B-mode Ultrasound Images Research Articles

Breast cancer imaging-clinical experience with two-dimensional-shear wave elastography: A retrospective study.

Breast cancer morbidity has been increasing worldwide, but treatments are improving. The therapeutic response depends on the stage at which the disease is diagnosed. Therefore, early diagnosis has never been more essential for successful treatment and a reduction in mortality rates. Radiology plays a pivotal role in cancer detection, and advances in ultrasound (US) palpation have shown promising results for breast cancer imaging. The addition of two-dimensional-shear wave elastography (2D-SWE) US in the routine breast imaging exam can increase early cancer detection and promote better surveillance. To evaluate the clinical applications of 2D-SWE US in breast cancer detection and its combination with other imaging modalities. The 200 consecutive female patients aged 50-80 were examined to evaluate palpable breast lesions. All patients underwent mammography, bright mode (B-mode) US, and 2D-SWE followed by US-guided biopsy in two consecutive sessions. Combining B-mode and shear wave US imaging with X-ray mammography revealed 100% of the suspicious lesions, resulting in greater sensitivity, specificity, and negative predictive value. The result improves compared to either B-mode or 2D-SWE alone (P = 0.02). Combining 2D-SWE with conventional US and X-ray techniques improves the chance of early cancer detection. Including 2D-SWE in regular breast imaging routines can reduce the need for biopsies and improve the chance of early cancer detection and survivability with the proper line of therapy.

Two-Stage Multimodal Method for Predicting Intramuscular Fat in Pigs

Intramuscular fat (IMF) content significantly influences pork tenderness, flavor, and juiciness. Maintaining an optimal IMF range not only enhances nutritional value but also improves the taste of pork products. However, traditional IMF measurement methods are often invasive and time-consuming. Ultrasound imaging technology offers a non-destructive solution capable of predicting IMF content and assessing backfat thickness as well as longissimus dorsi muscle area size. A two-stage multimodal network model was developed in this study. First, using B-mode ultrasound images, we employed the UNetPlus segmentation network to accurately delineate the longissimus dorsi muscle area. Subsequently, we integrated data on backfat thickness and longissimus dorsi muscle area to create a multimodal input for IMF content prediction using our model. The results indicate that UNetPlus achieves a 94.17% mean Intersection over Union (mIoU) for precise longissimus dorsi muscle area segmentation. The multimodal network achieves an R2 of 0.9503 for IMF content prediction, with Spearman and Pearson correlation coefficients of 0.9683 and 0.9756, respectively, all within a compact model size of 4.96 MB. This study underscores the efficacy of combining segmented longissimus dorsi muscle images with data on backfat thickness and muscle area in a two-stage multimodal approach for predicting IMF content.

Effects of altered contractile environment on muscle shape change in the triceps surae.

Skeletal muscles change shape when they contract. Current insights into the effects of shape change on muscle function have primarily come from experiments on isolated muscles operating at maximal activation levels. However, when muscles contract and change shape, the forces they apply onto surrounding muscles will also change. The impact of an altered contractile environment (i.e., mechanical behaviour of surrounding muscle) on muscle shape change, remains unknown. To address this, we altered the mechanical contributions of the gastrocnemii during isometric plantarflexion contractions [via changing knee angle] and determined if there were associated changes in how the muscles of the triceps surae bulged in thickness during a ramped contraction. We combined B-mode ultrasound imaging with surface electromyography to quantify the neuromechanical contributions of the medial (MG) and lateral gastrocnemius (MG) and soleus (SOL) muscles during isometric plantarflexion contractions. Our results demonstrated that at the same SOL activity levels, altering knee angle had no influence on the magnitude of muscle shape change (thickness) in the triceps surae muscles. We observed high levels of inter-individual variability in muscle bulging patterns, particularly in the knee flexed position, suggesting a complex relationship between muscle bulging and activation strategies in the triceps surae, which may be related to differences in muscle mechanical properties between participants or across muscles. Our findings highlight the dynamics of in vivo bulging interactions among muscles within the triceps surae and provide insights for future investigations into the impact of altered contractile environments on three-dimensional muscle deformations and force production.

Differences in Abdominal and Lumbar Muscle Thickness and Contractile Function Between Nulliparous, Primiparous, and Multiparous Women 6 Months Postpartum.

