1
|
Zhou J, Guo Y, Sun Q, Lin F, Jiang C, Xu K, Ta D. Transcranial ultrafast ultrasound Doppler imaging: A phantom study. ULTRASONICS 2024; 144:107430. [PMID: 39173276 DOI: 10.1016/j.ultras.2024.107430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 07/02/2024] [Accepted: 08/09/2024] [Indexed: 08/24/2024]
Abstract
Ultrafast ultrasound Doppler imaging facilitates the assessment of cerebral hemodynamics with high spatio-temporal resolution. However, the significant acoustic impedance mismatch between the skull and soft tissue results in phase aberrations, which can compromise the quality of transcranial imaging and introduce biases in velocity and direction quantification of blood flow. This paper proposed an aberration correction method that combines deep learning-based skull sound speed modelling with ray theory to realize transcranial plane-wave imaging and ultrafast Doppler imaging. The method was validated through phantom experiments using a linear array with a center frequency of 6.25 MHz, 128 elements, and a pitch of 0.3 mm. The results demonstrated an improvement in the imaging quality of intracranial targets when using the proposed method. After aberration correction, the average locating deviation decreased from 1.40 mm to 0.27 mm in the axial direction, from 0.50 mm to 0.20 mm in the lateral direction, and the average full-width-at-half-maximum (FWHM) decreased from 1.37 mm to 0.97 mm for point scatterers. For circular inclusions, the average contrast-to-noise ratio (CNR) improved from 8.1 dB to 11.0 dB, and the average eccentricity decreased from 0.36 to 0.26. Furthermore, the proposed method was applied to transcranial ultrafast Doppler flow imaging. The results showed a significant improvement in accuracy and quality for blood Doppler flow imaging. The results in the absence of the skull were considered as the reference, and the average normalized root-mean-square errors of the axial velocity component on the five selected axial profiles were reduced from 17.67% to 8.02% after the correction.
Collapse
Affiliation(s)
- Jiangjin Zhou
- Department of Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200438, China
| | - Yuanyang Guo
- Department of Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200438, China
| | - Qiandong Sun
- Department of Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200438, China
| | - Fanglue Lin
- Ultrasound BU, Wuhan United Imaging Healthcare Co., Ltd., Wuhan 430206, China
| | - Chen Jiang
- Yiwu Research Institute of Fudan University, Zhejiang 322000, China.
| | - Kailiang Xu
- Department of Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200438, China; Yiwu Research Institute of Fudan University, Zhejiang 322000, China; PodaMed Medical Technology Co., Ltd., Shanghai 200433, China.
| | - Dean Ta
- Department of Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200438, China; Yiwu Research Institute of Fudan University, Zhejiang 322000, China
| |
Collapse
|
2
|
Li B, Lu M, Zhou T, Bu M, Gu W, Wang J, Zhu Q, Liu X, Ta D. Removing Artifacts in Transcranial Photoacoustic Imaging With Polarized Self-Attention Dense-UNet. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:1530-1543. [PMID: 39013725 DOI: 10.1016/j.ultrasmedbio.2024.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 05/28/2024] [Accepted: 06/16/2024] [Indexed: 07/18/2024]
Abstract
OBJECTIVE Photoacoustic imaging (PAI) is a promising transcranial imaging technique. However, the distortion of photoacoustic signals induced by the skull significantly influences its imaging quality. We aimed to use deep learning for removing artifacts in PAI. METHODS In this study, we propose a polarized self-attention dense U-Net, termed PSAD-UNet, to correct the distortion and accurately recover imaged objects beneath bone plates. To evaluate the performance of the proposed method, a series of experiments was performed using a custom-built PAI system. RESULTS The experimental results showed that the proposed PSAD-UNet method could effectively implement transcranial PAI through a one- or two-layer bone plate. Compared with the conventional delay-and-sum and classical U-Net methods, PSAD-UNet can diminish the influence of bone plates and provide high-quality PAI results in terms of structural similarity and peak signal-to-noise ratio. The 3-D experimental results further confirm the feasibility of PSAD-UNet in 3-D transcranial imaging. CONCLUSION PSAD-UNet paves the way for implementing transcranial PAI with high imaging accuracy, which reveals broad application prospects in preclinical and clinical fields.
Collapse
Affiliation(s)
- Boyi Li
- Academy for Engineering and Technology, Fudan University, Shanghai 200438, China
| | - Mengyang Lu
- Academy for Engineering and Technology, Fudan University, Shanghai 200438, China
| | - Tianhua Zhou
- Department of Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200438, China
| | - Mengxu Bu
- Academy for Engineering and Technology, Fudan University, Shanghai 200438, China
| | - Wenting Gu
- Academy for Engineering and Technology, Fudan University, Shanghai 200438, China
| | - Junyi Wang
- Department of Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200438, China
| | - Qiuchen Zhu
- Academy for Engineering and Technology, Fudan University, Shanghai 200438, China
| | - Xin Liu
- Academy for Engineering and Technology, Fudan University, Shanghai 200438, China.
| | - Dean Ta
- Academy for Engineering and Technology, Fudan University, Shanghai 200438, China; Department of Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200438, China
| |
Collapse
|
3
|
Li M, Liang S, Lu M. Fourier-based beamforming for 3D plane wave imaging and application in vector flow imaging using selective compounding. Phys Med Biol 2024; 69:185008. [PMID: 39168145 DOI: 10.1088/1361-6560/ad7224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 08/21/2024] [Indexed: 08/23/2024]
Abstract
Objective. Ultrafast ultrasound imaging using planar or diverging waves for transmission is a promising approach for efficient 3D imaging with matrix arrays. This technique has advantages for B-mode imaging and advanced techniques, such as 3D vector flow imaging (VFI). The computation load of the cross-beam technique is associated with the number of transmit anglesmand receive anglesn. The full velocity vector is obtained using the least square fashion. However, the beamforming is repeatedm × ntimes using a conventional time-domain delay-and-sum (DAS) beamformer. In the 3D case, the collection and processing of data from different beams increase the amount of data that must be processed, requiring more storage capacity and processing power. Furthermore, the large computation complexity of DAS is another major concern. These challenges translate into longer computational times, increased complexity in data processing, and difficulty in real-time applications.Approach. In response to this issue, this study proposes a novel Fourier domain beamformer for 3D plane wave imaging, which significantly increases the computational speed. Additionally, a selective compounding strategy is proposed for VFI, which reduces the beamforming process fromm × ntom(wheremandnrepresent the number of transmission and reception, respectively), effectively shortening the processing time. The underlying principle is to decompose the receive wavefront into a series of plane waves with different slant angles. Each slant angle can produce a sub-volume for coherent or selective compounding. This method does not rely on the assumption that the plane wave is perfect and the results show that our proposed beamformer is better than DAS in terms of resolution and image contrast. In the case of velocity estimation, for the Fourier-based method, only Tx angles are assigned in the beamformer and the selective compounding method produces the final image with a specialized Rx angle.Main results. Simulation studies andin vitroexperiments confirm the efficacy of this new method. The proposed beamformer shows improved resolution and contrast performance compared to the DAS beamformer for B-mode imaging, with a suppressed sidelobe level. Furthermore, the proposed technique outperforms the conventional DAS method, as evidenced by lower mean bias and standard deviation in velocity estimation for VFI. Notably, the computation time has been shortened by 40 times, thus promoting the real-time application of this technique. The efficacy of this new method is verified through simulation studies andin vitroexperiments and evaluated by mean bias and standard deviation. Thein vitroresults reveal a better velocity estimation: the mean bias is 2.3%, 3.4%, and 5.0% forvx,vy, andvz, respectively. The mean standard deviation is 1.8%, 1.7%, and 3.4%. With DAS, the evaluated mean bias is 9.8%, 4.6%, and 6.7% and the measured mean standard deviation is 7.5%, 2.5%, and 3.9%.Significance. In this work, we propose a novel Fourier-based method for both B-mode imaging and functional VFI. The new beamformer is shown to produce better image quality and improved velocity estimation. Moreover, the new VFI computation time is reduced by 40 times compared to conventional methods. This new method may pave a new way for real-time 3D VFI applications.
Collapse
Affiliation(s)
- Menghan Li
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, People's Republic of China
| | - Siyi Liang
- United Imaging Research Institute of Innovative Medical Equipment, Shenzhen, People's Republic of China
| | - Minhua Lu
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, People's Republic of China
| |
Collapse
|
4
|
Voulgaridou V, Nicolas B, McDougall S, Arthur L, Papageorgiou G, Butler M, Kanoulas E, Diamantis K, Lu W, Sboros V. Vessel recovery using ultrasound localisation microscopy: An in silico comparative study between minimum variance and delay-and-sum beamformers. ULTRASONICS 2024; 145:107451. [PMID: 39276632 DOI: 10.1016/j.ultras.2024.107451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/26/2024] [Accepted: 08/29/2024] [Indexed: 09/17/2024]
Abstract
The use of particle localisation and tracking algorithms on Contrast Enhanced Ultrasound (CEUS) or other ultrasound mode image data containing sparse microbubble (MB) populations, can produce super-resolved vascularization maps. Typically such data stem from conventional delay and sum (DAS) beamforming that is used widely in ultrasound imaging modes. Recently, adaptive beamforming has shown significant improvement in spatial resolution, but its value to super-resolution image analysis approaches is not fully understood. The in silico study here evaluates the performance of combining minimum variance beamformers (MV BF), established to provide improved lateral resolution, compared to DAS BFs with single particle detection. The isolated effect of a range of simplified image-affecting factors such as flow profile, pulse length, noise, vessel separations and data availability is considered. The study aims to assess the vessel recovery performance using the different beamformers and investigate the link with MB detection and localisation. The MV BF was shown to provide improved microvessel position accuracy compared to conventional DAS BFs. In particular, vessel separations between 0.3-4 λ provided superior localisation uncertainty with the MV. In addition, for a separation of 0.36λ, vessel recovery was achieved with both methods but the use of MV eliminated artifacts that appear as additional vessels. These results were found to be linked to improved MB detection and localisation for the MV BF, which is proposed as suitable for testing in Ultrasound Localisation Microscopy (ULM) imaging using patient data.
Collapse
Affiliation(s)
- Vasiliki Voulgaridou
- Translational Healthcare Technologies Team, Centre for Inflammation Research, Queen's Medical Research Institute University of Edinburgh, United Kingdom
| | - Barbara Nicolas
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1206, F-69621 Lyon, France
| | - Steven McDougall
- Institute of GeoEnergy Engineering Heriot Watt University Edinburgh, United Kingdom
| | - Lachlan Arthur
- School of Engineering and Physical Sciences Heriot Watt University, Edinburgh, United Kingdom
| | - Georgios Papageorgiou
- School of Engineering and Physical Sciences Heriot Watt University, Edinburgh, United Kingdom
| | - Mairead Butler
- School of Engineering and Physical Sciences Heriot Watt University, Edinburgh, United Kingdom
| | | | | | - Weiping Lu
- School of Engineering and Physical Sciences Heriot Watt University, Edinburgh, United Kingdom
| | - Vassilis Sboros
- School of Engineering and Physical Sciences Heriot Watt University, Edinburgh, United Kingdom.
| |
Collapse
|
5
|
Bentaleb A, Sintes C, Conze PH, Rousseau F, Guezou-Philippe A, Hamitouche C. Complex Residual Attention U-Net for Fast Ultrasound Imaging from a Single Plane-Wave Equivalent to Diverging Wave Imaging. SENSORS (BASEL, SWITZERLAND) 2024; 24:5111. [PMID: 39204807 PMCID: PMC11360587 DOI: 10.3390/s24165111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 07/12/2024] [Accepted: 08/05/2024] [Indexed: 09/04/2024]
Abstract
Plane wave imaging persists as a focal point of research due to its high frame rate and low complexity. However, in spite of these advantages, its performance can be compromised by several factors such as noise, speckle, and artifacts that affect the image quality and resolution. In this paper, we propose an attention-based complex convolutional residual U-Net to reconstruct improved in-phase/quadrature complex data from a single insonification acquisition that matches diverging wave imaging. Our approach introduces an attention mechanism to the complex domain in conjunction with complex convolution to incorporate phase information and improve the image quality matching images obtained using coherent compounding imaging. To validate the effectiveness of this method, we trained our network on a simulated phased array dataset and evaluated it using in vitro and in vivo data. The experimental results show that our approach improved the ultrasound image quality by focusing the network's attention on critical aspects of the complex data to identify and separate different regions of interest from background noise.
