Echo Intensity Measurements Research Articles

High correlation of quantitative susceptibility mapping and echo intensity measurements of nigral iron overload in Parkinson's disease.

Quantitative susceptibility mapping (QSM) and transcranial sonography (TCS) offer proximal evaluations of iron load in the substantia nigra. Our prospective study aimed to investigate the relationship between QSM and TCS measurements of nigral iron content in patients with Parkinson's disease (PD). In secondary analyses, we wanted to explore the correlation of substantia nigra imaging data with clinical and laboratory findings. Eighteen magnetic resonance imaging and TCS examinations were performed in 15 PD patients at various disease stages. Susceptibility measures of substantia nigra were calculated from referenced QSM maps. Echogenicity of substantia nigra on TCS was measured planimetrically (echogenic area) and by digitized analysis (echo-intensity). Iron-related blood serum parameters were measured. Clinical assessments included the Unified PD Rating Scale and non-motor symptom scales. Substantia nigra susceptibility correlated with echogenic area (Pearson correlation, r = 0.53, p = 0.001) and echo-intensity (r = 0.78, p < 0.001). Individual asymmetry indices correlated between susceptibility and echogenic area measurements (r = 0.50, p = 0.042) and, more clearly, between susceptibility and echo-intensity measurements (r = 0.85, p < 0.001). Substantia nigra susceptibility (individual mean of bilateral measurements) correlated with serum transferrin saturation (Spearman test, r = 0.78, p < 0.001) and, by trend, with serum iron (r = 0.69, p = 0.004). Nigral echogenicity was not clearly related to serum values associated with iron metabolism. Susceptibility and echogenicity measurements were unrelated to PD duration, motor subtype, and severity of motor and non-motor symptoms. The present results support the assumption that iron accumulation is involved in the increase of nigral echogenicity in PD. Nigral echo-intensity probably reflects ferritin-bound iron, e.g. stored in microglia.

Evaluation of the Relationship Between Echo Intensity and Young's modulus of the Soleus Muscle Using Ultrasound Images After Ankle Fracture Surgery.

Although shear-wave elastography (SWE) can be used to assess muscle stiffness, SWE assessments are expensive. Echo intensity (EI) is an indicator of muscle quality and can potentially be used to assess muscle stiffness. This study aimed to determine the relationship between the EI and Young's modulus of the soleus (SOL) muscle after ankle fracture surgery. Eighteen participants who had undergone ankle fracture surgery were evaluated (mean age: 48.8 ± 20.6 years). Three months post-surgery, Young's modulus and EI of the SOL muscle were measured using SWE and the combination of B-mode ultrasound and ImageJ software, respectively. EI and Young's modulus measurements were obtained with the participant kneeling with knees bent 90°, upper body supported on a table, and ankles dorsiflexed 10°. The regions of interest used to measure EI and Young's modulus were identical. The EI value corrected for the subcutaneous fat thickness was also calculated. Pearson's correlation coefficients were calculated to examine the relationship of Young's modulus with the uncorrected and corrected EI. Although the uncorrected EI was correlated with Young's modulus of the SOL muscle (r = 0.567; p = 0.014), the corrected EI showed a stronger correlation (r = 0.637; p = 0.005).High intra-rater was also found reliability for the EI and Young's modulus measurements of the SOL muscle in participants after ankle fracture surgery. The EI and Young's modulus of the SOL muscle were positively correlated. In particular, the corrected EI showed a stronger correlation with Young's modulus than the uncorrected EI. Clinically, EI measurements may facilitate objective evaluation of muscle stiffness.

