In unfocused ultrasound imaging, a delay-and-sum algorithm is commonly used to reconstruct one image per emission. When multiple emissions are performed, individual images can be combined by coherent compounding to improve image quality. Alternative methods based on tomographic inverse problems have been recently introduced and prove a superior image quality. However, the high dimensionality of the operators involved in such tomographic problems –especially in the case of multiple emissions– leads to prohibitive computation times and memory requirements, preventing their use in practice. We propose to use an angular framework in which plane waves are considered both in emission and reception. In this new framework, we show that the delay-an-sum and the compounding operators are commutative. Using this property, we formulate a low-dimensional tomographic inverse problem and describe a matrix-free method able to reconstruct high-quality images with a computation time independent of the number of emissions.
{"title":"Inverse Problems With Multiple Plane Waves: The Angular Simplification","authors":"Baptiste Heriard-Dubreuil;Adrien Besson;Claude Cohen-Bacrie;Jean-Philippe Thiran","doi":"10.1109/OJUFFC.2025.3551318","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3551318","url":null,"abstract":"In unfocused ultrasound imaging, a delay-and-sum algorithm is commonly used to reconstruct one image per emission. When multiple emissions are performed, individual images can be combined by coherent compounding to improve image quality. Alternative methods based on tomographic inverse problems have been recently introduced and prove a superior image quality. However, the high dimensionality of the operators involved in such tomographic problems –especially in the case of multiple emissions– leads to prohibitive computation times and memory requirements, preventing their use in practice. We propose to use an angular framework in which plane waves are considered both in emission and reception. In this new framework, we show that the delay-an-sum and the compounding operators are commutative. Using this property, we formulate a low-dimensional tomographic inverse problem and describe a matrix-free method able to reconstruct high-quality images with a computation time independent of the number of emissions.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"33-37"},"PeriodicalIF":0.0,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10926886","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For ring-array ultrasound tomography, two-dimensional frequency-domain full waveform inversion is the clinical gold standard for high-resolution imaging of the breast. While yielding high-resolution images in the plane of the ring-array, the resulting slice-wise approach yields lower resolution out of plane when used to reconstruct the full volume. Instead, this work proposes a fully three-dimensional full-waveform inversion based on a multi-row ring-array transducer to improve out-of-plane resolution, while using cylindrical-wave transmissions to minimize acquisition and reconstruction time. For each numerical breast phantom tested, the root-mean-square error of three-dimensional full-waveform inversion is less than that of two-dimensional slice-wise full-waveform inversion by 6.3-13.7 m/s.
{"title":"3D Frequency-Domain Full Waveform Inversion for Whole-Breast Imaging With a Multi-Row Ring Array","authors":"Rehman Ali;Gaofei Jin;Melanie Singh;Trevor Mitcham;Nebojsa Duric","doi":"10.1109/OJUFFC.2025.3570253","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3570253","url":null,"abstract":"For ring-array ultrasound tomography, two-dimensional frequency-domain full waveform inversion is the clinical gold standard for high-resolution imaging of the breast. While yielding high-resolution images in the plane of the ring-array, the resulting slice-wise approach yields lower resolution out of plane when used to reconstruct the full volume. Instead, this work proposes a fully three-dimensional full-waveform inversion based on a multi-row ring-array transducer to improve out-of-plane resolution, while using cylindrical-wave transmissions to minimize acquisition and reconstruction time. For each numerical breast phantom tested, the root-mean-square error of three-dimensional full-waveform inversion is less than that of two-dimensional slice-wise full-waveform inversion by 6.3-13.7 m/s.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"77-81"},"PeriodicalIF":0.0,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11003981","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144108320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-10DOI: 10.1109/OJUFFC.2025.3550096
Chaoran Han;Sven Peter Näsholm;Andreas Austeng;Håvard Kjellmo Arnestad
Null subtraction imaging (NSI) is a non-linear beamformer that aims to improve the spatial resolution of ultrasound images. NSI incoherently combines three delay-and-sum (DAS) outputs from the same RF data using three related apodizations on receive. NSI has been advocated to have many advantages in different domains such as B-mode imaging, plane wave imaging, power Doppler imaging, and for large-pitch arrays. However, despite its increasing popularity, an explicit relationship between NSI resolution (interpreted as the mainlobe width) and various parameters (such as the DC offset value c, array aperture, and wavelength) is not known, making system design and intuitive reasoning about the method difficult. Therefore, in the current work, we derive the theoretical NSI array pattern and give an approximate expression for the −6dB mainlobe width. Our derivation is based on a Taylor series-expansion of the analytical NSI array pattern, which is valid over the mainlobe region for the range of c values typically seen in the literature. The results show that the NSI mainlobe width is proportional to $c lambda /D$ , which is the DC offset value multiplied by the wavelength and divided by the aperture size, and therefore has a similar wavelengh and aperture dependency as the classical DAS mainlobe. The work is validated numerically, also showing that the NSI mainlobe width approaches the DAS mainlobe width as c approaches infinity.
