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Objectives: To evaluate the diagnostic performance of ultrasound guided attenuation parameter (UGAP) for evaluating liver fat content with different probe forces and body positions, in relation to sex, and compared with proton density fat fraction (PDFF).

Methods: We prospectively enrolled a metabolic dysfunction-associated steatotic liver disease (MASLD) cohort that underwent UGAP and PDFF in the autumn of 2022. Mean UGAP values were obtained in supine and 30° left decubitus body position with normal 4 N and increased 30 N probe force. The diagnostic performance was evaluated by the area under the receiver operating characteristic curve (AUC).

Results: Among 60 individuals (mean age 52.9 years, SD 12.9; 30 men), we found the best diagnostic performance with increased probe force in 30° left decubitus position (AUC 0.90; 95% CI 0.82–0.98) with a cut-off of 0.58 dB/cm/MHz. For men, the best performance was in supine (AUC 0.91; 95% CI 0.81–1.00) with a cut-off of 0.60 dB/cm/MHz, and for women, 30° left decubitus position (AUC 0.93; 95% CI 0.83–1.00), with a cut-off 0.56 dB/cm/MHz, and increased 30 N probe force for both genders. No difference was in the mean UGAP value when altering body position. UGAP showed good to excellent intra-reproducibility (Intra-class correlation 0.872; 95% CI 0.794–0.921).

Conclusion: UGAP provides excellent diagnostic performance to detect liver fat content in metabolic dysfunction-associated steatotic liver diseases, with good to excellent intra-reproducibility. Regardless of sex, the highest diagnostic accuracy is achieved with increased probe force with men in supine and women in 30° left decubitus position, yielding different cut-offs.

Clinical relevance statement: The ultrasound method ultrasound-guided attenuation parameter shows excellent diagnostic accuracy and performs with good to excellent reproducibility. There is a possibility to alter body position and increase probe pressure, and different performances for men and women should be considered for the highest accuracy.

Purpose: Aortic stiffness, assessed as estimated aortic pulse wave velocity (aPWV), and carotid intima-media thickness (cIMT) are markers of vascular age, and carotid plaques are a marker of early atherosclerosis. In this cross-sectional study we aimed to investigate the association between aPWV, cIMT and plaques across different age groups and in women and men, in a middle-aged healthy population.

Materials and methods: Participants in the 6.5-year follow-up of the VIPVIZA trial who were aged 47, 57 and 67 underwent an oscillometric measurement which estimates aPWV between 2020 and 2023. Carotid ultrasound examinations were also performed. Linear and ordinal regression models were used to investigate how aPWV associates with cIMT and with carotid plaques, for the overall study group and stratified for age groups and sex.

Results: A total of 1046 subjects were included in the analyses. Linear associations between aPWV and cIMT (β = 0.018, 95% CI: 0.006–0.030, p = 0.003), and between aPWV and plaques (OR: 1.19, 95% CI: 1.03–1.38, p = 0.018), were seen in the 57-year-olds. In the 47-year-olds a significant association was seen between aPWV and plaques (OR: 2.98 95% CI: 1.44–6.14, p = 0.003). No significant associations were seen in the 67-year-olds. For women, a significant association between aPWV and cIMT (β = 0.011, 95% CI: 0.004–0.017, p = 0.002) was shown.

Conclusion: Estimated aPWV was positively associated with increasing cIMT and the presence of carotid plaques in younger middle-aged individuals, and with cIMT in women, suggesting that measurement of estimated aPWV may improve cardiovascular risk assessment in younger middle-aged individuals and women.

Clinical Trial Registration date 8 May 2013: URL: www.clinicaltrials.gov. Unique identifier: NCT01849575.