The purpose of this study was to evaluate the differences between primiparous and multiparous women at 6 months postpartum and nulliparous women regarding the thickness (including thickness pattern) and contractile function of the abdominal and lumbar muscles. A cross-sectional observational study of 80 women, both primiparous (n = 29) and multiparous (n = 25), as well as including nulliparous as a comparison group (n = 26), was conducted. B-mode ultrasound imaging was used for the measurement of abdominal and lumbar muscle thickness in 2 conditions (resting and activation). Moreover, the contractile function of these muscles was determined by the thickness ratio. Significant differences between groups were observed in abdominal muscle thickness. During activation, the obliques showed a lower thickness in both groups of postpartum women compared to nulliparous women, while lower values for the thickness for the transverse abdominis (TrA) were only observed in primiparous women. The thickness pattern observed in nulliparous women both in resting and in activation (internal oblique [IO] > external oblique [EO] > TrA) was also achieved among postpartum women, despite no statistical differences observed between IO and EO in these groups. No significant differences between groups were observed for contractile function, showing the TrA greater values, followed by IO and EO in both nulliparous and postpartum women. This study suggests that the thickness (and the thickness pattern) of the abdominal muscles in women at 6 months postpartum differs from nulliparous, while for the lumbar muscles, it is comparable to nulliparous. However, despite the obliques being thinner in postpartum women, the abdominal muscles are functionally competent. This is believed to be the first study to compare abdominal and lumbar muscles thickness and contractile function specifically between primiparous and multiparous women. Although at 6 months' postpartum abdominal thickness differs from nulliparous women, these muscles are functionally competent. These findings provide valuable insights for use in the development of postpartum interventions.

8402 The Usefulness Of The Contrast-Enhanced Ultrasound (CEUS) In Preoperative Localization Of Parathyroid Gland Adenomas

Abstract Disclosure: A. Żyłka: None. K. Dobruch-Sobczak: None. H. Piotrzkowska-Wróblewska: None. P. Góralski: None. J. Gałczyński: None. E. Bakuła-Zalewska: None. M. Dedecjus: None. Objectives: Preoperative localization of parathyroid gland adenomas in patients diagnosed with primary hyperparathyroidism (pHPT) is challenging process. The aim of the study was to assessed the usefulness of contrast-enhanced ultrasound (CEUS) as complimentary diagnostic modality to conventional ultrasonography for detection of hyperfunctioning parathyroid gland lesions. Methods: Between the years 2021 and 2022, 36 adult patients (33 women and 3 men, aged 37-76) diagnosed with pHPT, underwent high-resolution ultrasound (US) and CEUS of parathyroid gland adenomas, suspected after fine-needle aspiration biopsy with positive parathormone (PTH) wash-out results and/or avid in 99mTechnetium -sestamibi scintigraphy. During CEUS examination 1.5 ml of SonoVue contrast has been injected and followed by analysing of qualitative CEUS enhancement features. All patients were qualified to surgical treatment according to clinical symptoms, laboratory and imaging findings and underwent parathyroidectomy with histopathologic results confirming parathyroid gland adenomas. Analysis of the B-mode features and visual CEUS enhancement patterns was performed retrospectively. Ten CEUS qualitative parameters of lesions were assessed including: homo- or heterogenous enhancement; hyper- or hypoenhancement; distribution of contrast in wash-in phase as: centripetal, centrifugal or combined and in wash-out phase as: centrally, peripherally or combined. Then the model was extended using the results based on US B-mode imaging which involved size, echogenicity, calcifications, cystic components and vascularity patterns assessed in Color Doppler (CD) and superb microvascular imaging (SMI). Results: Histopathologic results included 36 parathyroid adenomas (in 33 women and 3 men), the medium size 18.8mm (±11.1) and volume 3.7mm3 (±8.2). In B-mode US examination the majority of lesions were assessed as hypoechoic (n=36; 100%) with dominant inhomogenous echostructure (n=20; 55.5%), mixed vascularity (n=24; 66.6%) and polar vessel observed in 14 lesions (38.8%). There were no adenomas with calcifications, cystic components were observed only in 4 nodules (11.1%). In the CEUS study, dominated qualitative features were homogenous (n=22; 61,1%) and hyperenhancement (n=27; 75%), with centripetal distribution of contrast in wash-in phase (n=24; 66,6%) and dominant centrally wash-out of the contrast (n=20; 55,5%). Conclusions: Preliminary results indicate ultrasonographic patterns characteristic for parathyroid gland adenomas in multiparametric ultrasound involved CEUS examination, which seemed to be valuable tool for localization hyperfunctional parathyroid glands. Further multicenter studies should be performed to standardize qualitative CEUS features in order to diagnose primary hyperparathyroidism preoperatively. Presentation: 6/1/2024