空减成像（NSI）是一种非线性波束成形器，旨在提高超声波图像的空间分辨率。NSI 在接收时使用三个相关的调焦，将来自同一射频数据的三个延迟和（DAS）输出不连贯地组合在一起。NSI 被认为在不同领域（如 B 型成像、平面波成像、功率多普勒成像和大间距阵列）具有许多优势。然而，尽管 NSI 越来越受欢迎，但它的分辨率（解释为主波束宽度）与各种参数（如直流偏移值 c、阵列孔径和波长）之间的明确关系并不为人所知，这使得系统设计和有关该方法的直观推理变得困难。因此，在目前的工作中，我们推导出了理论上的 NSI 阵列模式，并给出了 -6dB 主波束宽度的近似表达式。我们的推导基于对解析 NSI 阵列模式的泰勒级数展开，它在文献中常见的 c 值范围内的主波束区域有效。结果表明，NSI 主波束宽度与 $c lambda /D$ 成正比，即直流偏移值乘以波长再除以孔径大小，因此与经典 DAS 主波束具有类似的波长和孔径依赖性。这项工作得到了数值验证，还表明当 c 接近无穷大时，NSI 主波束宽度接近 DAS 主波束宽度。
{"title":"Taylor-Series-Based Derivation of the Resolution of Null Subtraction Imaging for a Uniform Linear Array","authors":"Chaoran Han;Sven Peter Näsholm;Andreas Austeng;Håvard Kjellmo Arnestad","doi":"10.1109/OJUFFC.2025.3550096","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3550096","url":null,"abstract":"Null subtraction imaging (NSI) is a non-linear beamformer that aims to improve the spatial resolution of ultrasound images. NSI incoherently combines three delay-and-sum (DAS) outputs from the same RF data using three related apodizations on receive. NSI has been advocated to have many advantages in different domains such as B-mode imaging, plane wave imaging, power Doppler imaging, and for large-pitch arrays. However, despite its increasing popularity, an explicit relationship between NSI resolution (interpreted as the mainlobe width) and various parameters (such as the DC offset value c, array aperture, and wavelength) is not known, making system design and intuitive reasoning about the method difficult. Therefore, in the current work, we derive the theoretical NSI array pattern and give an approximate expression for the −6dB mainlobe width. Our derivation is based on a Taylor series-expansion of the analytical NSI array pattern, which is valid over the mainlobe region for the range of c values typically seen in the literature. The results show that the NSI mainlobe width is proportional to <inline-formula> <tex-math>$c lambda /D$ </tex-math></inline-formula>, which is the DC offset value multiplied by the wavelength and divided by the aperture size, and therefore has a similar wavelengh and aperture dependency as the classical DAS mainlobe. The work is validated numerically, also showing that the NSI mainlobe width approaches the DAS mainlobe width as c approaches infinity.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"19-22"},"PeriodicalIF":0.0,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10918915","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143667224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-05DOI: 10.1109/OJUFFC.2025.3566928
Tina Gabriel;Omid Chaghaneh;Julian Kober;Tönnis Trittler;Edgar M. G. Dorausch;Cornelius Kühnöl;Jakob Schäfer;Richard Nauber;Paul-Henry Koop;Carolin Schneider;Jochen Hampe;Gerhard Fettweis;Moritz Herzog
Handheld ultrasound (H-US) offers a widely accessible and cost-effective option for future medicine. Quantitative US methods, such as H-Scan, could broaden its impact by leveraging the enormous potential of radiofrequency (RF) ultrasound data. H-US derived steatosis and fibrosis assessments would reduce the need for expensive FibroScan® devices, especially supporting low-resource areas. By filtering for lower (GH2) and higher (GH8) frequencies, the method allows for differentiation of scatter sizes related to varying degrees of steatosis, which is crucial for early detection of metabolic-associated steatotic liver disease (MASLD). Considering a substantial and various patient cohort of 468 patients, reducing potential selection bias inherent in smaller study cohorts, this study aims to investigate whether H-Scan analysis of RF-data captured with inexpensive H-US yields comparable results to those seen in previous studies. A strong correlation (r=0.852, p<0.0001)> $alpha $ . No significant correlation was observed between H-Scan and the degree of liver fibrosis, suggesting that the current H-Scan alone might not be suitable for this application. Further research is needed to test and refine the methodology, especially regarding individual attenuation correction.
