Ultrasonic Imaging最新文献

{"title":"Contrast-Enhanced Ultrasound Imaging of Uterine Disorders: A Systematic Review.","authors":"Barbara Stoelinga,&nbsp;Lynda Juffermans,&nbsp;Anniek Dooper,&nbsp;Marleen de Lange,&nbsp;Wouter Hehenkamp,&nbsp;Thierry Van den Bosch,&nbsp;Judith Huirne","doi":"10.1177/01617346211017462","DOIUrl":"10.1177/01617346211017462","url":null,"abstract":"<p><p>Uterine disorders are often presented with overlapping symptoms. The microvasculature holds specific information important for diagnosing uterine disorders. Conventional sonography is an established diagnostic technique in gynecology, but is limited by its inability to image the microvasculature. Contrast-enhanced ultrasound (CEUS), is capable of imaging the microvasculature by means of intravascular contrast agents; that is, gas-filled microbubbles. We provide a literature overview on the use of CEUS in diagnosing myometrial and endometrial disorders, that is, fibroids, adenomyosis, leiomyosarcomas and endometrial carcinomas, as well as for monitoring and enhancing the effectiveness of minimally invasive therapies. A systematic literature search with quality assessment was performed until December 2020. In total 34 studies were included, published between 2007 and 2020.The results entail a description of contrast-enhancement patterns obtained from healthy tissue and from malignant and benign tissue; providing a first base for potential diagnostic differentiation in gynecology. In addition it is also possible to determine the degree of myometrial invasion in case of endometrial carcinoma using CEUS. The effectiveness of minimally invasive therapies for uterine disorders can safely and accurately be assessed with CEUS. In conclusion, the abovementioned applications of CEUS are promising and it is worth further exploring its full potential for gynecology by designing innovative and methodologically high-quality clinical studies.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01617346211017462","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39019799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acoustic-Field Beamforming for Low-Power Portable Ultrasound.","authors":"Chang-Lin Hu,&nbsp;Guo-Zua Wu,&nbsp;Chih-Chi Chang,&nbsp;Meng-Lin Li","doi":"10.1177/01617346211013473","DOIUrl":"https://doi.org/10.1177/01617346211013473","url":null,"abstract":"<p><p>Portable ultrasound has been extensively used for diagnostic applications in health monitoring, emergency rooms, and ambulances. However, these handheld ultrasound systems may suffer from heat and battery issues attributed to the large power consumption of the transmitter. Additionally, the largest portion of the direct current (DC) power consumption can be attributed to the amplifier in the digital-to-analog converter (DAC) of the transmitter and to the analog-to-digital converter (ADC) of the receiver. Therefore, the number of transmit/receive channels in a portable ultrasound instrument is one of the crucial design factors regarding heat and battery related issues. To address these problems, we propose an acoustic-field beamforming (AFB) technique for low-power portable ultrasound systems with a single receive and five transmit channels. Finally, the simulation, experimental, and in vivo results verified the feasibility of this approach.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01617346211013473","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38956895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstracts for the 2021 International Symposium on Ultrasonic Imaging and Tissue Characterization","authors":"A. Samir, M. Alexander, S. Audière, C. Baiu, J. Bamber, T. Bigelow, P. Carson, A. Chauhan, S. Chen, Y. Chen, G. Cloutier, C. D. Korte, A. Engel, T. Erpelding, R. Esquivel-Sirvent, B. Fowlkes, J. Gao, J. Gay, Z. Hah, T. Hall, J. Henry, A. Lex, T. Liu, T. Lynch, Jonathan Mamou, R. Managuli, L. Mankowski-Gettle, S. McAleavy, G. McLauglin, A. Milkowski, K. Nam, G. Ng, N. Obuchowski, J. Ormachea, S. Ouhda, M. Robbin, B. Rogozinski, J. Rubin, L. Sandrin, A. Sanyal, P. Sidhu, K. Thomenius, M. Thornton, X. Wang, J. Zagzebski, R. Barr, G. Ferraioli, V. Kumar, A. Ozturk, A. Han, R. Lavarello, T. Tuthill, T. Pierce, S. Rosenzweig, D. Fetzer, T. Stiles, M. Wang, I. Rosado-Méndez","doi":"10.1177/01617346211031090","DOIUrl":"https://doi.org/10.1177/01617346211031090","url":null,"abstract":"S FROM THE 2021 INTERNATIONAL SYMPOSIUM ON ULTRASONIC IMAGING AND TISSUE CHARACTERIZATION Virtual Conference 02 to 04 June 2021 https://doi.org/10.1177/01617346211031090 Ultrasonic Imaging 2021, Vol. 43(4) 187 –233 © The Author(s) 2021 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/01617346211031090 journals.sagepub.com/home/uix Abstracts In vivo Lag-one Coherence Measurements Using Matrix Arrays Rifat Ahmed1, Nick Bottenus2, James Long1, David Bradway1, and Gregg Trahey1 1Dept. of Biomed. Eng., Duke University, NC, USA and 2Dept. of Mech. Eng., University of Colorado Boulder, CO, USA, rifat.ahmed@duke.edu Objectives: Diffuse reverberation is a significant source of image degradation in abdominal ultrasound. Clutter induced by reverberation is often considered to be spatially incoherent. The nearest element correlation of backscatter signals provides a robust measure of such incoherent clutter [1]. We recently presented Lag-one Spatial Coherence Adaptive Normalization (LoSCAN) [2], an image formation technique that