFLD (143 men and 164 women) who visited the University of Tsukuba Hospital between 2017 and 2022. The patients were stratified into the following tertiles of muscle quality according to their muscle echo-intensity on ultrasonography: modest (84.1 A.U.), intermediate (97.4 A.U.), and poor (113.6 A.U.). We then investigated the relationships between muscle quality and risk factors for advanced liver fibrosis and calculated appropriate cutoff values.
Results: Patients with poor muscle quality showed a significant, 7.6-fold greater risk of liver fibrosis compared to those with modest muscle quality. Receiver operating characteristic curve analysis showed that muscle quality assessment was as accurate as the Fibrosis-4 index and NAFLD fibrosis score in screening for liver fibrosis and superior to the assessment of muscle quantity and strength, respectively. Importantly, a muscle echo-intensity of ≥ 92.4 A.U. may represent a useful marker of advanced liver fibrosis.
Conclusion: Muscle quality may represent a useful means of identifying advanced liver fibrosis, and its assessment may become a useful screening tool in daily practice.
... Additionally, positive relationships have been found between measurements of knee extensor MT and muscle volume (measured by MRI) (Miyatani et al., 2002). Unlike MRI and CT, B mode US is an imaging tool which is portable, relatively inexpensive, does not have an extensive list of exclusions and the time taken to image the muscle and take measurements is relatively short (Reimers et al., 1993;Stringer & Wilson, 2018). The clinical utility of B mode US is advantageous, and research studies have evaluated measurements of anterior thigh MT across the adult lifespan in relation to muscle wasting in the lower and upper extremities (Abe et al., 2014a), site specific muscle loss in females and males (Abe et al., 2011), prevalence of site-specific thigh sarcopenia in females and males (Abe et al., 2014b) and muscle architectural differences in females (Kubo et al., 2003). ...
... Post-acquisition image analysis using ImageJ software has been reported as a suitable tool for measuring tissue echogenicity [39]. It has been demonstrated to be valuable in assessing muscle quality and alterations in intramuscular adipose tissue, particularly within the skeletal muscle [40,41,44,45]. Strong correlations have been found between the echogenicity assessments in ultrasound and their CT [40] and MRI [41] equivalents. ...
Background: The pericruciate fat pad (PCFP) in the knee joint is still insufficiently studied despite its potential role in knee pathologies. This is the first reported study which aimed to clarify the characteristics of the PCFP in healthy individuals and contrast them with cases of post-traumatic injuries. Methods: Conducted as a retrospective cross-sectional study (n = 110 knees each) following STROBE guidelines, it employed grayscale ultrasound with echogenicity measurement, compression elastography with elasticity measurement, and Color Doppler for blood flow assessment. Results: PCFP showed a homogenic and hyperechoic echostructure. The echogenicity of the PCFP was higher than that of the posterior cruciate ligament (PCL) (p < 0.001, z-score = 8.97) and of the medial head of gastrocnemius (MHG) (p = 0.007, z-score = 2.72) in healthy knees, but lower than subcutaneous fat (SCF) (p < 0.001, z-score = −6.52). Post-injury/surgery, PCFP echogenicity surpassed other structures (p < 0.001; z-score for PCL 12.2; for MHG 11.65 and for SCF 12.36) and notably exceeded the control group (p < 0.001, z-score = 8.78). PCFP elasticity was lower than MHG and SCF in both groups, with significantly reduced elasticity in post-traumatic knees (ratio SCF/PCFP 15.52 ± 17.87 in case group vs. 2.26 ± 2.4 in control group; p < 0.001; z-score = 9.65). Blood flow was detected in 71% of healthy PCFPs with three main patterns. Conclusions: The main findings, indicating increased echogenicity and reduced elasticity of PCFP post-trauma, potentially related to fat pad fibrosis, suggest potential applications of echogenicity and elasticity measurements in detecting and monitoring diverse knee pathologies. The description of vascularity variations supplying the PCFP adds additional value to the study by emphasizing the clinically important role of PCFP as a bridge for the middle genicular artery on its way to the inside of the knee joint.
... The whole cross-section approach is preferred, as it has been shown that the size and location of an ROI affect the repeatability and reproducibility in quantitative imaging [37]. It is conceivable that by considering a larger area of muscle, the measurement error related to regional intra-and extramuscular differences in muscle composition [38][39][40], as quantified by ROI placement, is reduced since muscle contours are traced manually using the ImageJ software. ...
Background: According to EWGSOP2, the diagnosis of sarcopenia is confirmed when in addition to low muscle strength, low muscle quantity or quality is present. Echo intensity (EI) determined by muscle ultrasound (US) has been proposed as an efficient method for the assessment of muscle quality. The effect of changing various US parameter settings on EI remains unclear. Therefore, the aim of this study was to assess the differences between EI values obtained by adjusting parameter settings over their entire range in a sample of middle-aged healthy subjects. Methods: Thirty-two repeated US scans of rectus femoris (RF) and rectus abdominis (RA) muscles were taken in eight men and three women with a portable Mindray M7 premium US machine, working in an Extended field-of-view, B-Mode setup, equipped with a linear 5.0-10.0 MHz transducer. The following US parameters and settings were fixed: gain 60dB, depth 6.5cm, and frequency 10 MHz. Readily adjustable parameters were dynamic range (DR), gray map (GM), line density, persistence, and IClear. A default setting DR65 was chosen as the reference setting. For each of the parameters, the settings of one single parameter of interest was changed over its entire range following a standardized protocol. The EI values were calculated using the open-source software ImageJ. Repeated measures analyses were performed to evaluate the effect of parameter settings on EI. Linear interpolation was used to determine non-significant ranges across a given parameter. Results: For the RF muscle, the EI values were significantly different across DR (p<0.001), GM (p<0.001), and IClear (p<0.001). Post hoc analysis confirmed the differences within these three settings. Echo intensity values within the range of DR55 to DR80 were not significantly different. For the RA muscle, the EI values were significantly different across DR (p=0.004) and GM (p=0.030). Post hoc pairwise comparisons revealed no significant difference with the default setting, except for DR150 (p=0.042). Conclusion: We showed that EI values differ across the DR and GM range, especially in the RF. We suggest using a DR setting within its midrange to minimize the effect of machine setting-dependent factors on EI values. These findings reconfirm the need for standardization of ultrasound echo intensity settings when applied for diagnostic purposes of muscle quality.
... The whole cross-section approach is preferred, as it has been shown that the size and location of an ROI affect the repeatability and reproducibility in quantitative imaging [48]. It is conceivable that by considering a larger area of muscle, the measurement error related to regional intra-and extramuscular differences in muscle composition [49][50][51], as quantified by ROI placement, is reduced since muscle contours are traced manually using the ImageJ software. ...
Echo intensity determined by muscle ultrasound has been proposed as an efficient method for the assessment of muscle quality. The influence of changing ultrasound parameter settings on echo intensity values was assessed using a standardized approach. In this repeated measures cross-sectional study, sixteen repeated scans of rectus femoris, gracilis, and rectus abdominis were taken in 21 middle-aged persons with a portable Mindray M7 premium ultrasound machine equipped with a linear 5.0–10.0 MHz transducer. The settings of three parameters were fixed: gain, depth, and frequency. The settings of the following adjustable parameters were changed over their entire range: dynamic range, gray map, line density, persistence, and IClear. Repeated measures analyses were performed to evaluate the effect of changing the settings on echo intensity values. In all three muscles, dynamic range, gray map, and IClear correlated significantly (rrm-values ranging between −0.86 and 0.45) with echo intensity. In all three muscles, the echo intensity values differed significantly across the dynamic range (p < 0.013), gray map (p < 0.003), and IClear (p < 0.003). In middle-aged subjects, echo intensity values of lower limb and trunk muscles are significantly related to ultrasound parameters and significantly differ across their respective setting range. For the assessment of muscle quality through ultrasound, it is suggested to fix parameter settings within their midrange in order to minimize the effect of setting-dependent factors on EI values.
... In addition, in this study we were careful not to include planes with visible adipose tissue, blood vessels or nerves that might cause increases in echo intensity. Nonetheless, for in-vivo studies this is sometimes unavoidable and it therefore remains a matter of discussion whether echo intensity truly reflects the amount of IMCT in a muscle 45,46 . ...
This study aimed to validate the concept of spatial gain sonography for quantifying texture-related echo intensity in B-mode ultrasound of skeletal muscle. Fifty-one bovine muscles were scanned postmortem using B-mode ultrasonography at varying fascicle probe angles (FPA). The relationship between mean gray values (MGV) and FPA was fitted with a sinusoidal and a linear function, the slope of which was defined as tilt echo gain (TEG). Macroscopic muscle cross sections were optically analyzed for intramuscular connective tissue (IMCT) content which was plotted against MGV at 0° FPA (MGV_00). MGV peaked at FPA 0°. Sine fits were superior to linear fits (adjusted r²-values 0.647 vs. 0.613), especially for larger FPAs. In mixed models, the pennation angle was related to TEG (P < 0.001) and MGV_00 (P = 0.035). Age was relevant for MGV_00 (P < 0.001), but not TEG (P > 0.10). The correlation between the IMCT percentage and MGV_00 was significant but weak (P = 0.026; adjusted r² = 0.103). The relationship between fascicle probe angle and echo intensity in B-mode ultrasound can be modeled more accurately with a sinusoidal but more practically for clinical use with a linear fit. The peak mean gray value MGV_00 can be used to compare echo intensity across muscles without the bias of pennation angle.
