Echo Intensity Research Articles

Acute Effects of Soft Tissue Modalities on Muscular Ultrasound Characteristics and Isometric Performance

Prior to training, many athletes perform different soft-tissue preparation protocols. Many of these protocols involve stretching, foam rolling, and/or percussion massage. Many of these modalities have been studied, but not as a group to observe muscle alterations and differences in males and females. In total, 40 (20 males, 20 females) participants performed five minutes of static stretching, foam rolling, and percussion massage. Pre- and post-isometric leg strength, muscle activation and ultrasound assessments (cross-sectional area, echo intensity, pennation angle, fascicle length, and muscle thickness) were taken. The results indicate that there is no significant difference among modalities, and that they do not significantly alter any muscle characteristic or improve performance. There is a significant difference in size between males and female, with males having larger muscle and greater pennation angles than females. This allows males to generate significantly more muscle force. However, they both respond similarly to each modality. In conclusion, the muscle response to static stretching, foam rolling, and percussion massage do not differ among modalities and do not contribute to an increase or decrease in maximal isometric knee extension with similar effects between males and females.

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.

Aerodynamic optimization of double S-duct caret intake by self-adapting non-dominated sorting genetic algorithm

The caret intake could not only provide compressed airflow to the aircraft engine stably but also should have applicable radar stealth performance. Radar stealth means that the echo intensity of the intake should be low when detected by radar, which could be measured by radar cross section (RCS). The airflow distribution of the double S-duct caret intake was numerically optimized to improve aerodynamic performance, with radar stealth performance as constraints. Self-adaptive genetic algorithm and Kriging model were used to improve the optimization efficiency. There could be multiple boundary-layer separations in the S-duct caret intake, resulting in obvious total pressure distortion at the outlet and secondary flow. To suppress these adverse airflow phenomena, the optimization of the double S-duct intake was defined as a problem with two targets and multiple constraints. By defining the probabilities of selection and variation as functions of the iteration number and the fitness, the self-adapting non-dominated sorting genetic algorithm can be applicable for such a problem. Using the Kriging model, which was proven to have satisfactory accuracy in predicting performance parameters, an optimized intake with both excellent aerodynamic and stealth performance was obtained, with a 30% reduction in DC60 value and a 47% reduction in SC60 value compared to the intake before optimization.

Automatic PAUT crack detection and depth identification framework based on inspection robot and deep learning method

Orthotropic steel bridge decks (OSD) are widely acclaimed for their lightweight, high load-carrying capacity, and adaptability, making them a popular choice in steel structure bridges. However, the complex nature of their structure makes them susceptible to fatigue cracking, posing significant safety concerns. To address the issues above, this study employs a robot equipped with an ultrasonic phased array probe to automate the detection of internal cracks within Orthotropic Steel Decks (OSD). A Deep Convolutional Generative Adversarial Network (DCGAN) is utilized to augment the training dataset of Phased Array Ultrasonic Testing (PAUT) images. The YOLO series algorithms are applied and compared for crack localization, with YOLO v7-tiny exhibiting the highest accuracy and speed. Integrating attention mechanisms into the YOLO v7-tiny algorithm to facilliate rapid and high-precision crack detection. Analyzing the echo region with an echo intensity bar enabled the identification of crack depth, with an identification error within 5%.

Associations of passive muscle stiffness and muscle echo-intensity with muscle strength