Collapse
Affiliation(s)
- Ahmed Bentaleb
- Département Image et Traitement de l’Information, Institue Mines-Télécom (IMT) Atlantique, 29200 Brest, France
| | | | | | | | | | | |
Collapse
|
6
|
Fredianelli L, Pedrini G, Bolognese M, Bernardini M, Fidecaro F, Licitra G. Features for Evaluating Source Localization Effectiveness in Sound Maps from Acoustic Cameras. SENSORS (BASEL, SWITZERLAND) 2024; 24:4696. [PMID: 39066093 PMCID: PMC11281292 DOI: 10.3390/s24144696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Revised: 07/12/2024] [Accepted: 07/18/2024] [Indexed: 07/28/2024]
Abstract
Acoustic cameras (ACs) have become very popular in the last decade as an increasing number of applications in environmental acoustics are observed, which are mainly used to display the points of greatest noise emission of one or more sound sources. The results obtained are not yet certifiable because the beamforming algorithms or hardware behave differently under different measurement conditions, but at present, not enough studies have been dedicated to clarify the issues. The present study aims to provide a methodology to extract analytical features from sound maps obtained with ACs, which are generally only visual information. Based on the inputs obtained through a specific measurement campaign carried out with an AC and a known sound source in free field conditions, the present work elaborated a methodology for gathering the coordinates of the maximum emission point on screen, its distance from the real position of the source and the uncertainty associated with this position. The results obtained with the proposed method can be compared, thus acting as a basis for future comparison studies among calculations made with different beamforming algorithms or data gathered with different ACs in all real case scenarios. The method can be applicable to any other sector interested in gathering data from intensity maps not related to sound.
Collapse
Affiliation(s)
- Luca Fredianelli
- National Research Council (CNR), a Moruzzi 1, 56124 Pisa, Italy;
| | - Gregorio Pedrini
- Department of Earth Sciences, University of Pisa, Via Santa Maria 53, 56127 Pisa, Italy;
| | - Matteo Bolognese
- Environmental Protection Agency of Tuscany Region (ARPAT), Via Vittorio Veneto, 27, 56127 Pisa, Italy
| | | | - Francesco Fidecaro
- Physics Department, University of Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy
| | - Gaetano Licitra
- National Research Council (CNR), a Moruzzi 1, 56124 Pisa, Italy;
- Environmental Protection Agency of Tuscany Region (ARPAT), Via Vittorio Veneto, 27, 56127 Pisa, Italy
| |
Collapse
|
7
|
Zhang H, Wang F, Lin J, Hua J. Lamb wave-based damage assessment for composite laminates using a deep learning approach. ULTRASONICS 2024; 141:107333. [PMID: 38692213 DOI: 10.1016/j.ultras.2024.107333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 04/11/2024] [Accepted: 04/24/2024] [Indexed: 05/03/2024]
Abstract
With the increasing utilization of composite materials due to their superior properties, the need for efficient structural health monitoring techniques rises rapidly to ensure the integrity and reliability of composite structures. Deep learning approaches have great potential applications for Lamb wave-based damage detection. However, it remains challenging to quantitatively detect and characterize damage such as delamination in multi-layered structures. These deep learning architectures still lack a certain degree of physical interpretability. In this study, a convolutional sparse coding-based UNet (CSCUNet) is proposed for ultrasonic Lamb wave-based damage assessment in composite laminates. A low-resolution image is generated using delay-and-sum algorithm based on Lamb waves acquired by transducer array. The encoder-decoder framework in the proposed CSCUNet enables the transformation of low-resolution input image to high-resolution damage image. In addition, the multi-layer convolutional sparse coding block is introduced into encoder of the CSCUNet to improve both performance and interpretability of the model. The proposed method is tested on both numerical and experimental data acquired on the surface of composite specimen. The results demonstrate its effectiveness in identifying the delamination location, size, and shape. The network has powerful feature extraction capability and enhanced interpretability, enabling high-resolution imaging and contour evaluation of composite material damage.
Collapse
Affiliation(s)
- Han Zhang
- Institute of Mechanics and Acoustics, National Institute of Metrology, Beijing 100029, China
| | - Fan Wang
- CISDI Group Co., Ltd., No.1 Shuanggang Road, Yuzhong District, Chongqing 400013, China
| | - Jing Lin
- Advanced Manufacturing Center, Ningbo Institute of Technology, Beihang University, Ningbo 315100, China; Science & Technology on Reliability and Environmental Engineering Laboratory, Beihang University, Xueyuan Road No. 37, Haidian District, Beijing 100191, China
| | - Jiadong Hua
- Advanced Manufacturing Center, Ningbo Institute of Technology, Beihang University, Ningbo 315100, China; Science & Technology on Reliability and Environmental Engineering Laboratory, Beihang University, Xueyuan Road No. 37, Haidian District, Beijing 100191, China.
| |
Collapse
|
8
|
An J, Sugita N, Shinshi T. Microbubble detection on ultrasound imaging by utilizing phase patterned waves. Phys Med Biol 2024; 69:135003. [PMID: 38843808 DOI: 10.1088/1361-6560/ad5511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 06/06/2024] [Indexed: 06/21/2024]
Abstract
Objective.Super-resolution ultrasonography offers the advantage of visualization of intricate microvasculature, which is crucial for disease diagnosis. Mapping of microvessels is possible by localizing microbubbles (MBs) that act as contrast agents and tracking their location. However, there are limitations such as the low detectability of MBs and the utilization of a diluted concentration of MBs, leading to the extension of the acquisition time. We aim to enhance the detectability of MBs to reduce the acquisition time of acoustic data necessary for mapping the microvessels.Approach.We propose utilizing phase patterned waves (PPWs) characterized by spatially patterned phase distributions in the incident beam to achieve this. In contrast to conventional ultrasound irradiation methods, this irradiation method alters bubble interactions, enhancing the oscillation response of MBs and generating more significant scattered waves from specific MBs. This enhances the detectability of MBs, thereby enabling the detection of MBs that were undetectable by the conventional method. The objective is to maximize the overall detection of bubbles by utilizing ultrasound imaging with additional PPWs, including the conventional method. In this paper, we apply PPWs to ultrasound imaging simulations considering bubble-bubble interactions to elucidate the characteristics of PPWs and demonstrate their efficacy by employing PPWs on MBs fixed in a phantom by the experiment.Main results.By utilizing two types of PPWs in addition to the conventional ultrasound irradiation method, we confirmed the detection of up to 93.3% more MBs compared to those detected using the conventional method alone.Significance.Ultrasound imaging using additional PPWs made it possible to increase the number of detected MBs, which is expected to improve the efficiency of bubble detection.
Collapse
Affiliation(s)
- Junseok An
- Department of Mechanical Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Naohiro Sugita
- Laboratory for Future Interdisciplinary Research of Science and Technology (FIRST), Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Tadahiko Shinshi
- Laboratory for Future Interdisciplinary Research of Science and Technology (FIRST), Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| |
Collapse
|
9
|
Spainhour J, Smart K, Becker S, Bottenus N. Optimization of array encoding for ultrasound imaging. Phys Med Biol 2024; 69:125024. [PMID: 38815603 DOI: 10.1088/1361-6560/ad5249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 05/30/2024] [Indexed: 06/01/2024]
Abstract
Objective. The transmit encoding model for synthetic aperture imaging is a robust and flexible framework for understanding the effects of acoustic transmission on ultrasound image reconstruction. Our objective is to use machine learning (ML) to construct scanning sequences, parameterized by time delays and apodization weights, that produce high-quality B-mode images.Approach. We use a custom ML model in PyTorch with simulated RF data from Field II to probe the space of possible encoding sequences for those that minimize a loss function that describes image quality. This approach is made computationally feasible by a novel formulation of the derivative for delay-and-sum beamforming.Main results. When trained for a specified experimental setting (imaging domain, hardware restrictions, etc), our ML model produces optimized encoding sequences that, when deployed in the REFoCUS imaging framework, improve a number of standard quality metrics over conventional sequences including resolution, field of view, and contrast. We demonstrate these results experimentally on both wire targets and a tissue-mimicking phantom.Significance. This work demonstrates that the set of commonly used encoding schemes represent only a narrow subset of those available. Additionally, it demonstrates the value for ML tasks in synthetic transmit aperture imaging to consider the beamformer within the model, instead of purely as a post-processing step.
Collapse
Affiliation(s)
- Jacob Spainhour
- Department of Applied Mathematics, University of Colorado Boulder, Boulder, CO, United States of America
| | - Korben Smart
- Department of Physics, University of Colorado Boulder, Boulder, CO, United States of America
| | - Stephen Becker
- Department of Applied Mathematics, University of Colorado Boulder, Boulder, CO, United States of America
| | - Nick Bottenus
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, United States of America
| |
Collapse
|
10
|
Xiao D, Torre PDL, Yu ACH. Real-Time Speed-of-Sound Estimation In Vivo via Steered Plane Wave Ultrasound. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2024; 71:673-686. [PMID: 38687663 DOI: 10.1109/tuffc.2024.3395490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Speed-of-sound (SoS) is an intrinsic acoustic property of human tissues and has been regarded as a potential biomarker of tissue health. To foster the clinical use of this emerging biomarker in medical diagnostics, it is important for SoS estimates to be derived and displayed in real time. Here, we demonstrate that concurrent global SoS estimation and B-mode imaging can be achieved live on a portable ultrasound scanner. Our innovation is hinged upon the design of a novel pulse-echo SoS estimation framework that is based on steered plane wave imaging. It has accounted for the effects of refraction and imaging depth when the medium SoS differs from the nominal value of 1540 m/s that is conventionally used in medical imaging. The accuracy of our SoS estimation framework was comparatively analyzed with through-transmit time-of-flight measurements in vitro on 15 custom agar phantoms with different SoS values (1508-1682 m/s) and in vivo on human calf muscles ( N = 9 ; SoS range: 1560-1586 m/s). Our SoS estimation framework has a mean signed difference (MSD) of - 0.6 ± 2.3 m/s in vitro and - 2.2 ± 11.2 m/s in vivo relative to the reference measurements. In addition, our real-time system prototype has yielded simultaneous SoS estimates and B-mode imaging at an average frame rate of 18.1 fps. Overall, by realizing real-time tissue SoS estimation with B-mode imaging, our innovation can foster the use of tissue SoS as a biomarker in medical ultrasound diagnostics.
Collapse
|
11
|
Wang C, Ma J, Bai X, Chen J. Defect detection and imaging using electromagnetic acoustic transducer with butterfly coil. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:064704. [PMID: 38832852 DOI: 10.1063/5.0198404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 05/20/2024] [Indexed: 06/06/2024]
Abstract
Electromagnetic ultrasonic detection technology utilizes the electromagnetic coupling method to generate and receive ultrasonic waves without a couplant, which is suitable for rapid detection. However, the detection can be affected by the spatial distribution of the acoustic field and the polarization direction of the shear wave, which can result in suboptimal detection performance. The acoustic field directivity of the shear wave generated by the butterfly coil electromagnetic acoustic transducer was measured using the transmission method. The data indicate that the acoustic pressure amplitude of the shear wave is maximized along the axis of the acoustic field, thereby meeting the requirements of synthetic aperture focusing technique imaging. We used the reflection method to detect the through-hole defects and investigated the effect of shear wave polarization direction. By comparing the experimental data and imaging results, it can be concluded that higher echo amplitudes are obtained when the polarization direction of the shear wave is perpendicular to the axis of the through-hole defects. Based on the explosive reflection model, the frequency domain phase shift migration (PSM) method converts the time-domain signal to the frequency domain for processing and uses a phase-shift factor for layer-by-layer imaging. We used the PSM method to process the experimental data, which not only produced high-resolution images but also had a high computational speed.
Collapse
Affiliation(s)
- Chaoqun Wang
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), 250104 Jinan, China
| | - Jian Ma
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), 250104 Jinan, China
| | - Xue Bai
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), 250104 Jinan, China
| | - Jianwei Chen
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), 250104 Jinan, China
| |
Collapse
|
12
|
Pan Y, Wang X, Qiang Y, Wang N, Liu R, Yang G, Zhang Z, He X, Yu Y, Zheng H, Qiu W. A New Method of Plane-Wave Ultrasound Imaging Based on Reverse Time Migration. IEEE Trans Biomed Eng 2024; 71:1628-1639. [PMID: 38133968 DOI: 10.1109/tbme.2023.3346194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
Coherent plane-wave compounding technique enables rapid ultrasound imaging with comparable image quality to traditional B-mode imaging that relies on focused beam transmission. However, existing methods assume homogeneity in the imaged medium, neglecting the heterogeneity in sound velocities and densities present in real tissues, resulting in noise reverberation. This study introduces the Reverse Time Migration (RTM) method for ultrasound plane-wave imaging to overcome this limitation, which is combined with a method for estimating the speed of sound in layered media. Simulation results in a homogeneous background demonstrate that RTM reduces side lobes and grating lobes by approximately 30 dB, enhancing the contrast-to-noise ratio by 20% compared to conventional delay and sum (DAS) beamforming. Moreover, RTM achieves superior imaging outcomes with fewer compounding angles. The lateral resolution of the RTM with 5-9 angle compounding is able to achieve the effectiveness of the DAS method with 15-19 angle compounding, and the CNR of the RTM with 11-angle compounding is almost the same as that of the DAS with 21-angle compounding. In a heterogeneous background, experimental simulations and in vitro wire phantom experiments confirm RTM's capability to correct depth imaging, focusing reflected waves on point targets. In vitro porcine tissue experiments enable accurate imaging of layer interfaces by estimating the velocities of multiple layers containing muscle and fat. The proposed imaging procedure optimizes velocity estimation in complex media, compensates for the impact of velocity differences, provides more reliable imaging results.