8402 The Usefulness of the Contrast-Enhanced Ultrasound (CEUS) in Preoperative Localization of Parathyroid Gland Adenomas

Abstract Disclosure: A. Żyłka: None. K. Dobruch-Sobczak: None. H. Piotrzkowska-Wróblewska: None. P. Góralski: None. J. Gałczyński: None. E. Bakuła-Zalewska: None. M. Dedecjus: None. Objectives: Preoperative localization of parathyroid gland adenomas in patients diagnosed with primary hyperparathyroidism (pHPT) is challenging process. The aim of the study was to assessed the usefulness of contrast-enhanced ultrasound (CEUS) as complimentary diagnostic modality to conventional ultrasonography for detection of hyperfunctioning parathyroid gland lesions. Methods: Between the years 2021 and 2022, 36 adult patients (33 women and 3 men, aged 37-76) diagnosed with pHPT, underwent high-resolution ultrasound (US) and CEUS of parathyroid gland adenomas, suspected after fine-needle aspiration biopsy with positive parathormone (PTH) wash-out results and/or avid in 99mTechnetium -sestamibi scintigraphy. During CEUS examination 1.5 ml of SonoVue contrast has been injected and followed by analysing of qualitative CEUS enhancement features. All patients were qualified to surgical treatment according to clinical symptoms, laboratory and imaging findings and underwent parathyroidectomy with histopathologic results confirming parathyroid gland adenomas. Analysis of the B-mode features and visual CEUS enhancement patterns was performed retrospectively. Ten CEUS qualitative parameters of lesions were assessed including: homo- or heterogenous enhancement; hyper- or hypoenhancement; distribution of contrast in wash-in phase as: centripetal, centrifugal or combined and in wash-out phase as: centrally, peripherally or combined. Then the model was extended using the results based on US B-mode imaging which involved size, echogenicity, calcifications, cystic components and vascularity patterns assessed in Color Doppler (CD) and superb microvascular imaging (SMI). Results: Histopathologic results included 36 parathyroid adenomas (in 33 women and 3 men), the medium size 18.8mm (±11.1) and volume 3.7mm3 (±8.2). In B-mode US examination the majority of lesions were assessed as hypoechoic (n=36; 100%) with dominant inhomogenous echostructure (n=20; 55.5%), mixed vascularity (n=24; 66.6%) and polar vessel observed in 14 lesions (38.8%). There were no adenomas with calcifications, cystic components were observed only in 4 nodules (11.1%). In the CEUS study, dominated qualitative features were homogenous (n=22; 61,1%) and hyperenhancement (n=27; 75%), with centripetal distribution of contrast in wash-in phase (n=24; 66,6%) and dominant centrally wash-out of the contrast (n=20; 55,5%). Conclusions: Preliminary results indicate ultrasonographic patterns characteristic for parathyroid gland adenomas in multiparametric ultrasound involved CEUS examination, which seemed to be valuable tool for localization hyperfunctional parathyroid glands. Further multicenter studies should be performed to standardize qualitative CEUS features in order to diagnose primary hyperparathyroidism preoperatively. Presentation: 6/1/2024

Combining ultrasound and elastography for the detection of a non-palpable, non-sonographically visualized Peyronie's plaques. Our experience.

B-mode ultrasound (US) medical imaging is very effective in localizing and describing Peyronie's disease (PD). Moreover, elastography is a new technique used to evaluate tissue elasticity to detect penile Peyronie's plaques that are not visible using standard B-mode US. The main objective of this study was to evaluate the diagnostic efficacy of real-time elastography (RTE) in PD patients and to determine whether its combined use with standard US improved diagnostic accuracy. RTE is also known as strain elastography (SE). Additionally, this study aimed to assess whether RTE was useful for monitoring PD patients undergoing conservative treatment. A group of 37 PD patients in the active phase was selected based on US examination showing isoechoic or hypo-isoechoic plaques, with or without associated hyperechoic or calcified plaque areas. All patients underwent traditional US combined with RTE before starting conservative treatment with antioxidants, during treatmentand after treatment. After each examination with RTE, a specific "Strain Ratio"(SR) was used to identify the specific elasticity of the tissue. Using B-mode US with RTE, we detected all 13 non-palpable penile plaques present in the 37 PD patients (100% of cases). Using only B-mode US, we detected only 8 of the 13 non-palpable plaques (61.5% of cases). The DI of the plaque decreased during and after treatment in all cases, indicating that RTE is effective for monitoring conservative PD treatment. A statistically significant correlation was found between the DI and plaque volume in all patients (p=0.002). Our study has shown that the combination of US and RTE methods allowed for a more accurate diagnosis in PD patients.