... Echogenicity of other important respiratory muscles can be assessed by POCUS-low echogenicity is characterised by lean muscle tissue, whereas fat and connective tissue within the muscles constitute high echogenicity (140). Formenti et al. reported that the echogenicity score for both parasternal intercostal muscles, diaphragm and rectus femoris were significantly lower in patients who survived compared to those who died (124). ...
Background and Objective
The coronavirus disease 2019 (COVID-19) pandemic that began in early 2020 resulted in significant mortality from respiratory tract infections. Existing imaging modalities such as chest X-ray (CXR) lacks sensitivity in its diagnosis while computed tomography (CT) scan carries risks of radiation and contamination. Point-of-care ultrasound (POCUS) has the advantage of bedside testing with higher diagnostic accuracy. We aim to describe the various applications of POCUS for patients with suspected severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in the emergency department (ED) and intensive care unit (ICU).
Methods
We performed literature search on the use of POCUS in the diagnosis and management of COVID-19 in MEDLINE, Embase and Scopus databases using the following search terms: “ultrasonography”, “ultrasound”, “COVID-19”, “SARS-CoV-2”, “SARS-CoV-2 variants”, “emergency services”, “emergency department” and “intensive care units”. Search was performed independently by two reviewers with any discrepancy adjudicated by a third member.
Key Content and Findings
Lung POCUS in patients with COVID-19 shows different ultrasonographic features from pulmonary oedema, bacterial pneumonia, and other viral pneumonia, thus useful in differentiating between these conditions. It is more sensitive than CXR, and more accessible and widely available than CT scan. POCUS can be used to diagnose COVID-19 pneumonia, screen for COVID-19-related pulmonary and extrapulmonary complications, and guide management of ICU patients, such as timing of ventilator weaning based on lung POCUS findings.
Conclusions
POCUS is a useful and rapid point-of-care modality that can be used to aid in diagnosis, management, and risk stratification of COVID-19 patients in different healthcare settings.
... These results could indicate structural muscle changes in patients with MC. However, although elevated echo intensities on ultrasound of muscles can signify elevated fat content and/or inflammation [27,28], they are not specific for those changes in muscle tissue. Another study of three Becker patients found no abnormalities on a wholebody MRI using T1 and T2 sequences [8]. ...
Background and purpose
Myotonia congenita (MC) is a muscle channelopathy in which pathogenic variants in a key sarcolemmal chloride channel Gene (CLCN1) cause myotonia. This study used muscle magnetic resonance imaging (MRI) to quantify contractile properties and fat replacement of muscles in a Danish cohort of MC patients.
Methods
Individuals with the Thomsen (dominant) and Becker (recessive) variants of MC were studied. Isometric muscle strength, whole‐body MRI, and clinical data were collected. The degree of muscle fat replacement of thigh, calf, and forearm muscles was quantitively calculated on Dixon MRI as fat fractions (FFs). Contractility was evaluated as the muscle strength per contractile muscle cross‐sectional area (PT/CCSA). Muscle contractility was compared with clinical data.
Results
Intramuscular FF was increased and contractility reduced in calf and in forearm muscles compared with controls (FF = 7.0–14.3% vs. 5.3–9.6%, PT/CCSA = 1.1–4.9 Nm/cm² vs. 1.9–5.8 Nm/cm² [p < 0.05]). Becker individuals also showed increased intramuscular FF and reduced contractility of thigh muscles (FF = 11.9% vs. 9.2%, PT/CCSA = 1.9 Nm/cm² vs. 3.2 Nm/cm² [p < 0.05]). Individual muscle analysis showed that increased FF was limited to seven of 18 examined muscles (p < 0.05). There was a weak correlation between reduced contractility and severity of symptoms.
Conclusions
Individuals with MC have increased fat replacement and reduced contractile properties of muscles. Nonetheless, changes were small and likely did not impact clinically on their myotonic symptoms.
... This may be due to a higher concentration of intramuscular fat content and architectural features in the muscle fascicles [19,20]. Reimers et al. [21], examined 86 muscle biopsies and measured EI and intramuscular fat content and concluded that increases in EI occurred due to the amount of intramuscular fat within the muscle, changing the acoustics of the ultrasound waves. Several other studies also reported high EI for females when compared to males [20,22]. ...
This study evaluated muscle composition, quality, and strength of non-weight bearing and weight bearing muscles between males and females. Twenty-eight, healthy males (n = 14; mean ± SD; age = 25.1 ± 4.2 years; height = 181.9 ± 10.6 cm; weight = 91.6 ± 17.2 kg) and females (n = 14; age = 25.0 ± 3.4 years; height = 165.9 ± 6.9 cm; weight = 66.0 ± 10.2 kg) underwent body composition assessment to estimate body fat (%BF) and total-body, arm, and leg fat-free mass (TFFM, ArmFFM, and LegFFM, respectively) and muscle composition via B-mode ultrasound to measure muscle cross-sectional area (mCSA), echo intensity (EI), and thickness (mT) of four muscles [rectus femoris (RF), vastus lateralis (VL), flexor digitorum superficialis (FDS), and flexor carpi radialis (FCR)]. Additionally, upper- [handgrip strength (HG)] and lower-body [leg extension (LE)] maximal strength were measured, recorded, and expressed relative to FFM to determine muscle quality (MQ) for the dominant arm and leg, respectively. Males had greater TFFM, ArmFFM, and LegFFM (p < 0.001), mCSA for RF, VL, FCR, and FDS (p < 0.001), and mT for RF, VL (p < 0.001–0.006). Females had greater EI for RF, VL, and FDS (p = 0.003–0.01). Negative correlations were identified between EI and MQ for all muscles in males and females, however, no significance was determined. Despite the sex differences in absolute strength and size, muscle quality (relative strength) was not different for the upper nor lower body.
... To bolster this proxy composition measure, analysis of muscle biopsy for contractile tissue, adipose, laminin, and collagen should be conducted. Recent studies have commonly cited an older, yet robust correlative study, relating muscle biopsy with US findings (35,39). However, this study indirectly measures connective tissue content and does not discriminate between specific proteins. ...
Mongold, SJ, Ricci, AW, Hahn, ME, and Callahan, DM. Skeletal muscle compliance and echogenicity in resistance-trained and nontrained women. J Strength Cond Res XX(X): 000–000, 2023—Noninvasive assessment of muscle mechanical properties in clinical and performance settings tends to rely on manual palpation and emphasizes examination of musculotendinous stiffness. However, measurement standards are highly subjective. The purpose of the study was to compare musculotendinous stiffness in adult women with varying resistance training history while exploring the use of multiple tissue compliance measures. We identified relationships between tissue stiffness and morphology, and tested the hypothesis that combining objective measures of morphology and stiffness would better predict indices of contractile performance. Resistance-trained (RT) women ( n = 11) and nontrained (NT) women ( n = 10) participated in the study. Muscle echogenicity and morphology were measured using B-mode ultrasonography (US). Vastus lateralis (VL) and patellar tendon (PT) stiffness were measured using digital palpation and US across submaximal isometric contractions. Muscle function was evaluated during maximal voluntary isometric contraction (MVIC) of the knee extensors (KEs). Resistance trained had significantly greater PT stiffness and reduced echogenicity ( p < 0.01). Resistance trained also had greater strength per body mass ( p < 0.05). Muscle echogenicity was strongly associated with strength and rate of torque development (RTD). Patellar tendon passive stiffness was associated with RTD normalized to MVIC (RTD rel ; r = 0.44, p < 0.05). Patellar tendon stiffness was greater in RT young women. No predictive models of muscle function incorporated both stiffness and echogenicity. Because RTD rel is a clinically relevant measure of rehabilitation in athletes and can be predicted by digital palpation, this might represent a practical and objective measure in settings where RTD may not be easy to measure directly.
... There is limited evidence for HIIT-induced skeletal muscle hypertrophy in young individuals (Estes et al. 2017). However, muscle quality as determined by echo intensity (EI), an ultrasound-derived quantitative gray-scale analysis of fat or fibrous tissue infiltration of muscle (Reimers et al. 1993;Pillen et al. 2009), is another increasingly popular skeletal muscle parameter. Evidence for the influence of HIIT on muscle quality is equivocal, but two studies showing no effect involved a short training period (≤4 weeks) (Blue et al. 2018;Moghaddam et al. 2020), while 8 weeks of training improved muscle quality (Hirsch et al. 2021). ...
High-intensity interval training (HIIT) is an effective alternative to moderate intensity continuous training for improvements in body composition and aerobic capacity; however, there is little work comparing different modalities of HIIT. The purpose of this study was to compare the effects of plyometric- (PLYO) and cycle-oriented (CYC) HIIT on body composition, aerobic capacity, and skeletal muscle size, quality, and function in recreationally trained females. Young (21.7 ± 3.1 yrs), recreationally active females were quasi-randomized (1:1 ratio) assigned to 8 weeks of twice weekly PLYO (n = 15) or CYC (n = 15) HIIT. Body composition (4-compartment model), VO2peak, countermovement jump performance, muscle size and echo intensity (muscle quality) as well as strength and power of the knee extensors and plantar flexors were measured before and after training. Both groups showed a similar decrease in body fat percentage (p < 0.001; η_p^2 = 0.409) and echo intensity (p < 0.001; η_p^2 = 0.558), and an increase in fat-free mass (p < 0.001; η_p^2 = 0.367) and VO2peak (p = 0.001; η_p^2 = 0.318). Muscle size was unaffected (p > 0.05), whereas peak torque was reduced similarly in both groups (p = 0.017; η_p^2 = 0.188) and rapid torque capacity was diminished only for the knee extensors after CYC (p = 0.022; d = -0.67). These results suggest that PLYO and CYC HIIT are similarly effective for improving body composition, aerobic capacity, and muscle quality, whereas muscle function may express moderate decrements in recreationally active females. ClinicalTrials.gov (NCT05821504).