手持式超声（H-US）为未来医学提供了一种广泛可及且具有成本效益的选择。定量的美国方法，如H-Scan，可以通过利用射频（RF）超声数据的巨大潜力来扩大其影响。H-US衍生的脂肪变性和纤维化评估将减少对昂贵的FibroScan®设备的需求，特别是支持低资源地区。通过过滤较低（GH2）和较高（GH8）频率，该方法可以区分与不同程度脂肪变性相关的散点大小，这对于代谢相关脂肪变性肝病（MASLD）的早期检测至关重要。考虑到468名患者的大量和不同的患者队列，减少了小型研究队列中固有的潜在选择偏倚，本研究旨在调查用廉价H-US捕获的射频数据的H-Scan分析是否产生与先前研究中看到的结果相当的结果。强相关性(r=0.852, p $alpha $。H-Scan与肝纤维化程度无明显相关性，提示目前单独的H-Scan可能不适合此应用。需要进一步的研究来测试和完善这种方法，特别是在个别衰减校正方面。
{"title":"Enhancing Liver Steatosis Classification: H-Scan Analysis of Handheld Ultrasound Data","authors":"Tina Gabriel;Omid Chaghaneh;Julian Kober;Tönnis Trittler;Edgar M. G. Dorausch;Cornelius Kühnöl;Jakob Schäfer;Richard Nauber;Paul-Henry Koop;Carolin Schneider;Jochen Hampe;Gerhard Fettweis;Moritz Herzog","doi":"10.1109/OJUFFC.2025.3566928","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3566928","url":null,"abstract":"Handheld ultrasound (H-US) offers a widely accessible and cost-effective option for future medicine. Quantitative US methods, such as H-Scan, could broaden its impact by leveraging the enormous potential of radiofrequency (RF) ultrasound data. H-US derived steatosis and fibrosis assessments would reduce the need for expensive FibroScan® devices, especially supporting low-resource areas. By filtering for lower (GH2) and higher (GH8) frequencies, the method allows for differentiation of scatter sizes related to varying degrees of steatosis, which is crucial for early detection of metabolic-associated steatotic liver disease (MASLD). Considering a substantial and various patient cohort of 468 patients, reducing potential selection bias inherent in smaller study cohorts, this study aims to investigate whether H-Scan analysis of RF-data captured with inexpensive H-US yields comparable results to those seen in previous studies. A strong correlation (r=0.852, p<0.0001)> <tex-math>$alpha $ </tex-math></inline-formula>. No significant correlation was observed between H-Scan and the degree of liver fibrosis, suggesting that the current H-Scan alone might not be suitable for this application. Further research is needed to test and refine the methodology, especially regarding individual attenuation correction.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"62-66"},"PeriodicalIF":0.0,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10985905","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144072927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conventional optical lenses only have one focal point. Whereas compound lens systems with multiple lenses and mechanical actuators are used in modules to focus on near and far objects. Camera modules with these systems tend to be bulky and have a slow time response. Electrically-controllable varifocal lenses will accelerate the development of compact photographic devices with high-speed responses. Here, we discuss an ultrasound varifocal liquid crystal (LC) lens that consists of an LC layer between two glass discs and an ultrasound transducer. The orientation of nematic LC molecules could be controlled by acoustic radiation forces, and the lens could change the refractive index distribution and its focal length by ultrasound vibration by utilizing the high LC liquidity and optical anisotropy. The effects of input waveforms on the optical characteristics of the ultrasonic LC lens were investigated in an industrial setting. We applied sinusoidal and square waves at the resonant frequency of the lenses to assess the impact on the optical characteristics. Those characteristics were largely similar. However, slight differences were observed in the vibrational distributions on the lens substrate, indicating that the lens could be controlled by a square-wave drive.