Collapse
|
13
|
Gardner M, Miller RJ, Oelze ML. Grating lobe mitigation on large-pitch arrays using null subtraction imaging. ULTRASONICS 2024; 140:107302. [PMID: 38531116 DOI: 10.1016/j.ultras.2024.107302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 03/14/2024] [Accepted: 03/18/2024] [Indexed: 03/28/2024]
Abstract
Null Subtraction Imaging (NSI) is a novel beamforming technique that can produce B-mode images resulting in high spatial resolution and low computational cost compared to other beamforming techniques. Previous work has demonstrated that in addition to a beam pattern with a narrow main lobe and low side lobes, NSI can also reduce or mitigate grating lobes, which can appear when the array pitch is larger than one half the wavelength of the transmitted pulse. These grating lobes can result in imaging artifacts that produce clutter and lower contrast. By lowering grating lobe levels, a larger pitch array could be used, which could allow arrays with a larger field of view while maintaining a standard element count. This could have important benefits for specific applications such as ultrasonic abdominal imaging. Experiments were conducted to examine the feasibility of using NSI with large pitch, wide field-of-view arrays. Grating lobe reduction was measured against array pitch, DC offset, and f-number. Experiments were conducted on wire targets and contrast targets in a phantom and results were further verified in vivo by imaging the liver of a rabbit. The results demonstrated that NSI was able to reduce grating lobe brightness by up to 45 dB compared to delay-and-sum (DAS) beamforming when using planewave transmissions, reduce the generalized contrast-to-noise ratio (gCNR) of grating lobe regions from 0.60 to 0.08, and maintain a similar speckle quality to DAS. The gCNR of anechoic regions also improves, increasing from 0.09 to 0.15 on an array with a pitch of 5 wavelengths. Due to significant grating lobe level reduction, NSI shows potential to improve image quality over DAS on a large pitch, wide field-of-view array.
Collapse
Affiliation(s)
- Mick Gardner
- Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 306 N Wright St, Urbana, IL, 61801, USA.
| | - Rita J Miller
- Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 306 N Wright St, Urbana, IL, 61801, USA
| | - Michael L Oelze
- Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 306 N Wright St, Urbana, IL, 61801, USA
| |
Collapse
|
14
|
Huang Y, Chen X, Badescu E, Kuenen M, Bonnefous O, Mischi M. Adaptive higher-order singular value decomposition clutter filter for ultrafast Doppler imaging of coronary flow under non-negligible tissue motion. ULTRASONICS 2024; 140:107307. [PMID: 38579486 DOI: 10.1016/j.ultras.2024.107307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 01/24/2024] [Accepted: 03/23/2024] [Indexed: 04/07/2024]
Abstract
BACKGROUND AND OBJECTIVE With the development of advanced clutter-filtering techniques by singular value decomposition (SVD) and leveraging favorable acquisition settings such as open-chest imaging by a linear high-frequency probe and plane waves, several studies have shown the feasibility of cardiac flow measurements during the entire cardiac cycle, ranging from coronary flow to myocardial perfusion. When applying these techniques in a routine clinical setting, using transthoracic ultrasound imaging, new challenges emerge. Firstly, a smaller aperture is needed that can fit between ribs. Consequently, diverging waves are employed instead of plane waves to achieve an adequate field of view. Secondly, to ensure imaging at a larger depth, the maximum pulse repetition frequency has to be reduced. Lastly, in comparison to the open-chest scenario, tissue motion induced by the heartbeat is significantly stronger. The latter complicates substantially the distinction between clutter and blood signals. METHODS This study investigates a strategy to overcome these challenges by diverging wave imaging with an optimal number of tilt angles, in combination with dedicated clutter-filtering techniques. In particular, a novel, adaptive, higher-order SVD (HOSVD) clutter filter, which utilizes spatial, temporal, and angular information of the received ultrasound signals, is proposed to enhance clutter and blood separation. RESULTS When non-negligible tissue motion is present, using fewer tilt angles not only reduces the decorrelation between the received waveforms but also allows for collecting more temporal samples at a given ensemble duration, contributing to improved Doppler performance. The addition of a third angular dimension enables the application of HOSVD, providing greater flexibility in selecting blood separation thresholds from a 3-D tensor. This differs from the conventional threshold selection method in a 2-D spatiotemporal space using SVD. Exhaustive threshold search has shown a significant improvement in Contrast and Contrast-to-Noise ratio for Power Doppler images filtered with HOSVD compared to the SVD-based clutter filter. CONCLUSION With the improved settings, the obtained Power Doppler images show the feasibility of measuring coronary flow under the influence of non-negligible tissue motion in both in vitro and ex vivo.
Collapse
Affiliation(s)
- Yizhou Huang
- Lab. of Biomedical Diagnostics, Eindhoven University of Technology, Eindhoven, The Netherlands.
| | - Xufei Chen
- Lab. of Biomedical Diagnostics, Eindhoven University of Technology, Eindhoven, The Netherlands
| | | | | | | | - Massimo Mischi
- Lab. of Biomedical Diagnostics, Eindhoven University of Technology, Eindhoven, The Netherlands
| |
Collapse
|
15
|
van Neer PLMJ, Peters LCJM, Verbeek RGFA, Peeters B, de Haas G, Hörchens L, Fillinger L, Schrama T, Merks-Swolfs EJW, Gijsbertse K, Saris AECM, Mozaffarzadeh M, Menssen JM, de Korte CL, van der Steen JLPJ, Volker AWF, Gelinck GH. Flexible large-area ultrasound arrays for medical applications made using embossed polymer structures. Nat Commun 2024; 15:2802. [PMID: 38555281 PMCID: PMC10981753 DOI: 10.1038/s41467-024-47074-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 03/12/2024] [Indexed: 04/02/2024] Open
Abstract
With the huge progress in micro-electronics and artificial intelligence, the ultrasound probe has become the bottleneck in further adoption of ultrasound beyond the clinical setting (e.g. home and monitoring applications). Today, ultrasound transducers have a small aperture, are bulky, contain lead and are expensive to fabricate. Furthermore, they are rigid, which limits their integration into flexible skin patches. New ways to fabricate flexible ultrasound patches have therefore attracted much attention recently. First prototypes typically use the same lead-containing piezo-electric materials, and are made using micro-assembly of rigid active components on plastic or rubber-like substrates. We present an ultrasound transducer-on-foil technology based on thermal embossing of a piezoelectric polymer. High-quality two-dimensional ultrasound images of a tissue mimicking phantom are obtained. Mechanical flexibility and effective area scalability of the transducer are demonstrated by functional integration into an endoscope probe with a small radius of 3 mm and a large area (91.2×14 mm2) non-invasive blood pressure sensor.
Collapse
Affiliation(s)
| | | | - Roy G F A Verbeek
- Holst Centre, TNO, High Tech Campus 31, 5656 AE, Eindhoven, The Netherlands
| | - Bart Peeters
- Holst Centre, TNO, High Tech Campus 31, 5656 AE, Eindhoven, The Netherlands
| | - Gerard de Haas
- Holst Centre, TNO, High Tech Campus 31, 5656 AE, Eindhoven, The Netherlands
| | - Lars Hörchens
- Acoustics & Underwater Warfare, TNO, The Hague, The Netherlands
| | | | - Thijs Schrama
- Acoustics & Underwater Warfare, TNO, The Hague, The Netherlands
| | | | | | - Anne E C M Saris
- Medical Ultrasound Imaging Center, Department of Medical Imaging, Radboud university medical centre, Nijmegen, The Netherlands
| | - Moein Mozaffarzadeh
- Medical Ultrasound Imaging Center, Department of Medical Imaging, Radboud university medical centre, Nijmegen, The Netherlands
| | - Jan M Menssen
- Medical Ultrasound Imaging Center, Department of Medical Imaging, Radboud university medical centre, Nijmegen, The Netherlands
| | - Chris L de Korte
- Medical Ultrasound Imaging Center, Department of Medical Imaging, Radboud university medical centre, Nijmegen, The Netherlands
- Physics of Fluids Group, Techmed Centre, Twente University, Enschede, the Netherlands
| | | | - Arno W F Volker
- Acoustics & Underwater Warfare, TNO, The Hague, The Netherlands
| | - Gerwin H Gelinck
- Holst Centre, TNO, High Tech Campus 31, 5656 AE, Eindhoven, The Netherlands.
| |
Collapse
|
16
|
Lin HCA, Deán-Ben XL, Ozbek A, Shao YH, Lafci B, Razansky D. Hybrid spherical array for combined volumetric optoacoustic and B-mode ultrasound imaging. OPTICS LETTERS 2024; 49:1469-1472. [PMID: 38489427 DOI: 10.1364/ol.503118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 01/14/2024] [Indexed: 03/17/2024]
Abstract
Optoacoustic (OA) imaging has achieved tremendous progress with state-of-the-art systems providing excellent functional and molecular contrast, centimeter scale penetration into living tissues, and ultrafast imaging performance, making it highly suitable for handheld imaging in the clinics. OA can greatly benefit from efficient integration with ultrasound (US) imaging, which remains the routine method in bedside clinical diagnostics. However, such integration has not been straightforward since the two modalities typically involve different image acquisition strategies. Here, we present a new, to our knowledge, hybrid optoacoustic ultrasound (OPUS) imaging approach employing a spherical array with dedicated segments for each modality to enable volumetric OA imaging merged with conventional B-mode US. The system performance is subsequently showcased in healthy human subjects. The new OPUS approach hence represents an important step toward establishing OA in point-of-care diagnostic settings.
Collapse
|
17
|
Prakash R, Manwar R, Avanaki K. Evaluation of 10 current image reconstruction algorithms for linear array photoacoustic imaging. JOURNAL OF BIOPHOTONICS 2024; 17:e202300117. [PMID: 38010300 DOI: 10.1002/jbio.202300117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 10/15/2023] [Accepted: 11/09/2023] [Indexed: 11/29/2023]
Abstract
Various reconstruction algorithms have been implemented for linear array photoacoustic imaging systems with the goal of accurately reconstructing the strength absorbers within the tissue being imaged. Since the existing algorithms have been introduced by different research groups and the context of performance evaluation was not consistent, it is difficult to make a fair comparison between them. In this study, we systematically compared the performance of 10 published image reconstruction algorithms (DAS, UBP, pDAS, DMAS, MV, EIGMV, SLSC, GSC, TR, and FD) using in-vitro phantom data. Evaluations were conducted based on lateral resolution of the reconstructed images, computational time, target detectability, and noise sensitivity. We anticipate the outcome of this study will assist researchers in selecting appropriate algorithms for their linear array PA imaging applications.
Collapse
Affiliation(s)
- Ravi Prakash
- The Richard and Loan Hill, Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Rayyan Manwar
- The Richard and Loan Hill, Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Kamran Avanaki
- The Richard and Loan Hill, Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois, USA
- Department of Dermatology, University of Illinois at Chicago, Chicago, Illinois, USA
| |
Collapse
|
18
|
Bourquin C, Porée J, Rauby B, Perrot V, Ghigo N, Belgharbi H, Bélanger S, Ramos-Palacios G, Cortes N, Ladret H, Ikan L, Casanova C, Lesage F, Provost J. Quantitative pulsatility measurements using 3D dynamic ultrasound localization microscopy. Phys Med Biol 2024; 69:045017. [PMID: 38181421 DOI: 10.1088/1361-6560/ad1b68] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 01/05/2024] [Indexed: 01/07/2024]
Abstract
A rise in blood flow velocity variations (i.e. pulsatility) in the brain, caused by the stiffening of upstream arteries, is associated with cognitive impairment and neurodegenerative diseases. The study of this phenomenon requires brain-wide pulsatility measurements, with large penetration depth and high spatiotemporal resolution. The development of dynamic ultrasound localization microscopy (DULM), based on ULM, has enabled pulsatility measurements in the rodent brain in 2D. However, 2D imaging accesses only one slice of the brain and measures only 2D-projected and hence biased velocities . Herein, we present 3D DULM: using a single ultrasound scanner at high frame rate (1000-2000 Hz), this method can produce dynamic maps of microbubbles flowing in the bloodstream and extract quantitative pulsatility measurements in the cat brain with craniotomy and in the mouse brain through the skull, showing a wide range of flow hemodynamics in both large and small vessels. We highlighted a decrease in pulsatility along the vascular tree in the cat brain, which could be mapped with ultrasound down to a few tens of micrometers for the first time. We also performed an intra-animal validation of the method by showing consistent measurements between the two sides of the Willis circle in the mouse brain. Our study provides the first step towards a new biomarker that would allow the detection of dynamic abnormalities in microvessels in the brain, which could be linked to early signs of neurodegenerative diseases.