Enhancing signal-to-noise ratio in active laser imaging under cloud and fog conditions through combined matched filtering and neural network

Active laser imaging utilizes time-of-flight and echo intensity measurements to generate distance and intensity images of targets. However, scattering caused by cloud and fog particles, leads to imaging quality deterioration. In this study, we introduce a novel approach for improving imaging clarity in these environments. We employed a matched filtering method that leverages the distinction between signal and noise in the time domain to preliminarily extract the signal from one-dimensional photon-counting echo data. We further denoised the data by utilizing the Long Short-Term Memory (LSTM) neural network in extracting features from extended time-series data. The proposed method displayed notable improvement in the signal-to-noise ratio (SNR), from 7.227 dB to 31.35 dB, following an analysis of experimental data collected under cloud and fog conditions. Furthermore, processing positively affected the quality of the distance image with an increase in the structural similarity (SSIM) index from 0.7883 to 0.9070. Additionally, the point-cloud images were successfully restored. These findings suggest that the integration of matched filtering and the LSTM algorithm effectively enhances beam imaging quality in the presence of cloud and fog scattering. This method has potential application in various fields, including navigation, remote sensing, and other areas susceptible to complex environmental conditions.

Investigating the Reliability of the Measurement of the Cervical Muscle’s Echo Intensity

Introduction: The skeletal muscle’s echo intensity (EI) is a measurement that can be used to assess the quality of the muscle and any muscle damage caused by training or activity. To determine its reliability, a limited number of studies have investigated the measurement of cervical muscles’ EI. This study determines whether the EI of the cervical muscles can be reliably quantified using the Adobe Photoshop software.&#x0D; Materials and Methods: The mean EI of the cervical muscles was measured using the standard histogram function of Adobe Photoshop CS6 in 20 healthy women.&#x0D; Results: The measurement of EI of cervical muscles using Adobe Photoshop CS6 is reliable in healthy women (intra-class coefficient &gt;0.9). The values of the standard error of measurements of longus coli, sternocleidomastoid, levator scapula, semispinalis capitis, rectus capitis posterior, and oblique capitis superior muscles were 1.81, 2.09, 1.46, 2.02, 1.47 and 1.26, respectively. The values of the smallest detectable difference of longus coli, sternocleidomastoid, levator scapula, semispinalis capitis, rectus capitis posterior, and oblique capitis superior muscles were 7.11, 8.22, 5.74, 7.93, 5.79, and 4.97, respectively.&#x0D; Conclusion: Assessing the EI of the cervical muscles with Adobe Photoshop software is a viable method to determine the quality of the muscles.

The Influence of Knee Position on Ultrasound Imaging of Femoral Cartilage in Individuals with Anterior Cruciate Ligament Reconstruction.

Articular cartilage is important for knee function and can be imaged using ultrasound. The purpose was to compare femoral cartilage thickness and echo intensity (EI) measured at 90° and 140° of knee flexion and between limbs in a cohort with unilateral anterior cruciate ligament reconstruction (ACLR). We also examined associations between gait biomechanics and cartilage outcomes. Twenty-seven individuals with primary unilateral ACLR participated (12 men, 15 women; age = 22.3 ± 3.8 years; time since ACLR = 71.2 ± 47.2 months). Ultrasound was used to obtain femoral cartilage measurements. Gait outcomes included peak KFA (knee flexion angle) and peak external knee flexion moment (KFM). Cartilage outcomes were compared using a 2 (position) × 2 (limb) repeated measures ANOVA (analysis of variance). Gait and cartilage associations were assessed using linear regression. There were no position × limb interactions for any cartilage outcome (all P > 0.05). Medial (P = 0.038) and central cartilage (P < 0.001) were thicker, whereas central (P = 0.029) and lateral cartilage EI (P = 0.003) were lower when measured at 90° than those at 140° of knee flexion. Medial cartilage was thicker in the ACLR than that in the contralateral limb (P = 0.016). A larger KFM was associated with thicker medial cartilage (ΔR2 = 0.146, P = 0.021) and central cartilage (ΔR2 = 0.159, P = 0.039) measured at 140° of knee flexion in the ACLR limb but not at 90°. Findings suggest that imaging position influences cartilage thickness and EI measurements in individuals with ACLR and should be considered in study designs and clinical evaluation. A greater KFM was associated with thicker cartilage within specific portions of the distal femur.

