Reliability and validity of ultrasound to estimate muscles: A comparison between different transducers and parameters

Skeletal Muscle Compliance and Echogenicity in Resistance-Trained and Nontrained Women

ABSTRACT

Mongold, SJ, Ricci, AW, Hahn, ME, and Callahan, DM. Skeletal muscle compliance and echogenicity in resistance-trained and nontrained women. J Strength Cond Res 38(4): 671-680, 2024-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 (RTDrel; 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 RTDrel 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.

Centile reference curves of the ultrasound-based characteristics of the rectus femoris muscle composition in children at 4-11 years old

Quantitative diagnostic ultrasound has been proposed as a way to characterize muscle structure, but there is a lack of normative data for children. This study aims to establish age-specific normal ranges for echo-intensity (EI), cross-sectional area (CSA), muscular thickness (MT), and subcutaneous adipose thickness (SAT) values of the rectus femoris muscle in typically developing children. The study recruited 497 children (288 boys and 209 girls) aged 4-10.9 years (mean age 7.39 years), and muscle parameters were measured using 2D B-mode ultrasound. Percentile values and reference curves were calculated using the Lambda, Mu, and Sigma method (LMS). The results showed small variation between measurements for boys compared to girls, with the most significant difference in EI, CSA, and MT values. EI decreased with age, with the most pronounced curve in boys. SAT increased in both sexes, with a slightly higher increase in girls after the age of 9.0 years. This study provides the first age-specific reference norms for the rectus femoris muscle architecture in children, and further research is needed to validate these curves and determine their clinical utility.

"SARCOPENIA MEASURED BY ULTRASOUND IN HOSPITALIZED OLDER ADULTS" (ECOSARC): multi-centre, prospective observational study protocol

BACKGROUND

Measurement of muscle mass and function, and thereafter, screening and diagnosis of sarcopenia, is a challenge and a need in hospitalized older adults. However, it is difficult in complex real-world old patients, because usually they are unable to collaborate with clinical, functional, and imaging testing. Ultrasound measurement of quadriceps rectus femoris (QRF) provides a non-invasive, real-time assessment of muscle quantity and quality, and is highly acceptable to participants with excellent inter-rater and intra-rater variability. However, normative data, protocol standardization, and association with longitudinal outcomes, needs further research and consensus.

METHODS

Prospective exploratory multicenter study in older adults admitted to Acute Geriatric Units (AGUs) for medical reasons. 157 subjects from 7 AGUs of Spain were recruited between May 2019 and January 2022. Muscle ultrasound measurements of the anterior vastus of the QRF were acquired on admission and on discharge, using a previously validated protocol, using a Chieson model ECO2 ultrasound system (Chieson Medical Technologies, Co. Ltd, Wimxu District Wuxi, Jiangsu, China). Measurements included the cross-sectional area, muscle thickness in longitudinal view, intramuscular central tendon thickness, echogenicity, and the presence or absence of edema and fasciculations. Functional, nutritional, and DXA measurements were provided. Clinical follow-up was completed at discharge, and 30 and 90 days after discharge. Variations between hospital admission and discharge ultrasound values, and the relationship with clinical variables, will be analyzed using paired t-tests, Wilcoxon tests, or Mc Nemar chi-square tests when necessary. Prevalence of sarcopenia will be calculated, as well as sensitivity and specificity of ultrasound measurements to determine sarcopenia. Kappa analysis will be used to analyze the concordance between measurements, and sensitivity analysis will be conducted for each participating center.

DISCUSSION

The results obtained will be of great interest to the scientific geriatric community to assess the utility and validity of ultrasound measurements for the detection and follow-up of sarcopenia in hospitalized older adults, and its association with adverse outcomes.

TRIAL REGISTRATION

NCT05113758. Registration date: November 9^th 2021. Retrospectively registered.

Mapping peripheral and abdominal sarcopenia acquired in the acute phase of COVID-19 during 7 days of mechanical ventilation

Our aim was to map acquired peripheral and abdominal sarcopenia in mechanically ventilated adults with COVID-19 through ultrasound measurements. On Days 1, 3, 5 and 7 after admission to critical care, the muscle thickness and cross-sectional area of the quadriceps, rectus femoris, vastus intermedius, tibialis anterior, medial and lateral gastrocnemius, deltoid, biceps brachii, rectus abdominis, internal and external oblique, and transversus abdominis were measured using bedside ultrasound. A total of 5460 ultrasound images were analyzed from 30 patients (age: 59.8 ± 15.6 years; 70% men). Muscle thickness loss was found in the bilateral anterior tibial and medial gastrocnemius muscles (range 11.5-14.6%) between Days 1 and 3; in the bilateral quadriceps, rectus femoris, lateral gastrocnemius, deltoid, and biceps brachii (range 16.3-39.1%) between Days 1 and 5; in the internal oblique abdominal (25.9%) between Days 1 and 5; and in the rectus and transversus abdominis (29%) between Days 1 and 7. The cross-sectional area was reduced in the bilateral tibialis anterior and left biceps brachii (range 24.6-25.6%) between Days 1 and 5 and in the bilateral rectus femoris and right biceps brachii (range 22.9-27.7%) between Days 1 and 7. These findings indicate that the peripheral and abdominal muscle loss is progressive during the first week of mechanical ventilation and is significantly higher in the lower limbs, left quadriceps and right rectus femoris muscles in critically ill patients with COVID-19.