Collapse
Affiliation(s)
- Chloé Bourquin
- Department of Engineering Physics, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada
| | - Jonathan Porée
- Department of Engineering Physics, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada
| | - Brice Rauby
- Department of Engineering Physics, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada
| | - Vincent Perrot
- Department of Engineering Physics, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada
| | - Nin Ghigo
- Department of Engineering Physics, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada
| | - Hatim Belgharbi
- Department of Engineering Physics, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC 27599, United States of America
| | | | | | - Nelson Cortes
- School of Optometry, University of Montreal, Montréal, QC H3T 1P1, Canada
| | - Hugo Ladret
- School of Optometry, University of Montreal, Montréal, QC H3T 1P1, Canada
- Institut de Neurosciences de la Timone, UMR 7289, CNRS and Aix-Marseille Université, Marseille, F-13005, France
| | - Lamyae Ikan
- School of Optometry, University of Montreal, Montréal, QC H3T 1P1, Canada
| | - Christian Casanova
- School of Optometry, University of Montreal, Montréal, QC H3T 1P1, Canada
| | - Frédéric Lesage
- Department of Electrical Engineering, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada
- Montreal Heart Institute, Montréal, QC H1T 1C8, Canada
| | - Jean Provost
- Department of Engineering Physics, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada
- Montreal Heart Institute, Montréal, QC H1T 1C8, Canada
| |
Collapse
|
19
|
Kukk AF, Scheling F, Panzer R, Emmert S, Roth B. Non-invasive 3D imaging of human melanocytic lesions by combined ultrasound and photoacoustic tomography: a pilot study. Sci Rep 2024; 14:2768. [PMID: 38307985 PMCID: PMC10837440 DOI: 10.1038/s41598-024-53220-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/30/2024] [Indexed: 02/04/2024] Open
Abstract
The accurate determination of the size and depth of infiltration is critical to the treatment and excision of melanoma and other skin cancers. However, current techniques, such as skin biopsy and histological examination, pose invasiveness, time-consumption, and have limitations in measuring at the deepest level. Non-invasive imaging techniques like dermoscopy and confocal microscopy also present limitations in accurately capturing contrast and depth information for various skin types and lesion locations. Thus, there is a pressing need for non-invasive devices capable of obtaining high-resolution 3D images of skin lesions. In this study, we introduce a novel device that combines 18 MHz ultrasound and photoacoustic tomography into a single unit, enabling the acquisition of colocalized 3D images of skin lesions. We performed in vivo measurements on 25 suspicious human skin nevi that were promptly excised following measurements. The combined ultrasound/photoacoustic tomography imaging technique exhibited a strong correlation with histological Breslow thickness between 0.2 and 3 mm, achieving a coefficient of determination (R[Formula: see text]) of 0.93, which is superior to the coefficients from the individual modalities. The results procured in our study underscore the potential of combined ultrasound and photoacoustic tomography as a promising non-invasive 3D imaging approach for evaluating human nevi and other skin lesions. Furthermore, the system allows for integration of other optical modalities such as optical coherence tomography, microscopy, or Raman spectroscopy in future applications.
Collapse
Affiliation(s)
- Anatoly Fedorov Kukk
- Hannover Centre for Optical Technologies, Leibniz University of Hannover, Nienburger Straße 17, 30167, Hannover, Germany.
| | - Felix Scheling
- Hannover Centre for Optical Technologies, Leibniz University of Hannover, Nienburger Straße 17, 30167, Hannover, Germany
| | - Rüdiger Panzer
- Clinic and Policlinic for Dermatology and Venereology, University Medical Center Rostock, Strempelstraße 13, 18057, Rostock, Germany
| | - Steffen Emmert
- Clinic and Policlinic for Dermatology and Venereology, University Medical Center Rostock, Strempelstraße 13, 18057, Rostock, Germany
| | - Bernhard Roth
- Hannover Centre for Optical Technologies, Leibniz University of Hannover, Nienburger Straße 17, 30167, Hannover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines), Welfengarten 1a, 30167, Hannover, Germany
| |
Collapse
|
20
|
Gao F, Li B, Chen L, Wei X, Shang Z, Liu C. Ultrasound image super-resolution reconstruction based on semi-supervised CycleGAN. ULTRASONICS 2024; 137:107177. [PMID: 37832382 DOI: 10.1016/j.ultras.2023.107177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 08/31/2023] [Accepted: 10/05/2023] [Indexed: 10/15/2023]
Abstract
In ultrasonic testing, diffraction artifacts generated around defects increase the challenge of quantitatively characterizing defects. In this paper, we propose a label-enhanced semi-supervised CycleGAN network model, referred to as LESS-CycleGAN, which is a conditional cycle generative adversarial network designed for accurately characterizing defect morphology in ultrasonic testing images. The proposed method introduces paired cross-domain image samples during model training to achieve a defect transformation between the ultrasound image domain and the morphology image domain, thereby eliminating artifacts. Furthermore, the method incorporates a novel authenticity loss function to ensure high-precision defect reconstruction capability. To validate the effectiveness and robustness of the model, we use simulated 2D images of defects and corresponding ultrasonic detection images as training and test sets, and an actual ultrasonic phased array image of a test block as the validation set to evaluate the model's application performance. The experimental results demonstrate that the proposed method is convenient and effective, achieving subwavelength-scale defect reconstruction with good robustness.
Collapse
Affiliation(s)
- Fei Gao
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Bing Li
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Lei Chen
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Xiang Wei
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Zhongyu Shang
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Chunman Liu
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| |
Collapse
|
21
|
Rosselló JM, Izak Ghasemian S, Ohl CD. High-speed ultrasound imaging of bubbly flows and shear waves in soft matter. SOFT MATTER 2024; 20:823-836. [PMID: 38167938 DOI: 10.1039/d3sm01546g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
In this methods paper, we explore the capabilities of high-speed ultrasound imaging (USI) to study fast varying and complex multi-phase structures in liquids and soft materials. Specifically, we assess the advantages and the limitations of this imaging technique through three distinct experiments involving rapid dynamics: the underwater flow induced by an external jet, the dissolution of sub-micron bubbles in water, and the propagation of shear waves in a soft elastic material. The phenomena were simultaneously characterized using optical microscopy and USI. In water, we use compounded USI for tracking a multi-phase flow produced by a jetting bubble diving into a liquid pool at speeds around 20 m s-1. These types of jets are produced by focusing a single laser pulse below the liquid surface. Upon breakup, they create a bubbly flow that exhibits high reflectivity to the ultrasound signal, enabling the visualization of the subsequent turbulent flow. In a second experiment, we demonstrate the potential of USI for recording the diffusive shrinkage of micro- and nanobubbles in water that could not be optically resolved. Puncturing an elastic material with a liquid jet creates shear waves that can be utilized for elastography measurements. We analysed the shape and speed of shear waves produced by different types of jetting bubbles in industrial gelatin. The wave characteristics were simultaneously determined by implementing particle velocimetry in optical and ultrasound measurements. For the latter, we employed a novel method to create homogeneously distributed micro- and nanobubbles in gelatin by illuminating it with a collimated laser beam.
Collapse
Affiliation(s)
- Juan Manuel Rosselló
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia.
- Otto von Guericke University Magdeburg, Institute of Physics, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Saber Izak Ghasemian
- Otto von Guericke University Magdeburg, Institute of Physics, Universitätsplatz 2, 39106 Magdeburg, Germany
| | - Claus-Dieter Ohl
- Otto von Guericke University Magdeburg, Institute of Physics, Universitätsplatz 2, 39106 Magdeburg, Germany
| |
Collapse
|
22
|
Tian Z, Olmstead M, Jing Y, Han A. Transcranial Phase Correction Using Pulse-Echo Ultrasound and Deep Learning: A 2-D Numerical Study. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2024; 71:117-126. [PMID: 38060357 PMCID: PMC10858766 DOI: 10.1109/tuffc.2023.3340597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Phase aberration caused by human skulls severely degrades the quality of transcranial ultrasound images, posing a major challenge in the practical application of transcranial ultrasound techniques in adults. Aberration can be corrected if the skull profile (i.e., thickness distribution) and speed of sound (SOS) are known. However, accurately estimating the skull profile and SOS using ultrasound with a physics-based approach is challenging due to the complexity of the interaction between ultrasound and the skull. A deep learning approach is proposed herein to estimate the skull profile and SOS using ultrasound radiofrequency (RF) signals backscattered from the skull. A numerical study was performed to test the approach's feasibility. Realistic numerical skull models were constructed from computed tomography (CT) scans of five ex vivo human skulls in this numerical study. Acoustic simulations were performed on 3595 skull segments to generate array-based ultrasound backscattered signals. A deep learning model was developed and trained to estimate skull thickness and SOS from RF channel data. The trained model was shown to be highly accurate. The mean absolute error (MAE) was 0.15 mm (2% error) for thickness estimation and 13 m/s (0.5% error) for SOS estimation. The Pearson correlation coefficient between the estimated and ground-truth values was 0.99 for thickness and 0.95 for SOS. Aberration correction performed using deep-learning-estimated skull thickness and SOS values yielded significantly improved beam focusing (e.g., narrower beams) and transcranial imaging quality (e.g., improved spatial resolution and reduced artifacts) compared with no aberration correction. The results demonstrate the feasibility of the proposed approach for transcranial phase aberration correction.
Collapse
|
23
|
Voorneveld J, Bosch JG. The Effect of Spatial Velocity Gradients on Block-Matching Accuracy for Ultrasound Velocimetry. ULTRASOUND IN MEDICINE & BIOLOGY 2024; 50:67-76. [PMID: 37821243 DOI: 10.1016/j.ultrasmedbio.2023.09.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 08/17/2023] [Accepted: 09/02/2023] [Indexed: 10/13/2023]
Abstract
OBJECTIVE Block matching serves as the foundation for ultrasound velocimetry techniques such as blood speckle tracking and echo-particle image velocimetry. Any spatial velocity gradients (SVGs) inside a block-matching pair will result in tracking error, due to both the finite block size and the ultrasound point-spread-function. We assess, using an in silico sinusoidal flow phantom, the effect of SVG magnitude and beam-to-flow angle on block-matching bias and precision. Secondarily we assess the effect that SVGs have on velocimetry bias when using angled plane-wave compounding. METHODS The magnitude and angle of SVGs were varied by adjusting the wavelength and direction of a sinusoidal flow profile. Scatterers displaced by this flow profile were used for simulating ultrasound radio frequency data at discrete time points. After beamforming, the 2-D flow field was estimated using block matching. Two imaging sequences were tested, a single plane-wave and a three-angled plane-wave. RESULTS Smaller sinusoidal flow wavelengths resulted in increased bias and reduced precision, revealing an inverse relationship between sinusoidal flow wavelength and tracking error, with median errors ranging from 69%-90% for the smallest flow wavelengths (highest SVGs) down to 3%-5% for the largest (lowest SVGs). The SVG angle was also important, in which lateral SVGs (with axially oriented flows) resulted in significant speckle decorrelation and high tracking errors in regions with high SVGs. Conversely, axial SVGs (laterally oriented flow) experienced higher bias in the peak velocity regions of the flow profile. Coherent compounding resulted in higher velocity errors than using a single transmission for lateral SVGs but not for axial SVGs. CONCLUSION The highest SVGs that could be measured with ≤10% error was when the sinusoidal flow wavelength was less than 20 times the ultrasound pulse wavelength. The clinical significance is that the high SVGs present in high kinetic energy flows, such as severe carotid stenosis and aortic regurgitation, will limit the ability to accurately quantify the velocities in these flow structures.