Quantification of Extramyocellular Lipids and Intramuscular Fat from Muscle Echo Intensity in Lower Limb Muscles: A Comparison of Four Ultrasound Devices against Magnetic Resonance Spectroscopy.

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.

Exploring Relationships Between Ultrasound-Measured Pre-Operative Median Nerve Echointensity and Successful Carpal Tunnel Release-A Retrospective Review (P14-8.002)

<h3>Objective:</h3> The purpose of this study is to explore the association between preoperative median nerve echointensity and outcomes of carpal tunnel release (CTR). <h3>Background:</h3> Published success rates of CTR vary from 27–100%. With the advancement of neuromuscular ultrasound (NMUS), nerve echointensity has gained increased attention as an indicator of intraneural edema. <h3>Design/Methods:</h3> We performed a retrospective review of the electronic medical record to identify patients who underwent sonographic evaluation of the median nerve and CTR surgery at Duke University within 4 months. Those with concurrent polyneuropathy were excluded. Surgical outcomes were determined by 2 independent reviewers based upon chart review of the postoperative visit 4–6 weeks after surgery. A 3^rd reviewer assessed the outcome in the event of disagreement. Complete resolution was defined in the absence of paresthesia, pain, and functional limitation pertinent to carpal tunnel syndrome. <h3>Results:</h3> A total of 56 nerves from 50 patients were identified. Of these patients, 33 (66%) were women and the mean age was 57.2 years (SD = 14.2). Complete resolution occurred in 39 (69.6%) surgeries. Multivariable logistic regression model, adjusted for age and gender, showed no association between median nerve echointensity and complete versus partial resolution (OR=1.01; 95% CI = 0.99–1.03). Inter-rater reliability was excellent in both outcome assessment (% agreement = 96.4, kappa =0.92) and measurement of echointensity (interclass correlation: 0.914). <h3>Conclusions:</h3> Our study did not demonstrate differences in preoperative median nerve echointensity between patients with complete and partial resolution of symptoms following CTR surgery. However, the measurement of echointensity and outcomes assessment had excellent interrater reliability. A multi-center prospective study should be pursued for better understandings of the relationship between NUS parameters and the outcomes of CTR surgery. <b>Disclosure:</b> Dr. Harada has nothing to disclose. Dr. Wannarong has nothing to disclose. Dr. Neely has received personal compensation for serving as an employee of Duke University . An immediate family member of Prof. Williams has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for SQZ Biotech. An immediate family member of Prof. Williams has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Viracta Therapeutics. Prof. Williams has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Origin Editorial. The institution of Prof. Williams has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for PCORI. The institution of Prof. Williams has received research support from PCORI. The institution of Prof. Williams has received research support from NIH. Prof. Williams has received publishing royalties from a publication relating to health care. Dr. Pidgeon has received personal compensation in the range of $500-$4,999 for serving as a Consultant for QPix. Dr. Pidgeon has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Tissium. The institution of Dr. Pidgeon has received research support from Acumed. An immediate family member of Dr. Hobson-Webb has received personal compensation for serving as an employee of G1 Therapeutics. Dr. Hobson-Webb has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Wiley Publishing. The institution of Dr. Hobson-Webb has received research support from Sanofi Genzyme.

Comparison of multifidus muscle intramuscular fat by ultrasound echo intensity and fat-water based MR images in individuals with chronic low back pain

