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Search Results (371)

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Keywords = 1–5 MHz ultrasounds

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15 pages, 1699 KB  
Article
Influence of Body Position Changes on Diaphragmatic Excursion Assessed by Ultrasonography in a Healthy Population
by Leonardo Arzayus-Patiño, Jorge Enrique Daza-Arana, Santiago Vásquez Cartagena, Carolina Villamizar, Juan Meléndez Diaz and Diego Fernando Muñoz-Escudero
J. Funct. Morphol. Kinesiol. 2026, 11(1), 64; https://doi.org/10.3390/jfmk11010064 - 31 Jan 2026
Viewed by 131
Abstract
Background: The diaphragm is the primary respiratory muscle, and its proper function is essential for efficient breathing. Respiratory muscle weakness is a common complication that can hinder the withdrawal of mechanical ventilation. This weakness not only negatively affects patients’ quality of life but [...] Read more.
Background: The diaphragm is the primary respiratory muscle, and its proper function is essential for efficient breathing. Respiratory muscle weakness is a common complication that can hinder the withdrawal of mechanical ventilation. This weakness not only negatively affects patients’ quality of life but also represents an economic challenge for healthcare systems, as it significantly increases medical costs due to prolonged hospitalization and the need for additional procedures to manage associated complications. Ultrasonography has emerged as a precise technique for assessing diaphragmatic function through measurements such as diaphragmatic excursion and thickening fraction, with the right hemidiaphragm being the most suitable for evaluation. However, several studies have shown that diaphragmatic ultrasound measurements vary considerably in both healthy individuals and patients, mainly due to the lack of standardization of body position during assessment. Therefore, it is necessary to investigate how patient posture influences diaphragmatic ultrasound measurements in order to standardize protocols, improve diagnostic accuracy, and support reliable clinical decision-making. We employed ultrasonography to determine the influence of changes in body position on diaphragmatic excursion in a healthy population from the city of Cali. Methods: A descriptive cross-sectional study was conducted in 36 healthy adults aged 18 to 65 years, distributed into sex and age groups. Diaphragmatic excursion was assessed using a 3.5–5 MHz ultrasound transducer. Participants were evaluated in five body positions: supine at 0°, and head-of-bed inclinations of 30°, 45°, 70°, and 90°. Results: A progressive increase in diaphragmatic excursion was observed from the supine position (0°) up to 70° inclination. The 70° inclination showed the greatest diaphragmatic mobility as measured by ultrasonography. This finding suggests the existence of an optimal intermediate position in which biomechanical conditions and intra-abdominal pressure allow more efficient diaphragmatic contraction. Conclusions: The results of this study demonstrate that changes in body position significantly influence diaphragmatic excursion in healthy individuals, with a trunk inclination of 70° yielding the greatest diaphragmatic mobility. These findings support the importance of considering body posture as a key determinant in the functional assessment of the diaphragm using ultrasonography. Full article
(This article belongs to the Section Functional Anatomy and Musculoskeletal System)
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12 pages, 2780 KB  
Article
A Deep-Learning-Enhanced Ultrasonic Biosensing System for Artifact Suppression in Sow Pregnancy Diagnosis
by Xiaoying Wang, Jundong Wang, Ziming Gao, Xinjie Luo, Zitong Ding, Yiyang Chen, Zhe Zhang, Hao Yin, Yifan Zhang, Xuan Liang and Qiangqiang Ouyang
Biosensors 2026, 16(2), 75; https://doi.org/10.3390/bios16020075 - 27 Jan 2026
Viewed by 175
Abstract
The integration of artificial intelligence (AI) with ultrasonic biosensing presents a transformative opportunity for enhancing diagnostic accuracy in agricultural and biomedical applications. This study develops a data-driven deep learning model to address the challenge of acoustic artifacts in B-mode ultrasound imaging, specifically for [...] Read more.