Objective: Muscle tissue parameters including composition and stiffness of muscle can have an important effect on muscle strength. In this study, we aimed to investigate the relationships between muscle echo-intensity (EI), tendon stiffness and muscle strength in young men and women. Methods: Ultrasound B-mode images of the Rectus Femoris (RF), Vastus Medialis (VM) and Patellar Tendon (PT) were acquired in fifty-two healthy subjects (mean age; 27.43±5.3 years). RF, VM and PT stiffness were characterized by shear-wave elastography measurements. Quantitative evaluations were performed, including measurement of muscle and tendon thickness and muscle EI. Isometric knee extension muscle strength was measured using hand-held dynamometer. Results: RF stiffness had a good correlation with muscle strength (r=-0.46, p<0.05) and had a fair correlation with EIRF(r=-0.37,p<0.05), VM stiffness had a good correlation with muscle strength (r=0.42, p<0.05) and had a fair correlation with EIVM (r=-0.43,p<0.05) in women. RF stiffness had a good correlation with muscle strength (r=-0.54, p<0.05), had a good correlation with EIRF(r=-0.41,p<0.05) in men.VM stiffness had a good correlation with muscle strength(r=-0.50; p<0.05), and had a good correlation with EIVM(r=-0.60,p<0.05) in men. EIRF and EIVM had a good relation with muscle strength in men and women (For EIRF; r=-0.46; r=-0.54; for EIVM; r=-0.42; r=-0.50 p<0.05, respectively) Conclusions: This study demonstrates that there is a relationship between isometric muscle strength and passive muscle stiffness, muscle EI. Additionally, muscle EI affects muscle stiffness in healthy men and women. Our results should be considered in elite athletes for whom the strengthening program is important.

Dietary factors may be associated with measures of ultrasound-derived skeletal muscle echo intensity.

Skeletal muscle echo intensity (EI) is affected by ageing and physical activity; however, the effects of nutrition are less understood. The aim of this study was to explore whether habitual nutrient intake may be associated with ultrasound-derived EI. Partial least squares regression (PLSR) models were trained on an initial sample (n=100, M=45; F=55; 38±15 years) to predict EI of two quadriceps muscles from 19 variables, using the "jack-knife" function within the "pls" package (RStudio), which was then tested in an additional dataset (n=30, M=13; F=17; 38±16 years). EI was determined using B-mode ultrasonography of the rectus femoris (RF) and vastus lateralis (VL) and nutritional intake determined via 3-day weighed food diaries. Mean daily intake of specific nutrients were included as predictor variables with age, sex, and self-reported physical activity. PLSR training model 1 explained ∼52% and model 2 ∼46% of the variance in RF and VL EI, respectively. Model 1 also explained ∼35% and model 2 ∼30% of the variance in RF and VL EI in the additional testing dataset. Age and biological sex were associated with EI in both models (P<0.025). Dietary protein (RF: β = -7.617, VL: β = -7.480), and selenium (RF: β = -7.144, VL: β = -4.775) were associated with EI in both muscles (P<0.05), whereas fibre intake (RF: β = -5.215) was associated with RF EI only and omega-3 fatty acids (n-3/ω-3 FAs, RF: β = 3.145) with VL EI only (P<0.05). Therefore, absolute protein, selenium, fibre, and n-3 FAs may be associated with skeletal muscle EI, although further mechanistic work is required before claiming causal inference.

Association between quadriceps muscle thickness or echo intensity, malnutrition, and activities of daily living in an integrated medical and long-term care facility: A cross-sectional study

Background &AimsMalnutrition and physical function impairment are prevalent concerns in long-term care facilities. This study investigated the relationship between quadriceps muscle thickness (QMT) or echo intensity (QEI), nutritional status, and activities of daily living (ADL) in residents of an Integrated Facility for Medical and Long-term Care (IFMLC) in Japan. MethodsUsing a cross-sectional design, 126 residents (86 women, median age 89 years) at an IFMLC were assessed. Malnutrition was diagnosed using the Global Leadership Initiative on Malnutrition (GLIM) criteria including disease burden/inflammation, while ADL status was evaluated using the Barthel Index (BI). QMT and QEI, indicative of muscle mass and intramuscular adipose tissue, were measured by ultrasound. Multivariate logistic and linear regression analyses were conducted to explore the association of QMT or QEI with malnutrition and ADL. Results62 residents (49%) were in the lower QMT group and 63 residents (50%) were in the upper QEI group. The prevalence of severe malnutrition in the lower QMT group was significantly higher than that in the upper QMT group. Moreover, the lower QMT group had significantly lower BI points than the upper QMT group. The upper QEI group had significantly lower BI points than the lower QEI group. lower QMT was associated with severe malnutrition (odds ratio 3.170; 95% CI 1.238 to 8.725; P = 0.016). Furthermore, both lower QMT (B = −12.520; 95% CI −17.069 to −7.973; P < 0.001) and upper QEI (B = −7.598; 95% CI −12.565 to −2.631; P = 0.003) showed an independent correlation with lower BI scores. ConclusionThis study found a relationship between lower QMT correlated with severe malnutrition and poor ADL, while higher QEI is associated with poor ADL.