{"title":"Square-Wave Driven Ultrasonic Liquid Crystal Optical Lenses","authors":"Ryoya Mizuno;Yuma Kuroda;Akira Emoto;Mami Matsukawa;Daisuke Koyama","doi":"10.1109/OJUFFC.2025.3566354","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3566354","url":null,"abstract":"Conventional optical lenses only have one focal point. Whereas compound lens systems with multiple lenses and mechanical actuators are used in modules to focus on near and far objects. Camera modules with these systems tend to be bulky and have a slow time response. Electrically-controllable varifocal lenses will accelerate the development of compact photographic devices with high-speed responses. Here, we discuss an ultrasound varifocal liquid crystal (LC) lens that consists of an LC layer between two glass discs and an ultrasound transducer. The orientation of nematic LC molecules could be controlled by acoustic radiation forces, and the lens could change the refractive index distribution and its focal length by ultrasound vibration by utilizing the high LC liquidity and optical anisotropy. The effects of input waveforms on the optical characteristics of the ultrasonic LC lens were investigated in an industrial setting. We applied sinusoidal and square waves at the resonant frequency of the lenses to assess the impact on the optical characteristics. Those characteristics were largely similar. However, slight differences were observed in the vibrational distributions on the lens substrate, indicating that the lens could be controlled by a square-wave drive.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"53-57"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10981748","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143943912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-25DOI: 10.1109/OJUFFC.2025.3545600
Chung-Shiang Mei;Wei-Hsiang Shen;Meng-Lin Li
To address the inherent complexity associated with fabricating fully-sampled (FS) 2-D arrays, row-column-addressed (RCA) arrays offer a promising alternative by significantly reducing the number of active elements. However, RCA arrays are limited by reduced image quality, as they only allow one-way focusing along both the x- and y-axes. This study introduces a post-filtering scheme that leverages a retrospective filtering method combined with filter-derived coherence-index (FCI) weighting to enhance RCA focusing quality, aiming to emulate the performance of FS arrays. Preliminary simulations were conducted to assess the efficacy of this approach, including point spread function (PSF) analysis and anechoic vessel phantom imaging. In the PSF analysis, our method achieved a 14.63-dB reduction in the sidelobe level, with improvements of 11.3% and 14.29% observed in the -6 dB and -20 dB full-width at half-maximum (FWHM), respectively. For anechoic vessel phantom imaging, the proposed scheme demonstrated substantial gains, with a 15.77 dB enhancement in contrast ratio (CR), a 1.615 increase in contrast-to-noise ratio (CNR), and a 27.03% improvement in generalized contrast-to-noise ratio (gCNR).