Surgery-Related Muscle Loss after Pancreatic Resection and Its Association with Postoperative Nutritional Intake

To study the occurrence of surgery-related muscle loss (SRML) and its association with in-hospital nutritional intake, we conducted a prospective observational cohort study including patients who underwent pancreatic surgery because of (suspected) malignant diseases. Muscle diameter was measured by using bedside ultrasound 1 day prior to surgery and 7 days postoperatively. Clinically relevant SRML was defined as ≥10% muscle diameter loss in minimally one arm and leg muscle within 1 week after surgery. Protein and caloric intake was measured by nutritional diaries. The primary endpoint included the number of patients with SRML. Secondary endpoints included the association between SRML and postoperative nutritional intake. Of the 63 included patients (60.3% men; age 67.1 ± 10.2 years), a total of 24 patients (38.1%) showed SRML. No differences were observed in severe complication rate or length of hospital stay between patients with and without SRML. During the first postoperative week, patients with clinically relevant SRML experienced more days without any nutritional intake compared with the non-SRML group (1 [0-4] versus 0 [0-1] days, p = 0.007). Significantly lower nutritional intake was found in the SRML group at postoperative days 2, 3 and 5 (p < 0.05). Since this study shows that SRML occurred in 38.1% of the patients and most of the patients failed to reach internationally set nutritional goals, it is suggested that more awareness concerning direct postoperative nutritional intake is needed in our surgical community.

Agreement and reliability of lower limb muscle architecture measurements using a portable ultrasound device

High end ultrasonography devices lack in portability and are expensive. We investigated the agreement and reliability of a handheld and portable ultrasound system for human lower limb muscle architecture measurements. We captured ultrasound images of the rectus femoris (RF), vastus lateralis (VL) and gastrocnemius medialis (GM) in 36 active healthy participants (15 female, 21 male) at 50% of muscle length using the handheld Lumify (L12-4, linear-array 37 mm, Philips Healthcare, Amsterdam, Netherlands) and a high-end laboratory device (ACUSON Juniper, linear-array 54 mm, 12L3, SIEMENS Healthineers, Erlangen, Germany). We compared measurements of muscle fascicle length, pennation angle and thickness. To assess inter-session reliability of the Lumify system, participants were measured twice within 1 week. Comparing RF architecture measurements of both devices resulted in intra-class correlations (ICCs) ranging from 0.46–0.82 and standardized mean difference (SMDs) ranging from −0.45–0.05. For VL, ICCs ranged from 0.60–0.89 and SMDs ranged from −0.11–0.13. ICCs and SMDs for the GM ranged from 0.82–0.86 and −0.07–0.07. Calculating inter-session reliability for RF resulted in ICCs ranging from 0.44–0.76 and SMDs ranging from −0.38–0.15. For VL, ICCs and SMDs ranged from 0.57–0.75 and −0.13–0.02. ICCs for GM ranged from 0.75–0.92 and SMDs ranged from −0.15–0.16. Measurement of muscle thickness demonstrated the highest agreement (ICC ≥0.82) and reliability (ICC ≥0.75) across all muscles. The Lumify system was comparable to a high-end device and reliable for GM measurements. However, agreement and reliability were lower for the RF and VL. Of all evaluated architectural parameters, muscle thickness exhibited highest agreement and reliability.

Human skeletal muscle size with ultrasound imaging: a comprehensive review

Skeletal muscle size is an important factor in assessing adaptation to exercise training and detraining, athletic performance, age-associated atrophy and mobility decline, clinical conditions associated with cachexia, and overall skeletal muscle health. Magnetic resonance (MR) imaging and computed tomography (CT) are widely accepted as the gold standard methods for skeletal muscle size quantification. However, it is not always feasible to use these methods (e.g., field studies, bedside studies, large cohort studies). Ultrasound has been available for skeletal muscle examination for more than 50 years and the development, utility, and validity of ultrasound imaging are underappreciated. It is now possible to use ultrasound in situations where MR and CT imaging are not suitable. This review provides a comprehensive summary of ultrasound imaging and human skeletal muscle size assessment. Since the first study in 1968, more than 600 articles have used ultrasound to examine the cross-sectional area and/or volume of 107 different skeletal muscles in more than 27,500 subjects of various ages, health status, and fitness conditions. Data from these studies, supported by decades of technological developments, collectively show that ultrasonography is a valid tool for skeletal muscle size quantification. Considering the wide-ranging connections between human health and function and skeletal muscle mass, the utility of ultrasound imaging will allow it to be employed in research investigations and clinical practice in ways not previously appreciated or considered.

Application of ultrasound for muscle assessment in sarcopenia: 2020 SARCUS update

PURPOSE

In 2018, the SARCUS working group published a first article on the standardization of the use of ultrasound to assess muscle. Recommendations were made for patient positioning, system settings and components to be measured. Also, shortcomings in knowledge were mentioned. An important issue that still required standardization was the definition of anatomical landmarks for many muscles.

METHODS

A systematic search was performed in Medline, SCOPUS and Web of Sciences looking for all articles describing the use of ultrasound in the assessment of muscle not described in the first recommendations, published from 01/01/2018 until 31/01/2020. All relevant terms used for older people, ultrasound and muscles were used.

RESULTS

For 39 muscles, different approaches for ultrasound assessment were found that likely impact the values measured. Standardized anatomical landmarks and measuring points were proposed for all muscles/muscle groups. Besides the five already known muscle parameters (muscle thickness, cross-section area, pennation angle, fascicle length and echo-intensity), four new parameters are discussed (muscle volume, stiffness, contraction potential and microcirculation). The former SARCUS article recommendations are updated with this new information that includes new muscle groups.

CONCLUSIONS

The emerging field of ultrasound assessment of muscle mass only highlights the need for a standardization of measurement technique. In this article, guidelines are updated and broadened to provide standardization instructions for a large number of muscles.