Ultrasound imaging can be used to non-invasively assess muscle structure, musculoskeletal properties, and, more recently, neuromechanics in vivo. This technology can provide great spatial and temporal resolution, opening exciting avenues for investigating health, disease, and neural interfacing technology. This talk will build upon state-of-the-art ultrasound imaging technology and discuss future perspectives and translational capabilities of ultrasound imaging for the neuromechanical characterisation of muscle tissue.An ultrasound transducer on the skin parallel to the muscle fibres can be used to detect and analyse the muscle-tendon unit, muscle thickness, pennation angle, fascicle length, aponeuroses and muscle gearing. This is usually performed using a clinical ultrasound scanner with B-mode (grayscale) imaging, making it accessible to researchers, clinicians, etc. On the other hand, these scanners operate at relatively low frame rates and do not enable access to raw data to calculate displacement fields. These displacement fields are important for identifying transient events like the subtle displacements of muscle fibres in response to the neural discharges of a single motoneuron. Thus, for these applications, a programmable ultrasound research system is used. Moreover, the ultrasound transducer is usually placed perpendicular to the fibres to increase the identification yield.The above cannot all be done simultaneously due to probe positioning. However, it would enable the study of the musculoskeletal structure and properties along with the neuromechanical properties and motoneuron spike trains. Here, I will present the advancements in 3D imaging that could be applied and how they could further enable the study of dynamic contractions. For some translational activities, these systems and probes are too bulky, leading to the incentives for the rise of wearable systems. Finally, I will discuss the feasibility of studying neuromechanics and identifying neural spike trains using a clinical system through an innovative post- processing method. Such a method would increase the accessibility of neural information since a programmable ultrasound research system is currently needed.

Ultrasonic echolucent carotid intima-media (IM) complex and accelerated progression of carotid intima mediathickness (cIMT) have both separately been shown to predict future cardiovascular events. The aim of this studywas to evaluate if the echogenicity of the IM-complex is associated with the 3-year progression of cIMT. B-modeultrasound images captured at baseline and 3-year follow-up in the ‘Visualization of asymptomatic atherosclerotic disease for optimum cardiovascular prevention’ (VIPVIZA) trial were included (n: 3154). The bilateral mean cIMT and IM-echogenicity by greyscale median (GSM) were measured in the common carotid artery. Associations between IM-GSM at baseline and the 3-year cIMT progression were investigated using linear regression models for the whole population and stratified by sex, age and VIPVIZA study group (intervention versus control). In addition, adjusted analyses for confounding factors were performed. Unadjusted analysis showed that decreased IM-GSM at baseline was associated with increased progression of cIMT (p < 0.001). Stratified by age, the association was significant among 40 (p < 0.001) and 60 years old (p < 0.001). The association was statistically significant in both sexes and on comparison of VIPVIZA study subgroups. Adjustments for confounding factors did not alter the estimated relationship between IM-GSM and cIMT progression. Echolucent carotid intima media at baseline associates with increased 3-year cIMT progression among an asymptomatic, middle-aged population. Echogenicity of the intima media may identify individuals at risk for accelerated vascular aging.

AIMS: Poor exercise capacity and muscle strength in early adulthood are risk factors for cardiovascular disease (CVD). However, it is unclear how these factors relate to subclinical atherosclerosis due to a lack of longitudinal studies. This study investigated whether early adulthood exercise capacity and muscle strength associated with later adulthood subclinical atherosclerosis.

METHODS AND RESULTS: This study included Swedish men (n = 797) who were eligible for military conscription (at ∼18-years of age) and who participated in the baseline assessment of the visualization of asymptomatic atherosclerotic disease for optimum cardiovascular prevention trial between 2013 and 2016 (at 60 years of age). At conscription, isometric muscle strength (dynamometer) and maximum exercise capacity (maximal load cycle ergometer test) were measured. During later adulthood (at 60 years old), the presence of carotid plaques and intima media thickness were measured by using high-resolution ultrasound. At follow-up, plaques were present in 62% (n = 493) of men. Exercise capacity in early adulthood associated with 19% lower odds of plaques [odds ratio (OR) 0.81, 95% confidence interval (CI) 0.68-0.96], independent of muscle strength. This association was not mediated by any single CVD risk factor. However, the total indirect effect of later, but not early, adulthood CVD risk factors was significant, while the direct effect was non-significant (OR 0.85, 95% CI 0.71-1.02). Associations between muscle strength and subclinical atherosclerosis were non-significant.