... Z merjenjem ehogenosti mišice lahko pridobimo informacijo o mišični sestavi (42). Povečana ehogenost mišice je kazalnik mišične degeneracije, ki se kaže s povečanjem deleža maščobe v mišici in vezivnega tkiva -miosteatoza (43). ...
Sarkopenija je izguba mišične mase in funkcije, ki zmanjša kakovost življenja, povzroči fizično oslabelost in je povezana z večjo umrljivostjo. Za postavitev zgodnje diagnoze in za uspešno zdravljenje sarkopenije so potrebne varne, dostopne in natančne diagnostične metode. Ultrazvočna slikovna preiskovalna metoda se vse pogosteje uporablja za oceno mišične mase in kakovosti mišic. S pomočjo različnih ultrazvočnih parametrov lahko sklepamo o količini mišične mase kot tudi o kakovosti mišičnega tkiva. Z uporabo standardiziranih protokolov opravljanja meritev lahko dosežemo večjo natančnost in ponovljivost preiskave. Pomanjkanje jasno določenih mejnih vrednosti in nepopolna standardizacija protokolov in ponekod slaba korelacija parametrov z dejansko fizično zmogljivostjo bolnikov za zdaj še zavirajo širšo uporabo ultrazvočne preiskave v kliničnem okolju. Kljub temu z naraščujočim številom raziskav na tem področju ultrazvočna preiskava pridobiva veljavo pri vsakdanji klinični obravnavi sarkopeničnih bolnikov.
... On the other hand, echo intensity is a promising new tool for studying muscle quality [48]. Echo intensity has high echogenicity when more fibrous tissue is present and low echogenicities when more lean body mass is present [49,50]. Echo intensity in the quadriceps muscle at baseline in older hospitalized patients was independently associated with a higher risk of undernutrition as assessed using the Geriatric Nutritional Risk Index (b ¼ À0.18, P ¼ 0.02, 95% CI: ¼ À0.60 to À0.14) [51]. ...
... High ultrasound echogenicity values, reflecting extensive fat infiltration in the muscle, has been correlated with lower muscle quality and grip strength. 20,26,27 As a point-of-care tool in the clinic, BIA is an attractive option due to the speed of performing it (under a minute), albeit if the BIA device is available in the clinic to be used routinely. However, BIA requires more attention to confounders. ...
Background
Disturbance of skeletal muscle mass has clinically important implications in patients with inflammatory bowel disease (IBD), but accurate quantification requires radiation‐intense techniques.
Aims
We aimed to compare point‐of‐care muscle assessments and their change with therapy with those using reference‐standard whole‐body dual energy X‐ray absorptiometry (DXA).
Methods
Adult patients with IBD and healthy controls underwent prospective assessment of muscularity by ultrasound of the dominant arm and both thighs, bioelectrical impedance analysis (BIA), anthropometric measurements, and DXA. Patients with active IBD were assessed again ≥13 weeks after initiating biologic induction therapy.
Results
In 54 patients with IBD and 30 controls, all muscle assessments correlated significantly with DXA‐derived skeletal muscle index (SMI). In IBD, ultrasound of the arm and legs had the best agreement with DXA‐derived SMI (mean difference 0 kg/m², 95% limits of agreement −1.3 to 1.3), while BIA overestimated DXA‐derived SMI by 1.07 (−0.16 to +2.30) kg/m². In 17 patients who underwent biologic therapy, the percentage change in DXA‐derived SMI correlated significantly with the percentage change in all other muscle assessment techniques. Responders (n = 9) increased SMI from baseline to follow‐up when derived from DXA (mean 7.8–8.5 kg/m², p = 0.004), ultrasound of the arm and legs (300–343 cm², p = 0.021) and BIA (9.2–9.6 kg/m², p = 0.011).
Conclusions
Ultrasound of the arm and legs out‐performed other point‐of‐care methods in its accuracy of measuring muscle mass. All methods, except mid‐arm circumference, were responsive to therapy‐induced change. Ultrasound is the preferred non‐invasive test for measuring muscle mass in patients with IBD.
... The EI-IMF relationships were stronger than EMCL-EI relationships, suggesting that ultrasound imaging can quantify at least part of the IMCL included in the IMF content. This good ability of ultrasound imaging to quantify IMF is consistent with previous studies comparing muscle EI to the percentage of IMF quantified from a muscle biopsy sample [40,41] or from MRS data [36]. As previously mentioned, corrected EI from subcutaneous fat thickness improved EI-IMF relationship quality. ...
This study aimed to compare different ultrasound devices with magnetic resonance spectroscopy (MRS) to quantify muscle lipid content from echo intensity (EI). Four different ultrasound devices were used to measure muscle EI and subcutaneous fat thickness in four lower-limb muscles. Intramuscular fat (IMF), intramyocellular (IMCL) and extramyocellular lipids (EMCL) were measured using MRS. Linear regression was used to compare raw and subcutaneous fat thickness-corrected EI values to IMCL, EMCL and IMF. IMCL had a poor correlation with muscle EI (r = 0.17–0.32, NS), while EMCL (r = 0.41–0.84, p < 0.05–p < 0.001) and IMF (r = 0.49–0.84, p < 0.01–p < 0.001) had moderate to strong correlation with raw EI. All relationships were improved when considering the effect of subcutaneous fat thickness on muscle EI measurements. The slopes of the relationships were similar across devices, but there were some differences in the y-intercepts when raw EI values were used. These differences disappeared when subcutaneous fat thickness-corrected EI values were considered, allowing for the creation of generic prediction equations (r = 0.41–0.68, p < 0.001). These equations can be used to quantify IMF and EMCL within lower limb muscles from corrected-EI values in non-obese subjects, regardless of the ultrasound device used.
... Reimers et al. examined whether high echo intensities are caused mainly by interstitial fat or fibrosis using echo intensity measurements, morphometry, and biochemical testing. Fatty replacement was found to correlate better with increased muscle echogenicity than fibrosis [26]. Interestingly, Pillen et al. compared quantitative echo intensity values with muscle structure in golden retriever dogs with muscular dystrophy and found a significant correlation between echo intensity and interstitial fibrosis [27]. ...
Ultrasound (US) is an important imaging tool for skeletal muscle analysis. The advantages of US include point-of-care access, real-time imaging, cost-effectiveness, and absence of ionizing radiation. However, US can be highly dependent on the operator and/or US system, and a portion of the potentially useful information carried by raw sonographic data is discarded in image formation for routine qualitative US. Quantitative ultrasound (QUS) methods provide analysis of the raw or post-processed data, revealing additional information about normal tissue structure and disease status. There are four QUS categories that can be used on muscle and are important to review. First, quantitative data derived from B-mode images can help determine the macrostructural anatomy and microstructural morphology of muscle tissues. Second, US elastography can provide information about muscle elasticity or stiffness through strain elastography or shear wave elastography (SWE). Strain elastography measures the induced tissue strain caused either by internal or external compression by tracking tissue displacement with detectable speckle in B-mode images of the examined tissue. SWE measures the speed of induced shear waves traveling through the tissue to estimate the tissue elasticity. These shear waves may be produced using external mechanical vibrations or internal “push pulse” ultrasound stimuli. Third, raw radiofrequency signal analyses provide estimates of fundamental tissue parameters, such as the speed of sound, attenuation coefficient, and backscatter coefficient, which correspond to information about muscle tissue microstructure and composition. Lastly, envelope statistical analyses apply various probability distributions to estimate the number density of scatterers and quantify coherent to incoherent signals, thus providing information about microstructural properties of muscle tissue. This review will examine these QUS techniques, published results on QUS evaluation of skeletal muscles, and the strengths and limitations of QUS in skeletal muscle analysis.
... All muscle specimens from the included patients underwent extensive evaluation at the NCNP. We performed histochemical and immunohistochemical staining using hematoxylin and eosin (H&E) and modi- Because endomysial fibrosis and intramuscular adiposity, findings suggestive of chronic muscle degeneration, may significantly affect muscle EI, 24 we developed novel methods to quantitatively assess these histological changes using ImageJ. Endomysial fibrosis was quantified by manually tracing endomysial areas using mGT staining. ...
Introduction/Aims: In idiopathic inflammatory myopathies (IIMs), the change in muscle echogenicity and its histopathological basis are not well understood. We quantitatively measured muscle echogenicity in patients with IIMs and evaluated its correlation with disease activity and histopathological findings.
Methods: This study involved patients with IIMs who underwent both ultrasonography (US) and muscle biopsy, as well as age- and sex-matched rheumatoid arthritis patients as inflammatory disease controls. On US, axial images of the right biceps brachii and vastus medialis were obtained. Standardized histopathological scoring was used to quantitatively measure each pathological domain.