PurposeThe aim of this observational cross-sectional study was to examine correlations of intramuscular fat content in lumbar multifidus (LM) by comparing muscle echo intensity (EI) and percent fat signal fraction (%FSF) generated from ultrasound (US) and magnetic resonance (MR) images, respectively. MethodsMRI and US images from 25 participants (16 females, 9 males) selected from a cohort of patients with chronic low back pain (CLBP) were used. Images were acquired bilaterally, at the L4 and L5 levels (e.g., 4 sites). EI measurements were acquired by manually tracing the cross-sectional border of LM. Mean EI of three US images per site were analyzed (e.g., raw EI). A correction factor for subcutaneous fat thickness (SFT) was also calculated and applied (e.g., corrected EI). Corresponding fat and water MR images were used to acquire %FSF measurements. Intra-rater reliability was assessed by intraclass coefficients (ICC). Pearson correlations and simple linear regression were used to assess the relationship between %FSF, raw EI and corrected EI measurements. ResultsThe intra-rater ICCs for all measurements were moderate to excellent. Correlations between %FSF vs. raw EI and corrected EI were moderate to strong (0.40 < r < 0.52) and (0.40 < r < 0.51), respectively. Moderate correlations between SFT and EI were also identified. ConclusionUS is a low-cost, non-invasive, accessible, and reliable method to examine muscle composition, and presents a promising solution for assessing and monitoring the effect of different treatment options for CLBP in clinical settings.

Do Intramuscular Temperature and Fascicle Angle Affect Ultrasound Echo Intensity Values?

Ultrasound-derived echo intensity (EI) has been used as a physiological marker for changes in skeletal muscle "quality" with physical training, disuse, aging, and neuromuscular disorders. However, the methodological and physiological factors influencing EI and its longitudinal change are still unclear. Here, we performed two separate experiments to investigate the effects of muscle temperature and fascicle angle, which are known to influence muscle tissue and sound wave properties and therefore affect EI. In experiment 1 ( n = 16, 28.0 ± 6.6 yr), vastus lateralis (VL) ultrasonographic images were acquired and intramuscular temperature continuously recorded for 15 min after 20 min of heating to 40.4°C ± 0.7°C using a microwave device. In experiment 2 ( n = 17, 30.2 ± 9.8 yr), VL sonographic images were obtained with the knee both fully extended (0°) and flexed to 90° and EI and fascicle angle measured post hoc . Fascicle movement was tracked during the passive knee flexion to ensure that sonographic images were obtained at the same muscle region. Knee flexion reduced muscle thickness, and we therefore reran analyses calculating EI using identical dimensions to minimize this effect. EI decreased only immediately after the passive heating, and although a moderate, negative correlation was observed between EI and temperature ( rrm = -0.36), the effect of muscle temperature was small ( β = 0.97 (-1.89 to -0.06) per degree Celsius, P = 0.051). Nonetheless, EI increased as fascicle angle decreased, and a large, negative correlation ( rrm = -0.85) was observed; the effect of fascicle angle on EI was large ( β = 3.0 (-3.8 to -2.2) per degree, P < 0.01), and this was maintained when analyses were performed at a constant depth of the region of interest ( β = 3.5 (-4.4 to -2.7) per degree, P < 0.01). These findings support the hypothesis that fascicle angle meaningfully affects VL EI but provides weak evidence of a temperature effect in vivo . Thus, acute fascicle angle alterations should be accounted for in studies using EI measurements, and longer-term studies should consider whether changes in EI might be partly explained by a change in fascicle angle.

Effect of beam attenuation on muscle ultrasound echogenicity measurement in muscular dystrophies.

In advanced muscular dystrophies (AMD), quantification of muscle echo-intensity (EI) may be influenced by ultrasound beam attenuation, due to fibrosis and fatty infiltration of muscle tissue. Objective of the study was to compare EI measurements using grayscale analysis between a superficial and whole-muscle region of interest (ROI) in subjects with advanced and mild-to-moderate muscular dystrophy (MMD). Thirty-two adult subjects diagnosed with a muscular dystrophy and twenty-five matched healthy controls underwent ultrasound assessment of the biceps brachii (BB), rectus femoris (RF) and tibialis anterior (TA) muscles. Based on Heckmatt grading scale of muscles, two disease groups, an AMD (Heckmatt grades 3 or 4) and a MMD (Heckmatt grade 2), were analyzed. Superficial ROI was set as one-fourth of the whole-muscle area, located immediately below the superficial fascia and always inside muscle boundaries. Muscle EI was significantly higher in the superficial compared to whole-muscle ROI, in all evaluated muscle groups of AMD subjects (BB, p=0.004/RF, p=0.027/TA, p=0.002). EI values in superficial ROIs, for individual muscle analysis using z-scores, were more representative in assessments of muscle abnormality in advanced stages of the disease course (Heckmatt grades 3 and 4). In MMD and healthy muscles, no statistical difference was found in EI measurements between the two ROI types. In AMD, selection of superficial ROI is better representative of changes in muscle texture, although caution should be exercised when comparing ROIs of different sizes.