Collapse
Affiliation(s)
- Jason Voorneveld
- Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, The Netherlands.
| | - Johan G Bosch
- Department of Biomedical Engineering, Thorax Center, Erasmus Medical Center, Rotterdam, The Netherlands
| |
Collapse
|
24
|
Holmes PM, Lee HK, Urban MW. F-number optimization for synthetic aperture delay-multiply-and-sum reconstruction. ULTRASONICS 2024; 136:107158. [PMID: 37699304 DOI: 10.1016/j.ultras.2023.107158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/31/2023] [Accepted: 09/01/2023] [Indexed: 09/14/2023]
Abstract
The choices of transmit and receive f-numbers impact both ultrasound image contrast and spatial resolution. Although previous studies have evaluated the impact of receive f-number in delay-and-sum (DAS) plane wave imaging, there has not been a systematic study of f-numbers in DAS or delay-multiply-and-sum (DMAS) synthetic aperture (SA) imaging. In this study, we measured the impact on main lobe to side lobe energy ratio (MSER), generalized contrast-to-noise ratio (gCNR), and spatial resolution when varying receive and transmit f-numbers from 1 to 5 in 0.2 increments in DAS and DMAS reconstructed SA images. A wire target in a water tank and a standard imaging phantom were used to measure these metrics. From the water tank wire target images, higher MSER values were achieved with middle-range transmit f-numbers (2-4) and high receive f-numbers (>4) for both DAS and DMAS. From the phantom contrast target images, DAS produced images with high gCNR when using high transmit f-numbers (>4) and high receive f-numbers (>4). This came at the cost of reduced spatial resolution. DMAS produced images with high gCNR when using low transmit f-numbers (<3) and high receive f-numbers (>4). DMAS was not found to have as severe of a tradeoff in spatial resolution when seeking maximum gCNR. However, gCNR was typically lower for DMAS than DAS. For both DAS and DMAS, point target images had high spatial resolution when using low receive f-numbers (<2). Spatial resolution was typically higher for DMAS than DAS. Hanning apodization was found to produce similar trends as those found with rectangular apodization. These findings give insight on the behaviors of DAS and DMAS SA reconstruction algorithms and could be used to guide f-number selection.
Collapse
Affiliation(s)
- Philip M Holmes
- Mayo Clinic Graduate School of Biomedical Sciences, 200 First Street SW, Rochester, MN 55905, USA.
| | - Hyoung-Ki Lee
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
| | - Matthew W Urban
- Department of Radiology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
| |
Collapse
|
25
|
Yoon H, Kim J, Lee K, Song TK. Design and Implementation of Analog-Digital Hybrid Beamformers for Low-Complexity Ultrasound Systems: A Feasibility Study. Bioengineering (Basel) 2023; 11:8. [PMID: 38275576 PMCID: PMC10813642 DOI: 10.3390/bioengineering11010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/17/2023] [Accepted: 12/19/2023] [Indexed: 01/27/2024] Open
Abstract
Low-complexity ultrasound systems are increasingly desired for both wearable, point-of-care ultrasound and high-end massive-channel ultrasound for 3-D matrix imaging. However, the imaging capabilities, including spatial resolution and contrast, could suffer as low complexity systems are pursued, which remains as an unresolved tradeoff. To mitigate this limitation, this study revisits the general structures of analog and digital beamformers and introduces a hybrid approach, referred to as analog-digital hybrid beamforming, to implement efficient ultrasound systems. The suggested hybrid beamforming takes two stages sequentially, where the first analog stage partially beamforms M-channel RF signals to N sum-out data (i.e., M-to-N beamforming), and the second digital stage beamforms N partial sums to single final beamformed data (i.e., N-to-1 beamforming). Our approach was systematically designed and implemented with only four major integrated circuits, which was capable of driving full 64-channel transmission and reception. The developed system was demonstrated with a customized 64-channel 1-D phased array using a commercial tissue mimicking phantom. From the phantom imaging results, signal-to-noise ratio, contrast-to-noise ratio, and full beam width at half maximum values were quantitatively evaluated. The demonstrated results indicate that the analog-digital hybrid beamforming can be applied to any type of array for sophisticated 3-D imaging and tiny wearable ultrasound applications.
Collapse
Affiliation(s)
- Heechul Yoon
- School of Electronics and Electrical Engineering, Dankook University, Yongin-si 16890, Republic of Korea;
| | - Junseung Kim
- Department of Electronic Engineering, Sogang University, Seoul 04107, Republic of Korea
| | - Kunkyu Lee
- Department of Electronic Engineering, Sogang University, Seoul 04107, Republic of Korea
| | - Tai-Kyong Song
- Department of Electronic Engineering, Sogang University, Seoul 04107, Republic of Korea
| |
Collapse
|
26
|
Schiffner MF, Schmitz G. Comment on "So you think you can DAS? A viewpoint on delay-and-sum beamforming" [Ultrasonics 111 (2021) 106309]. ULTRASONICS 2023; 138:107221. [PMID: 38134514 DOI: 10.1016/j.ultras.2023.107221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023]
Abstract
It is shown herein that Perrot et al., who reviewed delay-and-sum beamforming for ultrafast ultrasound imaging in [Ultrasonics 111 (2021) 106309], misinterpreted the purpose of dynamic receive apertures. Such apertures widen with the focal length as a function of a given f-number and improve the image quality by suppressing grating lobes. Perrot et al., however, attributed erroneously the image quality improvement to suppression of measurement noise and, in doing so, proposed a suboptimal method to determine an f-number.
Collapse
Affiliation(s)
- Martin F Schiffner
- Chair of Medical Engineering, Ruhr University Bochum, 44780 Bochum, Germany.
| | - Georg Schmitz
- Chair of Medical Engineering, Ruhr University Bochum, 44780 Bochum, Germany.
| |
Collapse
|
27
|
Garcia D, Tamraoui M, Varray F. Think twice before f-numbering. ULTRASONICS 2023; 138:107222. [PMID: 38290386 DOI: 10.1016/j.ultras.2023.107222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 12/11/2023] [Indexed: 02/01/2024]
Abstract
In a 2021 paper, we delved into the details of delay-sum beamforming (DAS) in high-frame-rate ultrasound for medical imaging [1]. We also proposed a simple and fast method of determining an f-number, which is based on the directivity of the transducer elements. In their comment, Martin F. Schiffner and Georg Schmitz argue that we mistakenly link image quality enhancement to the reduction of measurement noise. They disapprove our proposed f-number, claiming it deteriorates the signal-to-noise ratio (SNR). Based on their previous work [2], they also highlight that the f-number should be derived from the grating lobe angles. In this reply, we explain their error in the SNR argument. We also illustrate the potential drawbacks of exclusively relying on grating lobes to establish an f-number with a DAS, suggesting that alternative approaches might be worthy of consideration.
Collapse
Affiliation(s)
- Damien Garcia
- CREATIS, CNRS UMR 5220, INSERM U1294, Université Lyon 1, INSA Lyon, France.
| | - Mohamed Tamraoui
- CREATIS, CNRS UMR 5220, INSERM U1294, Université Lyon 1, INSA Lyon, France.
| | - François Varray
- CREATIS, CNRS UMR 5220, INSERM U1294, Université Lyon 1, INSA Lyon, France.
| |
Collapse
|
28
|
Paul S, Mulani S, Singh MKA, Singh MS. Improvement of LED-based photoacoustic imaging using lag-coherence factor (LCF) beamforming. Med Phys 2023; 50:7525-7538. [PMID: 37843980 DOI: 10.1002/mp.16780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/18/2023] Open
Abstract
BACKGROUND Owing to its portability, affordability, and energy-efficiency, LED-based photoacoustic (PA) imaging is increasingly becoming popular when compared to its laser-based alternative, mainly for superficial vascular imaging applications. However, this technique suffers from low SNR and thereby limited imaging depth. As a result, visual image quality of LED-based PA imaging is not optimal, especially in sub-surface vascular imaging applications. PURPOSE Combination of linear ultrasound (US) probes and LED arrays are the most common implementation in LED-based PA imaging, which is currently being explored for different clinical imaging applications. Traditional delay-and-sum (DAS) is the most common beamforming algorithm in linear array-based PA detection. Side-lobes and reconstruction-related artifacts make the DAS performance unsatisfactory and poor for a clinical-implementation. In this work, we explored a new weighting-based image processing technique for LED-based PAs to yield improved image quality when compared to the traditional methods. METHODS We are proposing a lag-coherence factor (LCF), which is fundamentally based on the combination of the spatial auto-correlation of the detected PA signals. In LCF, the numerator contains lag-delay-multiply-and-sum (DMAS) beamformer instead of a conventional DAS beamformer. A spatial auto-correlation operation is performed between the detected US array signals before using DMAS beamformer. We evaluated the new method on both tissue-mimicking phantom (2D) and human volunteer imaging (3D) data acquired using a commercial LED-based PA imaging system. RESULTS Our novel correlation-based weighting technique showed LED-based PA image quality improvement when it is combined with conventional DAS beamformer. Both phantom and human volunteer imaging results gave a direct confirmation that by introducing LCF, image quality was improved and this method could reduce side-lobes and artifacts when compared to the DAS and coherence-factor (CF) approaches. Signal-to-noise ratio, generalized contrast-to-noise ratio, contrast ratio and spatial resolution were evaluated and compared with conventional beamformers to assess the reconstruction performance in a quantitative way. Results show that our approach offered image quality enhancement with an average signal-to-noise ratio and spatial resolution improvement of around 20% and 25% respectively, when compared with conventional CF based DAS algorithm. CONCLUSIONS Our results demonstrate that the proposed LCF based algorithm performs better than the conventional DAS and CF algorithms by improving signal-to-noise ratio and spatial resolution. Therefore, our new weighting technique could be a promising tool to improve the performance of LED-based PA imaging and thus accelerate its clinical translation.
Collapse
Affiliation(s)
- Souradip Paul
- School of physics, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | - Sufayan Mulani
- School of physics, Indian Institute of Science Education and Research, Thiruvananthapuram, Kerala, India
| | | | | |
Collapse
|
29
|
Lu J, Millioz F, Varray F, Poree J, Provost J, Bernard O, Garcia D, Friboulet D. Ultrafast Cardiac Imaging Using Deep Learning for Speckle-Tracking Echocardiography. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:1761-1772. [PMID: 37862280 DOI: 10.1109/tuffc.2023.3326377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
High-quality ultrafast ultrasound imaging is based on coherent compounding from multiple transmissions of plane waves (PW) or diverging waves (DW). However, compounding results in reduced frame rate, as well as destructive interferences from high-velocity tissue motion if motion compensation (MoCo) is not considered. While many studies have recently shown the interest of deep learning for the reconstruction of high-quality static images from PW or DW, its ability to achieve such performance while maintaining the capability of tracking cardiac motion has yet to be assessed. In this article, we addressed such issue by deploying a complex-weighted convolutional neural network (CNN) for image reconstruction and a state-of-the-art speckle-tracking method. The evaluation of this approach was first performed by designing an adapted simulation framework, which provides specific reference data, i.e., high-quality, motion artifact-free cardiac images. The obtained results showed that, while using only three DWs as input, the CNN-based approach yielded an image quality and a motion accuracy equivalent to those obtained by compounding 31 DWs free of motion artifacts. The performance was then further evaluated on nonsimulated, experimental in vitro data, using a spinning disk phantom. This experiment demonstrated that our approach yielded high-quality image reconstruction and motion estimation, under a large range of velocities and outperforms a state-of-the-art MoCo-based approach at high velocities. Our method was finally assessed on in vivo datasets and showed consistent improvement in image quality and motion estimation compared to standard compounding. This demonstrates the feasibility and effectiveness of deep learning reconstruction for ultrafast speckle-tracking echocardiography.
Collapse
|
30
|
Pi-Martín I, Cebrecos A, García-Garrigós JJ, Jiménez N, Camarena F. Spatial resolution and reconstructed size accuracy using advanced beamformers in linear array-based PAT systems. PHOTOACOUSTICS 2023; 34:100576. [PMID: 38174104 PMCID: PMC10761304 DOI: 10.1016/j.pacs.2023.100576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 11/14/2023] [Accepted: 11/27/2023] [Indexed: 01/05/2024]
Abstract
Limitations associated with linear-array probes in photoacoustic tomography are partially compensated by using advanced beamformers that exploit the temporal and spatial coherence of the recorded signals, such as Delay Multiply and Sum (DMAS), Minimum Variance (MV) or coherence factor (CF), among others. However, their associated signal processing leads to an overestimation of the spatial resolution, as well as alterations in the reconstructed object size. Numerical and experimental results reported here support this hypothesis. First, we show that the Rayleigh criterion (RC) is the most suitable choice to characterize the spatial resolution instead of the Point Spread Function (PSF) when considering advanced beamformers. Then, we observe that several advanced beamformers fail to properly reconstruct target sizes slightly above the spatial resolution, underestimating their size. This work sheds light on the suitability of this type of beamformers combined with linear probes for determining sizes and morphology in photoacoustic images.