B-mode Ultrasound Related Combined Predictive Indicators for Benign Versus Malignant Subpleural Pulmonary Lesions

ObjectiveThe purpose of this study was to analyze the independent risk factors of malignant subpleural pulmonary lesions (SPLs) on B-mode ultrasound (US) images, to construct the combined predictive indicators, and to prospectively verify their predictive efficacy. MethodsA total of 336 patients with SPLs were included in the prospective study, of whom the single-center included patients between September 2019 and December 2019 were the development cohort (DC) (n = 219); Patients who were concurrently enrolled in three centers between January and February 2020 were the validation cohort (VC) (n = 117). The clinical features and B-mode US parameters were collected. Based on the DC, a combined predictive indicators model was developed using binary logistic regression. Then the discrimination was verified externally in the VC. The reference criteria were from the comprehensive diagnosis of clinical-radiological-pathological made by two senior respiratory physicians. ResultsThe combined predictive indicators model was finally constructed by five parameters: age, borderline, angle between the lesion border and thoracic wall, posterior echo of the lesion and invasion of the pleura. The fitting degree of the model was good (χ2 = 9.198, p = 0.326). The area under ROC curve of the model was 0.872 (DC) and 0.808 (VC), yielding a higher net benefit than individual risk factors. ConclusionThe combined predictive indicators are useful in the assessment of malignant SPLs and are a useful adjunct diagnostic tool, especially in primary healthcare settings in developing countries.

CWC-MP-MC Image-based breast tumor classification using an optimized Vision Transformer (ViT)

This study introduces a novel approach to improve breast tumor classification by integrating advanced image processing techniques and a state-of-the-art Vision Transformer (ViT) model. Our methodology involves transforming B-mode ultrasound images into Cross-Correlated Weighted Contourlet Multi-Parametric Multi-channel (CWC-MP-MC) images. This process includes applying Nakagami, Normal Inverse Gaussian (NIG), and Rician Inverse Gaussian (RiIG) statistical modeling to generate three distinct channels representing different statistical properties of the ultrasound data. These ultrasound data undergo a multi-resolution transform domain like contourlet transform and are weighted by cross-correlation to produce the CWC-MP-MC image. This composite image encapsulates comprehensive information about breast tissue characteristics, offering a robust representation for tumor classification. For classification, we utilize a optimized Vision Transformer (ViT) architecture specially designed to be lightweight, fine-tuned, and suitable for operating in a low-configuration GPU environment. Our experiments, conducted on three publicly available datasets (Mendeley, UDIAT, and BUSI), demonstrate that our proposed methodology achieves accuracy, sensitivity, specificity, NPV, PPV, and F1 scores exceeding 98% when employing CWC-MP-MC images.

GLCV-NET: An automatic diagnosis system for advanced liver fibrosis using global–local cross view in B-mode ultrasound images

Background and objective: Advanced liver fibrosis is a critical stage in the evaluation of chronic liver disease (CLD), holding clinical significance in the development of treatment strategies and estimating the disease progression. Methods:This paper proposes an innovative Global–Local Cross-View Network (GLCV-Net) for the automatic diagnosis of advanced liver fibrosis from ultrasound (US) B-mode images. The proposed method consists of three main components: 1. A Segmentation-enhanced Global Hybrid Feature Extractor for segmenting the liver parenchyma and extracting global features; 2. A Heatmap-weighted Local Feature Extractor for selecting candidate regions and automatically identifying suspicious areas to construct local features; 3. A Scale-adaptive Fusion Module to balance the contributions of global and local scales in evaluating advanced liver fibrosis. Results:The predictive performance of the model was validated on an internal dataset of 1003 chronic liver disease (CLD) patients and an external dataset of 46 CLD patients, both subjected to liver fibrosis staging through pathological assessment. On the internal dataset, GLCV-Net achieved 86.9% accuracy, 85.0% recall, 85.4% precision, and 85.2% F1-score. Further validation on the external dataset confirmed its robustness, with scores of 86.1% in accuracy, 83.1% in recall, 80.8% in precision, and 81.9% in F1-score. Conclusion:These results underscore the GLCV-Net’s potential as a promising approach for non-invasively and accurately diagnosing advanced liver fibrosis in CLD patients, breaking through the limitations of traditional methods by integrating global and local information of liver fibrosis, significantly enhancing diagnostic accuracy.