The integration of artificial intelligence (AI) with ultrasonic biosensing presents a transformative opportunity for enhancing diagnostic accuracy in agricultural and biomedical applications. This study develops a data-driven deep learning model to address the challenge of acoustic artifacts in B-mode ultrasound imaging, specifically for sow pregnancy diagnosis. We designed a biosensing system centered on a mechanical sector-scanning ultrasound probe (5.0 MHz) as the core biosensor for data acquisition. To overcome the limitations of traditional filtering methods, we introduced a lightweight Deep Neural Network (DNN) based on the YOLOv8 architecture, which was data-driven and trained on a purpose-built dataset of sow pregnancy ultrasound images featuring typical artifacts like reverberation and acoustic shadowing. The AI model functions as an intelligent detection layer that identifies and masks artifact regions while simultaneously detecting and annotating key anatomical features. This combined detection–masking approach enables artifact-aware visualization enhancement, where artifact regions are suppressed and diagnostic structures are highlighted for improved clinical interpretation. Experimental results demonstrate the superiority of our AI-enhanced approach, achieving a mean Intersection over Union (IOU) of 0.89, a Peak Signal-to-Noise Ratio (PSNR) of 34.2 dB, a Structural Similarity Index (SSIM) of 0.92, and clinically tested early gestation accuracy of 98.1%, significantly outperforming traditional methods (IoU: 0.65, PSNR: 28.5 dB, SSIM: 0.72, accuracy: 76.4). Crucially, the system maintains a single-image processing time of 22 ms, fulfilling the requirement for real-time clinical diagnosis. This research not only validates a robust AI-powered ultrasonic biosensing system for improving reproductive management in livestock but also establishes a reproducible, scalable framework for intelligent signal enhancement in broader biosensor applications. Full article
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16 pages, 1576 KB  
Article
Hip Joint Synovial Cavity Thickness in Early Juvenile Idiopathic Arthritis Without Effusion: A Cross-Sectional Ultrasound Study
by Zbigniew Żuber, Wojciech Kmiecik, Krzysztof Batko, Elżbieta Mężyk, Joanna Ożga, Magdalena Krajewska-Włodarczyk, Tomasz Madej and Bogdan Batko
J. Clin. Med. 2026, 15(3), 962; https://doi.org/10.3390/jcm15030962 - 25 Jan 2026
Viewed by 186
Abstract
Background: The clinical meaning of hip joint synovial cavity thickness (HJSCT) on ultrasound (US) in juvenile idiopathic arthritis (JIA) without effusion is uncertain. Methods: In this cross-sectional study, we analyzed 369 children (187 JIA; 182 controls) undergoing hip US at a [...] Read more.
Background: The clinical meaning of hip joint synovial cavity thickness (HJSCT) on ultrasound (US) in juvenile idiopathic arthritis (JIA) without effusion is uncertain. Methods: In this cross-sectional study, we analyzed 369 children (187 JIA; 182 controls) undergoing hip US at a referral center in Kraków, Poland. JIA examinations were performed upon initial referral, early in the care pathway. We excluded patients with hip effusion and pre-existing inflammatory, traumatic or degenerative hip pathology. HJSCT was defined as the distance from the outer capsule margin to the femoral neck cortex. We used a Toshiba Aplio 400 system with a 12 MHz probe to measure and derive mean bilateral HJSCT. Bilateral concordance was assessed. Iterative multivariable linear regression modeling was used to compare groups, adjusting for non-linear age effects (natural splines) and WHO height-for-age z-scores (HAZ). Results: Left–right HJSCT agreement was high (ICC 0.947; mean difference 0.03 mm; 95% limits of agreement −0.64–0.70). In unadjusted analysis, mean (SD) HJSCT was similar in JIA versus controls: 5.83 (1.09) vs. 5.95 (0.99) mm, respectively (p = 0.25). In the final model (adj. R2 0.656), HJSCT was strongly associated with age (non-linear, p < 0.001) but not significantly associated with HAZ (β = 0.04; p = 0.11) or JIA status (β = 0.07; p = 0.30). Predicted HJSCT showed a steep increment in childhood and plateau in adolescence. Conclusions: In children without hip effusion, HJSCT mainly reflects physiological growth and does not differ significantly between early JIA patients and healthy controls. These findings suggest that capsular thickening is not a reliable standalone marker for early disease in the absence of effusion. Full article
(This article belongs to the Special Issue Arthritis: From Diagnosis to Treatment)
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15 pages, 1284 KB  
Systematic Review
The Role of Ultrasound in the Diagnosis and Treatment of Cellulite: A Systematic Review
by Dora Intagliata and Maria Luisa Garo
J. Clin. Med. 2026, 15(3), 943; https://doi.org/10.3390/jcm15030943 - 23 Jan 2026
Viewed by 168
Abstract
Background: Cellulite is a highly prevalent condition with dermal and subcutaneous alterations poorly captured by visual grading systems. Ultrasound has emerged as a non-invasive imaging modality capable of objectively quantifying morphological features relevant to cellulite. This systematic review evaluated the evidence on [...] Read more.