Results: Forty-two patients (17 with inclusion body myositis [IBM] and 25 with IIMs other than IBM) and 25 controls were included. The muscle echo intensity (EI) of patients with IIMs was significantly higher than that of controls. Muscle EI showed
significant correlations with creatine kinase (r = 0.66, p < .001) and muscle strength (r = -0.73, p < .0001) in patients with non-IBM IIMs. In patients with IBM, moderate correlation was found between muscle EI and quadriceps muscle strength (r = -0.53,
p = .028). Histopathologically, the number of infiltrating CD3+ inflammatory cells correlated with muscle EI in the non-IBM group (r = 0.56, p = .017), but not in the IBM group.
Discussion: Muscle EI may be useful as a surrogate marker of muscle inflammation in non-IBM IIM. Increased muscle EI may be difficult to interpret in patients with long-standing IBM, which has advanced and complex histopathology.
... As a greater EI value is hypothesized to represent a greater amount of intramuscular fat [3,6,44], a muscle with a larger amount of type I muscle fibers may present with a greater echo intensity. Muscle biopsy work demonstrates intramuscular lipid content has a strong to moderate positive relationship with echo intensity, suggesting that this measure may be utilized as a cost-effective and non-invasive method to examine body composition [6,45]. The strong to moderate relationships between local muscle endurance and cEI in the current study further supports the use of echogenicity as a muscle fitness predictor. ...
Citation: Voskuil, C.; Dudar, M.; Zhang, Y.; Carr, J. Skeletal Muscle Ultrasonography and Muscle Fitness Relationships: Effects of Scanning Plane and Echogenicity Correction. Muscles 2023, 2, 109-118. https:// Abstract: This study examines the relationships between ultrasonography measurements of skeletal muscle size and echo intensity (EI) with muscle strength and local muscle endurance in a habitually resistance-trained population. Twenty young, healthy participants underwent imaging of the biceps brachii in the sagittal and transverse planes and with the extended field of view (EFOV) technique. Linear regression was used to examine measures of muscle thickness (MT), muscle cross-sectional area (mCSA), EI, and corrected EI (cEI) in each scanning plane for their associations with strength (1RM biceps curl) and local muscle endurance (4x failure @ 50%1RM). The strongest predictor of 1RM strength and local muscle endurance was sagittal MT (adj. R 2 = 0.682) and sagittal cEI (adj. R 2 = 0.449), respectively. Strength and transverse MT (R 2 = 0.661) and the EFOV mCSA (R 2 = 0.643) demonstrated a positive relationship. Local muscle endurance and cEI in the transverse plane (R 2 = 0.265) and the EFOV scan (R 2 = 0.309) demonstrated a negative relationship. No associations were shown with uncorrected EI. While each scanning plane supports the muscle size-strength and echogenicity-endurance relationships, sagittal plane imaging demonstrated the strongest associations with muscle fitness. These findings provide important methodological insights regarding ultrasound imaging and muscle fitness relationships.
... Typical values of quadricep thickness and rectus femoris CSA in healthy volunteers have been reported to be 2.6 cm [78] and between 4.53 and 8.68 cm 2 [78][79][80], respectively. On the other side, in critically ill patients, average values at ICU admission have ranged between 0.98 and 2.23 cm for quadricep thickness [81][82][83] and from 2.26 to 4.42 cm 2 for rectus femoris CSA [5,[82][83][84][85]. ...
Acute critical illnesses can alter vital functions with profound biological, biochemical, metabolic, and functional modifications. Despite etiology, patient’s nutritional status is pivotal to guide metabolic support. The assessment of nutritional status remains complex and not completely elucidated. Loss of lean body mass is a clear marker of malnutrition; however, the question of how to investigate it still remains unanswered. Several tools have been implemented to measure lean body mass, including a computed tomography scan, ultrasound, and bioelectrical impedance analysis, although such methods unfortunately require validation. A lack of uniform bedside measurement tools could impact the nutrition outcome. Metabolic assessment, nutritional status, and nutritional risk have a pivotal role in critical care. Therefore, knowledge about the methods used to assess lean body mass in critical illnesses is increasingly required. The aim of the present review is to update the scientific evidence regarding lean body mass diagnostic assessment in critical illness to provide the diagnostic key points for metabolic and nutritional support.
... 21,[23][24][25] For example, previous studies have demonstrated US-derived echo-intensity (EI) is related to the infiltration of non-contractile tissues, such as fat and fibrous tissues. [26][27][28] Thus, its portability, cost-effectiveness, reliability, 29 and lack of radiation exposure 23 make it an attractive alternative for muscle assessment for clinicians and researchers. ...
Peripheral quantitative computed tomography (pQCT) has promise to simultaneously examine muscle size and composition. The purpose of this study was to examine the between- and within-day test-retest reliability of pQCT-derived mid-thigh muscle cross-sectional area (CSA), lean muscle CSA, and muscle density (MD) of the dominant thigh among young and older men and women. All variables were determined using an automatic threshold-based edge detection software and an automated enclosing convex polygon approach. Thirty-nine participants enrolled in the study and visited the laboratory completing three scans on two separate occasions. The absolute (SEM (%): 0.92 – 4.91) and relative (ICC2,1: 0.643 – 0.999) consistency values were acceptable for both protocols for muscle CSA, lean muscle CSA, and MD. Further, relative and absolute consistency values were better for the enclosing convex polygon approach.
... Our findings agree with reports from several authors of EI as a surrogate measure of muscle quality (15,26,48). The enhanced EI represents changes in muscle quality; higher EI is associated with increased intramuscular adipose and fibrous tissue (49)(50)(51). ...
Background
Fatigue and muscle weakness are common complaints in COVID-19 survivors. However, little is still known about the skeletal muscle qualitative and quantitative characteristics after hospitalization due to moderate and severe COVID-19.
Objectives
To assess rectus femoris and vastus intermedius muscle thickness (MT) and rectus femoris echo intensity (EI) and to establish its association with demographic, clinical, functional, and inflammatory parameters in long COVID patients after hospital discharge.
Methods
Cross-sectional study with 312 COVID-19 patients (53.53% male; age: 54.59 ± 13.50 years), with a laboratory-confirmed diagnosis of COVID-19. Patients were assessed 3–11 months after hospital discharge. We evaluated MT of the right rectus femoris and v astus intermedius and EI of the right rectus femoris using a portable ultrasound system, 6–13 MHz, broadband linear transducer. We corrected EI using the subcutaneous fat thickness. Ultrasonographic parameters were tested in association with demographic (sex and age); functional (Handgrip strength measurement, Timed Up and Go, 1 min Sit-to-Stand test, EuroQoL-5 Dimensions-5 Levels, World Health Organization Disability Assessment Schedule (WHODAS 2.0), Post-COVID-19 Functional Status, Functional Assessment of Chronic Illness Therapy—Fatigue (FACIT), Medical Research Council (MRC) sum score, Borg Dyspnea Scale, MRC Dyspnea score, Visual Analogue Scale (VAS), Epworth Sleepiness Scale, Insomnia Severity Index, Functional Independence Measurement (FIM), and Functional Oral Intake Scale); clinical (length of hospital stay, intubation, and presence of comorbidities such as systemic hypertension, diabetes, obesity, chronic obstructive pulmonary disease, asthma), and inflammatory data assessed by the C-reactive protein and D-dimer serum concentrations.
Results
Rectus femoris MT was associated with age, handgrip strength, Epworth Sleepiness Scale, and subcutaneous fat thickness (r ² = 27.51%; p < 0.0001). Vastus intermedius MT was associated with age, pain intensity, handgrip strength, Epworth Sleepiness scale, FIM, and time since hospital discharge (r ² = 21.12%; p < 0.0001). Rectus femoris EI was significantly associated with the male sex, TUG, Epworth Sleepiness Scale, and C-Reactive Protein levels (r ² = 44.39%; p < 0.0001). Mean MT of rectus femoris and vastus intermedius are significantly different ( p < 0.001).
Conclusion
After hospital discharge, long COVID patients present qualitative and quantitative skeletal muscle characteristics associated with a combination of demographic, clinical, and functional parameters.
... From another perspective, excessive concentrations of non-contractile tissues, such as lipids and/or fibrous tissue, negatively affect muscle strength. Echo intensity (EI) determined by the black-towhite color scale from ultrasound images has been used to evaluate non-contractile tissue concentration Reimers et al., 1993). In addition, the relationship between maximal muscle strength and EI has been demonstrated in previous studies (Cadore et al., 2012;Rech et al., 2014). ...
This study aimed to investigate the relationship between maximal muscle strength and neuromuscular activation, muscle size, and quality of quadriceps (QF) and hamstring muscles (HM). The study included 24 young men and women. The neuromuscular activation parameter was recorded using a single-channel surface electromyography (EMG) with the root mean square (RMS) during maximal isometric knee extension and flexion from four muscles: rectus femoris and vastus lateralis for QF; biceps femoris and semitendinosus for HM. In addition, the peak torque was measured during the same session. B-mode ultrasonographic transverse images were obtained from the anterior, lateral, and posterior thighs. Furthermore, we calculated the muscle thickness (MT) and echo intensity (EI) of the four muscles as indicators of muscle size and quality. The averaged MT, EI, and absolute RMS of QF were calculated by averaging the values of the rectus femoris and vastus lateralis, and that of HM was calculated by averaging the values of the biceps femoris and semitendinosus. The knee extension peak torque was correlated with EI (r = -0.61, P < 0.01) and RMS (r = 0.53, P < 0.01) in the QF. In contrast, the knee flexion peak torque was correlated with RMS (r = 0.53, P < 0.05) but not with MT and EI in HM. In addition, EI and RMS in QF, and RMS in HM were selected as the major determinants of muscle strength in the stepwise regression analysis. These results suggest that muscle strength is moderately associated with different factors related to the thigh muscles in young individuals.