{"title":"Enhanced Row–Column-Addressed Array Imaging With Retrospective Filtering","authors":"Chung-Shiang Mei;Wei-Hsiang Shen;Meng-Lin Li","doi":"10.1109/OJUFFC.2025.3545600","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3545600","url":null,"abstract":"To address the inherent complexity associated with fabricating fully-sampled (FS) 2-D arrays, row-column-addressed (RCA) arrays offer a promising alternative by significantly reducing the number of active elements. However, RCA arrays are limited by reduced image quality, as they only allow one-way focusing along both the x- and y-axes. This study introduces a post-filtering scheme that leverages a retrospective filtering method combined with filter-derived coherence-index (FCI) weighting to enhance RCA focusing quality, aiming to emulate the performance of FS arrays. Preliminary simulations were conducted to assess the efficacy of this approach, including point spread function (PSF) analysis and anechoic vessel phantom imaging. In the PSF analysis, our method achieved a 14.63-dB reduction in the sidelobe level, with improvements of 11.3% and 14.29% observed in the -6 dB and -20 dB full-width at half-maximum (FWHM), respectively. For anechoic vessel phantom imaging, the proposed scheme demonstrated substantial gains, with a 15.77 dB enhancement in contrast ratio (CR), a 1.615 increase in contrast-to-noise ratio (CNR), and a 27.03% improvement in generalized contrast-to-noise ratio (gCNR).","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"15-18"},"PeriodicalIF":0.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10902463","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-11DOI: 10.1109/OJUFFC.2025.3541156
Kunfeng Xie;Liang Hu;Jianping Chen;Guiling Wu
In this letter, we proposed a point-to-multipoint fiber-optic time transfer scheme over a star-shaped fiber network based on bidirectional frequency division multiplexing without requiring link calibration. The time signals at the local station and remote stations are encoded into time-varying signals within in different spectral passbands, respectively. The optical carriers with the same wavelength are employed to transfer the two time-varying signals in both directions over a single fiber. The backscattering noises from fiber links can be effectively suppressed by simply electrical filtering due to the non-overlapping on spectrum between the forward and backward time-varying signals. The local station broadcasts the time signal of the reference clock to all remote stations based on space division multiplexing to support point-to-multipoint fiber-optic time transfer. The proposed scheme is demonstrated over a star-shaped fiber network with two remote stations. The results show that the measured mean clock difference can be less than -1.03 ps and 4.99 ps without link calibration, respectively. The measured time stability in terms of time deviation is better than 19.93 ps@1s, 0.50 ps@1000s and 25.35 ps@1s, 0.65 ps@1000s.
{"title":"Multiple-Node Time Transfer Over Star Fiber Network Without Requiring Link Calibration","authors":"Kunfeng Xie;Liang Hu;Jianping Chen;Guiling Wu","doi":"10.1109/OJUFFC.2025.3541156","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3541156","url":null,"abstract":"In this letter, we proposed a point-to-multipoint fiber-optic time transfer scheme over a star-shaped fiber network based on bidirectional frequency division multiplexing without requiring link calibration. The time signals at the local station and remote stations are encoded into time-varying signals within in different spectral passbands, respectively. The optical carriers with the same wavelength are employed to transfer the two time-varying signals in both directions over a single fiber. The backscattering noises from fiber links can be effectively suppressed by simply electrical filtering due to the non-overlapping on spectrum between the forward and backward time-varying signals. The local station broadcasts the time signal of the reference clock to all remote stations based on space division multiplexing to support point-to-multipoint fiber-optic time transfer. The proposed scheme is demonstrated over a star-shaped fiber network with two remote stations. The results show that the measured mean clock difference can be less than -1.03 ps and 4.99 ps without link calibration, respectively. The measured time stability in terms of time deviation is better than 19.93 ps@1s, 0.50 ps@1000s and 25.35 ps@1s, 0.65 ps@1000s.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"11-14"},"PeriodicalIF":0.0,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10879779","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143489203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Most clinical studies use a 2D parasternal long-axis view to measure natural shear waves after valve closure for myocardial stiffness assessment. However, its 3D wave propagation direction and its alignment with the 2D imaging plane are not well understood. Previous 3D research has mainly focused on wave propagation from an apical view, primarily tracking the longitudinal component of wave motion instead of the transverse component observed in the parasternal view. Therefore, this work aims to bridge this gap by using 3D high-frame-rate imaging in the parasternal view in 6 healthy volunteers (~750 volumes/s), and compared its results to 2D measurements (~1000 frames/s). We found a more complex wave propagation pattern after mitral valve closure encompassing two wave excitation sources, whereas the wave propagation after aortic valve closure clearly originated near the left ventricular outflow tract. The extent of the wave excitation region varied across volunteers. For the septal wall – tracked in 2D shear wave imaging, the overall wave propagation was from base to apex, which is theoretically in line with the 2D imaging plane orientation. However, wave speed estimations were lower for 3D measurements than for 2D (-0.7 m/s for mitral valve and -0.5 m/s for AVC, on average), potentially due to misalignment of the 2D imaging plane with the longitudinal direction of the heart.