First climatology of F-region UHF echoes observed by the AMISR-14 system at the Jicamarca radio observatory and comparison with the climatology of VHF echoes observed by the collocated JULIA radar

Coherent backscatter radar observations made at the Jicamarca Radio Observatory (JRO) have contributed significantly to our understanding of equatorial F-region irregularities. Radar observations, however, have been made predominantly at the Very-High Frequency (VHF) band (50 MHz), which corresponds to measurements of 3-m field-aligned irregularities. The deployment of the 14-panel version of the Advanced Modular Incoherent Scatter Radar (AMISR-14) at Jicamarca provided an opportunity for observations of Ultra-High Frequency (UHF - 445 MHz) echoes which correspond to measurements of irregularities with 0.34 m scale sizes. Here, we present what we believe to be the first report describing the quiet-time climatology of sub-meter equatorial F-region irregularities derived from UHF radar measurements. The measurements were made between August 2021 and February 2023 using a 10-beam AMISR-14 mode that scanned the F-region in the magnetic equatorial plane. The results show how F-region sub-meter irregularities respond to variations in season and solar flux conditions. The results also confirm, experimentally, that the occurrence of UHF F-region echoes is controlled by the occurrence of equatorial spread F (ESF). Higher occurrence rates were observed during pre-midnight hours and during Equinox and December solstice. Reduced occurrence rates were observed during June solstice. The results show that an increase in solar flux was followed by an increase in the altitude where noticeable occurrence rates (≳ 10%) start and in the maximum altitude of these occurrence rates. The observations also show that occurrence rates lasted longer (in local time) during low solar flux conditions. Comparisons with collocated VHF radar observations showed that, despite differences in radar parameters, observation days, and the scale size (one order of magnitude) of the scattering irregularities, the two systems show similar climatological variations with only minor differences in the absolute occurrence rates. Finally, the analysis of the occurrence rates for different beams did not show substantial climatological variations over local (within a few 100s of km) zonal distances around JRO. We point out, however, that observations on a single day can show strong local variations in echo detection and intensity within the AMISR-14 field of view due to the intrinsic development and decay of ESF structures.

Reliability of Ultrasound Assessment of Hamstring Morphology, Quality, and Stiffness Among Healthy Adults and Athletes: A Systematic Review.

The incidence and recurrence rate of hamstring strain injuries remain persistently high, with recurrent injuries leading to increased time lost during play and extended recovery periods compared with initial injury. Ultrasound imaging assesses important factors such as hamstring fascicle length (FL), pennation angle (PA), cross-sectional area (CSA), muscle thickness (MT), echo intensity (EI), and shear wave elastography (SWE), all impacting athletic performance. However, its reliability must be established before employing any measurement tool in research or clinical settings. To determine the reliability and measurement error of ultrasound for assessing hamstring FL, PA, CSA, MT, EI, and SWE among healthy adults and athletes; to synthesize the information regarding the operationalization of ultrasound. A systematic literature search was done from January 1990 to February 5, 2023, to identify reliability and validity studies of hamstring ultrasound assessment published in peer-reviewed journals with identifiable methodology of outcome measures. Intraclass correlation coefficient measurement of 14 included studies reported moderate to excellent intrarater, interrater, and test-retest reliabilities of FL, PA, and MT regardless of the site of muscle testing, probe size, and setting, state of muscle, and use of different techniques in the extrapolation of FL. Good to excellent test-retest reliability rates for all hamstring anatomic CSA along midmuscle and different percentages of thigh length using panoramic imaging. Good intrarater reliability of EI regardless of gender and orientation of the probe but with excellent intrarater reliability in transverse scan using maximum region of interest. Good intrarater, interrater, and interday repeatability on SWE with the muscle in a stretched position. Evidence from studies with a predominantly low risk of bias shows that ultrasound is a reliable tool to measure hamstring FL, PA, CSA, MT, EI, and SWE in healthy adults and athletes under various experimental conditions.