adaptively compensates for the SNR loss due to incoherent clutter. Here, we present in vivo LoSCAN images obtained with a 1024-element matrix array and explore the benefits of 2D clutter reduction. Methods: We developed a 2D LoSCAN framework applicable to matrix arrays. We validated this framework using Field II-simulated cyst phantoms of varying native contrasts and channel SNR, with a modeled 64x64 symmetric 2D array. Using these simulated data, we studied the impact of partially correlated noise (PCN) with controlled spatial correlation lengths (1λ to 3λ). Sub-aperture beamforming and a short-lag version of LoSCAN were explored as strategies to circumvent the PCN-induced contrast loss. We also acquired experimental data using a custom 64x16 2D array connected to a 1024-channel Verasonics system. We acquired fundamental and harmonic channel data from the liver of two healthy volunteers and performed 2D spatial coherencebased clutter analysis. Results: Compared to B-mode imaging, matrix LoSCAN preserved the native contrast and improved the lesion detectability, measured with the generalized contrast-to-noise ratio (gCNR), over a wider range of channel SNR. In vivo observations demonstrated the anisotropy of reverberation-noise correlation length. Matrix LoSCAN also improved the gCNR of abdominal anechoic targets from 0.92 to 0.97 in fundamental images and from 0.91 to 0.97 in harmonic images. Conclusions: Matrix LoSCAN effectively suppressed the incoherent clutter in abdominal ultrasound images. In vivo examples demonstrated the advantages of multi-dimensional clutter analysis. [1] Long et al., IEEE-TUFFC, 2018 [2] Long et al., IEEE-TUFFC, 202","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76163959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi-automated weak annotation for deep neural network skin thickness measurement.","authors":"Felix Q Jin,&nbsp;Anna E Knight,&nbsp;Adela R Cardones,&nbsp;Kathryn R Nightingale,&nbsp;Mark L Palmeri","doi":"10.1177/01617346211014138","DOIUrl":"https://doi.org/10.1177/01617346211014138","url":null,"abstract":"<p><p>Correctly calculating skin stiffness with ultrasound shear wave elastography techniques requires an accurate measurement of skin thickness. We developed and compared two algorithms, a thresholding method and a deep learning method, to measure skin thickness on ultrasound images. Here, we also present a framework for weakly annotating an unlabeled dataset in a time-effective manner to train the deep neural network. Segmentation labels for training were proposed using the thresholding method and validated with visual inspection by a human expert reader. We reduced decision ambiguity by only inspecting segmentations at the center A-line. This weak annotation approach facilitated validation of over 1000 segmentation labels in 2 hours. A lightweight deep neural network that segments entire 2D images was designed and trained on this weakly-labeled dataset. Averaged over six folds of cross-validation, segmentation accuracy was 57% for the thresholding method and 78% for the neural network. In particular, the network was better at finding the distal skin margin, which is the primary challenge for skin segmentation. Both algorithms have been made publicly available to aid future applications in skin characterization and elastography.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01617346211014138","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10211926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single Versus Multi-channel Dispersion Analysis of Ultrasonic Guided Waves Propagating in Long Bones.","authors":"Tho N H T Tran,&nbsp;Feng He,&nbsp;Zhenggang Zhang,&nbsp;Mauricio D Sacchi,&nbsp;Dean Ta,&nbsp;Lawrence H Le","doi":"10.1177/01617346211006660","DOIUrl":"https://doi.org/10.1177/01617346211006660","url":null,"abstract":"<p><p>Ultrasonic guided wave techniques have been applied to characterize cortical bone for osteoporosis assessment. Compared with the current gold-standard X-ray-based diagnostic methods, ultrasound-based techniques pose some advantages such as compactness, low cost, lack of ionizing radiation, and their ability to detect the mechanical properties of the cortex. Axial transmission technique with a source-receiver offset is employed to acquire the ultrasound data. The dispersion characteristics of the guided waves in bones are normally analyzed in the transformed domains using the dispersion curves. The transformed domain can be time-frequency map using a single channel or wavenumber-frequency (or phase velocity-frequency) map with multi-channels. In terms of acquisition effort, the first method is more cost- and time-effective than the latter. However, it remains unclear whether single-channel dispersion analysis can provide as much quantitative guided-wave information as the multi-channel analysis. The objective of this study is to compare the two methods using numerically simulated and ex vivo data of a simple bovine bone plate and explore their advantages and disadvantages. Both single- and multi-channel signal processing approaches are implemented using sparsity-constrained optimization algorithms to reinforce the focusing power. While the single-channel data acquisition and processing are much faster than those of the multi-channel, modal identification and analysis of the multi-channel data are straightforward and more convincing.