... [26][27][28] The higher numerical value of EI reflects more fat and fibrous tissue in the body. 29,30 The majority of reports on muscle US have used the quadriceps femoris muscle (QFM) for measurement purposes, [13][14][15][16][17][18][19][20][21]26,27 but when performing QFM US in practice, it is necessary to expose and image the part above the knee, which makes it difficult to perform QFM US easily in clinical settings. To solve this problem, we previously investigated a method that uses the tibialis anterior muscle (TA) to determine whether US of this easier-to-approach site is useful to diagnose sarcopenia and evaluate muscle quality. ...
Purpose
Muscle mass, a key index for the diagnosis of sarcopenia, is currently assessed using the appendicular skeletal muscle mass index (ASMI) by bioelectrical impedance analysis (BIA). Muscle thickness (MT) assessed by ultrasonography (US) may be a better determinant and/or predictor of muscle condition than ASMI. Thus, we compared it to the ASMI determined by the BIA.
Patients and Methods
Our study included 165 ambulatory older adults (84 males, 81 females, mean age: 76.82 years). The ASMI by the BIA method, MT by US, and the distribution of body mass index (BMI) and body fat percentage (BFP) were examined using defined values for men and women. These were used as the basis for examining the association of MT and ASMI with handgrip strength (HGS), leg muscle strength (LMS), gait speed (GS), and echo intensity (EI). We compared HGS, LMS, GS, and EI for high and low ASMI among lower BMI or BFP. The same was also done for MT assessed by US.
Results
MT, as well as ASMI, was strongly associated with HGS and LMS. There was a correlation between MT and GS and EI but not between ASMI and GS and EI. There were significant differences in the prevalence between high ASMI and high MT or low ASMI and low MT in those with lower BMI or BFP. In non-overweight participants, HGS, LMS, GS, and EI were significantly higher in those with high MT than in those with low MT; however, there were no significant differences in them between those with high and low ASMI.
Conclusion
In the non-overweight group, the MT assessment by US showed a stronger relationship to muscle strength and muscle quality than the ASMI assessment by BIA. The MT assessment using US is a useful alternative to BIA-assessed ASMI, especially in non-overweight participants.
... While more specific and precise imaging approaches exist to measure these changes, along with more invasive methods, it appears that some rehabilitative ultrasound imaging (RUSI) parameters may be sensitive enough to detect these remodelling processes (Langevin et al., 2009;Whittaker et al., 2013;Young et al., 2015). RUSI echogenicity is affected by MFI (Reimers et al., 1993) and fibrous content (Arts et al., 2012;Pillen et al., 2009). As for all imaging techniques, however, it cannot differentiate between the two. ...
Patients with chronic low back pain (CLBP) exhibit remodelling of the lumbar soft tissues such as muscle fatty infiltrations (MFI) and fibrosis of the lumbar multifidus (LuM) muscles, thickness changes of the thoracolumbar fascia (TLF) and perimuscular connective tissues (PMCT) surrounding the abdominal lateral wall muscles. Rehabilitative ultrasound imaging (RUSI) parameters such as thickness and echogenicity are sensitive to this remodelling. This experimental laboratory study aimed to explore whether these RUSI parameters (LuM echogenicity and fascia thicknesses), hereafter called dependent variables (DV) were linked to independent variables (IV) such as (1) other RUSI parameters (trunk muscle thickness and activation) and (2) physical and psychological measures. RUSI measures, as well as a clinical examination comprising physical tests and psychological questionnaires, were collected from 70 participants with LBP. The following RUSI dependent variables (RUSI‐DV), measures of passive tissues were performed bilaterally: (1) LuM echogenicity (MFI/fibrosis) at three vertebral levels (L3/L4, L4/L5 and L5/S1); (2) TLF posterior layer thickness, and (3) PMCT thickness of the fasciae between subcutaneous tissue thickness (STT) and external oblique (PMCTSTT/EO), between external and internal oblique (PMCTEO/IO), between IO and transversus abdominis (PMCTIO/TrA) and between TrA and intra‐abdominal content (PMCTTrA/IA). RUSI measures of trunk muscle's function (thickness and activation), also called measures of active muscle tissues, were considered as independent variables (RUSI‐IV), along with physical tests related to lumbar stability (n = 6), motor control deficits (n = 7), trunk muscle endurance (n = 4), physical performance (n = 4), lumbar posture (n = 2), and range of motion (ROM) tests (n = 6). Psychosocial measures included pain catastrophizing, fear‐avoidance beliefs, psychological distress, illness perceptions and concepts related to adherence to a home‐based exercise programme (physical activity level, self‐efficacy, social support, outcome expectations). Six multivariate regression models (forward stepwise selection) were generated, using RUSI‐DV measures as dependent variables and RUSI‐IV/physical/psychosocial measures as independent variables (predictors). The six multivariate models included three to five predictors, explaining 63% of total LuM echogenicity variance, between 41% and 46% of trunk superficial fasciae variance (TLF, PMCTSTT/EO) and between 28% and 37% of deeper abdominal wall fasciae variance (PMCTEO/IO, PMCTIO/TrA and PMCTTrA/IA). These variables were from RUSI‐IV (LuM thickness at rest, activation of IO and TrA), body composition (percent fat) and clinical physical examination (lumbar and pelvis flexion ROM, aberrant movements, passive and active straight‐leg raise, loaded‐reach test) from the biological domain, as well as from the lifestyle (physical activity level during sports), psychological (psychological distress—cognitive subscale, fear‐avoidance beliefs during physical activities, self‐efficacy to exercise) and social (family support to exercise) domains. Biological, psychological, social and lifestyle factors each accounted for substantial variance in RUSI‐passive parameters. These findings are in keeping with a conceptual link between tissue remodelling and factors such as local and systemic inflammation. Possible explanations are discussed, in keeping with the hypothesis‐generating nature of this study (exploratory). However, to impact clinical practice, further research is needed to determine if the most plausible predictors of trunk fasciae thickness and LuM fatty infiltrations have an effect on these parameters. Patients with chronic low back pain exhibit remodelling of the lumbar soft tissues such as muscle fatty infiltrations of the lumbar multifidus muscles and thickness changes of fasciae surrounding back and abdominal muscles. Clinical examination findings from different domains (biological, psychological, social and lifestyle) were found to be related to the corresponding ultrasound imaging parameters. These results may have implications for rehabilitation as these clinical findings are modifiable.
... The mean EI of the VM was obtained by converting the image pixels to an 8-bit grayscale using image analysis software (ImageJ-WinJP; LISIT, Japan; Fig. 1) and expressed as a 256-point value from 0 (black) to 255 (white). The enhanced EI is associated with increased non-contractile tissue within the muscle, including fat tissue investigated by muscle biopsy [13,24]. The EI analyses of VM were performed by another investigator blinded to the clinical data. ...
Patients with knee osteoarthritis (OA) experience muscle quality loss, and is characterized by the enhanced echo intensity (EI) of the vastus medialis (VM) muscles and a high extracellular water-to-intracellular water (ECW/ICW) ratio of the thigh. This study aimed to elucidate the association between muscle degeneration and the worsening of functional disabilities and symptoms in patients with KOA over 3 years duration. Thirty-three patients with KOA who completed follow-up over 3 years were included in the analysis. The knee scoring system (KSS) was used to evaluate the functional abilities and symptoms. Based on the 3 years change in KSS scores, patients were classified into progressive or non-progressive groups. Muscle thickness (MT) and EI of the VM were determined using ultrasonography. The ECW/ICW ratio was measured using segmental-bioelectrical impedance spectroscopy. Multivariable logistic regression analyses were conducted with the groups as the dependent variables and VM-MT, VM-EI, and ECW/ICW ratio at baseline as independent variables, including potential confounders. Thirteen (39.4%) patients showed progressive features. VM-EI at baseline was significantly associated with the progression of functional disabilities (adjusted odds ratio [OR] 1.24; 95% confidence interval [CI] 1.03 − 1.50) and symptoms (adjusted OR 1.13; 95% CI 1.01 − 1.25). Enhanced VM-EI was associated with the worsening of functional disabilities and symptoms in patients with KOA over a period of 3 years. Therefore, the assessment of VM-EI using ultrasonography is a useful indicator for predicting the future worsening of KOA.
... Along with an increase in echo intensity, a decrease in muscle thickness indicates muscle atrophy [30][31][32]. However, in addition to muscle atrophy, PPS patients present other symptoms such as myalgia, arthralgia, dysphagia, and fatigue, as a consequence of neurological deficits. ...
There is no specific designed diagnostic test for post-poliomyelitis syndrome. The most important symptoms of this syndrome are new loss of muscle strength and more fatigue. Previous studies have investigated muscle ultrasound parameters to distinguish neuromuscular disease patients from healthy controls. The aim of this study was to investigate if muscle thickness and echo intensity measured by ultrasound can discriminate post-poliomyelitis syndrome patients from healthy controls. A total of 29 post-polio patients and 27 healthy controls participated in this cross-sectional study. Anthropometric measures, muscle thickness, echo intensity using B-mode ultrasound in rectus femoris and biceps brachii muscles, and muscle strength test data were collected. Muscle thickness in rectus femoris was significantly lower in post-poliomyelitis patients than in healthy controls, but not in biceps brachii. Echo intensity in rectus femoris and biceps brachii was higher in post-poliomyelitis syndrome patients than in healthy controls. Correlations were found between muscle thickness and strength in the upper and lower limbs. The results of the present study showed that muscle thickness in rectus femoris and echo intensity in rectus femoris and biceps brachii can discriminate post-poliomyelitis syndrome patients from healthy controls. A better assessment is possible because it can observe differences and relevant parameters in this clinical population.