Precipitation nowcasting method based on Spatial-Temporal Dual Discriminators

Abstract The prediction of radar echo sequence images is a spatiotemporal sequence forecasting problem, which is one of the main challenges in precipitation nowcasting. Addressing issues such as poor extraction of spatiotemporal features by previous models and blurry image sequence predictions, this study proposes a Spatial-Temporal dual Discriminator Precipitation Nowcasting Model (STD-SNGAN) based on spectral normalization generative adversarial networks (SNGAN). The model utilizes multi-scale convolution modules (Inception) to extract spatial features from radar echo images and convolutional gated recurrent units (ConvGRU) to extract temporal features between feature maps. By introducing a hidden feature sampler to enhance the extraction capability of the convolutional gated recurrent units and designing spatial-temporal dual discriminators to constrain the generator’s predicted samples, the spatiotemporal forecasting ability is enhanced. Experimental results demonstrate that the proposed STD-SNGAN model outperforms other algorithms in critical success index (CSI) and probability of detection (POD) for high echo intensity and long-term regions.

Drizzle microphysical property and vertical air motions retrieval using Doppler lidar and radar measurements

The microphysical changes in cloud formation and development are closely related to the vertical air motions. It is difficult to simultaneously detect microphysical parameters of drizzle and vertical air motions. This study proposes a method for the drizzle microphysical property and vertical air motions retrieval using Doppler lidar and radar measurements. The wavelength of lidar is 1.55 µm, and it undergoes Mie scattering or geometric scattering in drizzle. The wavelength of radar is 8.6 mm, and it undergoes Rayleigh scattering or Mie scattering in drizzle. The difference in scattering mechanisms of two wavelengths enables them to retrieve the microphysical parameters of vertical air motions and raindrops. This wavelength-dependent backscattering cross section causes differently shaped reflectivity-weighted Doppler velocity spectra leading to wavelength-dependent mean Doppler velocity, and spectra width. In this algorithm, the echo power intensity, mean Doppler velocity and spectra width of lidar and radar are used for the retrieval of microphysical parameters and vertical air motions. The feasibility of the proposed method is simulated and analyzed, which is suitable for stratiform clouds rainfall with low turbulence. Finally, an observation case is provided and analyzed.

Association between muscle quality and nutritional status among community-dwelling older adults: A cross-sectional study.

Background: Decline in muscle quality is associated with poorer health in community-dwelling older adults. Although there is evidence that malnutrition is associated with the decline of muscle quality in older adults, few analyses have considered important factors related to muscle quality. Aim: The purpose of this study was to determine the relationship between muscle quality and nutritional status in community-dwelling older adults, taking into account muscle mass, muscle strength, and amount of physical activity. Methods: This was a cross-sectional study. Data were obtained from a health checkup program in Japan. Participants were older adults aged ≥65 years living in the community who participated in the health checkup program. The data collected were echo intensity, scores on the Global Leadership Initiative on Malnutrition criteria, skeletal muscle mass, grip strength, physical activity level, and demographic data. Multiple regression analysis was used to examine the association between muscle quality and nutritional status. Results: Data were analyzed for 50 participants (mean age 77.62 years, standard deviation 6.16 years, 78.0% women). Multiple regression analysis showed that nutritional status affected muscle quality even when various factors were taken into account (B = 6.95, β = 0.31, p = 0.04, 95% confidence interval: 0.01-0.62). Conclusion: The observed association suggests that providing nutritional support for older adults living in the community may be a useful strategy to maintain muscle quality.