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01617346211006660","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25579110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Evaluation of the Effectiveness of Image-based Texture Features Extracted from Static B-mode Ultrasound Images in Distinguishing between Benign and Malignant Ovarian Masses.","authors":"Dhurgham Al-Karawi,&nbsp;Hisham Al-Assam,&nbsp;Hongbo Du,&nbsp;Ahmad Sayasneh,&nbsp;Chiara Landolfo,&nbsp;Dirk Timmerman,&nbsp;Tom Bourne,&nbsp;Sabah Jassim","doi":"10.1177/0161734621998091","DOIUrl":"https://doi.org/10.1177/0161734621998091","url":null,"abstract":"<p><p>Significant successes in machine learning approaches to image analysis for various applications have energized strong interest in automated diagnostic support systems for medical images. The evolving in-depth understanding of the way carcinogenesis changes the texture of cellular networks of a mass/tumor has been informing such diagnostics systems with use of more suitable image texture features and their extraction methods. Several texture features have been recently applied in discriminating malignant and benign ovarian masses by analysing B-mode images from ultrasound scan of the ovary with different levels of performance. However, comparative performance evaluation of these reported features using common sets of clinically approved images is lacking. This paper presents an empirical evaluation of seven commonly used texture features (histograms, moments of histogram, local binary patterns [256-bin and 59-bin], histograms of oriented gradients, fractal dimensions, and Gabor filter), using a collection of 242 ultrasound scan images of ovarian masses of various pathological characteristics. The evaluation examines not only the effectiveness of classification schemes based on the individual texture features but also the effectiveness of various combinations of these schemes using the simple majority-rule decision level fusion. Trained support vector machine classifiers on the individual texture features without any specific pre-processing, achieve levels of accuracy between 75% and 85% where the seven moments and the 256-bin LBP are at the lower end while the Gabor filter is at the upper end. Combining the classification results of the top <i>k</i> (<i>k</i> = 3, 5, 7) best performing features further improve the overall accuracy to a level between 86% and 90%. These evaluation results demonstrate that each of the investigated image-based texture features provides informative support in distinguishing benign or malignant ovarian masses.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/0161734621998091","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25402591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Image Analysis for Ultrasound Quality Assurance.","authors":"Majed H Aljahdali,&nbsp;Alexander Woodman,&nbsp;Lamiaa Al-Jamea,&nbsp;Saeed M Albatati,&nbsp;Chris Williams","doi":"10.1177/0161734621992332","DOIUrl":"https://doi.org/10.1177/0161734621992332","url":null,"abstract":"<p><p>The quality assurance (QA) of ultrasound transducers is often identified as an area requiring continuous development in terms of the tools available to users. Periodic evaluation of the transducers as part of the QA protocol is important, since the quality of the diagnostics. Some of the key criteria determining the process of developing a QA protocol include the complexity of setup, the time required, accuracy, and potential automation to achieve scale. For the current study, a total of eight different ultrasound machines (12 transducers) with linear transducers were obtained separately. The results from these 12 transducers were used to validate the protocol. WAD-QC was used as part of this study to assess in-air reverberation patterns obtained from ultrasound transducers. Initially, three in-air reverberation images obtained from normal transducers and three obtained from defective transducers were used to calculate the uniformity parameters. The results were applied to 12 other images obtained from independent sources. Image processing results with WAD-QC were verified with imageJ. A comparison of raw data for uniformity showed consistency, and using controls based on mean absolute deviation yielded identical results. WAD-QC can be considered as a powerful mechanism for quick, efficient, and accurate analysis of in-air reverberation patterns obtained from ultrasound transducers.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/0161734621992332","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25371661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Muscle Ultrasonography Using 2D Textural Analysis: A Novel Approach to Assess Skeletal Muscle Structure and Quality in Chronic Kidney Disease.","authors":"Thomas J Wilkinson, Jed Ashman, Luke A Baker, Emma L Watson, Alice C Smith","doi":"10.1177/01617346211009788","DOIUrl":"10.1177/01617346211009788","url":null,"abstract":"<p><p>Chronic kidney disease (CKD) is characterized by progressive reductions in skeletal muscle function and size. The concept of muscle quality is increasingly being used to assess muscle health, although the best means of assessment remains unidentified. The use of muscle echogenicity is limited by an inability to be compared across devices. Gray level of co-occurrence matrix (GLCM), a form of image texture analysis, may provide a measure of muscle quality, robust to