... EI is a measurement of US image brightness of the identified muscle and is obtained through the histogram of the gray-scale pixels of the US image. EI is associated with the presence of intramuscular adipose tissue (Reimers et al. 1993) and muscle density (Sipil€ a and Suominen 1993). However, EI estimation takes into consideration only individual pixel intensity values; it ignores the spatial relationships between pixels and, finally, it is highly dependent on the US scanner settings (Paris and Mourtzakis 2021). ...
The aim of this study was to examine the intra- and inter-muscular differences of the hamstring muscles using textural analysis of ultrasound (US) images, and the relationship between textural indicators with hamstring torque. Transverse US scans were obtained from 10 young males from four different measurement sites along the thigh of each individual hamstring muscle at rest. Maximum-knee-flexion isometric torque measurements were also obtained. Texture analysis was applied to US images, and five gray-level co-occurrence matrix (GLCM) features were quantified: entropy (ENT), angular second moment (ASM), inverse difference moment (IDM), contrast (CON) and correlation (COR). The intraclass correlation coefficients ranged from 0.77 to 0.99, and the standard error of measurement ranged from 0.06 to 10.05%, indicating high test–retest reliability. Analysis of the variance indicated significant differences between measurement sites and individual muscles, with the proximal measurement sites having greater values for ASM, IDM and COR and lower values for ENT and CON compared with the distal sites. Additionally, only the COR at the proximal measurement site exhibited a significant relationship (r = –0.66) with strength. The present study indicated significant differences among hamstrings and measurement locations with respect to the textural analysis and may provide a novel indicator of hamstring functional properties.
... [26] Muscle quality assessed by muscle biopsy suggests that echogenicity is more strongly associated with intramuscular fat infiltration rather than fibrosis. [27] Thus, EI measurements using USG-derived images can be used as a measure of muscle quality. This technique is cheaper, noninvasive, readily available, and safer than that other imaging techniques such as CT and MRI in indicating fat infiltration in the muscle. ...
... EI reflects intramuscular fibrous and adipose tissue, so it is used to evaluate muscle quality [21][22][23][24] . Fukumoto 11,12) . ...
Objective:
This study aimed to determine the association between echo intensity (EI) of vastus lateralis and knee extension strength (KES) in patients with type 2 diabetes mellitus (T2DM).
Methods:
This retrospective study included a total of 304 patients (189 males and 115 females) with T2DM who were hospitalized for treatment or care. EI and muscle thickness (MT) of the right vastus lateralis were assessed from transverse ultrasound images. Maximal isometric KES was evaluated using a dynamometer and normalized for body weight (%KES).
Results:
%KES was significantly positively correlated with MT and stages of change for exercise behavior, and significantly negatively correlated with age, T2DM duration, and EI. %KES was significantly higher in male than in female. %KES was significantly higher in non-diabetic peripheral neuropathy (DPN) than in DPN. Stepwise multiple regression analysis showed that sex, age, T2DM duration, EI, and stages of change for exercise behavior were significant determinants of %KES.
Conclusion:
The study results suggest that EI is associated with %KES in patients with T2DM.
Ultrasound (US) imaging has seen major advancements over the last few decades, with this imaging modality becoming routinely used during the initial clinical assessment. The use of US as a medical imaging device can be traced back to 1942 and has been in use since. The cost, ease of access, and pain-free applications associated with US imaging, makes this imaging modality preferred by patients. US skills coupled with anatomical knowledge make clinical diagnosis using US more accurate in patient care.
US is used in both inflammatory and noninflammatory diseases. Rheumatologists have advanced the treatment of various forms of arthritis and have employed US as a means of assessing the type of arthritis present and determining the appropriate treatment plan. Medical examinations using US are advantageous to patient education and provide the rationale for the treatment choice. The advancement of US imaging has improved extensively and is in some settings documented as being as effective as MRI and CT imaging. US imaging in the treatment of musculoskeletal diseases has seen many improvements, with some applications noted in the assessment of pressure ulcers in patients presenting with a spinal cord injury. US is used to evaluate the tissue found superficial to the ischial tuberosity and is used to document tissue properties that make patients susceptible to the development of pressure ulcers.
This chapter outlines the history of US imaging and its role in the treatment of various musculoskeletal diseases such as arthritis. Probe selection plays an important role in diagnosis as it allows for the optimization of an image and as such disease monitoring. The role of US in the investigation of tissue composition below the ischial tuberosity and its role in the evaluation of pressure ulcers will be covered in this chapter, as well as the future direction of US imaging. Fusion imaging, 3D imaging and contrast-enhanced US are some of the recent advances made in rheumatology, which seek to combine and overcome the limitations associated with MRI and CT imaging. The high learning curve associated with US imaging when weighed against its benefits, makes point of care ultrasound (POCUS) ideal for the clinical setting.
This study aimed to investigate the associations between echocardiogram-based cardiac function indices and fibrosis of the abdominal and lower extremity muscles in Duchenne muscular dystrophy (DMD) and identify the indices predictive of cardiac function changes during disease progression. Twenty-one non-ambulant patients with DMD who consented to participate in the study were enrolled. The association between cardiac dysfunction and fibrosis of the abdominal and lower extremity muscles was determined by analyzing the echocardiography and elastography data for the abdominal and extremity muscles. The patients’ mean age was 18.45 ± 4.28 years. The strain ratios of the abdominal and quadriceps muscles were significantly higher than that of the medial gastrocnemius muscle (GCM). The rectus abdominis muscle showed a higher strain ratio than the biceps femoris muscle and GCM, and the quadriceps muscle showed a higher strain ratio than the GCM. The strain ratio of the rectus abdominis muscle was negatively correlated with the left ventricular ejection fraction. The degree of fibrosis of respiratory muscles was also significantly associated with cardiac dysfunction; therefore, it can be used as a predictor of cardiac dysfunction in patients with DMD in clinical practice.
Purpose:
We examined the association of activities of daily living (ADL), mobility and balance ability, and symptoms of Parkinson's disease (PD) with the masses and amounts of intramuscular non-contractile tissue of the trunk and lower extremity muscles in patients with PD.
Methods:
The subjects were 11 community-dwelling patients with PD. ADL were assessed using the Functional Independence Measure. Mobility capacity was assessed based on measurement of maximal walking speed and timed up-and-go time, while balance ability was evaluated based on measurement of one-legged stance time. The symptoms of PD were assessed based on measurement of the Hoehn and Yahr stage and Unified Parkinson's Disease Rating Scale. Muscle thickness (MT) and echo intensity (EI) of the trunk and lower extremity muscles were also measured using an ultrasound imaging device.
Results:
Partial correlation analysis revealed an association between reduced ADL and increased EI of the lumbar erector spinae muscle; reduced mobility capacity and increased EI of the rectus abdominis and gluteus minimus muscles; and reduced balance ability and decreased MT of the lumbar erector spinae muscle and increased EI of the lumbar erector spinae, semitendinosus, and tibialis posterior muscles. Partial correlation analysis also showed an association between symptoms of severe PD and decreased MT of the tibialis anterior muscles and increased EI of the lumbar erector spinae, gluteus minimus, and tibialis posterior muscles.
Conclusion:
The properties of the trunk and lower extremity muscles may be critical for ADL, mobility and balance ability, and symptoms of PD in patients with PD.
Objectives:
The aim of the study was to compare quantitative and qualitative ultrasound parameters between healthy young adults and post-acute hospitalized older adults with and without physical disability, as well as between normal weight and overweight/obese persons.
Design:
Cross-sectional observational study.
Setting and participants:
A total of 120 individuals were recruited: 24 healthy young adults, 24 normal weight and 24 overweight/obese community-dwelling adults, and 48 post-acute hospitalized older adults with different degrees of functional autonomy.
Methods:
The rectus femoris cross-sectional area (CSA), subcutaneous adipose tissue (SCAT) thickness, echogenicity, strain elastography, and compressibility were measured with ultrasound echography.
Results:
Post-acute older adults with a good level of autonomy showed higher echogenicity, a higher compressibility index and elastometry strain, and lower rectus femoris thickness and CSA as compared with young persons. Post-acute individuals with physical disability showed lower echogenicity and a greater stiffness compared with their still autonomous counterparts. Normal weight individuals showed lower stiffness as evaluated with elastometry and a lower SCAT thickness, as compared with individuals with age-matched overweight or obesity. From multiple regression analyses, using CSA as an independent variable, an inverse association with female sex and age was observed, explaining 16% and 51% of variance. Echogenicity was directly associated with age (34% of variance) and with the Barthel index (6% of variance). Elastometry showed association with age and body mass index (BMI), 30% and 16% of variance, respectively. Considering compressibility as a dependent variable, a direct association with age and an inverse association with BMI were observed, with 5% and 11% of variance respectively.
Conclusions and implications:
Muscle mass decreases with age and with physical disability. Echogenicity, which increases with age and disability level, seems to be associated with myofibrosis. Conversely, elastometry seems useful in the characterization of muscle quality in overweight or obese individuals and as a reliable indirect measure of myosteatosis.