Establishment and Validation of a Predictive Model for Sarcopenia Based on 2-D Ultrasound and Shear Wave Elastography in the Medial Gastrocnemius Muscle

ObjectiveTo develop and validate a predictive model for sarcopenia. MethodsA total of 240 subjects who visited our hospital between August 2021 and May 2023 were randomly divided by time of entry into a training set containing 2/3 of patients and a validation set containing 1/3 of patients. The muscle thickness (MT), echo intensity (EI), and shear wave velocity (SWV) of the medial gastrocnemius muscle were measured. Indicators that were meaningful in the univariate analysis in the training set were included in a binary logistic regression to derive a regression model, and the model was evaluated using a consistency index, calibration plot, and clinical validity curve. Diagnostic efficacy and clinical applicability were compared between the model and unifactorial indicators. ResultsFour meaningful variables, age, body mass index (BMI), MT, and SWV, were screened into the predictive model. The model was Logit Y = 21.292 + 0.065 × Age - 0.411 × BMI - 0.524 × MT - 3.072 × SWV. The model was well differentiated with an internally validated C-index of 0.924 and an external validation C-index of 0.914. The calibration plot predicted probabilities against actual probabilities showed excellent agreement. The specificity, sensitivity, and Youden's index of the model were 73.80%, 97.40%, and 71.20%, respectively, when using the diagnostic cut-off value of >0.279 for sarcopenia. The logistic model had higher diagnostic efficacy (p < 0.001) and higher net clinical benefit (p < 0.001) over the same threshold range compared to indicators. ConclusionThe logistic model of sarcopenia has been justified to have good discriminatory, calibrated, and clinical validity, and has higher diagnostic value than indicators.

Normal Weight Obesity Associated with Enhanced Echo Intensity, Insulin Resistance, and Decreased Muscle Strength in Young Adults

Abstract Context: Obesity refers to the accumulation of excess body fat. Even individuals with a normal body mass index (BMI) of &lt;23 Kg/m2 but a high percentage of body fat have an increased risk for noncommunicable disease. This condition is referred to as normal weight obesity (NWO). Aim: To assess the association between muscle strength, ultrasound-derived muscle thickness, insulin resistance, and echo intensity in NWO and normal weight nonobese (NWNO) young adults. Methods and Material: Eighty young adults of a normal BMI of 18.5 to 22.9 Kg/m2 were recruited in this current study. Forty subjects with cutoff points of body fat percentage ≥ 20.6% for men and ≥ 33.4% for women were taken as NWO group and 40 were NWNO. Fasting glucose and insulin were used for calculating insulin resistance, sensitivity, and beta cell function. Ultrasonography (USG) was done to measure forearm radial and ulna muscle thickness. The echo intensity was measured from an ultrasound image as a mean pixel value using Adobe Photoshop. Subjects were tested for handgrip strength using hand dynamometry. Results: Hand grip strength was higher in NWNO group, and subcutaneous fat thickness and echo intensity were higher in the NWO group. Glucose, insulin, and insulin resistance were significantly higher in the NWO group. Linear regression showed a significant correlation between ulna muscle thickness, forearm circumference, echo intensity, and insulin resistance with handgrip strength (r = 0.835 P &lt; 0.001). Conclusions: NWO adults have higher insulin resistance and echo intensity, indicating decreased muscle quality compared to NWNO individuals.

Ultrasonic Evaluation of Muscle Echogenicity in the Lower Limbs for the Detection of Diabetic Peripheral Neuropathy

Purpose: This study aimed to test the ability of high-frequency muscle ultrasound in detecting changes in muscle Echo Intensity (EI) in patients with type 2 Diabetes Mellitus (T2DM) and to correlate muscle ultrasonography findings with Nerve Conduction study (NCS) parameters in those patients. Additionally, we aimed to assess the usefulness of muscle ultrasound in diagnosing diabetic peripheral neuropathy. Materials and Methods: In this case-control study, 26 diabetic patients with Diabetic Peripheral Neuropathy (DPN) and 25 controls were enrolled. Among the controls, 15 were healthy individuals, and the remaining 10 were diabetic patients without DPN. All participants underwent Nerve Conduction Studies (NCS) of the peroneal and tibial motor nerves, as well as quantitative muscle ultrasound. Ultrasound (US) images of the Abductor Hallucis (AH) muscle, Tibialis Anterior (TA) muscle, and Rectus Femoris (RF) muscle were taken and analyzed using grayscale analysis to measure quantitative Echo Intensity (EI). A comparison between the groups regarding EI was made, and correlations between NCS and quantitative US results were assessed. Results: Our Study unveiled a statistically significant augmentation in muscular EI within two of the scrutinized muscle groups among individuals afflicted by DPN, relative to the control cohorts. Moreover, a noteworthy correlation was discerned between the parameters of NCS and muscular EI. Conclusion: Quantitating muscle EI using grayscale analysis of US images is a useful supplementary test for the detection of DPN.