Background: Cellulite is a highly prevalent condition with dermal and subcutaneous alterations poorly captured by visual grading systems. Ultrasound has emerged as a non-invasive imaging modality capable of objectively quantifying morphological features relevant to cellulite. This systematic review evaluated the evidence on ultrasound for the diagnosis, structural characterization, and treatment monitoring of cellulite, identifying methodological limitations and research gaps. Methods: This systematic review (PROSPERO:CRD420251185486) followed the PRISMA statement. Searches were conducted in PubMed, Scopus, and CENTRAL up to November 2025. Risk of bias was evaluated using ROBINS-I and the Newcastle–Ottawa Scale. Results: Nine studies involving 785 participants were included. Ultrasound frequencies ranged from 12 to 35 MHz, with some scanners operating across broader bandwidths. Despite variability in devices, acquisition protocols, and clinical comparators, all studies consistently demonstrated that ultrasound quantifies key structural characteristics of cellulite. Diagnostic investigations reported moderate-to-strong correlations (r ≈ 0.31–0.64) between ultrasound-derived measures and clinical severity scores. Interventional studies showed measurable reductions in dermal and subcutaneous thickness, decreased adipose protrusion height, and improved dermal echogenicity across multiple treatment modalities. Ultrasound frequently detected microstructural remodeling not readily visible on clinical examination. Conclusions: Ultrasound is a valuable imaging modality for objectively characterizing cellulite and monitoring treatment-induced tissue remodeling. Standardized acquisition protocols, validated analytic criteria, and larger controlled studies are needed to support integration into routine dermatologic and esthetic practice. The quantitative and reproducible nature of ultrasound-derived parameters also provides a suitable foundation for future integration with data-driven and artificial intelligence–based image analysis frameworks. Full article
(This article belongs to the Special Issue Artificial Intelligence and Deep Learning in Medical Imaging)
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10 pages, 863 KB  
Article
Destruction/Inactivation of SARS-CoV-2 Virus Using Ultrasound Excitation: A Preliminary Study
by Almunther Alhasawi, Fajer Alassaf and Alshimaa Hassan
Viruses 2026, 18(2), 152; https://doi.org/10.3390/v18020152 - 23 Jan 2026
Viewed by 523
Abstract
SARS-CoV-2, the causative virus of the COVID-19 pandemic, is a highly transmissible, enveloped, single-stranded RNA virus that has mutated into several variants, complicating vaccine strategies and drug resistance. Novel treatment modalities targeting conserved structural vulnerable points are essential to combat these variants. The [...] Read more.
SARS-CoV-2, the causative virus of the COVID-19 pandemic, is a highly transmissible, enveloped, single-stranded RNA virus that has mutated into several variants, complicating vaccine strategies and drug resistance. Novel treatment modalities targeting conserved structural vulnerable points are essential to combat these variants. The primary aim of the current study is to test the mechanical vulnerability of the SARS-CoV-2 virus envelope and spike proteins to focused, high-frequency ultrasound waves (25 MHz) in vitro. Utilizing a preliminary pretest and posttest study design, the study was conducted on a virus sample within a distilled water matrix, under controlled laboratory biosafety conditions. Since detailed imaging tools were unavailable, viral disruption was indirectly measured using real-time PCR cycle threshold (Ct) values. Ct values increased significantly after high-frequency ultrasound exposure, indicating a reduction in amplifiable viral genomic material. A paired t-test indicated a significant difference between the pretest and posttest Ct (p < 0.001), which is supported by Monte Carlo test results that revealed statistically significant shifting in viral load categories (p = 0.001, two-sided). Specifically, 85.7% of high-viral-load samples converted to low or moderate content, 46.7% of low or moderate samples were shifted to negative content. This intervention produced a large effect size (Cohen’s d = 2.422). These results indicate that ultrasound may offer a promising non-pharmacological approach to destroy or inactivate SARS-CoV-2 variants in an aqueous environment. Full article
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11 pages, 1880 KB  
Article
High-Frequency Ultrasound Assessment of Basal Cell Carcinoma: Correlations Between Histopathological Subtype, Vascularity, and Age/Sex Distribution
by Klára Szalai, Klaudia Tóth, Judit Hársing, Miklós Gyöngy and Péter Holló
Cancers 2026, 18(2), 274; https://doi.org/10.3390/cancers18020274 - 15 Jan 2026
Viewed by 189
Abstract
Background: High-frequency ultrasound (HFUS) has emerged as a valuable non-invasive imaging modality for the preoperative assessment of basal cell carcinoma (BCC). However, its ability to reliably differentiate between histopathological subtypes based on morphological and vascular characteristics requires further validation. Methods: Between January [...] Read more.