Reliability of muscle thickness and echo intensity measurements of the quadriceps: A novice examiner

IntroductionThis study aimed to investigate the reliability of muscle thickness (MT) and echo intensity (EI) of the quadriceps muscles using ultrasound imaging for a novice examiner. MethodsSixteen healthy adult women were included in the study, and images of the rectus femoris, vastus intermedius, vastus lateralis, and vastus medialis were obtained on the same day and after one week by an examiner who had not performed an experiment on the measurement of ultrasound imaging. The measurers who analyzed all images were completely blind to the subject's name and date and order of measurements. Intraclass correlation coefficients (ICCs) were used as relative within-day and between-day reliability of measurement. Absolute reliability was based on Bland–Altman analysis, standard error of measurement, and minimum detectable change. ResultsThe ICCs ranged from 0.76 to 0.95. As the results of the Bland–Altman analysis, all MTs and EIs included 0 in the 95% confidence interval of the mean difference. DiscussionOur results suggest that quadriceps ultrasound images have high reliability for MT and EI for all muscles. There were no systematic errors in both MT and EI. ConclusionIt might indicate that even novice examiners could obtain MT and EI measurements without systematic error after a few hours of practice.

Measurement of ultrasonic echo intensity predicts the mass and strength of the tongue muscles in the elderly.

The purpose of this study was to investigate the relationship between the echo intensity (EI) on ultrasound images of the tongue, tongue thickness, and tongue pressure to examine the effectiveness of EI measurement for assessing the tongue function. A total of 100 elderly outpatients were enrolled. Tongue thickness and EI were measured using ultrasonography. The distance from mylohyoid muscle surface to dorsal surface of the tongue was measured for tongue thickness. Subsequently, this area was vertically divided into four areas: top of tongue dorsal side (DT), bottom of tongue dorsal side (DB), top of basal tongue side (BT), and bottom of basal tongue side (BB), and the EI was measured in each area. The mean EIs of DT and DB were lower than those of BT and BB. In the three areas apart from BB, the EI decreased with an increase in tongue thickness. In particular, a significant correlation between the EI in DB and tongue thickness was found. In all areas, the EI decreased with an increase in tongue pressure. The results of this study suggested that the measurement of EI could be an important indicator for assessing the tongue function in the elderly.

Ultrasound Imaging Analysis of the Lumbar Multifidus Muscle Echo Intensity: Intra-Rater and Inter-Rater Reliability of a Novice and an Experienced Rater

Background and Objectives: Ultrasound echo intensity (EI) of the lumbar multifidus muscle (LMM) could offer valuable insights regarding muscle quality in people with low back pain (LBP). However, whether the rater’s experience noticeably influences the reliability and precision of LMM EI measurements has not been established. The aims of this study were to investigate the intra-rater and inter-rater reliability of LMM EI measurements, and to compare the reliability and SEM between a novice and an experienced rater. Materials and Methods: Twenty athletes (10 females, 10 males) with a history of LBP were included in this study. Transverse ultrasound images of LMM were taken at L5 in prone. LMM EI measurements were obtained bilaterally by tracing the maximum ROI representing the LMM cross-sectional area (CSA), avoiding the inclusion of bone or surrounding fascia. All measurements were performed by two novice raters and an experienced researcher. Each measurement was acquired by each rater three times for each side on three different images, and the average was used in the analyses. Raters were blinded to each other’s measurements and the participant’s clinical information. Intra-class correlation coefficients (ICCs) were obtained to assess the intra-rater and inter-rater reliability. Results: The intra-rater ICC values for the LMM measurements for the experienced rater were excellent (ICC all > 0.997). The inter-rater reliability ICC values showed moderate to excellent reliability (0.614 to 0.994) and agreement between the novice raters and the experienced rater, except for Novice 1 for the right LMM, which revealed lower ICCs and a wider 95% CI. Intra-rater and inter-rater reliability results were similar when separately looking at the right and left side of the muscle and participant gender. Conclusions: Our findings support the clinical use of ultrasound imaging for the assessment of LMM EI in individuals with LBP.