{"title":"3D High-Frame-Rate Imaging of Natural Shear Waves in the Parasternal View of the Heart","authors":"Annette Caenen;Konstantina Papangelopoulou;Laurine Wouters;Ekaterina Seliverstova;Jens-Uwe Voigt;Jan D’Hooge","doi":"10.1109/OJUFFC.2025.3538819","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3538819","url":null,"abstract":"Most clinical studies use a 2D parasternal long-axis view to measure natural shear waves after valve closure for myocardial stiffness assessment. However, its 3D wave propagation direction and its alignment with the 2D imaging plane are not well understood. Previous 3D research has mainly focused on wave propagation from an apical view, primarily tracking the longitudinal component of wave motion instead of the transverse component observed in the parasternal view. Therefore, this work aims to bridge this gap by using 3D high-frame-rate imaging in the parasternal view in 6 healthy volunteers (~750 volumes/s), and compared its results to 2D measurements (~1000 frames/s). We found a more complex wave propagation pattern after mitral valve closure encompassing two wave excitation sources, whereas the wave propagation after aortic valve closure clearly originated near the left ventricular outflow tract. The extent of the wave excitation region varied across volunteers. For the septal wall – tracked in 2D shear wave imaging, the overall wave propagation was from base to apex, which is theoretically in line with the 2D imaging plane orientation. However, wave speed estimations were lower for 3D measurements than for 2D (-0.7 m/s for mitral valve and -0.5 m/s for AVC, on average), potentially due to misalignment of the 2D imaging plane with the longitudinal direction of the heart.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10870294","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-03DOI: 10.1109/OJUFFC.2025.3537962
Yohkoh Shimano;Motoshi Suzuki;Takahiko Yanagitani
A method for estimating intrinsic electromechanical coupling coefficient ${k}_{{33}}^{{2}}$ of piezoelectric thin films using piezoelectrically stiffened acoustic velocity ${V}^{text {D}}$ and unstiffened acoustic velocity ${V}^{text {E}}$ was proposed. ${V}^{text {D}}$ and ${V}^{text {E}}$ velocities of thin films in the sub-GHz range were estimated by ultrasonic reflectometry. Directly depositing a film specimen on the backside of the ultrasonic delay line eliminates the need for a coupler layer and avoids acoustic attenuation in the layer. The ${V}^{text {D}}$ velocity can be estimated from the phase differences of the echoes: before and after the film specimen is deposited. In contrast, ${V}^{text {E}}$ velocity can be estimated from the phase difference when the film specimen is under the open circuit and the short circuit. The intrinsic ${k}_{{33}}^{{2}}{}$ can be obtained from the relationship of ${k}_{{33}}^{{2}}~text {=}$ 1 – (${V}^{text {E}}$ /${V}^{text {D}})^{{2}}$ . For the Sc0.4Al0.6N thin film specimen, ${k}_{{33}}^{{2}}$ was determined to be 11.6% from ${V}^{text {D}}$ and ${V}^{text {E}}$ of 8400 m/s and 7900 m/s, respectively. For the ZnO thin film specimen, ${k}_{{33}}^{{2}}$ was estimated to be 4.7% from ${V}^{text {D}}$ and ${V}^{text {E}}$ of 6250 m/s and 6100 m/s, respectively. These values are in good agreement with previously reported results.