Achieving Single Cell Acoustic Localisation with Deactivation Super Resolution.

Super-resolution optical microscopy enables optical imaging of cells, molecules and other biological structures beyond the diffraction limit. However, no similar method exists to super-resolve specific cells with ultrasound. Here we introduce Deactivation Super Resolution (DSR), an ultrasound imaging method that uses the acoustic deactivation of genetically encodable contrast agents to super-resolve individual cells with ultrasound as they navigate through structures that cannot be resolved by conventional imaging methods. DSR takes advantage of gas vesicles, which are air-filled sub-micron protein particles that can be expressed in genetically engineered cells to produce ultrasound contrast. Our experimental results show that DSR can distinguish sub-wavelength microstructures that standard B-mode ultrasound images fail to resolve by super- localizing individual mammalian cells. This study provides a proof of concept for the potential of DSR to serve as a super- resolution ultrasound technique for individual cell localization, opening new horizons in the field.

In vivo assessment of cardiac radiofrequency ablation in a large-animal model using photoacoustic-ultrasound imaging.

One of the fundamental unmet clinical needs within cardiac electrophysiology is intraoperative assessment of catheter ablation, which can lead to recurrent arrhythmias and subsequent complications if ineffective. This work demonstrates photoacoustic imaging (PAI) of radiofrequency ablation (RFA) lesions in an in vivo swine model (n=3). Spectral unmixing of PAI data provides local myocardial characterization (e.g., oxygen saturation & tissue ablation) by overlaying unmixed PAI images with B-mode ultrasound imaging (PAI/US), with the latter providing anatomical context. Based on stained gross pathology, areas of central tissue necrosis coincided with increases in unmixed ablated regions of the myocardium. An average contrast-to-noise ratio of 2.8±0.2 confirmed lesion detectability, while the lesion dimensions quantified from PAI and pathology did not present significant differences. In vivo PAI of RFA lesions to determine ablation characteristics could lead to a paradigm shift in catheter ablation assessment and improve clinical outcomes.

Variability in Liver Size Measurements Using Different View Angles in Ultrasound Imaging.

The aim of this study was to compare liver size measurements in different conventional B-mode ultrasound image (US) field views using magnetic resonance imaging (MRI) measurement as a reference. After receiving Institutional Review Board approval and informed consent, three operators measured the largest sagittal and transverse dimensions of adult livers on three US image field views (90°, 120°, and 140°) with a single curvilinear transducer. We analyzed the differences in liver size across three image field views using one-way analysis of variance (ANOVA) and examined the correlations between MRI and ultrasound measurements using Spearman regression. We used 95% Bland-Altman limits of agreement (95% LOA) to analyze the confidence interval for liver size measurements between MRI and US. Intra-observer and inter-observer reliability in measuring liver size were assessed using intraclass correlation coefficient (ICC). Based on sagittal liver length, 28 adult participants (7 men and 21 women, mean age 43 years) were divided into Group 1 (<17 cm, n = 10) or Group 2 (≥17 cm, n = 18). There was a significant difference in the liver size measurements across the three image field views (P < .001) in both groups. The highest correlation in liver size measurements between MRI and US was with ultra-wide-view (R2 = .87 in sagittal; R2 = .79 in transverse). Bland-Altman LOA also indicated good agreement between MRI and ultra-wide-view measurements. Intra-observer and inter-observer reliability in measuring liver size were good (ICC = 0.82-0.98). The study suggests that ultrasound ultra-wide-view provides the most accurate liver size measurement and good intra- and inter-operator reliability.