scanner settings. This study aimed to identify GLCM values from skeletal muscle images in CKD and investigate their association with physical performance and strength (a surrogate of muscle function). Transverse images of the rectus femoris muscle were obtained using B-mode 2D ultrasound imaging. Texture analysis (GLCM) was performed using ImageJ. Five different GLCM features were quantified: energy or angular second moment (ASM), entropy, homogeneity, or inverse difference moment (IDM), correlation, and contrast. Physical function and strength were assessed using tests of handgrip strength, sit to stand-60, gait speed, incremental shuttle walk test, and timed up-and-go. Correlation coefficients between GLCM indices were compared to each objective functional measure. A total of 90 CKD patients (age 64.6 (10.9) years, 44% male, eGFR 33.8 (15.7) mL/minutes/1.73 m²) were included. Better muscle function was largely associated with those values suggestive of greater image texture homogeneity (i.e., greater ASM, correlation, and IDM, lower entropy and contrast). Entropy showed the greatest association across all the functional assessments (<i>r</i> = -.177). All GLCM parameters, a form of higher-order texture analysis, were associated with muscle function, although the largest association as seen with image entropy. Image homogeneity likely indicates lower muscle infiltration of fat and fibrosis. Texture analysis may provide a novel indicator of muscle quality that is robust to changes in scanner settings. Further research is needed to substantiate our findings.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01617346211009788","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25600389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of High Temporal Frequency Photoacoustic Guidance of Laser Ablation Procedures.","authors":"Yan Yan,&nbsp;Samuel John,&nbsp;Jurgita Meiliute,&nbsp;Loay Kabbani,&nbsp;Mohammad Mehrmohammadi","doi":"10.1177/01617346211010488","DOIUrl":"https://doi.org/10.1177/01617346211010488","url":null,"abstract":"<p><p>Inaccurate placement of the ablation catheter and the inability to monitor the real-time temperature within the tissue of interest such as veins curbs the treatment efficacy of laser ablation procedures during thermal therapies. Our previous studies have validated the efficacy of photoacoustic (PA) imaging during endovenous laser ablation (EVLA) procedures. However, the PA-guided therapies suffer from low temporal resolution, due to the low pulse repetition rates of pulsed lasers, which could cause a problem during fast catheter motion and rapid temperature changes. Herein, to enhance the accuracy and sensitivity for tracking the ablation catheter tip and temperature monitoring, we proposed to develop a high frame rate (500 Hz), combined ultrasound (US), and PA-guided ablation system. The proposed PA-guided ablation system was evaluated in a set of ex vivo tissue studies. The developed system provides a 2 ms temporal resolution for tracking and monitoring the ablation catheter tip's location and temperature, which is 50 times higher temporal resolution compared to the previously proposed 10 Hz system. The proposed system also provided more accurate feedback about the temperature variations during rapid temperature increments of 10°C per 250 ms. The co-registered US and PA images have an imaging resolution of about 200 μm and a field of view of 45 × 40 mm². Tracking the ablation catheter tip in an excised tissue layer shows higher accuracy during a relatively fast catheter motion (0.5-3 mm/s). The fast US/PA-guided ablation system will potentially enhance the outcome of ablation procedures by providing location and temperature feedback.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/01617346211010488","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38974051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrasonic Imaging of High-contrasted Objects Based on Full-waveform Inversion: Limits under Fluid Modeling.","authors":"Luis Espinosa,&nbsp;Elise Doveri,&nbsp;Simon Bernard,&nbsp;Vadim Monteiller,&nbsp;Régine Guillermin,&nbsp;Philippe Lasaygues","doi":"10.1177/0161734621990011","DOIUrl":"https://doi.org/10.1177/0161734621990011","url":null,"abstract":"<p><p>Quantitative ultrasound techniques have been previously used to evaluate biological hard tissues, characterized by a large acoustic impedance contrast. Here, we are interested in the imaging of experimental data from different test-targets with high acoustic impedance contrast, using the Full Waveform Inversion (FWI) method to solve the inverse problem. This method is based on high-resolution numerical modeling of the forward problem of interaction between waves and medium, considering the full time series. To reduce the complexity of the numerical implementation, the model considers a fluid medium. Therefore, the aim is to evaluate the precision of the reconstruction under this assumption for materials with a different level of attenuation of shear waves, to study the limits of this hypothesis. Images of the sound speed obtained using the experimental data are presented, and the precision of the reconstruction is evaluated. Future work should include viscoelastic materials.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/0161734621990011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25350866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}