{"title":"k²₃₃Estimation of Thin Films via Piezoelectric Stiffening Using Ultrasonic Reflectometry","authors":"Yohkoh Shimano;Motoshi Suzuki;Takahiko Yanagitani","doi":"10.1109/OJUFFC.2025.3537962","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3537962","url":null,"abstract":"A method for estimating intrinsic electromechanical coupling coefficient <inline-formula> <tex-math>${k}_{{33}}^{{2}}$ </tex-math></inline-formula> of piezoelectric thin films using piezoelectrically stiffened acoustic velocity <inline-formula> <tex-math>${V}^{text {D}}$ </tex-math></inline-formula> and unstiffened acoustic velocity <inline-formula> <tex-math>${V}^{text {E}}$ </tex-math></inline-formula> was proposed. <inline-formula> <tex-math>${V}^{text {D}}$ </tex-math></inline-formula> and <inline-formula> <tex-math>${V}^{text {E}}$ </tex-math></inline-formula> velocities of thin films in the sub-GHz range were estimated by ultrasonic reflectometry. Directly depositing a film specimen on the backside of the ultrasonic delay line eliminates the need for a coupler layer and avoids acoustic attenuation in the layer. The <inline-formula> <tex-math>${V}^{text {D}}$ </tex-math></inline-formula> velocity can be estimated from the phase differences of the echoes: before and after the film specimen is deposited. In contrast, <inline-formula> <tex-math>${V}^{text {E}}$ </tex-math></inline-formula> velocity can be estimated from the phase difference when the film specimen is under the open circuit and the short circuit. The intrinsic <inline-formula> <tex-math>${k}_{{33}}^{{2}}{}$ </tex-math></inline-formula> can be obtained from the relationship of <inline-formula> <tex-math>${k}_{{33}}^{{2}}~text {=}$ </tex-math></inline-formula> 1 – (<inline-formula> <tex-math>${V}^{text {E}}$ </tex-math></inline-formula>/<inline-formula> <tex-math>${V}^{text {D}})^{{2}}$ </tex-math></inline-formula>. For the Sc0.4Al0.6N thin film specimen, <inline-formula> <tex-math>${k}_{{33}}^{{2}}$ </tex-math></inline-formula> was determined to be 11.6% from <inline-formula> <tex-math>${V}^{text {D}}$ </tex-math></inline-formula> and <inline-formula> <tex-math>${V}^{text {E}}$ </tex-math></inline-formula> of 8400 m/s and 7900 m/s, respectively. For the ZnO thin film specimen, <inline-formula> <tex-math>${k}_{{33}}^{{2}}$ </tex-math></inline-formula> was estimated to be 4.7% from <inline-formula> <tex-math>${V}^{text {D}}$ </tex-math></inline-formula> and <inline-formula> <tex-math>${V}^{text {E}}$ </tex-math></inline-formula> of 6250 m/s and 6100 m/s, respectively. These values are in good agreement with previously reported results.","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"5 ","pages":"6-10"},"PeriodicalIF":0.0,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10869444","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143446233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-31DOI: 10.1109/OJUFFC.2025.3537476
{"title":"2024 Index IEEE Open Journal of Ultrasonics, Ferroelectrics, and Frequency Control Vol. 4","authors":"","doi":"10.1109/OJUFFC.2025.3537476","DOIUrl":"https://doi.org/10.1109/OJUFFC.2025.3537476","url":null,"abstract":"","PeriodicalId":73301,"journal":{"name":"IEEE open journal of ultrasonics, ferroelectrics, and frequency control","volume":"4 ","pages":"247-254"},"PeriodicalIF":0.0,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10864476","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143106221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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