Multi-angle speed-of-sound imaging with sparse sampling to characterize medical tissue properties

Medical Speed-of-sound (SoS) imaging, which can characterize medical tissue properties better by quantifying their different SoS, is an effective imaging method compared with conventional B-mode ultrasound imaging. As a commonly used diagnostic instrument, a hand-held array probe features convenient and quick inspection. However, artifacts will occur in the single-angle SoS imaging, resulting in indistinguishable tissue boundaries. In order to build a high-quality SoS image, a number of raw data are needed, which will bring difficulties to data storage and processing. Compressed sensing (CS) theory offers theoretical support to the feasibility that a sparse signal can be rebuilt with random but less sampling data. In this study, we proposed an SoS reconstruction method based on CS theory to process signals obtained from a hand-held linear array probe with a passive reflector positioned on the opposite side. The SoS reconstruction method consists of three parts. Firstly, a sparse transform basis is selected appropriately for a sparse representation of the original signal. Then, considering the mathematical principles of SoS imaging, the ray-length matrix is used as a sparse measurement matrix to observe the original signal, which represents the length of the acoustic propagation path. Finally, the orthogonal matching pursuit algorithm is introduced for image reconstruction. The experimental result of the phantom proves that SoS imaging can clearly distinguish tissues that show similar echogenicity in B-mode ultrasound imaging. The simulation and experimental results show that our proposed method holds promising potential for reconstructing precision SoS images with fewer signal samplings, transmission, and storage.

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&lt;0.05) and had a fair correlation with EIRF(r=-0.37,p&lt;0.05), VM stiffness had a good correlation with muscle strength (r=0.42, p&lt;0.05) and had a fair correlation with EIVM (r=-0.43,p&lt;0.05) in women. RF stiffness had a good correlation with muscle strength (r=-0.54, p&lt;0.05), had a good correlation with EIRF(r=-0.41,p&lt;0.05) in men.VM stiffness had a good correlation with muscle strength(r=-0.50; p&lt;0.05), and had a good correlation with EIVM(r=-0.60,p&lt;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&lt;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.

Ultrasonic Assessment of Liver Fibrosis Using One-Dimensional Convolutional Neural Networks Based on Frequency Spectra of Radiofrequency Signals with Deep Learning Segmentation of Liver Regions in B-Mode Images: A Feasibility Study.

The early detection of liver fibrosis is of significant importance. Deep learning analysis of ultrasound backscattered radiofrequency (RF) signals is emerging for tissue characterization as the RF signals carry abundant information related to tissue microstructures. However, the existing methods only used the time-domain information of the RF signals for liver fibrosis assessment, and the liver region of interest (ROI) is outlined manually. In this study, we proposed an approach for liver fibrosis assessment using deep learning models on ultrasound RF signals. The proposed method consisted of two-dimensional (2D) convolutional neural networks (CNNs) for automatic liver ROI segmentation from reconstructed B-mode ultrasound images and one-dimensional (1D) CNNs for liver fibrosis stage classification based on the frequency spectra (amplitude, phase, and power) of the segmented ROI signals. The Fourier transform was used to obtain the three kinds of frequency spectra. Two classical 2D CNNs were employed for liver ROI segmentation: U-Net and Attention U-Net. ROI spectrum signals were normalized and augmented using a sliding window technique. Ultrasound RF signals collected (with a 3-MHz transducer) from 613 participants (Group A) were included for liver ROI segmentation and those from 237 participants (Group B) for liver fibrosis stage classification, with a liver biopsy as the reference standard (Fibrosis stage: F0 = 27, F1 = 49, F2 = 51, F3 = 49, F4 = 61). In the test set of Group A, U-Net and Attention U-Net yielded Dice similarity coefficients of 95.05% and 94.68%, respectively. In the test set of Group B, the 1D CNN performed the best when using ROI phase spectrum signals to evaluate liver fibrosis stages ≥F1 (area under the receive operating characteristic curve, AUC: 0.957; accuracy: 89.19%; sensitivity: 85.17%; specificity: 93.75%), ≥F2 (AUC: 0.808; accuracy: 83.34%; sensitivity: 87.50%; specificity: 78.57%), and ≥F4 (AUC: 0.876; accuracy: 85.71%; sensitivity: 77.78%; specificity: 94.12%), and when using the power spectrum signals to evaluate ≥F3 (AUC: 0.729; accuracy: 77.14%; sensitivity: 77.27%; specificity: 76.92%). The experimental results demonstrated the feasibility of both the 2D and 1D CNNs in liver parenchyma detection and liver fibrosis characterization. The proposed methods have provided a new strategy for liver fibrosis assessment based on ultrasound RF signals, especially for early fibrosis detection. The findings of this study shed light on deep learning analysis of ultrasound RF signals in the frequency domain with automatic ROI segmentation.

