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Introduction: Remotely-sensed acoustic backscatter is an indispensable tool for seabed mapping, among other disciplines. Almost a decade after the GeoHab Backscatter Working Group published its guidelines and recommendations report, new technologies, new challenges and new questions have emerged. Given the range of potential backscatter research avenues, it can be difficult to align research programs with the priorities of the community of practice. Prioritization of backscatter research topics is thus necessary to establish a roadmap for acoustic backscatter research efforts. Methods: We asked the international community working with acoustic backscatter to submit their priority research questions over a 5- to 10-year horizon. We analyzed and curated a total of 177 research questions from 73 contributors, and the resulting 104 questions were grouped into eight broad recurring themes: "Technologies", "Calibration", "Data acquisition and ground-truthing", "Data processing", "Post-processing, quality control, data handling, and curation", "Data analysis", "Data interpretation", and "Applications and end uses". A follow-up survey based on the final list of questions was distributed to characterize the community working with backscatter and to identify key research priorities. Results: A total of 120 responses originating from 23 countries were used for the analyses. Most respondents were researchers (68%), while others were technicians (25%) or department or program managers (11%), among other roles. Affiliations of respondents included academia (43%), governmental agencies (37%), and industry/private sector (18%). After scaling the responses, the most commonly selected theme was "Post-processing, quality control, data handling, and curation", followed by "Calibration" and "Data analysis". Respondents consistently ranked several research questions as priorities. The two questions that were identified as priorities by over 25% of respondents were "How can we move towards absolute calibration of different systems to allow interregional comparisons?", and "How can we quantify seafloor backscatter quality and develop standards similar to what exists with bathymetry?". Discussion: All eight themes are represented in the top 10 priority questions, underscoring the need for contributions to backscatter research from multiple perspectives to advance the field. The ranking of priority questions encourages collaboration within the community and will serve as a roadmap for backscatter research programs over the next decade. [ABSTRACT FROM AUTHOR]

Corneal densitometry (CD) uses the biological properties of the cornea to visualize the morphology of the cornea and determine the degree of corneal transparency. At present, it is an emerging metric that has shown promise in various clinical diagnosis and evaluation of eye diseases and surgeries. We introduce the different methodologies used to measure CD. Furthermore, we systematically categorize the diagnostic value of CD into high, medium, and low levels based on its clinical significance. By analyzing a wide range of conditions, including keratoconus, postrefractive surgery changes, and other corneal pathologies, we assess the utility of CD in each context. We also discuss the potential implications of these classifications for disease monitoring and prognosis evaluation. Our review underscores the importance of integrating CD assessments into routine clinical practice to enhance the accuracy and effectiveness of diagnostic processes for corneal disorders. [ABSTRACT FROM AUTHOR]

Purpose: This retrospective study was conducted to investigate the diagnostic accuracy of ultrasound-derived fat fraction (UDFF) for grading hepatic steatosis using liver histology as the reference standard. Methods: Seventy-three patients with liver disease were assessed using UDFF and liver biopsy. Pearson's test and the Bland–Altman plot were used to assess the correlation between UDFF and histological fat content in liver sections. The UDFF cutoff values for histologically proven steatosis grades were determined using the area under the receiver operating characteristic curve (AUROC). Results: The median age of the patients was 66 (interquartile range 54–74) years, and 33 (45%) were females. The UDFF values showed a stepwise increase with increasing steatosis grade (p <.001) and were strongly correlated with the histological fat content (r =.7736, p <.001). The Bland–Altman plot revealed a mean bias of 2.384% (95% limit of agreement, − 6.582 to 11.351%) between them. Univariate regression analysis revealed no significant predictors of divergence. The AUROCs for distinguishing steatosis grades of ≥ 1, ≥2, and 3 were 0.956 (95% confidence interval [CI], 0.910–1.00), 0.926 (95% CI, 0.860–0.993), and 0.971 (95% CI, 0.929–1.000), respectively. The UDFF cutoff value of > 6% had a sensitivity and specificity of 94.8% and 82.3%, respectively, for diagnosing steatosis grade ≥ 1. There was no association between UDFF and the fibrosis stage. Conclusion: UDFF shows strong agreement with the histological fat content and excellent diagnostic accuracy for grading steatosis. UDFF is a promising tool for detecting and quantifying hepatic steatosis in clinical practice. [ABSTRACT FROM AUTHOR]