Clinical performance of ultrasonic backscatter parametric and nonparametric statistics in detecting early hepatic steatosis

Diagnosis of early hepatic steatosis would allow timely intervention. B-mode ultrasound imaging was in question for detecting early steatosis, especially with a variety of concomitant parenchymal disease. This study aimed to use the surgical specimen as a reference standard to elucidate the clinical performance of ultrasonic echogenicity and backscatter parametric and nonparametric statistics in real-world scenarios. Ultrasound radio-frequency (RF) signals of right liver lobe and patient data were collected preoperatively. Surgical specimen was then used to histologically determine staging of steatosis. A backscatter nonparametric statistic (h), a known backscatter parametric statistic, i.e., the Nakagami parameter (m), and a quantitative echo intensity (env) were calculated. Among the 236 patients included in the study, 93 were grade 0 (<5% fat) and 143 were with steatosis. All the env, m and h statistics had shown significant discriminatory power of steatosis grades (AUC = 0.643–0.907 with p-value < 0.001). Mann-Whitney U tests, however, revealed that only the backscatter statistics m and h were significantly different between the groups of grades 0 and 1 steatosis. The two-way ANOVA showed a significant confounding effect of the elevated ALT on env (p-value = 0.028), but no effect on m or h. Additionally, the severe fibrosis was found to be a significant covariate for m and h. Ultrasonic signals acquired from different scanners were found linearly comparable.

Relationship between progressive improvement in gait ability one year after discharge and skeletal muscle characteristics of stroke survivors

BackgroundThe clinical importance of skeletal muscle characteristics for improving gait ability of stroke survivors is increasing. We aimed to examine the association between muscle quantity and quality at discharge and changes in gait independence at the time of 1 year after discharge in patients with stroke. MethodsThis prospective observational study included 100 patients with stroke who were admitted to a convalescent rehabilitation ward. We defined muscle quantity and quality operationally as muscle thickness and echo intensity observed in ultrasonography images, respectively, and measured quadriceps muscle on the paretic and non-paretic sides at the time of discharge. The outcome measured in our study was changes in gait independence 1 year after discharge, as assessed by the Functional Independence Measure gait assessment tool score. ResultsAmong the study participants, 23 (23.0 %) were assessed to have reduced gait independence, while 77 (77.0 %) were evaluated to have improved or maintained gait independence. Our multivariate logistic regression analysis revealed that only muscle quantity on the paretic side was significantly associated with an improvement or maintenance of gait independence (odds ratios 3.32; 95 % confidence interval 1.01–10.95; p = 0.049). ConclusionsOur findings revealed that an improvement in gait independence 1 year after discharge was influenced by quadriceps muscle quantity on the paretic side at the time of discharge in patients with subacute stroke. This finding highlights the importance of lower limb muscle quantity on the paretic side as a clinically significant factor that influences the improvement in gait ability after hospital discharge.