Background: High-frequency ultrasound (HFUS) has emerged as a valuable non-invasive imaging modality for the preoperative assessment of basal cell carcinoma (BCC). However, its ability to reliably differentiate between histopathological subtypes based on morphological and vascular characteristics requires further validation. Methods: Between January 2010 and December 2011, 320 patients with a total of 330 histologically confirmed BCC lesions were examined using HFUS (15–18 MHz linear transducer). Lesions were classified according to ultrasound contour (sharp vs. irregular) and vascularity (hypervascular vs. hypovascular) and correlated with histopathological subtype (solid vs. infiltrative). Postoperative ultrasound follow-up was performed in a subset of patients for recurrence detection. Results: Solid BCCs were predominantly characterised by sharp, well-defined margins, whereas infiltrative tumours more frequently exhibited irregular contours. This association was highly significant (χ2 = 24.7, df = 1, p < 0.001; OR = 71.9, 95% CI: 37.0–139.8). Vascularity patterns also differed significantly between subtypes: solid tumours were more likely to present with hypervascular features, while infiltrative tumours more frequently exhibited hypovascular patterns (χ2 = 23.8, df = 1, p < 0.001; OR = 3.24). No statistically significant associations were observed between ultrasound morphology and patient sex or age. Among patients who participated in postoperative HFUS follow-up, seven histologically confirmed recurrences were detected. Conclusions: HFUS provides reliable preoperative information on BCC morphology and vascularity, enabling accurate differentiation between solid and infiltrative subtypes. These findings support the role of HFUS as a valuable adjunct to dermatoscopy in treatment planning and postoperative surveillance of BCC. Full article
(This article belongs to the Section Methods and Technologies Development)
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12 pages, 752 KB  
Article
Dermoscopy-Guided High-Frequency Ultrasound Imaging of Subcentimeter Cutaneous and Subcutaneous Neurofibromas in Patients with Neurofibromatosis Type 1
by Krisztina Kerekes, Mehdi Boostani, Zseraldin Metyovinyi, Norbert Kiss and Márta Medvecz
J. Clin. Med. 2026, 15(2), 475; https://doi.org/10.3390/jcm15020475 - 7 Jan 2026
Viewed by 377
Abstract
Background: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder characterized by cutaneous and subcutaneous neurofibromas, which impact quality of life. Dermoscopy-guided high-frequency ultrasound (DG-HFUS) integrates dermoscopy with 33 MHz ultrasound, enabling precise lesion localization and reproducible measurements. Objective: To characterize neurofibromas [...] Read more.
Background: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder characterized by cutaneous and subcutaneous neurofibromas, which impact quality of life. Dermoscopy-guided high-frequency ultrasound (DG-HFUS) integrates dermoscopy with 33 MHz ultrasound, enabling precise lesion localization and reproducible measurements. Objective: To characterize neurofibromas in NF1 patients using DG-HFUS and identify imaging parameters for diagnosis, monitoring, and treatment planning. Methods: 14 genetically confirmed NF1 patients underwent DG-HFUS imaging (Dermus SkinScanner). 100 neurofibromas were assessed for size, location, shape, contours, surface, echogenicity, global echogenicity, and posterior acoustic features. Results: Lesions were dermal (79%) or subcutaneous (21%), round (28%), ovoid (63%), or spiked (9%). Mean vertical and lateral diameters were 5.37 ± 2.66 mm and 2.28 ± 1.39 mm. All were hypoechoic; 62% homogeneous, 38% heterogeneous. Margins were well-defined in 57% and poorly defined in 43%. Posterior enhancement occurred in 3% and shadowing in 10%. Conclusions: DG-HFUS provides a detailed, reproducible assessment of neurofibromas, supporting differential diagnosis, surgical planning, and longitudinal monitoring. The evaluated imaging parameters offer objective insights for optimizing NF1 management. Future developments, including 3D reconstruction and AI-assisted analysis, may further enhance its clinical utility. Full article
(This article belongs to the Special Issue Fresh Insights in Skin Disease)
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11 pages, 759 KB  
Perspective
Caveolin-1 in Skin Protection Against Radiation-Induced Skin Injuries: Pathophysiological Mechanisms and New Avenues for Prevention
by Ilja L. Kruglikov
Int. J. Mol. Sci. 2026, 27(1), 415; https://doi.org/10.3390/ijms27010415 - 30 Dec 2025
Viewed by 444
Abstract
The identification of caveolin-1 (CAV1) as a universal pathophysiological factor and target for treating various cutaneous conditions and the recognition of its role as a universal factor and target in the protection of cells from genotoxic stress have opened new avenues for protecting [...] Read more.