Collapse
Affiliation(s)
- Irene Pi-Martín
- Instituto de Instrumentación para Imagen Molecular (i3M), CSIC – Universitat Politècnica de València, Camino de Vera S/N, 46022, Valencia, Spain
| | - Alejandro Cebrecos
- Instituto de Instrumentación para Imagen Molecular (i3M), CSIC – Universitat Politècnica de València, Camino de Vera S/N, 46022, Valencia, Spain
| | - Juan J. García-Garrigós
- Instituto de Instrumentación para Imagen Molecular (i3M), CSIC – Universitat Politècnica de València, Camino de Vera S/N, 46022, Valencia, Spain
| | - Noé Jiménez
- Instituto de Instrumentación para Imagen Molecular (i3M), CSIC – Universitat Politècnica de València, Camino de Vera S/N, 46022, Valencia, Spain
| | - Francisco Camarena
- Instituto de Instrumentación para Imagen Molecular (i3M), CSIC – Universitat Politècnica de València, Camino de Vera S/N, 46022, Valencia, Spain
| |
Collapse
|
31
|
Alvarez López Y, Las-Heras Andrés F. Improved Methods for Fourier-Based Microwave Imaging. SENSORS (BASEL, SWITZERLAND) 2023; 23:9250. [PMID: 38005636 PMCID: PMC10674512 DOI: 10.3390/s23229250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/08/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023]
Abstract
Fourier-based imaging has been widely adopted for microwave imaging thanks to its efficiency in terms of computational complexity without compromising image resolution. Together with other backpropagation imaging algorithms like delay-and-sum (DAS), they are based on a far-field approach to the electromagnetic expression relating to fields and sources. To improve the accuracy of these techniques, this contribution presents a modified version of the well-known Fourier-based algorithm by taking into account the field radiated by the Tx/Rx antennas of the microwave imaging system. The impact on the imaged targets is discussed, providing a quantitative and qualitative analysis. The performance of the proposed method for subsampled microwave imaging scenarios is compared against other well-known aliasing mitigation methods.
Collapse
Affiliation(s)
- Yuri Alvarez López
- Area of Signal Theory and Communications, Department of Electrical Engineering, Universidad de Oviedo, Edificio Polivalente, Mod. 8, Campus Universitario de Gijón, 33203 Gijón, Spain;
| | | |
Collapse
|
32
|
Wang W, Mokhtari AA, Srivastava A, Amirkhizi AV. Angle-dependent phononic dynamics for data-driven source localization. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 154:2904-2916. [PMID: 37938049 DOI: 10.1121/10.0022325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 10/14/2023] [Indexed: 11/09/2023]
Abstract
The source angle localization problem is studied based on scattering of elastic waves in two dimensions by a phononic array and the exceptional points of its band structure. Exceptional points are complex singularities of a parameterized eigen-spectrum, where two modes coalesce with identical mode shapes. These special points mark the qualitative transitions in the system behavior and have been proposed for sensing applications. The equi-frequency band structures are analyzed with focus on the angle-dependent modal behaviors. At the exceptional points and critical angles, the eigen-modes switch their energy characteristics and symmetry, leading to enhanced sensitivity as the scattering response of the medium is inherently angle-dependent. An artificial neural network is trained with randomly weighted and superposed eigen-modes to achieve deep learning of the angle-dependent dynamics. The trained algorithm can accurately classify the incident angle of an unknown scattering signal, with minimal sidelobe levels and suppressed main lobewidth. The neural network approach shows superior localization performance compared with standard delay-and-sum technique. The proposed application of the phononic array highlights the physical relevance of band topology and eigen-modes to a technological application, adds extra strength to the existing localization methods, and can be easily enhanced with the fast-growing data-driven techniques.
Collapse
Affiliation(s)
- Weidi Wang
- Department of Mechanical Engineering, University of Massachusetts, Lowell, Lowell, Massachusetts 01854, USA
| | - Amir Ashkan Mokhtari
- Department of Mechanical, Materials, and Aerospace Engineering, Illinois Institute of Technology, Chicago, Illinois 60616, USA
| | - Ankit Srivastava
- Department of Mechanical, Materials, and Aerospace Engineering, Illinois Institute of Technology, Chicago, Illinois 60616, USA
| | - Alireza V Amirkhizi
- Department of Mechanical Engineering, University of Massachusetts, Lowell, Lowell, Massachusetts 01854, USA
| |
Collapse
|
33
|
Malamal G, Schwab HM, Panicker MR. Enhanced Needle Visualization With Reflection Tuned Apodization Based on the Radon Transform for Ultrasound Imaging. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:1482-1493. [PMID: 37721881 DOI: 10.1109/tuffc.2023.3316284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
In ultrasound (US)-guided interventions, accurately tracking and visualizing needles during in-plane insertions are significant challenges due to strong directional specular reflections. These reflections violate the geometrical delay and apodization estimations in the conventional delay and sum beamforming (DASB) degrading the visualization of needles. This study proposes a novel reflection tuned apodization (RTA) to address this issue and facilitate needle enhancement through DASB. The method leverages both temporal and angular information derived from the Radon transforms of the radio frequency (RF) data from plane-wave imaging to filter the specular reflections from the needle and their directivity. The directivity information is translated into apodization center maps through time-to-space mapping in the Radon domain, which is subsequently integrated into DASB. We assess the influence of needle angulations, projection angles in the Radon transform, needle gauge sizes, and the presence of multiple specular interfaces on the approach. The analysis shows that the method surpasses conventional DASB in enhancing the image quality of needle interfaces while preserving the diffuse scattering from the surrounding tissues without significant computational overhead. The work offers promising prospects for improved outcomes in US-guided interventions and better insights into characterizing US reflections with Radon transforms.
Collapse
|
34
|
Bureau F, Robin J, Le Ber A, Lambert W, Fink M, Aubry A. Three-dimensional ultrasound matrix imaging. Nat Commun 2023; 14:6793. [PMID: 37880210 PMCID: PMC10600255 DOI: 10.1038/s41467-023-42338-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 10/05/2023] [Indexed: 10/27/2023] Open
Abstract
Matrix imaging paves the way towards a next revolution in wave physics. Based on the response matrix recorded between a set of sensors, it enables an optimized compensation of aberration phenomena and multiple scattering events that usually drastically hinder the focusing process in heterogeneous media. Although it gave rise to spectacular results in optical microscopy or seismic imaging, the success of matrix imaging has been so far relatively limited with ultrasonic waves because wave control is generally only performed with a linear array of transducers. In this paper, we extend ultrasound matrix imaging to a 3D geometry. Switching from a 1D to a 2D probe enables a much sharper estimation of the transmission matrix that links each transducer and each medium voxel. Here, we first present an experimental proof of concept on a tissue-mimicking phantom through ex-vivo tissues and then, show the potential of 3D matrix imaging for transcranial applications.
Collapse
Affiliation(s)
- Flavien Bureau
- Institut Langevin, ESPCI Paris, PSL University, CNRS, 75005, Paris, France
| | - Justine Robin
- Institut Langevin, ESPCI Paris, PSL University, CNRS, 75005, Paris, France
- Physics for Medicine, ESPCI Paris, PSL University, INSERM, CNRS, Paris, France
| | - Arthur Le Ber
- Institut Langevin, ESPCI Paris, PSL University, CNRS, 75005, Paris, France
| | - William Lambert
- Institut Langevin, ESPCI Paris, PSL University, CNRS, 75005, Paris, France
- Hologic / SuperSonic Imagine, 135 Rue Emilien Gautier, 13290, Aix-en-Provence, France
| | - Mathias Fink
- Institut Langevin, ESPCI Paris, PSL University, CNRS, 75005, Paris, France
| | - Alexandre Aubry
- Institut Langevin, ESPCI Paris, PSL University, CNRS, 75005, Paris, France.
| |
Collapse
|
35
|
Kukk AF, Scheling F, Panzer R, Emmert S, Roth B. Combined ultrasound and photoacoustic C-mode imaging system for skin lesion assessment. Sci Rep 2023; 13:17947. [PMID: 37864039 PMCID: PMC10589211 DOI: 10.1038/s41598-023-44919-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 10/13/2023] [Indexed: 10/22/2023] Open
Abstract
Accurate assessment of the size and depth of infiltration is critical for effectively treating and removing skin cancer, especially melanoma. However, existing methods such as skin biopsy and histologic examination are invasive, time-consuming, and may not provide accurate depth results. We present a novel system for simultaneous and co-localized ultrasound and photoacoustic imaging, with the application for non-invasive skin lesion size and depth measurement. The developed system integrates an acoustical mirror that is placed on an ultrasound transducer, which can be translated within a flexible water tank. This allows for 3D (C-mode) imaging, which is useful for mapping the skin structure and determine the invasion size and depth of lesions including skin cancer. For efficient reconstruction of photoacoustic images, we applied the open-source MUST library. The acquisition time per 2D image is <1 s and the pulse energies are below the legal Maximum Permissible Exposure (MPE) on human skin. We present the depth and resolution capabilities of the setup on several self-designed agar phantoms and demonstrate in vivo imaging on human skin. The setup also features an unobstructed optical window from the top, allowing for simple integration with other optical modalities. The perspective towards clinical application is demonstrated.
Collapse
Affiliation(s)
- Anatoly Fedorov Kukk
- Hannover Centre for Optical Technologies, Leibniz University of Hannover, Nienburger Straße 17, 30167, Hannover, Germany.
| | - Felix Scheling
- Hannover Centre for Optical Technologies, Leibniz University of Hannover, Nienburger Straße 17, 30167, Hannover, Germany
| | - Rüdiger Panzer
- Clinic and Policlinic for Dermatology and Venereology, University Medical Center Rostock, Strempelstraße 13, 18057, Rostock, Germany
| | - Steffen Emmert
- Clinic and Policlinic for Dermatology and Venereology, University Medical Center Rostock, Strempelstraße 13, 18057, Rostock, Germany
| | - Bernhard Roth
- Hannover Centre for Optical Technologies, Leibniz University of Hannover, Nienburger Straße 17, 30167, Hannover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines), Welfengarten 1a, 30167, Hannover, Germany
| |
Collapse
|
36
|
Park H, Yao J, Jing Y. A frequency-domain model-based reconstruction method for transcranial photoacoustic imaging: A 2D numerical investigation. PHOTOACOUSTICS 2023; 33:100561. [PMID: 38021290 PMCID: PMC10658607 DOI: 10.1016/j.pacs.2023.100561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 12/01/2023]
Abstract
Phase aberration caused by the skull is a major barrier to achieving high quality photoacoustic images of human and non-human primates' brains. To address this issue, time-reversal methods have been used but they are computationally demanding and slow due to relying on solving the full-wave equation. The proposed approach is based on model-based image reconstruction in the frequency-domain to achieve near real-time image reconstruction. The relationship between an imaging region and transducer array elements can be mathematically described as a model matrix and the image reconstruction can be performed by pseudo-inverse of the model matrix. The model matrix is numerically calculated due to the lack of analytical solutions for transcranial ultrasound. However, this calculation only needs to be performed once for a given experimental setup and the same acoustic medium, and is an offline process not affecting the actual image reconstruction time. This non-iterative mode-based method demonstrates a substantial improvement in image reconstruction time, being approximately 18 times faster than the time-reversal method, all while maintaining comparable image quality.
Collapse
Affiliation(s)
- Hyungjoo Park
- The Graduate Program in Acoustics, The Pennsylvania State University, University Park, PA 16802, USA
| | - Junjie Yao
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Yun Jing
- The Graduate Program in Acoustics, The Pennsylvania State University, University Park, PA 16802, USA
| |
Collapse
|
37
|
Schweizer D, Rau R, Bezek CD, Kubik-Huch RA, Goksel O. Robust Imaging of Speed of Sound Using Virtual Source Transmission. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:1308-1318. [PMID: 37549087 DOI: 10.1109/tuffc.2023.3303172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Speed of sound (SoS) is a novel imaging biomarker for assessing the biomechanical characteristics of soft tissues. SoS imaging in the pulse-echo mode using conventional ultrasound (US) systems with hand-held transducers has the potential to enable new clinical uses. Recent work demonstrated that diverging waves (DWs) from a single element (SE) transmit to outperform plane-wave sequences. However, SE transmits have severely limited power and hence produce a low signal-to-noise ratio (SNR) in echo data. We herein propose Walsh-Hadamard (WH) coded and virtual-source (VS) transmit sequences for the improved SNR in SoS imaging. We additionally present an iterative method of estimating beamforming (BF) SoS in the medium, which otherwise confounds SoS reconstructions due to beamforming inaccuracies in the images used for reconstruction. Through numerical simulations, phantom experiments, and in vivo imaging data, we show that WH is not robust against motion, which is often unavoidable in clinical imaging scenarios. Our proposed VS sequence is shown to provide the highest SoS reconstruction performance, especially robust to motion artifacts. In phantom experiments, despite having a comparable SoS root-mean-square error (RMSE) of 17.5-18.0 m/s at rest, with a minor axial probe motion of ≈ 0.67 mm/s the RMSE for SE, WH, and VS already deteriorate to 20.2, 105.4, and 19.0 m/s, respectively, showing that WH produces unacceptable results, not robust to motion. In the clinical data, the high SNR and motion resilience of VS sequences are seen to yield superior contrast compared to SE and WH sequences.