Acoustically responsive scaffolds: Unraveling release kinetics and mechanisms for sustained, steady drug delivery

Hydrogels can serve as local drug delivery depots that protect the biological activity of labile therapeutics. However, drug release from conventional hydrogels is typically rapid, which is not ideal for many therapeutic agents. We developed a composite hydrogel that enables sustained drug release in response to ultrasound. The composite, termed an acoustically responsive scaffold (ARS), consists of a fibrin hydrogel and a phase-shift emulsion. Upon exposure to ultrasound, the emulsion is vaporized into bubbles, which leads to release of drugs contained within the emulsion. Previously, ARSs have been used in regenerative applications to stimulate blood vessel growth. Here, we characterize the release kinetics and mechanisms of ARSs. Release exhibits a triphasic pattern compromising a slow phase prior to ultrasound exposure; a transient, fast phase immediately after ultrasound exposure that follows a sigmoidal profile; and a sustained, steady phase. In each phase, we demonstrate how derived kinetics parameters are impacted by the ARS composition (e.g., fibrin and emulsion concentrations) and ultrasound properties (e.g., acoustic pressure, pulse duration). Using confocal microscopy, protein assays, and B-mode ultrasound imaging, we demonstrate that drug release from an ARS is independent of fibrin degradation and dependent on bubble growth. These results are critical in optimizing ARSs for delivery of therapeutic agents.

Retraction Note: Automated detection of chronic kidney disease using higher-order features and elongated quinary patterns from B-mode ultrasound images

Retraction Note: Automated detection of chronic kidney disease using higher-order features and elongated quinary patterns from B-mode ultrasound images

Exercise selection plays an important role in inducing non-uniform acute responses on elbow flexors muscle thickness

The muscle thickness (MT) acutely increases in response to the redirection of blood flow during exercise, with this muscle swelling being a proxy to quantify the degree of muscle stimuli and involvement in an exercise. The present study aims to compare the MT acute variations between the biceps brachii (BB) and brachialis (BRA) muscles in two different unilateral exercises, the dumbbell curl (DC) and dumbbell row (DR). Sixteen well-trained young males performed a 10-repetition maximum (10RM) load test and retest for each exercise. Four sets were performed with the 10RM load for each exercise until the concentric failure. The BB and BRA muscles MT were measured pre and post-intervention with a B-mode ultrasound images. The main finding of this study was that, when DC is performed, the BB presented greater MT changes (18.67% ± 6.23) compared to BRA (12.27% ± 6.20) (p = 0.025), and compared to BB when performed in DR (12.23% ± 6.03) (p = 0.024). It was also found that BB greatest increase from BRA was not observed in DR and the BRA results were similar in both exercises. These results indicate that the structural acute responses can be muscle-specific among the elbow flexors muscles for the single-joint exercise and also exercise-specific. Therefore, either one of these two exercises can be chosen to stimulate BRA, but it would be interesting to use DC to offer greater stimuli for BB.

Carotid Plaque Score is Associated with 10-year Major Adverse Cardiovascular Events in Low-Intermediate Risk Patients Referred to a General Cardiology Community Clinic.

Atherosclerotic carotid plaque assessments have not been integrated into routine clinical practice due to the time-consuming nature of both imaging and measurements. Plaque score, Rotterdam method, is simple, quick, and only requires 4-6 B-mode ultrasound images. The aim was to assess the benefit of plaque score in a community cardiology clinic to identify patients at risk for major adverse cardiovascular events (MACE). Patients ≥40 years presenting for risk assessment were given a carotid ultrasound. Exclusions included a history of vascular disease or MACE and being >75 years. Kaplan-Meier curves and hazard ratios were performed. The left and right common carotid artery (CCA), bulb, and internal carotid artery (ICA) were given 1 point per segment if plaque present (plaque score 0 to 6). Administrative data holdings at ICES were used for 10-year event follow-up. Of 8,472 patients, 60% were females (n = 5,121). Plaque was more prevalent in males (64% vs 53.9%; P <0.0001). The 10-year MACE cumulative incidence estimate was 6.37% with 276 events (males 6.9 % vs females 6.0%; P = 0.004). Having both maximal CCA IMT <1.00 mm and plaque score = 0, was associated with less events. A plaque score <2 was associated with a low 10-year event rate (4.1%) compared to 2-4 (8.7%) and 5-6 (20%). A plaque score ≥2 can re-stratify low-intermediate risk patients to a higher risk for events. Plaque score may be used as a quick assessment in a cardiology office to guide treatment management of patients.