The identification of caveolin-1 (CAV1) as a universal pathophysiological factor and target for treating various cutaneous conditions and the recognition of its role as a universal factor and target in the protection of cells from genotoxic stress have opened new avenues for protecting skin against radiation-induced skin injuries (RISIs). A significant and rapid increase in CAV1 content in irradiated cells, reaching a maximum at 30–60 min after irradiation, coupled with internalization of epidermal growth factor receptors involved in the activation of homologous recombination and non-homologous end-joining repairing of double-strand breaks in affected cells, can protect the cells from irradiation to some degree. However, a higher level of protection can be achieved when the CAV1 content in the skin is increased before irradiation. Such an enhancement in the expression and translocation of CAV1 can be induced by the local application of thermo-mechanical stress with parameters inducing reinforcement of the actin cytoskeleton in treated cells. The application of very-high-frequency ultrasound waves with frequencies above 10 MHz or combined multi-frequency ultrasound waves can provide new means of protecting against RISIs during radiation therapy without reducing the radiosensitivity of cancer cells. Full article
(This article belongs to the Section Molecular Pathology, Diagnostics, and Therapeutics)
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10 pages, 1029 KB  
Article
Resolution Comparison of a Standoff Gel Pad Versus a Liquid Gel Barrier for Nasal Bone Fracture Sonography: A Standardized Crossover Study
by Dong Gyu Kim and Kyung Ah Lee
Diagnostics 2026, 16(1), 92; https://doi.org/10.3390/diagnostics16010092 - 26 Dec 2025
Viewed by 337
Abstract
Background: High-frequency ultrasonography (US) is increasingly used to guide closed reduction in nasal bone fractures, but near-field resolution over the curved nasal dorsum depends critically on the acoustic coupling medium. We aimed to determine whether a semi-solid standoff gel pad (PAD) provides [...] Read more.
Background: High-frequency ultrasonography (US) is increasingly used to guide closed reduction in nasal bone fractures, but near-field resolution over the curved nasal dorsum depends critically on the acoustic coupling medium. We aimed to determine whether a semi-solid standoff gel pad (PAD) provides superior image contrast and signal stability compared with a liquid gel barrier (LGB) during intraoperative nasal bone fracture sonography. Methods: In this prospective, single-center, within-subject crossover study, 30 adults with isolated nasal bone fractures underwent intraoperative high-frequency US of the nasal dorsum under two coupling conditions differing only by the medium used: a 7 mm hydrogel standoff pad (PAD) and a custom-made 7 mm liquid gel barrier (LGB). All scans were acquired on the same platform using fixed B-mode presets (10 MHz, 4.0 cm depth, single focal zone at the cortex). Rectangular regions of interest (ROIs) were placed on the cortical interface (bone ROI) and adjacent soft tissue (soft-tissue ROI) at matched depth. For each subject and condition, contrast-to-noise ratio (CNR) and two signal-to-noise ratios (SNR_bone, SNR_soft) were derived from ROI gray-level statistics and compared using paired t-tests. Results: The PAD yielded a significantly higher CNR at the cortical interface compared to the LGB (3.46 ± 0.17 vs. 2.50 ± 0.19; mean paired difference 0.96, 95% CI 0.88–1.04; p < 0.0001). SNR_bone was also higher with PAD (4.31 ± 0.35 vs. 3.63 ± 0.34; difference 0.68, 95% CI 0.52–0.83; p < 0.0001). Using the soft-tissue ROI as the noise reference (SNR_soft), PAD again outperformed LGB (7.64 ± 0.73 vs. 6.68 ± 0.78; difference 0.96, 95% CI 0.59–1.33; p = 0.000012). Conclusions: Compared with a liquid gel barrier of similar thickness, a semi-solid standoff gel pad provides higher near-field CNR and SNR at the nasal cortical interface under standardized intraoperative conditions. These quantitative differences support the use of a gel pad as a practical coupling medium for real-time ultrasound guidance during closed reduction in nasal bone fractures, although the impact on clinical outcomes remains to be determined. Full article
(This article belongs to the Special Issue Advances in Plastic Surgery: Diagnosis, Management and Prognosis)
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14 pages, 3659 KB  
Article
Laser Deflection Acoustic Field Quantification: A Non-Invasive Measurement Technique for Focused Ultrasound Field Characterization
by Yang Xu, Hongde Liu, Yaoan Ma, Xiaoxue Bai, Qiangwei Hu, Yunpiao Cai, Hui Zhang, Tao Huang, Mengmeng Liu, Jing Li, Mingyue Ding and Ming Yuchi
Bioengineering 2026, 13(1), 22; https://doi.org/10.3390/bioengineering13010022 - 26 Dec 2025
Viewed by 389
Abstract
Focused ultrasound (FU) technology is extensively employed in clinical applications such as tumor ablation, Parkinson’s disease treatment, and neuropathic pain management. The safety and efficacy of FU therapy critically depend on the accurate quantification of the acoustic field, particularly the high-pressure distribution in [...] Read more.