Introduction/aims:
Orofacial muscle ultrasound images can be evaluated quantitatively or using a visual grading system. Quantitative muscle ultrasound (QMUS) is currently the most sensitive technique to detect pathology, but can be time-consuming. The aim of this study was to investigate the validity and reliability of two visual grading systems (the original Heckmatt scale or a modified 3-point version) for the optimal grading of orofacial muscle images.
Methods:
A retrospective, comparative, reliability and validity study was performed. Ultrasound images of the digastric, geniohyoid, masseter, temporalis muscles, and intrinsic muscles of the tongue of healthy participants and of patients (suspected of) having a neuromuscular disease were included. QMUS was used as the "gold standard." Two expert raters and one inexperienced rater rated all ultrasound images using both visual grading systems.
Results:
A total of 511 ultrasound images were included. Criterion validity showed Spearman rho correlation coefficients of >0.59. Construct validity analysis showed strong to very strong associations between the visual grading systems and mastication and/or swallowing. Inter- and intrarater reliability of the original Heckmatt scale and the modified scale were good and comparable. Rater experience had a beneficial effect on the interrater reliability of both scales.
Discussion:
Both the original Heckmatt and the modified Heckmatt scale are valid and reliable tools for the visual grading of orofacial ultrasound images. The modified Heckmatt scale, with only three grades and including an "uncertain" category, is considered easier to use in clinical practice.
Adipokines secreted from adipose tissue, such as adiponectin and leptin, enhance skeletal muscle metabolism. Animal studies have shown that adipokine knockout leads to a reduction in muscle function. Muscle function is determined by muscle size and quality; therefore, it is speculated that lower adipokine levels affect skeletal muscle size and quality, eventually leading to lower muscle function. This study aimed to investigate the relationship between adipokines and skeletal muscle morphology and function in young individuals. A total of 21 young women participated in this study. Adiponectin and leptin levels were analyzed using fasting blood samples from all participants. B-mode ultrasound images of the thigh and calf were obtained, and the muscle thickness and echo intensity were measured in the vastus lateralis (VL) and medial gastrocnemius (MG). The shear modulus was measured from the VL and MG using shear wave elastography. Knee extension and plantar flexion peak torques were measured as muscle functions. Adiponectin and leptin were not related to echo intensity, shear modulus and muscle thickness in the VL and MG (rs= ˗0.26−0.37, P>0.05). Furthermore, no relationship was observed between adiponectin, leptin, knee extension, and dorsiflexion peak torque (rs= ˗0.28−0.41, P>0.05). These negative results suggest that adiponectin and leptin levels in young women are not associated with muscle size and quality, nor are they related to muscle function.
Objectives
This study aimed to examine whether the decrease in muscular echo-intensity of the quadriceps by ultrasound in older inpatients is related to the improvement of gait independence than the increase of muscle thickness.DesignLongitudinal studySettingHospital-based studyParticipantsThis study included 171 inpatients aged ≥ 65 years (median age: 84.0 [77.0–88.0], 56.1% female). Patients who were able to walk independently at hospital admission were excluded from the study.MeasurementsImprovement of gait independence during hospital stay was assessed using the change in Functional Independence Measure (FIM) gait score (i.e., FIM gait score at hospital discharge minus FIM gait score at hospital admission) and FIM gait score at hospital discharge. Muscular echo-intensity and muscle thickness of the quadriceps were assessed at hospital admission and discharge using ultrasound images, respectively. Muscular echo-intensity has been shown to be mainly related to intramuscular adipose tissue. Multiple linear regression analysis was performed to identify the factors independently associated with the change in FIM gait score and FIM gait score at discharge.ResultsChange in quadriceps echo-intensity was independently and significantly associated with the change in FIM gait score (β = −0.22, p = 0.017) and FIM gait score at hospital discharge (β = −0.21, p = 0.017). In contrast, change in quadriceps thickness was not independently and significantly associated with the change in FIM gait score (β = 0.16, p = 0.050) and FIM gait score at hospital discharge (β = 0.15, p = 0.050).Conclusions
Our study indicates that a decrease in muscular echo-intensity of the quadriceps by ultrasound is more related to the improvement of gait independence than an increase of muscle thickness in older inpatients. Intervention for intramuscular adipose tissue of the quadriceps may be important for improving gait independence in older inpatients.
Cancer cachexia causes significant declines in skeletal muscle mass and strength and is associated with a poor prognosis and impaired activities of daily living and quality of life. Therefore, treating cachexia is an important aim in physical therapy in patients with cancer. Although many studies have reported that training exercises can reduce cancer-related declines in muscle mass and strength, there is still no consensus on the most effective exercise protocol. The first part of this paper reviews the effectiveness of various exercise protocols in animal models of cancer cachexia and in patients with advanced cancer. The review includes resistance training, aerobic training, and combined training performed at least twice per week at an intensity of at least 60% of the maximal strength or heart rate. Protocols that included resistance training appeared to yield the greatest improvements in muscle strength. However, improvements in muscle mass are rarely reported, and the methods used to measure muscle mass are inconsistent. Therefore, the latter half of this paper describes clinically relevant methods for assessing muscle mass and quality. To develop the field of cancer rehabilitation, further studies should examine in detail how physical activity affects muscle mass and muscle quality, in addition to muscle strength.
Background & Aims
Cancer cachexia is commonly associated with poor prognosis in patients with head and neck cancer (HNC). However, its pathophysiology and treatment are not well established. The current study aimed to assess the muscle mass/quality/strength, physical function and activity, resting energy expenditure (REE), and respiratory quotient (RQ) in cachectic patients with HNC.
Methods
This prospective cross-sectional study analyzed 64 patients with HNC. Body composition was measured via direct segmental multifrequency bioelectrical impedance analysis, and muscle quality was assessed using echo intensity on ultrasonography images. Muscle strength was investigated utilizing handgrip strength and isometric knee extension force (IKEF). Physical function was evaluated using the 10-m walking speed test and the five times sit-to-stand (5-STS) test. Physical activity was examined using a wearable triaxial accelerometer. REE and RQ were measured via indirect calorimetry. These parameters were compared between the cachectic and noncachectic groups.
Results
In total, 23 (36%) patients were diagnosed with cachexia. The cachectic group had a significantly lower muscle mass than the noncachectic group. Nevertheless, there was no significant difference in terms of fat between the two groups. The cachectic group had a higher quadriceps echo intensity and a lower handgrip strength and IKEF than the noncachectic group. Moreover, they had a significantly slower normal and maximum walking speed and 5-STS speed. The number of steps, total activity time, and time of activity (<3 Mets) did not significantly differ between the two groups. The cachectic group had a shorter time of activity (≥3 Mets) than the noncachectic group. Furthermore, the cachectic group had a significantly higher REE/body weight and REE/fat free mass and a significantly lower RQ than the noncachectic group.
Conclusions
The cachectic group had a lower muscle mass/quality/strength and physical function and activity and a higher REE than the noncachectic group. Thus, REE and physical activity should be evaluated to determine energy requirements. The RQ was lower in the cachectic group than that in the noncachectic group, indicating changes in energy substrate. Further studies must be conducted to examine effective nutritional and exercise interventions for patients with cancer cachexia.
Background and objectives:
The loss of muscle mass in post-critical COVID-19 outpatients is difficult to assess due to the limitations of techniques and the high prevalence of obesity. Ultrasound is an emerging technique for evaluating body composition. The aim is to evaluate sarcopenia and its risk factors, determining ultrasound usefulness as a potential tool for this purpose according to established techniques, such as the bioimpedance vector analysis (BIVA), handgrip strength, and timed up-and-go test.
Methods:
This is a transversal study of 30 post-critical COVID-19 outpatients. We evaluated nutritional status by ultrasound (Rectus Femoris-cross-sectional-area (RF-CSA), thickness, and subcutaneous-adipose-tissue), BIVA, handgrip strength, timed up-and-go test, and clinical variables during admission.
Results:
According to The European Society for Clinical Nutrition and Metabolism and the European Association for the Study of Obesity (ESPEN&EASO) Consensus for Sarcopenic and Obesity, in terms of excess fat mass and decreased lean mass, the prevalence of class-1 sarcopenic obesity was 23.4% (n = 7), and class-2 sarcopenic obesity was 33.3% (n = 10) in our study. A total of 46.7% (n = 14) of patients had a handgrip strength below the 10th percentile, and 30% (n = 9) achieved a time greater than 10s in the timed up-and-go test. There were strong correlations between the different techniques that evaluated the morphological (BIVA, Ultrasound) and functional measurements of muscle. Intensive care unit stay, mechanical ventilation, and age all conditioned the presence of sarcopenia in COVID-19 outpatients (R2 = 0.488, p = 0.002). Predictive models for sarcopenic diagnosis based on a skeletal muscle index estimation were established by RF-CSA (R2 0.792, standard error of estimate (SEE) 1.10, p < 0.001), muscle-thickness (R2 0.774, SEE 1.14, p < 0.001), and handgrip strength (R2 0.856, SEE 0.92, p < 0.001). RF-CSA/weight of 5.3 cm2/kg × 100 was the cut-off value for predicting sarcopenia in post-critical COVID-19 outpatients, with 88.2 sensitivity and 69.2% specificity.
Conclusion:
More than half of the post-critical COVID-19 survivors had sarcopenic obesity and functional impairment of handgrip strength. Intensive care unit stay, age, and mechanical ventilation all predict sarcopenia. An ultrasound, when applied to the assessment of body composition in post-critical COVID-19 patients, provided the possibility of assessing sarcopenia in this population.