Canadian Physicians’ Use of Ultrasound in Spasticity Treatment: A National Cross-Sectional Survey

ObjectiveTo identify potential barriers and obstacles preventing clinicians from adopting ultrasound for spasticity management. DesignA prospective, cross-sectional national survey. SettingWeb-based platform. ParticipantsThirty-six physicians and surgeons from across Canada. InterventionsSurvey completion. Main Outcome MeasuresThe use of ultrasound in clinical spasticity practice, perceived barriers, and risks associated with its implementation. ResultsIn total, 36 Canadian physicians and surgeons responded. A total of 91% reported using the US in their practice. Nearly all of them used ultrasonography (US) to guide injections and reported using more than 1 guidance technique for their injections. Less than half of the survey respondents reported using the US for muscle architecture assessment or longitudinal evaluation of muscle echo intensity. A total of 47% of survey respondents reported that they believe there are disadvantages associated with US use in spasticity practice. Disadvantages included increased time requirements resulting in discomfort for the injector and patient, the risk of infection after the procedure, and the risk of needle-stick injury. The most important barrier identified was the increased time demands of US compared with other guidance techniques. Other barriers included a lack of feedback on identifying a spastic muscle compared with electrical guidance techniques, a lack of additional remuneration to complete injections under ultrasound guidance, and a lack of adequate training. ConclusionsFuture educational efforts should address clinicians’ lack of familiarity with US purposes outside of injection guidance. This survey has highlighted the need for a curriculum shift in spasticity education to improve physician's scanning and injection technique, to address concerns about increased time requirements for injecting under ultrasound guidance and to address perceived disadvantages from clinicians.

Echo characteristics of pulsed lasers in non-uniform smoke environments.

This work establishes a pulsed laser backscattering echo signal model based on an improved semi-analytical Monte Carlo method. The developed model is applied in non-uniform smoke environments to mitigate the smoke interference of laser fuzes for ground proximity detection. The model considers variations of the photon step size according to the concentration of the smoke environment, and the computational speed is accelerated by implementing an improved semi-analytical reception method. The proposed echo signal model is employed to investigate the effects of smoke-related parameters and laser detection system parameters on the backscattering echo waveform of smoke. Finally, the model is validated based on experiments. The results show that the intensity of the smoke backscattering echo and the emission pulse width approximately conform to a logarithmic relationship. Specifically, the echo intensity is positively correlated with the emission pulse width, and the ratio of the time between the rising edge and the falling edge of the echo signal is positively correlated with the pulse width. Meanwhile, the intensity of the smoke backscattering echo and the distance between the transmitter and receiver approximately adopt an exponential relationship. Herein, we describe the characteristics of a laser backscattering echo in a non-uniform smoke environment. The results can guide future research regarding laser fuze detection methods and strategies relevant for ground targets in smoke environments.

Effects of High-Velocity Versus Low-Velocity Resistance Training on Muscle Echo Intensity in Healthy Young Women: A Randomized Controlled Trial.

Improving muscle quality to prevent and treat muscle dysfunction is critical. However, effective measures to improve muscle quality remain poorly understood. We investigated the effects of high- and low-velocity resistance training (RT) on muscle quality, mass, and function before and after an 8-week intervention. High-velocity RT would improve muscle quality more effectively than low-velocity RT. Randomized controlled trial. Level 1. A total of 33 healthy young women (23.1 ± 2.2 years) were assigned randomly to high-velocity (n = 16) or low-velocity (n = 17) groups. Both groups underwent concentric knee extension RT with a 60% 1-repetition maximum (1RM) load, performing 10 repetitions of 4 sets, 3 times per week for 8 weeks. The high-velocity group was instructed to complete each repetition as quickly as possible (mean repetition duration of 0.5 seconds), while the low-velocity group was required to execute each repetition in 3 seconds. Before and after the 8-week intervention, quadriceps femoris echo intensity (EI), muscle thickness (MT), isokinetic peak torque (60 and 300 deg/s), rate of velocity development (RVD) at 300 deg/s, and 1RM were assessed. Split-plot factorial design analysis of variance was used to compare the group × time interaction. A group×time interaction was observed for EI (P < 0.01). Only the high-velocity group showed a significant reduction in EI after the intervention. MT revealed a main effect of time (P < 0.01), with both groups significantly increasing MT. RVD showed a group × time interaction (P < 0.05), with significant increase only in the high-velocity group. Isokinetic peak torque and 1RM showed main effects of time (P < 0.01), with significant increases in both groups. High-velocity RT may be superior to low-velocity RT in enhancing muscle quality and RVD. These results emphasize the importance of RT velocity for muscle quality improvement.