Focused ultrasound (FU) technology is extensively employed in clinical applications such as tumor ablation, Parkinson’s disease treatment, and neuropathic pain management. The safety and efficacy of FU therapy critically depend on the accurate quantification of the acoustic field, particularly the high-pressure distribution in focal region. To address the limitations of existing acoustic measurement techniques—including invasiveness, inability to measure high sound pressure, and system complexity—this study proposes a non-invasive method termed Laser Deflection Acoustic Field Quantification (LDAQ), based on the laser deflection principle. An experimental system was constructed utilizing the acousto-optic deflection effect, which incorporates precision displacement control, rotational scanning, and synchronized triggering. Through tomographic scanning, laser deflection images of the acoustic field were acquired at multiple orientations. An inversion algorithm using Radon transforms was proposed to reconstruct the refractive index gradient distributions from the variations of light intensity and spot displacement. An adaptive weighted fusion strategy was then employed to map these optical signals to the sound pressure field. To validate the LDAQ technique, an acoustic field generated by an FU transducer operating at 0.84 MHz was measured. The reconstructed results were compared with both hydrophone measurements and numerical simulations. The findings demonstrated high consistency among all three results within the focal zone. Full-field analysis yielded a root mean square error (RMSE) of 0.1102 between LDAQ and simulation, and an RMSE of 0.1422 between LDAQ and hydrophone measurements. These results confirm that LDAQ enables non-invasive and high-precision quantification of megapascal-level focused acoustic fields, offering a reliable methodology for acoustic field characterization to support FU treatment optimization and device standardization. Full article
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12 pages, 3355 KB  
Article
Fat Content Quantification with US Attenuation Coefficient: Phantom Correlation with MRI Proton Density Fat Fraction
by Rongying Chen, Genglin Zhang, Jie Zeng, Yin Zhang, Haixin Chen, Jie Ren, Xin Chen, Manli Wu, Haoming Lin and Ting Zhang
Diagnostics 2026, 16(1), 80; https://doi.org/10.3390/diagnostics16010080 - 25 Dec 2025
Viewed by 349
Abstract
Objective: The aim of this study was to evaluate the consistency and reproducibility of attenuation coefficient (AC) measurements using different commercial ultrasound (US) across via a phantom experiment to investigate the relationship between the AC and MRI-derived proton density fat fraction (MRI-PDFF) values [...] Read more.
Objective: The aim of this study was to evaluate the consistency and reproducibility of attenuation coefficient (AC) measurements using different commercial ultrasound (US) across via a phantom experiment to investigate the relationship between the AC and MRI-derived proton density fat fraction (MRI-PDFF) values and the conversion equation. Methods: Twelve phantoms containing varying fat proportions (0–100%) were constructed. Phantom ACs were estimated via three US attenuation systems, including attenuation imaging (ATI), ultrasound attenuation analysis (USAT), and the US-guided attenuation parameter (UGAP), along with MRI-PDFF. Agreement among the AC values from the three ultrasonic attenuation systems was evaluated. Linear correlation analysis was used to explore the ACs, fat concentrations of the phantom, and MRI-PDFF measurements, from which a linear conversion formula between the ultrasonic attenuation parameters and the MRI-PDFF was derived. Results: MRI-PDFF and phantom fat concentration measurements appeared with a strong linear correlation (R2 = 0.996, p < 0.001). For the three US attenuation parameters, both inter-operator and intra-operator intraclass correlation coefficients (ICCs) ranged from 0.990 to 0.995 and 0.989 to 0.995, respectively. Bland–Altman analysis revealed no significant differences between the above three (all p > 0.05). Significant linear relationships were demonstrated between ultrasound attenuation parameters and phantom fat concentration (r = 0.938–0.986; all p < 0.001), as well as between ultrasound attenuation parameters and MRI-PDFF values (r = 0.922–0.982; all p < 0.001). A conversion formula (fat proportions ≤ 50%) was derived: US (dB/cm/MHz) = 0.501 + 0.012 MRI-PDFF (%). Conclusions: AC across different commercial ultrasound devices demonstrated significant diagnostic value in fat concentrations that appeared good consistency in measuring phantom fat concentration both between and within groups. The linear relationship between AC and MRI-PDFF enables the application of a conversion formula. Full article
(This article belongs to the Section Medical Imaging and Theranostics)
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9 pages, 1208 KB  
Article
Augmentation and Increased Projection of Buttocks with a Sofiderm® Cross-Linked Hyaluronic Acid Filler: A Deep and Superficial Implantation Technique
by Giordano Vespasiani, Giuseppina Ricci, Simone Michelini, Federica Trovato, Antonio Di Guardo, Lorenzo Califano, Laura Nesticò, Stefania Guida and Giovanni Pellacani
Surgeries 2026, 7(1), 3; https://doi.org/10.3390/surgeries7010003 - 25 Dec 2025
Viewed by 456
Abstract
Background: In recent years, hyaluronic acid filler for the restoration and increase in buttock volume has been a procedure that has seen increasing success, both thanks to the considerable increase in patient demand and thanks to the improvement of implant techniques and device [...] Read more.