CONCLUSION: Higher exercise capacity during early adulthood, but not muscle strength, may protect against carotid plaque development during adulthood mediated by the combination rather than a single later adulthood CVD risk factors.

Objectives: The risk of cardiovascular disease is associated with the echo intensity of carotid plaques in ultrasound images and their cardiac cycle-induced intensity variations. In this study, we aimed to 1) explore the underlying origin of echo intensity variations by using simulations and 2) evaluate the association between the two-dimensional (2D) spatial distribution of these echo intensity variations and plaque vulnerability.

Methods: First, we analyzed how out-of-plane motion and compression of simulated scattering spheres of different sizes affect the ultrasound echo intensity. Next, we propose a method to analyze the features of the 2D spatial distribution of interframe plaque echo intensity in carotid ultrasound image sequences and explore their associations with plaque vulnerability in experimental data.

Results: The simulations showed that the magnitude of echo intensity changes was similar for both the out-of-plane motion and compression, but for scattering objects smaller than 1 mm radius, the out-of-plane motion dominated. In experimental data, maps of the 2D spatial distribution of the echo intensity variations had a low correlation with standard B-mode echo intensity distribution, indicating complementary information on plaque tissue composition. In addition, we found the existence of ∼1 mm diameter subregions with pronounced echo intensity variations associated with plaque vulnerability.

Conclusions: The results indicate that out-of-plane motion contributes to intra-plaque regions of high echo intensity variation. The 2D echo intensity variation maps may provide complementary information for assessing plaque composition and vulnerability. Further studies are needed to verify this method's role in identifying vulnerable plaques and predicting cardiovascular disease risk.

Artificial Intelligence (AI)-based models can help in diagnosing COVID-19 from lung CT scans and X-ray images; however, these models require large amounts of data for training and validation. Many researchers studied Generative Adversarial Networks (GANs) for producing synthetic lung CT scans and X-Ray images to improve the performance of AI-based models. It is not well explored how good GAN-based methods performed to generate reliable synthetic data. This work analyzes 43 published studies that reported GANs for synthetic data generation. Many of these studies suffered data bias, lack of reproducibility, and lack of feedback from the radiologists or other domain experts. A common issue in these studies is the unavailability of the source code, hindering reproducibility. The included studies reported rescaling of the input images to train the existing GANs architecture without providing clinical insights on how the rescaling was motivated. Finally, even though GAN-based methods have the potential for data augmentation and improving the training of AI-based models, these methods fall short in terms of their use in clinical practice. This paper highlights research hotspots in countering the data scarcity problem, identifies various issues as well as potentials, and provides recommendations to guide future research. These recommendations might be useful to improve acceptability for the GAN-based approaches for data augmentation as GANs for data augmentation are increasingly becoming popular in the AI and medical imaging research community.

We aimed to explore the prevalence of atherosclerosis by using multi-view ultrasound examination of the carotid arteries and its association with clinical risk factors in a middle-aged population at low to intermediate risk of cardiovascular disease (CVD). Carotid vascular ultrasound was performed in 3532 participants in the VIPVIZA trial. Mean and maximal carotid intima media thickness (cIMT) at prespecified angles and plaque presence were examined on the left and right side. Associations between CVD risk factors and ultrasound variables were quantified by partial least squares (PLS) regression. A combined ultrasound variable was computed using weights of the first PLS component. Associations between CVD risk factors and the combined multi-view ultrasound variable, single cIMT and plaque measurements, respectively, were determined using linear regression modelling. The participants’ mean age was 55.7 years and 52.9% were women. Plaque prevalence was 51.1% in men and 39.0% in women. cIMT was higher in men than in women and in the left compared with the right carotid artery. The strongest association of CVD risk factors was observed with the combined multi-view ultrasound variable (R2 = 24%), compared with single cIMT variables (R2 = 14–18%) and plaque presence (R2 = 15%). The pattern was similar in both sexes. The association with CVD risk factors and the combined ultrasound variable was stronger in 40-year olds (R2 = 22%) compared with 50- or 60-year olds (R = 12%). CVD risk factors are stronger associated with a combined ultrasound variable than plaque presence or single cIMT measures suggesting that carotid multi-view ultrasonography better captures the focality of early atherosclerosis. Clinical Trial Registration: ClinicalTrials.gov, number NCT01849575. May 8, 2013.