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

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

Reliability and Minimal Detectable Change of Muscle Thickness and Echo Intensity Measurements in the Lower Extremities of Inpatients with Stroke

Reliability and Minimal Detectable Change of Muscle Thickness and Echo Intensity Measurements in the Lower Extremities of Inpatients with Stroke

Bedload Velocity and Backscattering Strength from Mobile Sediment Bed: A Laboratory Investigation Comparing Bistatic Versus Monostatic Acoustic Configuration

Despite the many advantages of using active ultrasound sonars, recent studies have shown that the specific acoustic geometry, signal-processing configuration, and complex surface-volume scattering process at the riverbed introduce several uncertainties in bedload estimation. This study presents a comparison of bedload velocity and bottom echo intensity measurements performed by monostatic and bistatic active ultrasound systems. The monostatic configuration is widely applied in the field to measure the apparent velocity at the riverbed with an acoustic current Doppler profiler (ADCP). Two laboratory investigations were conducted in two different hydraulic facilities deploying ADCP Stream Pro, monostatic and bistatic acoustic velocity profilers, manufactured by Ubertone. The bistatic instruments provided more accurate bedload velocity measurements and helped in understanding the acoustic sampling of the monastic systems. The bistatic profiles succeeded in measuring a profile over the active bedload layer, and the monostatic instruments resulted in different bedload velocity estimations depending on the acoustic resolution and sampling. The echo intensity increased in the cells measured within the active bedload layer with respect to the cell measuring the water column above. The cells that sampled the immobile bed surface beneath the bedload layer showed a reduction of the echo intensity compared with the cells above. The acoustic sampling, which combines the measurement volume geometry and internal processing, seems crucial for more accurate outputs. Future research about the use of monostatic instruments in the field should aim to define the best possible setting for the acoustic parameters at a given bedload condition that may be tuned by evaluating the backscattering at the river bottom together with the apparent bedload velocity.

Echo intensity as an indicator of skeletal muscle quality: applications, methodology, and future directions.

This narrative review provides an overview of the current knowledge of B-mode ultrasound-derived echo intensity (EI) as an indicator of skeletal muscle quality. PubMed and Google Scholar were used to search the literature. Advanced search functions were used to find original studies with the terms 'echo intensity' and/or 'muscle quality' in the title and/or abstract. Publications that conceptually described muscle quality but did not include measurement of EI were not a focus of the review. Importantly, the foundational premise of EI remains unclear. While it is likely that EI reflects intramuscular adiposity, data suggesting that these measurements are influenced by fibrous tissue is limited to diseased muscle and animal models. EI appears to show particular promise in studying muscular aging. Studies have consistently reported an association between EI and muscle function, though not all chronic interventions have demonstrated improvements. Based on the existing literature, it is unclear if EI can be used as a marker of muscle glycogen following exercise and nutritional interventions, or if EI is influenced by hydration status. Inconsistent methodological approaches used across laboratories have made comparing EI studies challenging. Image depth, rest duration, participant positioning, probe tilt, and the decision to correct for subcutaneous adipose tissue thickness are all critical considerations when interpreting the literature and planning studies. While some areas show conflicting evidence, EI shows promise as a novel tool for studying muscle quality. Collaborative efforts focused on methodology are necessary to enhance the consistency and quality of the EI literature.

Superficial and deep lumbar multifidus layers of asymptomatic individuals: intraday and interday reliability of the echo intensity measurement.