Objectives:
Assess changes in lower extremity musculotendinous thickness, tissue echogenicity, and muscle pennation angles among adolescent runners enrolled in a 6-month distance running program.
Methods:
We conducted prospective evaluations of adolescent runners' lower extremity musculotendinous changes at three timepoints (baseline, 3 months, and 6 months) throughout a progressive marathon training program. Two experienced researchers used an established protocol to obtain short- and long-axis ultrasound images of the medial gastrocnemius, tibialis anterior, flexor digitorum brevis, abductor hallicus, and Achilles and patellar tendons. ImageJ software was used to calculate musculotendinous thickness and echogenicity for all structures, and fiber pennation angles for the ankle extrinsic muscles. Repeated measures within-subject analyses of variance were conducted to assess the effect of endurance training on ultrasound-derived measures.
Results:
We assessed 11 runners (40.7% of eligible runners; 6F, 5M; age: 16 ± 1 years; running experience: 3 ± 2 years) who remained injury-free and completed all ultrasound evaluation timepoints. Medial gastrocnemius muscle (F2,20 = 3.48, P = .05), tibialis anterior muscle (F2,20 = 7.36, P = .004), and Achilles tendon (F2,20 = 3.58, P = .05) thickness significantly increased over time. Echogenicity measures significantly decreased in all muscles (P-range: <.001-.004), and increased for the patellar tendon (P < .001) during training. Muscle fiber pennation angles significantly increased for ankle extrinsic muscles (P < .001).
Conclusions:
Adolescent runners' extrinsic foot and ankle muscles increased in volume and decreased in echogenicity, attributed to favorable distance training adaptations across the 6-month timeframe. We noted tendon thickening without concomitantly increased echogenicity, signaling intrasubstance tendon remodeling in response to escalating distance.
1. An experiment was carried out to validate techniques as predictive diagnostic tools for breast myopathies and to study the allometric growth of distinct parts of the body and meat quality of broilers.
2. Infrared thermography was performed at 35 d of age. The surface temperatures of breasts of 300 birds were recorded, followed by ultrasound imaging.
3. The birds were slaughtered and the cuts were made to weigh the body parts. Then, the breasts were evaluated as for the presence and severity of myopathies, from which nine treatments were established represented by the associated degrees of the myopathies white striping and wooden breast and breasts classified as normal.
4. There was no difference in surface temperatures and echogenicity values between normal breasts and breasts affected by myopathies. At 35 d of age few fillets classified as normal were found.
5. The breast showed late growth in relation to the body, regardless of characteristic lesions of myopathies. The most severe score of wooden breast affected meat quality variables.
Spasticity develops because of injury to the central nervous system. However, secondary changes within the connective tissue of the muscle also contribute to muscle stiffness. The hyaluronan hypothesis postulates that the accumulation and biophysical alteration of hyaluronan, a high molecular weight glycosaminoglycan that normally acts as a lubricant within the extracellular matrix of muscles, promotes the development of muscle stiffness and progression to fibrosis and muscle contracture. Intramuscular injections of the enzyme hyaluronidase, which catabolizes the altered hyaluronan polymer, were shown to reduce muscle stiffness and increase passive and active range of motion in patients with spasticity-associated muscle stiffness. This chapter discusses the preliminary evidence for the emerging treatment of muscle stiffness using the enzyme hyaluronidase and its potential to prevent fibrosis and contracture.
Triacylglycerol metabolism has been studied in kidney cortex tubules from starved rats, prepared by collagenase treatment. Triacylglycerol was determined by a newly developed fully enzymic method. Incubation of tubules in the absence of fatty acids led to a decrease of endogenous triacylglycerol by about 50% in 1h. Addition of albuminbound oleate or palmitate resulted in a steady increase of tissue triacylglycerol over 2h. The rate of triacylglycerol synthesis was linearly dependent on oleate concentration up to 0.8mm, reaching a saturation at higher concentrations. Triacylglycerol formation from palmitate was less than that from oleate. This difference was qualitatively the same when net synthesis was compared with incorporation of labelled fatty acids. Quantitatively, however, the difference was less with the incorporation technique. Gluconeogenic substrates, which by themselves had no effect on triacylglycerol concentrations, stimulated neutral lipid formation from fatty acids. Glucose and lysine did not have such a stimulatory effect. Inhibition of gluconeogenesis from lactate by mercaptopicolinic acid likewise inhibited triacylglycerol formation. This inhibitory effect was seen with oleate as well as with oleate plus lactate. When [2-(14)C]lactate was used the incorporation of label into triacylglycerol was found in the glycerol moiety exclusively. Addition of dl-beta-hydroxybutyrate (5mm) to the incubation medium in the presence of oleate or oleate plus lactate led to a significant increase in triacylglycerol formation. In contrast with the gluconeogenic substrates, dl-beta-hydroxybutyrate had no stimulatory effect on fatty acid uptake. The results suggest that renal triacylglycerol formation is a quantitatively important metabolic process. The finding that gluconeogenic substrates, but not glucose, increase lipid formation, indicates that the glycerol moiety is formed by glyceroneogenesis in the proximal tubules. The effect of ketone bodies seems to be caused by the sparing action of these substrates on fatty acid oxidation. The decrease of triacylglycerol in the absence of exogenous substrates confirms previous conclusions that endogenous lipids provide fatty acids for renal energy metabolism.
Ultrasound imaging of muscle was performed on 40 patients of Duchenne muscular dystrophy on lower and upper extremities. In the control subjects, there was good visualization of bone and fascia with echo-free muscle tissue. With progression of the disease, the muscle echo was increased with corresponding loss of fascia echo in muscular dystrophy. A few advanced cases showed relatively echo-free muscle because of diffuse adipose tissue infiltration. Ultrasound imaging can reveal the muscular lesion and its distribution, and is valuable for monitoring the progression of the disease.
A prospective study was done on 222 consecutive new patients referred to our pediatric muscle clinic to assess the diagnostic value of ultrasound imaging. Ultrasound scans were interpreted without knowledge of clinical presentation or results of other tests. Muscular dystrophy produced a brightly speckled pattern of increased echo from the muscle, whereas spinal muscular atrophy showed a moderate increase in muscle echo and associated muscle atrophy. Acute dermatomyositis produced a moderate increase in echo that varied markedly with the direction of the ultrasound beam in relation to the muscle fibres. The ultrasound scan was normal in children with hypotonia of cerebral origin, Prader Willi syndrome, ligamentous laxity, and other "nonneuromuscular" causes. In eight patients ultrasound scanning showed a striking degree of selective involvement of individual components of the quadriceps muscle, which provided considerable diagnostic help for selective needle biopsy. Ultrasound scanning in children has the major advantage of being a noninvasive and pleasant out-patient procedure, which can be readily done on multiple sites. It is a valuable screening test in the investigation of children with neuromuscular disorders.
The applicability was tested of real-time ultrasound imaging to the high musculature for the carrier detection of Becker muscular dystrophy (BMD). A total of 17 obligate carriers were examined. Ultrasound images in 3 patients, aged between 46 and 59 years, showed moderate differences compared with the controls. In 3 other obligate carriers, aged between 46 and 71 years, only doubtfully abnormal findings could be made; ultrasound images showed no differences in 11 BMD carriers aged between 10 and 47 years. In women aged over 40 years, compared with adequate controls of the same body type, real-time ultrasound imaging may provide additional evidence and thus help in the detection of BMD carriers.
We describe a noninvasive quantitative way of measuring muscle with a specially-designed digital ultrasound scanner. Reliability and reproducibility of echo amplitude were determined in 16 normal male volunteers--10 runners and 6 non-runners. Echo amplitudes were recorded from the quadriceps femoris muscle. The muscle was scanned at mid-thigh in a relaxed state with 18 degrees flexion and in an isometrically contracted state with the leg in full extension. Echo amplitudes obtained in the non-runner group were: (1) mean value of the muscle in the relaxed state (174.9 +/- 30.8) and (2) mean value of the muscle in the contracted state (121.8 +/- 31.4). The difference in these values (53.1) was significant at p less than 0.05. Echo amplitudes for runners were: (1) mean value of the muscle in the relaxed state (146.6 +/- 39.2) and (2) mean value of the muscle in the contracted state (107.1 +/- 30.1). The difference in these values (39.5) was significant at p less than -0.01. The data indicate that: values of echo amplitudes are reproducible; there is a statistically significant difference in the mean amplitudes of muscle in a contracted and relaxed state; and while the difference between runner and non-runner muscle is not statistically significant (p greater than 0.1), there is a trend toward significance. Because ultrasound amplitude is a function of tissue structure, this technique may provide a noninvasive method for quantifying muscle collagen and fat.
Vergleich sonographischer und myosonographischer Befunde bei generalisierten neuromuskularen Erkrankungen. Thesis
- K Reimers
Reimers K: Vergleich sonographischer und myosonographischer Befunde bei generalisierten neuromuskularen Erkrankungen. Thesis, Ludwig-Maximilians-University, Munich (in preparation)
Statistik in der Praxis
- P Zofel
Zofel P: Statistik in der Praxis. Stuttgart, Gustav Fischer, 1985
- C D Reimers
- M Naegele
- G Fenzl
Reimers CD, Naegele M, Fenzl G, et al: Entzi.indliche
Myopathien: Diagnostische Wertigkeit bildgebender
Verfahren an der Skelettmuskulatur. Therapiewoche
39:560,1989