Background: In recent years, hyaluronic acid filler for the restoration and increase in buttock volume has been a procedure that has seen increasing success, both thanks to the considerable increase in patient demand and thanks to the improvement of implant techniques and device manufacturing technologies. Aims: The primary objective of this pilot study is to demonstrate the validity of an innovative filler inoculation technique in the upper quadrants of the buttocks and in the supra- and subfascial area in order to optically restore the appearance of a pleasant lumbar lordosis and to lift the upper quadrants with reduction in the infragluteal fold. The secondary objective is to evaluate the safety and efficacy of Sofiderm SubSkin® (Techderm Biological Products Co., Ltd., Hangzhou, China), a highly versatile hyaluronic acid filler, formulated with a rheology suitable for use on the face and body. Patients/Methods: Five female subjects (50–63 years) were subjected to gluteal fillers in the supra- and subfascial areas; the correct positioning of the filler was investigated by means of a 20 Mhz ultrasound probe. Results: All patients obtained a significant improvement in the projection of the upper part of the buttocks. The implantation technique and the optimal rheological properties of the device brought about a natural and well-defined increase in volume, with a projection of the upper part of the buttocks and a consequent lifting of the lower parts and reduction in the length of the infragluteal fold. Conclusions: This study confirmed the efficacy and safety of the cross-linked hyaluronic acid Sofiderm Derm SubSkin® in increasing the projection of the upper part of the buttocks, using an innovative mixed implantation technique, in a sample of selected patients. Full article
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22 pages, 4064 KB  
Article
Effect of Dispersed Particle Concentration on Photoacoustic Flowmetry Using Low-Frequency Transducers
by Haruka Tsuboi, Taichi Kaizuka and Katsuaki Shirai
Metrology 2025, 5(4), 79; https://doi.org/10.3390/metrology5040079 - 18 Dec 2025
Viewed by 356
Abstract
Photoacoustic (PA) velocimetry offers a promising solution to the limitations of conventional techniques for measuring blood flow velocity. Given its moderate penetration depth and high spatial resolution, PA imaging is considered suitable for measuring low-velocity blood flow in capillaries located at moderate depths. [...] Read more.
Photoacoustic (PA) velocimetry offers a promising solution to the limitations of conventional techniques for measuring blood flow velocity. Given its moderate penetration depth and high spatial resolution, PA imaging is considered suitable for measuring low-velocity blood flow in capillaries located at moderate depths. High-resolution measurements based on PA signals from individual blood cells can be achieved using a high-frequency transducer. However, high-frequency signals attenuate rapidly within biological tissue, restricting the measurable depth. Consequently, low-frequency transducers are required for deeper measurements. To date, PA flow velocimetry employing low-frequency transducers remains insufficiently explored. In this study, we investigated the effect of the concentration of particles that mimic blood cells within vessels under low-concentration conditions. The performance of flow velocity measurement was evaluated using an ultrasonic transducer (UST) with a center frequency of 10 MHz. The volume fraction of particles in the solution was systematically varied, and the spatially averaged flow velocity was assessed using two different distinct analysis methods. One method employed a time-shift approach based on cross-correlation analysis. Flow velocity was estimated from PA signal redpairs generated by particles dispersed in the fluid, using consecutive pulsed laser irradiations at fixed time intervals. The other method employed a pulsed Doppler method in the frequency domain, widely applied in ultrasound Doppler measurements. In this method, flow velocity redwas estimated from the Doppler-shifted frequency between the transmitted and received signals of the UST. For the initial analysis, numerical simulations were performed, followed by experiments based on displacement measurements equivalent to velocity measurements. The target was a capillary tube filled with an aqueous solution containing particles at different concentration levels. The time–domain method tended to underestimate flow velocity as particle concentration increased, whereas the pulsed Doppler method yielded estimates consistent with theoretical values, demonstrating its potential for measurements at high concentrations. Full article
(This article belongs to the Special Issue Advancements in Optical Measurement Devices and Technologies)
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22 pages, 4171 KB  
Article
Evaluation of Subcutaneous and Intermuscular Adipose Tissues by Application of Pattern Recognition and Neural Networks to Ultrasonic Data: A Model Study
by Alexey Tatarinov, Aleksandrs Sisojevs, Vladislavs Agarkovs and Jegors Lukjanovs
Bioengineering 2025, 12(12), 1373; https://doi.org/10.3390/bioengineering12121373 - 17 Dec 2025
Viewed by 456
Abstract
Distinguishing subcutaneous adipose tissue (SAT) from intermuscular adipose tissue (IMAT) is clinically important because IMAT infiltration is strongly associated with age-related functional decline, sarcopenia, diabetes, cardiovascular disease, and obesity. Current assessments rely on MRI or CT, which are stationary, costly, and labor-intensive. Portable [...] Read more.
