1
|
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
|
2
|
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
|
3
|
Manwar R, Kratkiewicz K, Mahmoodkalayeh S, Hariri A, Papadelis C, Hansen A, Pillers DAM, Gelovani J, Avanaki K. Development and characterization of transfontanelle photoacoustic imaging system for detection of intracranial hemorrhages and measurement of brain oxygenation: Ex-vivo. PHOTOACOUSTICS 2023; 32:100538. [PMID: 37575972 PMCID: PMC10413353 DOI: 10.1016/j.pacs.2023.100538] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 06/28/2023] [Accepted: 07/19/2023] [Indexed: 08/15/2023]
Abstract
We have developed and optimized an imaging system to study and improve the detection of brain hemorrhage and to quantify oxygenation. Since this system is intended to be used for brain imaging in neonates through the skull opening, i.e., fontanelle, we called it, Transfontanelle Photoacoustic Imaging (TFPAI) system. The system is optimized in terms of optical and acoustic designs, thermal safety, and mechanical stability. The lower limit of quantification of TFPAI to detect the location of hemorrhage and its size is evaluated using in-vitro and ex-vivo experiments. The capability of TFPAI in measuring the tissue oxygenation and detection of vasogenic edema due to brain blood barrier disruption are demonstrated. The results obtained from our experimental evaluations strongly suggest the potential utility of TFPAI, as a portable imaging modality in the neonatal intensive care unit. Confirmation of these findings in-vivo could facilitate the translation of this promising technology to the clinic.
Collapse
Affiliation(s)
- Rayyan Manwar
- University of Illinois at Chicago, Department of Biomedical Engineering, Chicago, IL, United States
| | - Karl Kratkiewicz
- Barbara Ann Karmanos Cancer Institute, Detroit, MI, United States
| | | | - Ali Hariri
- Department of Nanoengineering, University of California, San Diego, CA, United States
| | - Christos Papadelis
- Jane and John Justin Neurosciences Center, Cook Children’s Health Care System, Fort Worth, TX, United States
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX, United States
| | - Anne Hansen
- Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
| | - De-Ann M. Pillers
- Department of Pediatrics, UI Health Children’s Hospital of the University of Illinois at Chicago, Chicago, IL, United States
| | - Juri Gelovani
- College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, Abu Dhabi, UAE
- Department of Biomedical Engineering, College of Engineering and School of Medicine, Wayne State University, Detroit, MI 48201, United States
- Dept. Radiology, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Kamran Avanaki
- University of Illinois at Chicago, Department of Biomedical Engineering, Chicago, IL, United States
- Department of Pediatrics, UI Health Children’s Hospital of the University of Illinois at Chicago, Chicago, IL, United States
- Department of Dermatology, University of Illinois at Chicago, Chicago, IL, United States
| |
Collapse
|
4
|
Guo H, Xie HW, Zhou GQ, Nguyen NQ, Prager RW. Pixel-based approach to delay multiply and sum beamforming in combination with Wiener filter for improving ultrasound image quality. ULTRASONICS 2023; 128:106864. [PMID: 36308794 DOI: 10.1016/j.ultras.2022.106864] [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: 04/18/2022] [Revised: 10/05/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Unified pixel-based (PB) beamforming has been implemented for ultrasound imaging, offering significant enhancements in lateral resolution compared to the conventional dynamic focusing. However, it still suffers from clutter and off-axis artifacts, limiting the contrast resolution. This paper proposes an efficient method to improve image quality by integrating filtered delay multiply and sum (F-DMAS) into the framework. This hybrid strategy incorporates the spatial coherence of the received data into the beamforming process to improve contrast resolution and clutter rejection in the generated image. We also integrate a Wiener filter to suppress the spatiotemporal spreading using signals echoed from a single scatterer at the transmit focus as a kernel for the deconvolution. The Wiener filter is applied to the received waveforms before performing the hybrid strategy. The Wiener filter is shown to reduce interference due to the interaction between the excitation pulse and the transfer functions of the transducer elements, thus benefiting the axial resolution of the generated images. We validate the proposed method and compare it with other beamforming strategies through a series of experiments, including simulation, phantom, and in vivo studies. The results show that our approach can substantially improve both spatial resolution and contrast over the unified PB algorithm, while still maintaining the good features of this beamformer. The simplicity and good performance of our method show its potential for use in clinical applications.