Collapse
|
38
|
Schiffner MF, Schmitz G. Frequency-Dependent F-Number Suppresses Grating Lobes and Improves the Lateral Resolution in Coherent Plane-Wave Compounding. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:1101-1117. [PMID: 37399162 DOI: 10.1109/tuffc.2023.3291612] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
Ultrafast imaging modes, such as coherent plane-wave compounding (CPWC), increase image uniformity and reduce grating lobe artifacts by dynamic receive apertures. The focal length and the desired aperture width maintain a given ratio, which is called the F -number. Fixed F -numbers, however, exclude useful low-frequency components from the focusing and reduce the lateral resolution. Herein, this reduction is avoided by a frequency-dependent F -number. This F -number derives from the far-field directivity pattern of a focused aperture and can be expressed in closed form. The F -number, at low frequencies, widens the aperture to improve the lateral resolution. The F -number, at high frequencies, narrows the aperture to avoid lobe overlaps and suppress grating lobes. Phantom and in vivo experiments with a Fourier-domain beamforming algorithm validated the proposed F -number in CPWC. The lateral resolution, which was measured by the median lateral full-widths at half-maximum of wires, improved by up to 46.8% and 14.9% in a wire and a tissue phantom, respectively, in comparison to fixed F -numbers. Grating lobe artifacts, which were measured by the median peak signal-to-noise ratios of wires, reduced by up to 9.9 dB in comparison to the full aperture. The proposed F -number thus outperformed F -numbers that were recently derived from the directivity of the array elements.
Collapse
|
39
|
Hashemi HS, Mohammed SK, Zeng Q, Azar RZ, Rohling RN, Salcudean SE. 3-D Ultrafast Shear Wave Absolute Vibro-Elastography Using a Matrix Array Transducer. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:1039-1053. [PMID: 37235463 DOI: 10.1109/tuffc.2023.3280450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Real-time ultrasound imaging plays an important role in ultrasound-guided interventions. The 3-D imaging provides more spatial information compared to conventional 2-D frames by considering the volumes of data. One of the main bottlenecks of 3-D imaging is the long data acquisition time, which reduces practicality and can introduce artifacts from unwanted patient or sonographer motion. This article introduces the first shear wave absolute vibro-elastography (S-WAVE) method with real-time volumetric acquisition using a matrix array transducer. In S-WAVE, an external vibration source generates mechanical vibrations inside the tissue. The tissue motion is then estimated and used in solving a wave equation inverse problem to provide the tissue elasticity. A matrix array transducer is used with a Verasonics ultrasound machine and a frame rate of 2000 volumes/s to acquire 100 radio frequency (RF) volumes in 0.05 s. Using plane wave (PW) and compounded diverging wave (CDW) imaging methods, we estimate axial, lateral, and elevational displacements over 3-D volumes. The curl of the displacements is used with local frequency estimation to estimate elasticity in the acquired volumes. Ultrafast acquisition extends substantially the possible S-WAVE excitation frequency range, now up to 800 Hz, enabling new tissue modeling and characterization. The method was validated on three homogeneous liver fibrosis phantoms and on four different inclusions within a heterogeneous phantom. The homogeneous phantom results show less than 8% (PW) and 5% (CDW) difference between the manufacturer values and the corresponding estimated values over a frequency range of 80-800 Hz. The estimated elasticity values for the heterogeneous phantom at 400-Hz excitation frequency show the average errors of 9% (PW) and 6% (CDW) compared to the provided average values by magnetic resonance elastography (MRE). Furthermore, both imaging methods were able to detect the inclusions within the elasticity volumes. An ex vivo study on a bovine liver sample shows less than 11% (PW) and 9% (CDW) difference between the estimated elasticity ranges by the proposed method and the elasticity ranges provided by MRE and acoustic radiation force impulse (ARFI).
Collapse
|
40
|
Lee HK, Holmes PM, Greenleaf JF, Urban MW. Comb Detection for Measuring Shear Wave Propagation. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:1135-1145. [PMID: 37471186 PMCID: PMC10529181 DOI: 10.1109/tuffc.2023.3297394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Plane wave compounding (PWC) is widely used to measure the propagation of shear waves. Implementing PWC on most commercial ultrasound scanners is challenging because all channel (>128) data must be processed or transferred to the host computing unit in real time. Comb detection transmits multiple focused beams simultaneously and results in a reduced number of receive lines to be processed in parallel. These comb beams are scanned laterally to acquire receive lines at different lateral positions in order to obtain data over a large region of interest (ROI). One of the potential issues with using multiple simultaneously transmitted beams is the issue of crosstalk between the beams. Crosstalk is analyzed through simulated beam patterns, simulated B-mode images, and motion data from shear wave elastography (SWE) experiments. Using a Hamming window on transmit and receive can suppress crosstalk to 1.2% root-mean-square error (RMSE, normalized RMSE to the peak magnitude of the reference signal) for shear wave motion signals. Four comb beams with three laterally scanned locations cover almost the entire field of view (FOV) and achieve the same frame rate as PWC with three angles. Phantom and in vivo studies demonstrate comparable motion data of comb detection to PWC in terms of motion signal quality and measured phase velocity. In addition, comb detection provides motion with lower noise and stronger signals than PWC, which is believed to be due to the advantages of transmitting focused beams rather than plane waves (PWs).
Collapse
|
41
|
Wasih M, Ahmad S, Almekkawy M. A robust cascaded deep neural network for image reconstruction of single plane wave ultrasound RF data. ULTRASONICS 2023; 132:106981. [PMID: 36913830 DOI: 10.1016/j.ultras.2023.106981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 05/29/2023]
Abstract
Reconstruction of ultrasound data from single plane wave Radio Frequency (RF) data is a challenging task. The traditional Delay and Sum (DAS) method produces an image with low resolution and contrast, if employed with RF data from only a single plane wave. A Coherent Compounding (CC) method that reconstructs the image by coherently summing the individual DAS images was proposed to enhance the image quality. However, CC relies on a large number of plane waves to accurately sum the individual DAS images, hence it produces high quality images but with low frame rate that may not be suitable for time-demanding applications. Therefore, there is a need for a method that can create a high quality image with higher frame rates. Furthermore, the method needs to be robust against the input transmission angle of the plane wave. To reduce the method's dependence on the input angle, we propose to unify the RF data at different angles by learning a linear data transformation from different angled data to a common, 0° data. We further propose a cascade of two independent neural networks to reconstruct an image, similar in quality to CC, by making use of a single plane wave. The first network, denoted as "PixelNet", is a fully Convolutional Neural Network (CNN) which takes in the transformed time-delayed RF data as input. PixelNet learns optimal pixel weights that get element-wise multiplied with the single angle DAS image. The second network is a conditional Generative Adversarial Network (cGAN) which is used to further enhance the image quality. Our networks were trained on the publicly available PICMUS and CPWC datasets and evaluated on a completely separate, CUBDL dataset obtained from different acquisition settings than the training dataset. The results thus obtained on the testing dataset, demonstrate the networks' ability to generalize well on unseen data, with frame rates better than the CC method. This paves the way for applications that require high-quality images reconstructed at higher frame rates.
Collapse
Affiliation(s)
- Mohammad Wasih
- The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Sahil Ahmad
- The Pennsylvania State University, University Park, PA, 16802, USA.
| | | |
Collapse
|
42
|
Pialot B, Augeul L, Petrusca L, Varray F. A simplified and accelerated implementation of SVD for filtering ultrafast power Doppler images. ULTRASONICS 2023; 134:107099. [PMID: 37418815 DOI: 10.1016/j.ultras.2023.107099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/05/2023] [Accepted: 06/28/2023] [Indexed: 07/09/2023]
Abstract
BACKGROUND AND OBJECTIVE Ultrafast Power Doppler (UPD) is a growing ultrasound modality for imaging and diagnosing microvasculature disease. A key element of UPD is using singular value decomposition (SVD) as a highly selective filter for tissue and electronic noise. However, two significant drawbacks of SVD are its computational burden and the complexity of its algorithms. These limitations hinder the development of fast and specific SVD algorithms for UPD imaging. This study introduces power SVD (pSVD), a simplified and accelerated algorithm for filtering tissue and noise in UPD images. METHODS pSVD exploits several mathematical properties of SVD specific to UPD images. In particular, pSVD allows the direct computation of blood-related SVD components from the temporal singular vectors. This feature simplifies the expression of SVD while significantly accelerating its computation. After detailing the theory behind pSVD, we evaluate its performances in several in vitro and in vivo experiments and compare it to SVD and randomized SVD (rSVD). RESULTS pSVD strongly decreases the running time of SVD (between 5 and 12 times in vivo) without impacting the quality of UPD images. Compared to rSVD, pSVD can be significantly faster (up to 3 times) or slightly slower but gives access to more estimators to isolate tissue subspaces. CONCLUSION pSVD is highly valuable for implementing UPD imaging in clinical ultrasound and provides a better understanding of SVD for ultrasound imaging in general.
Collapse
Affiliation(s)
- Baptiste Pialot
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, CREATIS UMR 5220, U1294, F-69621, Lyon, France.
| | - Lionel Augeul
- INSERM UMR-1060, Laboratoire CarMeN, Université Lyon 1, Faculté de Médecine, Rockefeller, Lyon, France
| | - Lorena Petrusca
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, CREATIS UMR 5220, U1294, F-69621, Lyon, France
| | - François Varray
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, CREATIS UMR 5220, U1294, F-69621, Lyon, France
| |
Collapse
|
43
|
Holmes PM, Chen KH, Lee HK, Fitzsimmons JS, O'Driscoll SW, Urban MW. Improving Visualization of Osteochondritis Dissecans Using Delay-Multiply-and-Sum Reconstruction. ULTRASOUND IN MEDICINE & BIOLOGY 2023:S0301-5629(23)00147-3. [PMID: 37357080 DOI: 10.1016/j.ultrasmedbio.2023.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 04/26/2023] [Accepted: 05/01/2023] [Indexed: 06/27/2023]
Abstract
OBJECTIVE Osteochondritis dissecans (OCD) of the capitellum is a joint defect that is common among adolescent athletes. It is important to diagnose OCD as early as possible, because early-stage OCD lesions have a high rate of spontaneous healing with rest. Medical ultrasound could potentially be used as a screening tool for OCD but is limited by the use of delay-and-sum (DAS) reconstruction. In this study, we tested conventional delay-multiply-and-sum (DMAS) and novel low-pass DMAS reconstruction algorithms for better visualization of OCD lesions. METHODS We created phantom and cadaveric OCD models that simulated a range of OCD lesion severities and stabilities. We also imaged an in vivo case of OCD in a patient study. In the reconstructed images, several profiles were taken to measure OCD lesion contrast, cartilage contrast, crack thickness error and bone interface clarity. RESULTS In the phantom and cadaveric OCD models, we found that histogram-matched conventional DMAS reconstruction improved lesion contrast by up to 16%, cartilage contrast by 26% and bone interface clarity by 15% on average compared with DAS reconstruction. Histogram-matched low-pass DMAS reconstruction improved lesion contrast by up to 22%, cartilage contrast by 45%, and bone interface clarity by 29% on average compared with DAS reconstruction. In the in vivo case of OCD, we found that histogram-matched conventional and low-pass DMAS reconstruction improved lesion contrast by 22% and 26%, respectively. CONCLUSION The application of DMAS reconstruction improved the ability of medical ultrasound to detect OCD lesions of the capitellum when compared with DAS reconstruction.