INTRODUCTION:Resistance training is a well-known intervention to improve muscle strength (1), with motor unit (MU) adaptation playing an important role (2). Recently, MUs were tracked in humans before and after resistance training using high-density surface electromyography (HDsEMG), showing a correlation between maximal force increase and MUs’ average discharge rate (3). Although these results demonstrate the relationship between an increase in strength and MU activity, only MU-level neural adaptation was considered. Indeed, neural and muscular information needs to be studied jointly to understand the exact adaptations of the MUs in response to resistance training (4).Recently, a method based on ultrafast ultrasound was presented, providing estimates of MU territories in cross-section and the train of twitches evoked by the spinal motoneurons’ discharges (5). In this study, as a proof-of-concept, we combined ultrafast ultrasound and HDsEMG to explore the spatial distribution of individual MUs.

METHODS:In a cross-sectional study, four participants performed low-force isometric contractions of the biceps brachii muscle while recording HDsEMG and ultrafast ultrasound signals from the biceps brachii muscle.The HDsEMG signals were decomposed into individual MU discharge timings (6), and the ultrafast ultrasound signals were decomposed into many components, each having a spatial map and temporal signal (5). We matched each discharge timing of a MU with a component based on spike-triggered averaging of the component’s temporal signal. Given a selected component, we applied a threshold to the spatial map and calculated the centroid and an equivalent diameter.

RESULTS:Out of 16 recordings from four subjects, we decomposed 82 MUs from HDsEMG. Given this, we found 32 matches between individual MU discharges and ultrasound components where the triggered twitches had a significant amplitude. The estimated territories were 4.6 ± 1.1 mm (ranging from 2.8 to 8.6 mm), in line with findings from previous research using scanning-EMG (7). Moreover, the components were located 12.7 ± 3.4 mm below the skin (ranging from 6.4 to 19.4 mm).

CONCLUSION:Our results show that using ultrafast ultrasound and HDsEMG in a strength training intervention, we should be able to quantify the relative contribution of the nervous system and skeletal muscle at the MU level. This information may provide the time course of both neural and hypertrophic adaptations to resistance training and elucidate the relative contributions of each to strength gain.

Objectives: Reduced progression of atherosclerosis can decrease the risk of cardiovascular disease (CVD). This study aimed at evaluating the effect of a pictorial intervention showing atherosclerotic severity on the progression of carotid atherosclerosis.

Methods: A prospective randomised open-label blinded end-point trial with participants aged 40–60 years enroled from a routine CVD prevention programme. The intervention group (n: 1575) and their treating physicians received an image based presentation of subclinical atherosclerotic severity measured by carotid ultrasound. The control group (n: 1579) did not receive any information about ultrasound results. Carotid ultrasound at baseline and at 3-year follow-up contained plaque detection and measurements of carotid intima media thickness (cIMT). The left, right and bilateral-mean-cIMT, plaque prevalence and total plaque area (TPA) at 3-year follow-up were compared between groups. Significance level was set to p = 0.01 to adjust for multiple comparisons.

Results: The intervention group revealed reduced cIMT progression in the left-mean-cIMT of −0.011 mm (p = 0.001) compared with the control group. The intervention effect on cIMT progression was most prominent in individuals with increased cIMT and plaque prevalence at baseline (−0.021 mm, p = 0.005). There were no differences in progression between groups for the right-and bilateral-mean-cIMT (−0.005 mm, p = 0.223 and −0.005 mm, p = 0.036, respectively), nor any differences between groups for plaque prevalence or TPA (odds ratio 0.88, p = 0.09 and 0.89, p = 0.21, respectively).

Conclusion: Pictorial presentation of subclinical atherosclerotic severity sent to both the individual and their treating physician resulted in significantly reduced left cIMT progression. Pictorial presentation has the potential to increase adherence in CVD prevention.