Collapse
Affiliation(s)
- Hao Guo
- The School of Biological Science and Medical Engineering, Southeast University, Nanjing, China; Jiangsu Key Laboratory of Biomaterials and Devices, Southeast University, Nanjing, China
| | - Hui-Wen Xie
- The School of Biological Science and Medical Engineering, Southeast University, Nanjing, China; Jiangsu Key Laboratory of Biomaterials and Devices, Southeast University, Nanjing, China
| | - Guang-Quan Zhou
- The School of Biological Science and Medical Engineering, Southeast University, Nanjing, China; Jiangsu Key Laboratory of Biomaterials and Devices, Southeast University, Nanjing, China.
| | - Nghia Q Nguyen
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK; Cambridge University - Nanjing Centre of Technology and Innovation, Nanjing, China
| | - Richard W Prager
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, UK; Cambridge University - Nanjing Centre of Technology and Innovation, Nanjing, China
| |
Collapse
|
5
|
Teng D, Liu L, Xiang Y, Xuan FZ. An optimized total focusing method based on delay-multiply-and-sum for nondestructive testing. ULTRASONICS 2023; 128:106881. [PMID: 36323058 DOI: 10.1016/j.ultras.2022.106881] [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: 06/14/2022] [Revised: 09/24/2022] [Accepted: 10/18/2022] [Indexed: 06/16/2023]
Abstract
Total focusing method (TFM) attracts much interest because of high image resolution and large inspection coverage. However, the synthetic focusing approach based on delay-and-sum beamforming employs only the defect information contained in the dataset while ignoring the spatial information of the array signals, leading to limited imaging performance mixed with artifacts and noise. In addition, the signal-to-noise ratio (SNR) suffers due to single-element emission of full matrix capture. This work combines a modified delay-multiply-and-sum (DMAS) beamforming approach with conventional synthetic focusing in the TFM algorithm, to achieve optimization of TFM imaging performance. DMAS-based TFM is able to take full advantage of the defect and spatial information in the array dataset, and to generate new frequency components for better image reconstruction. As demonstrated on a series of comparative simulation and experimental results, the imaging results of the optimized TFM provide a considerable improvement in SNR. Better lateral spatial resolution is also achieved due to the increased number of equivalent transducer elements and second harmonic component. Therefore, this work provides a quite promising alternative solution for the post-processing of ultrasonic phased array with improved imaging performance.
Collapse
Affiliation(s)
- Da Teng
- Key Laboratory of Pressure Systems and Safety, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Lishuai Liu
- Key Laboratory of Pressure Systems and Safety, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yanxun Xiang
- Key Laboratory of Pressure Systems and Safety, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China.
| | - Fu-Zhen Xuan
- Key Laboratory of Pressure Systems and Safety, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, China
| |
Collapse
|
6
|
Vayyeti A, Thittai AK. Novel spatio-temporal non-linear beamformers for sparse synthetic aperture ultrasound imaging. ULTRASONICS 2022; 126:106832. [PMID: 36027689 DOI: 10.1016/j.ultras.2022.106832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/01/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
The development of two modified non-linear beamformers, Spatio-Temporal Delay Multiply and Sum (ST-DMAS) and Spatio-Temporal Delay Euclidian-Weighted Multiply and Sum (ST-DewMAS) is reported in this paper. A sparse-transmit scheme (with only 8 transmits) on Synthetic Transmit Aperture technique (sparse STA) was chosen to evaluate the beamformers ability to generate the high-resolution Ultrasound image. These methods allow for obtaining superior-quality imaging at enhanced frame rates. The different beamformers of ST-DewMAS, ST-DMAS, Filtered Delay Multiply and Sum (F-DMAS), and Delay and Sum (DAS), were compared in terms of the Axial and Lateral Resolutions, AR and LR, respectively, Contrast-to-Noise Ratio (CNR), Contrast Ratio (CR), and Generalized CNR (GCNR). Experimental results demonstrate that the developed ST-DMAS and ST-DewMAS reconstruction on sparse STA technique resulted in better quality images compared to those obtained using DAS and F-DMAS. Specifically, the metrics of AR, LR CR, CNR, and GCNR showed improvements of more than 25% (for ST-DMAS) and 40 % (for ST-DewMAS) over those from DAS and F-DMAS beamformed images, respectively. Thus, the results demonstrate that the frame rate and image quality of an US system can both be enhanced by ST-DewMAS compared to the beamformers of F-DMAS and DAS.