Collapse
Affiliation(s)
- Philip M Holmes
- Mayo Clinic Graduate School of Biomedical Sciences, Rochester, MN, USA.
| | - Kun-Hui Chen
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Hyoung-Ki Lee
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | | | | | | |
Collapse
|
44
|
Liang S, Wang L. A study of wide unfocused wavefront for convex-array ultrasound imaging. ULTRASONICS 2023; 134:107080. [PMID: 37320966 DOI: 10.1016/j.ultras.2023.107080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/05/2023] [Accepted: 06/09/2023] [Indexed: 06/17/2023]
Abstract
Ultrafast ultrasound imaging modalities have attracted a lot of attention in the ultrasound community. It breaks the compromise between the frame rate and the region of interest by insonifying the whole medium with wide unfocused waves. Coherent compounding can be performed to enhance the image quality at a cost of frame rate. Ultrafast imaging has wide clinical applications, such as vector Doppler imaging and shear elastography. On the other hand, the use of unfocused waves is still marginal with convex-array transducers. For convex array, plane wave imaging is limited by the complicated transmission delay calculation, limited field-of-view, and inefficient coherent compounding. In this article, we study three wide unfocused wavefronts, namely, lateral virtual-source defined diverging wave imaging (latDWI), tilt virtual-source defined diverging wave imaging (tiltDWI), and Archimedean-spiral-based imaging (AMI) for convex-array imaging using the full-aperture transmission. The analytical monochromatic wave solutions to this three imaging are given. The mainlobe width and grating lobe position are given explicitly. Theoretical -6 dB beamwidth and synthetic transmit field response are studied. Simulation studies are carried on with the point targets and hypoechoic cysts. Time-of-flight formulas are given explicitly for beamforming. The conclusions are in good agreement with the theory: latDWI provides the finest lateral resolution but generates the severest axial lobe level for scatterers with large obliquities (i.e., for scatterers located at the image border) which degrades the image contrast. This effect gets worsen as the compound number increases. The tiltDWI and AMI give a very close performance on resolution and image contrast. AMI displays better contrast with a small compound number.
Collapse
Affiliation(s)
- Siyi Liang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong Special Administrative Region
| | - Lidai Wang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong Special Administrative Region.
| |
Collapse
|
45
|
Bezek CD, Goksel O. Analytical estimation of beamforming speed-of-sound using transmission geometry. ULTRASONICS 2023; 134:107069. [PMID: 37331051 DOI: 10.1016/j.ultras.2023.107069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/28/2023] [Accepted: 06/04/2023] [Indexed: 06/20/2023]
Abstract
Most ultrasound imaging techniques necessitate the fundamental step of converting temporal signals received from transducer elements into a spatial echogenecity map. This beamforming (BF) step requires the knowledge of speed-of-sound (SoS) value in the imaged medium. An incorrect assumption of BF SoS leads to aberration artifacts, not only deteriorating the quality and resolution of conventional brightness mode (B-mode) images, hence limiting their clinical usability, but also impairing other ultrasound modalities such as elastography and spatial SoS reconstructions, which rely on faithfully beamformed images as their input. In this work, we propose an analytical method for estimating BF SoS. We show that pixel-wise relative shifts between frames beamformed with an assumed SoS is a function of geometric disparities of the transmission paths and the error in such SoS assumption. Using this relation, we devise an analytical model, the closed form solution of which yields the difference between the assumed and the true SoS in the medium. Based on this, we correct the BF SoS, which can also be applied iteratively. Both in simulations and experiments, lateral B-mode resolution is shown to be improved by ≈25% compared to that with an initial SoS assumption error of 3.3% (50m/s), while localization artifacts from beamforming are also corrected. After 5 iterations, our method achieves BF SoS errors of under 0.6m/s in simulations. Residual time-delay errors in beamforming 32 numerical phantoms are shown to reduce down to 0.07μs, with average improvements of up to 21 folds compared to initial inaccurate assumptions. We additionally show the utility of the proposed method in imaging local SoS maps, where using our correction method reduces reconstruction root-mean-square errors substantially, down to their lower-bound with actual BF SoS.
Collapse
Affiliation(s)
- Can Deniz Bezek
- Department of Information Technology, Uppsala University, Sweden
| | - Orcun Goksel
- Department of Information Technology, Uppsala University, Sweden.
| |
Collapse
|
46
|
García-Unzueta EE, Mendez-Monroy PE, Rascon C. On the Challenges of Acoustic Energy Mapping Using a WASN: Synchronization and Audio Capture. SENSORS (BASEL, SWITZERLAND) 2023; 23:4645. [PMID: 37430559 DOI: 10.3390/s23104645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 07/12/2023]
Abstract
Acoustic energy mapping provides the functionality to obtain characteristics of acoustic sources, as: presence, localization, type and trajectory of sound sources. Several beamforming-based techniques can be used for this purpose. However, they rely on the difference of arrival times of the signal at each capture node (or microphone), so it is of major importance to have synchronized multi-channel recordings. A Wireless Acoustic Sensor Network (WASN) can be very practical to install when used for mapping the acoustic energy of a given acoustic environment. However, they are known for having low synchronization between the recordings from each node. The objective of this paper is to characterize the impact of current popular synchronization methodologies as part of the WASN to capture reliable data to be used for acoustic energy mapping. The two evaluated synchronization protocols are: Network Time Protocol (NTP) y Precision Time Protocol (PTP). Additionally, three different audio capture methodologies were proposed for the WASN to capture the acoustic signal: two of them, recording the data locally and one sending the data through a local wireless network. As a real-life evaluation scenario, a WASN was built using nodes conformed by a Raspberry Pi 4B+ with a single MEMS microphone. Experimental results demonstrate that the most reliable methodology is using the PTP synchronization protocol and audio recording locally.
Collapse
Affiliation(s)
- Emiliano Ehecatl García-Unzueta
- Posgrado de Ingeneria Electrica, Universidad Nacional Autónoma de México (UNAM), Universidad 3000, Mexico City 04510, Mexico
| | - Paul Erick Mendez-Monroy
- Unidad Académica del IIMAS en el Estado de Yucatán, Universidad Nacional Autónoma de México (UNAM), Parque Científico y Tecnológico de Yucatán, Yucatán 97302, Mexico
| | - Caleb Rascon
- Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas (IIMAS), Universidad Nacional Autónoma de México (UNAM), Circuito Escolar 3000, Mexico City 04510, Mexico
| |
Collapse
|
47
|
Ahmed R, Foiret J, Ferrara K, Trahey GE. Large-Array Deep Abdominal Imaging in Fundamental and Harmonic Mode. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2023; 70:406-421. [PMID: 37028314 PMCID: PMC10259265 DOI: 10.1109/tuffc.2023.3255800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Deep abdominal images suffer from poor diffraction-limited lateral resolution. Extending the aperture size can improve resolution. However, phase distortion and clutter can limit the benefits of larger arrays. Previous studies have explored these effects using numerical simulations, multiple transducers, and mechanically swept arrays. In this work, we used an 8.8-cm linear array transducer to investigate the effects of aperture size when imaging through the abdominal wall. We acquired channel data in fundamental and harmonic modes using five aperture sizes. To avoid motion and increase the parameter sampling, we decoded the full-synthetic aperture data and retrospectively synthesized nine apertures (2.9-8.8 cm). We imaged a wire target and a phantom through ex vivo porcine abdominal samples and scanned the livers of 13 healthy subjects. We applied bulk sound speed correction to the wire target data. Although point resolution improved from 2.12 to 0.74 mm at 10.5 cm depth, contrast resolution often degraded with aperture size. In subjects, larger apertures resulted in an average maximum contrast degradation of 5.5 dB at 9-11 cm depth. However, larger apertures often led to visual detection of vascular targets unseen with conventional apertures. An average 3.7-dB contrast improvement over fundamental mode in subjects showed that the known benefits of tissue-harmonic imaging extend to larger arrays.
Collapse
|
48
|
Wu X, Li Y, Su C, Li P, Wang X, Lin W. Ultrasound computed tomography based on full waveform inversion with source directivity calibration. ULTRASONICS 2023; 132:107004. [PMID: 37071945 DOI: 10.1016/j.ultras.2023.107004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 03/06/2023] [Accepted: 03/31/2023] [Indexed: 05/03/2023]
Abstract
Ultrasound computed tomography based on full waveform inversion has the potential to provide high-resolution images of human tissues in a quantitative manner. A successful ultrasound computed tomography system requires the decent knowledge of acquisition array, including the spatial position and the directivity of each transducer, to meet the high-level demand of clinical applications. The conventional full waveform inversion algorithm assumes a point source with the omni-directional emission. Such assumption does not hold when the directivity of emitting transducer is not negligible. For a practical implementation, an efficient and accurate self-checking evaluation of directivity is crucial prior to the reconstruction of images. We propose to measure the directivity of each emitting transducer using the full-matrix captured data obtained with a water-immersed and target-free experiment. We introduce the weighted virtual point-source array to act as the proxy of emitting transducer during the numerical simulation. The weights of different points in the virtual array can be calculated from the observed data using the gradient-based local optimization method. Although the full waveform imaging method relies on the finite-difference solver of wave equation, such directivity estimation benefits from the introduction of analytical solver. The trick significantly reduces the numerical cost, enabling an automatic directivity self-check at boot. We verify the feasibility, efficiency, and accuracy of the virtual array method through simulated and experimental tests. For the experimental test, we also illustrate that full waveform inversion with directivity calibration can reduce the artifacts introduced by the conventional point source assumption, improving the quality of reconstructed images..
Collapse
Affiliation(s)
- Xiaoqing Wu
- Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yubing Li
- Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China.
| | - Chang Su
- Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Panpan Li
- Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiangda Wang
- Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China; Ruyuan Yao Autonomous Dongyangguang Industrial Development Co. Ltd, Shaoguan 512721, China
| | - Weijun Lin
- Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
49
|
Boger-Lombard J, Slobodkin Y, Katz O. Towards passive non-line-of-sight acoustic localization around corners using uncontrolled random noise sources. Sci Rep 2023; 13:4952. [PMID: 36973284 PMCID: PMC10043274 DOI: 10.1038/s41598-023-31490-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 03/13/2023] [Indexed: 03/29/2023] Open
Abstract
Non-line-of-sight (NLoS) imaging is an important challenge in many fields ranging from autonomous vehicles and smart cities to defense applications. Several recent works in optics and acoustics tackle the challenge of imaging targets hidden from view (e.g. placed around a corner) by measuring time-of-flight information using active SONAR/LiDAR techniques, effectively mapping the Green functions (impulse responses) from several controlled sources to an array of detectors. Here, leveraging passive correlations-based imaging techniques (also termed 'acoustic daylight imaging'), we study the possibility of acoustic NLoS target localization around a corner without the use of controlled active sources. We demonstrate localization and tracking of a human subject hidden around a corner in a reverberating room using Green functions retrieved from correlations of broadband uncontrolled noise sources recorded by multiple detectors. Our results demonstrate that for NLoS localization controlled active sources can be replaced by passive detectors as long as a sufficiently broadband noise is present in the scene.
Collapse
Affiliation(s)
- Jeremy Boger-Lombard
- Department of Applied Physics, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel
| | - Yevgeny Slobodkin
- Department of Applied Physics, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel
| | - Ori Katz
- Department of Applied Physics, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel.
| |
Collapse
|
50
|
Malamal G, Panicker MR. On the physics of ultrasound transmission for in-plane needle tracking in guided interventions. Biomed Phys Eng Express 2023; 9. [PMID: 36898145 DOI: 10.1088/2057-1976/acc338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 03/10/2023] [Indexed: 03/12/2023]
Abstract
Objective.In ultrasound (US) guided interventions, the accurate visualization and tracking of needles is a critical challenge, particularly during in-plane insertions. An inaccurate identification and localization of needles lead to severe inadvertent complications and increased procedure times. This is due to the inherent specular reflections from the needle with directivity depending on the angle of incidence of the US beam, and the needle inclination.Approach.Though several methods have been proposed for improved needle visualization, a detailed study emphasizing the physics of specular reflections resulting from the interaction of transmitted US beam with the needle remains to be explored. In this work, we discuss the properties of specular reflections from planar and spherical wave US transmissions respectively through multi-angle plane wave (PW) and synthetic transmit aperture (STA) techniques for in-plane needle insertion angles between 15°-50°.Main Results.The qualitative and quantitative results from simulations and experiments reveal that the spherical waves enable better visualization and characterization of needles than planar wavefronts. The needle visibility in PW transmissions is severely degraded by the receive aperture weighting during image reconstruction than STA due to greater deviation in reflection directivity. It is also observed that the spherical wave characteristics starts to alter to planar characteristics due to wave divergence at large needle insertion depths.Significance.The study highlights that synergistic transmit-receive imaging schemes addressing the physical properties of reflections from the transmit wavefronts are imperative for the precise imaging of needle interfaces and hence have strong potential in elevating the quality of outcomes from US guided interventional practices.
Collapse
Affiliation(s)
- Gayathri Malamal
- Center for Computational Imaging, Dept. of Electrical Engineering, Indian Institute of Technology Palakkad, India
| | | |
Collapse
|