IntroductionRemotely-sensed acoustic backscatter is an indispensable tool for seabed mapping, among other disciplines. Almost a decade after the GeoHab Backscatter Working Group published its guidelines and recommendations report, new technologies, new challenges and new questions have emerged. Given the range of potential backscatter research avenues, it can be difficult to align research programs with the priorities of the community of practice. Prioritization of backscatter research topics is thus necessary to establish a roadmap for acoustic backscatter research efforts.MethodsWe asked the international community working with acoustic backscatter to submit their priority research questions over a 5- to 10-year horizon. We analyzed and curated a total of 177 research questions from 73 contributors, and the resulting 104 questions were grouped into eight broad recurring themes: “Technologies”, “Calibration”, “Data acquisition and ground-truthing”, “Data processing”, “Post-processing, quality control, data handling, and curation”, “Data analysis”, “Data interpretation”, and “Applications and end uses”. A follow-up survey based on the final list of questions was distributed to characterize the community working with backscatter and to identify key research priorities.ResultsA total of 120 responses originating from 23 countries were used for the analyses. Most respondents were researchers (68%), while others were technicians (25%) or department or program managers (11%), among other roles. Affiliations of respondents included academia (43%), governmental agencies (37%), and industry/private sector (18%). After scaling the responses, the most commonly selected theme was “Post-processing, quality control, data handling, and curation”, followed by “Calibration” and “Data analysis”. Respondents consistently ranked several research questions as priorities. The two questions that were identified as priorities by over 25% of respondents were “How can we move towards absolute calibration of different systems to allow interregional comparisons?”, and “How can we quantify seafloor backscatter quality and develop standards similar to what exists with bathymetry?”.DiscussionAll eight themes are represented in the top 10 priority questions, underscoring the need for contributions to backscatter research from multiple perspectives to advance the field. The ranking of priority questions encourages collaboration within the community and will serve as a roadmap for backscatter research programs over the next decade.

Particle size is a critical parameter for calculating the solid phase holdup and settling velocity in pipeline suspensions. However, accurately determining solid holdup remains challenging due to the complexity and variability in multiphase suspensions, especially when the physical size of the suspended particles is unknown. We have developed a novel multi-frequency particle size measurement system that utilizes acoustic backscatter techniques. Furthermore, we propose a new particle size inversion algorithm that integrates Empirical Mode Decomposition (EMD) and the Pearson Correlation Coefficient (PCC) with traditional algorithms. By applying EMD, the raw echo signal is decomposed into Intrinsic Mode Functions (IMFs), allowing for effective noise separation. The PCC is subsequently used to determine correlations between IMFs, improving signal reconstruction accuracy. The minimum concentration gradient continuous inversion algorithm we proposed effectively solves the multi-solution problem of the energy ratio algorithm through the minimum concentration difference method. This algorithm innovatively employs sliding window technology to accurately assess the optimal particle size range of suspended particles in the ultrasonic measurement path. Experimental results indicate that the Mean Absolute Percentage Error (MAPE) for particle diameters in the ranges of 280–350 μm, 450–550 μm, and 760–880 μm are 7.16 %, 3.87 %, and 4.66 %, respectively. This method provides a precise and efficient solution for measuring particle size distribution in underground pipelines, with broad applications in pipeline maintenance, sediment transport modeling, and drainage system design. • A multi-frequency acoustic system was developed for real-time assessment of particle size in urban rainwater pipelines. • EMD and PCC techniques were applied to decouple flow noise, significantly improving echo signal reconstruction accuracy. • A novel algorithm was proposed for particle size assessment in low-concentration suspensions, achieving MAPE below 10%. • The new algorithm reduces particle size inversion time by 67% compared to traditional methods without compromising accuracy. • Ultrasonic measurement reduces MAPE by 13% compared to image recognition techniques in particle size assessment. [ABSTRACT FROM AUTHOR]