Collapse
Affiliation(s)
- Anudeep Vayyeti
- Biomedical Ultrasound Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Arun K Thittai
- Biomedical Ultrasound Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India.
| |
Collapse
|
7
|
Schellenberg M, Gröhl J, Dreher KK, Nölke JH, Holzwarth N, Tizabi MD, Seitel A, Maier-Hein L. Photoacoustic image synthesis with generative adversarial networks. PHOTOACOUSTICS 2022; 28:100402. [PMID: 36281320 PMCID: PMC9587371 DOI: 10.1016/j.pacs.2022.100402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/03/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
Photoacoustic tomography (PAT) has the potential to recover morphological and functional tissue properties with high spatial resolution. However, previous attempts to solve the optical inverse problem with supervised machine learning were hampered by the absence of labeled reference data. While this bottleneck has been tackled by simulating training data, the domain gap between real and simulated images remains an unsolved challenge. We propose a novel approach to PAT image synthesis that involves subdividing the challenge of generating plausible simulations into two disjoint problems: (1) Probabilistic generation of realistic tissue morphology, and (2) pixel-wise assignment of corresponding optical and acoustic properties. The former is achieved with Generative Adversarial Networks (GANs) trained on semantically annotated medical imaging data. According to a validation study on a downstream task our approach yields more realistic synthetic images than the traditional model-based approach and could therefore become a fundamental step for deep learning-based quantitative PAT (qPAT).
Collapse
Affiliation(s)
- Melanie Schellenberg
- Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
- HIDSS4Health - Helmholtz Information and Data Science School for Health, Heidelberg, Germany
| | - Janek Gröhl
- Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Cancer Research UK Cambridge Institute, University of Cambridge, Robinson Way, Cambridge, CB2 0RE, UK
| | - Kris K. Dreher
- Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Jan-Hinrich Nölke
- Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
| | - Niklas Holzwarth
- Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
| | - Minu D. Tizabi
- Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Alexander Seitel
- Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Lena Maier-Hein
- Intelligent Medical Systems (IMSY), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
- HIDSS4Health - Helmholtz Information and Data Science School for Health, Heidelberg, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
- HIP Applied Computer Vision Lab, Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
8
|
Gao Y, Xu W, Chen Y, Xie W, Cheng Q. Deep Learning-Based Photoacoustic Imaging of Vascular Network Through Thick Porous Media. IEEE TRANSACTIONS ON MEDICAL IMAGING 2022; 41:2191-2204. [PMID: 35294347 DOI: 10.1109/tmi.2022.3158474] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Photoacoustic imaging is a promising approach used to realize in vivo transcranial cerebral vascular imaging. However, the strong attenuation and distortion of the photoacoustic wave caused by the thick porous skull greatly affect the imaging quality. In this study, we developed a convolutional neural network based on U-Net to extract the effective photoacoustic information hidden in the speckle patterns obtained from vascular network images datasets under porous media. Our simulation and experimental results show that the proposed neural network can learn the mapping relationship between the speckle pattern and the target, and extract the photoacoustic signals of the vessels submerged in noise to reconstruct high-quality images of the vessels with a sharp outline and a clean background. Compared with the traditional photoacoustic reconstruction methods, the proposed deep learning-based reconstruction algorithm has a better performance with a lower mean absolute error, higher structural similarity, and higher peak signal-to-noise ratio of reconstructed images. In conclusion, the proposed neural network can effectively extract valid information from highly blurred speckle patterns for the rapid reconstruction of target images, which offers promising applications in transcranial photoacoustic imaging.