Ultrasonography has been used to understand the functional and biomechanical aspects of the lumbar multifidus muscle in vivo. To characterize the multifidus echogenicity, the peculiarities of their superficial and deep layers must be considered. The present paper aimed to characterize the lumbar multifidus echo intensity (EI), in both superficial and deep layers, in ultrasonography images acquired in longitudinal and transversal orientations. Evaluator obtained two images in each side of the lumbar of the volunteer, who was lying on prone position. Ultrasonography images were taken with probe in transversal and longitudinal orientations. EI was estimated by means average value of the grayscale distribution histogram, by extracting from region of interest of the superficial and deep layer. All participants returned for a second test day. Two-way MANOVA test was applied to compare EI measurements, considering layers and side factors. The reliability and variability were analyzed by the intraclass correlation coefficient and standard error measurements (SEM), respectively. Two-way MANOVA found significant difference between the layers in the transversal and longitudinal images, but not between the sides. Interdays reliability ranged of reasonable to excellent, and SEM values were lower than 17.08%. The superficial layer of the multifidus muscle showed higher EI values than the deeper one. These analyses can serve as a basis for future studies approaching multifidus of the people with low back pain.

Echo Intensity Reliability From Two Ultrasound Systems

Objective: Echo intensity measurements are highly influenced by ultrasound system and parameters used for measurement, making comparisons of results obtained from different ultrasound machines difficult. Therefore, it is necessary to understand how reliability changes when using different ultrasound systems and parameters. Materials and Methods: ALOKA SSD4000 and GE LOGIQ P6 systems were used to compare rectus femoris echo intensity in 16 healthy young subjects (eight women) using different depths (D), gains (G), and frequencies (F). The following settings were adopted: ALOKA1 (D6/G30/F7.5), ALOKA2 (D6/G45/F7.5), ALOKA3 (D6/G30/F10), LOGIQ1 (D6/G50/F15), LOGIQ2 (D6/G0/F15), LOGIQ3 (D6/G0/F10), and LOGIQ4 (D6/G30/F10). Intraclass correlation coefficient, standard error of the measure, minimum difference, and Bland-Altman tests were performed to calculate reliability and agreement between systems’ settings. Results: ALOKA1 × LOGIQ1, ALOKA1 × LOGIQ4, and ALOKA3 × LOGIQ1 showed moderate to high ICCs and agreement on the Bland-Altman test. Conclusion: Echo intensity varies between systems and parameters, but reliability can be increased by adjusting the ultrasound settings.

Enhanced Echo Intensity of Skeletal Muscle Is Associated With Exercise Intolerance in Patients With Heart Failure

Skeletal muscle is quantitatively and qualitatively impaired in patients with heart failure (HF), which is closely linked to lowered exercise capacity. Ultrasonography (US) for skeletal muscle has emerged as a useful, noninvasive tool to evaluate muscle quality and quantity. Here we investigated whether muscle quality based on US-derived echo intensity (EI) is associated with exercise capacity in patients with HF. Fifty-eight patients with HF (61 ± 12 years) and 28 control subjects (58 ± 14 years) were studied. The quadriceps femoris echo intensity (QEI) was significantly higher and the quadriceps femoris muscle thickness (QMT) was significantly lower in the patients with HF than the controls (88.3 ± 13.4 vs 81.1 ± 7.5, P= .010; 5.21 ± 1.10 vs 6.54 ±1.34 cm, P< .001, respectively). By univariate analysis, QEI was significantly correlated with age, peak oxygen uptake (VO2), and New York Heart Association class in the HF group. A multivariable analysis revealed that the QEI was independently associated with peak VO2 after adjustment for age, gender, body mass index, and QMT: β-coefficient = -11.80, 95%CI (-20.73, -2.86), P= .011. Enhanced EI in skeletal muscle was independently associated with lowered exercise capacity in HF. The measurement of EI is low-cost, easily accessible, and suitable for assessment of HF-related alterations in skeletal muscle quality.