Distinguishing subcutaneous adipose tissue (SAT) from intermuscular adipose tissue (IMAT) is clinically important because IMAT infiltration is strongly associated with age-related functional decline, sarcopenia, diabetes, cardiovascular disease, and obesity. Current assessments rely on MRI or CT, which are stationary, costly, and labor-intensive. Portable ultrasound-based solutions could enable broader, proactive screening. This model study investigated the feasibility of differentially assessing SAT and IMAT using features extracted from propagating ultrasound signals. Twenty-five phantoms were constructed using gelatin as a muscle-mimicking matrix and oil as the SAT and IMAT compartments, arranged to provide gradual variations in fat fractions ranging from 0% to 50%. Ultrasound measurements were collected at 0.8 MHz and 2.2 MHz, and multiple evaluation criteria were computed, including ultrasound velocity and parameters derived from the signal intensity. Classification domains were then generated from intersecting decision rules associated with these criteria. In parallel, artificial neural networks (ANN/LSTM) were trained and tested on identical phantom subsets to evaluate data-driven classification performance. Both the rule-based and ANN/LSTM approaches achieved diagnostically meaningful separation of SAT and IMAT. The aim of this work was to perform an experimental proof-of-concept study on idealized tissue models to demonstrate that ultrasound measurements can reliably differentiate SAT and IMAT, supporting the development of future screening devices. Full article
(This article belongs to the Special Issue AI and Data Science in Bioengineering: Innovations and Applications)
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Ultrasound-Guided Lumbar Plexus Injection: A Cadaveric Validation
by Ondřej Naňka, Kamal Mezian, Ke-Vin Chang, Wei-Ting Wu, Vincenzo Ricci and Levent Özçakar
Diagnostics 2025, 15(23), 3017; https://doi.org/10.3390/diagnostics15233017 - 27 Nov 2025
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Abstract
Ultrasound (US) has gained increasing acceptance for evaluating the axial spine, including the lumbar region. While its accuracy for superficial structures such as facet joints and medial branches has been validated, evidence supporting its use for deeper targets, such as the lumbar plexus, [...] Read more.
Ultrasound (US) has gained increasing acceptance for evaluating the axial spine, including the lumbar region. While its accuracy for superficial structures such as facet joints and medial branches has been validated, evidence supporting its use for deeper targets, such as the lumbar plexus, remains limited. This cadaveric study aimed to assess the feasibility of US-guided lumbar plexus injection. A fresh-frozen female cadaver with a body mass index of 23 kg/m2, prepared using the “Fix-for-Life” technique, was utilized. Using a 2–5 MHz curved linear transducer (HS30; Samsung Medison, Seoul, Republic of Korea), injections were performed with an in-plane approach under continuous needle visualization. A 20-gauge, 7 cm spinal needle was used to deliver 5 mL of green dye targeting the L3 and L4 nerve roots. Dissection confirmed that L3 injection achieved dye spread to the extraforaminal region, whereas L4 injection demonstrated anterior dye distribution adjacent to the intervertebral foramen. The main limitations included the use of a single specimen and acoustic shadowing from articular processes, which impeded visualization of neural structures. This study demonstrates the feasibility of US-guided lumbar plexus injection and supports its potential application in clinical pain management, although further validation with larger sample sizes is warranted. Full article
(This article belongs to the Section Medical Imaging and Theranostics)
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