Collapse
|
9
|
Schellenberg M, Dreher KK, Holzwarth N, Isensee F, Reinke A, Schreck N, Seitel A, Tizabi MD, Maier-Hein L, Gröhl J. Semantic segmentation of multispectral photoacoustic images using deep learning. PHOTOACOUSTICS 2022; 26:100341. [PMID: 35371919 PMCID: PMC8968659 DOI: 10.1016/j.pacs.2022.100341] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/15/2022] [Accepted: 02/20/2022] [Indexed: 05/08/2023]
Abstract
Photoacoustic (PA) imaging has the potential to revolutionize functional medical imaging in healthcare due to the valuable information on tissue physiology contained in multispectral photoacoustic measurements. Clinical translation of the technology requires conversion of the high-dimensional acquired data into clinically relevant and interpretable information. In this work, we present a deep learning-based approach to semantic segmentation of multispectral photoacoustic images to facilitate image interpretability. Manually annotated photoacoustic and ultrasound imaging data are used as reference and enable the training of a deep learning-based segmentation algorithm in a supervised manner. Based on a validation study with experimentally acquired data from 16 healthy human volunteers, we show that automatic tissue segmentation can be used to create powerful analyses and visualizations of multispectral photoacoustic images. Due to the intuitive representation of high-dimensional information, such a preprocessing algorithm could be a valuable means to facilitate the clinical translation of photoacoustic imaging.
Collapse
Affiliation(s)
- Melanie Schellenberg
- Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
- HIDSS4Health - Helmholtz Information and Data Science School for Health, Heidelberg, Germany
- Corresponding author at: Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Kris K. Dreher
- Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Niklas Holzwarth
- Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Fabian Isensee
- HI Applied Computer Vision Lab, Division of Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Annika Reinke
- Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
- HI Applied Computer Vision Lab, Division of Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Nicholas Schreck
- Division of Biostatistics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Alexander Seitel
- Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Minu D. Tizabi
- Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Lena Maier-Hein
- Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
- HIDSS4Health - Helmholtz Information and Data Science School for Health, Heidelberg, Germany
- HI Applied Computer Vision Lab, Division of Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
- Corresponding author at: Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany.
| | - Janek Gröhl
- Computer Assisted Medical Interventions (CAMI), German Cancer Research Center (DKFZ), Heidelberg, Germany
| |
Collapse
|
10
|
Kirchner T, Jaeger M, Frenz M. Machine learning enabled multiple illumination quantitative optoacoustic oximetry imaging in humans. BIOMEDICAL OPTICS EXPRESS 2022; 13:2655-2667. [PMID: 35774340 PMCID: PMC9203099 DOI: 10.1364/boe.455514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 06/15/2023]
Abstract
Optoacoustic (OA) imaging is a promising modality for quantifying blood oxygen saturation (sO2) in various biomedical applications - in diagnosis, monitoring of organ function, or even tumor treatment planning. We present an accurate and practically feasible real-time capable method for quantitative imaging of sO2 based on combining multispectral (MS) and multiple illumination (MI) OA imaging with learned spectral decoloring (LSD). For this purpose we developed a hybrid real-time MI MS OA imaging setup with ultrasound (US) imaging capability; we trained gradient boosting machines on MI spectrally colored absorbed energy spectra generated by generic Monte Carlo simulations and used the trained models to estimate sO2 on real OA measurements. We validated MI-LSD in silico and on in vivo image sequences of radial arteries and accompanying veins of five healthy human volunteers. We compared the performance of the method to prior LSD work and conventional linear unmixing. MI-LSD provided highly accurate results in silico and consistently plausible results in vivo. This preliminary study shows a potentially high applicability of quantitative OA oximetry imaging, using our method.
Collapse
Affiliation(s)
- Thomas Kirchner
- Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany
- Biomedical Photonics, Institute of Applied Physics, University of Bern, Bern, Switzerland
| | - Michael Jaeger
- Biomedical Photonics, Institute of Applied Physics, University of Bern, Bern, Switzerland
| | - Martin Frenz
- Biomedical Photonics, Institute of Applied Physics, University of Bern, Bern, Switzerland
| |
Collapse
|
11
|
Gröhl J, Dreher KK, Schellenberg M, Rix T, Holzwarth N, Vieten P, Ayala L, Bohndiek SE, Seitel A, Maier-Hein L. SIMPA: an open-source toolkit for simulation and image processing for photonics and acoustics. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:JBO-210395SSR. [PMID: 35380031 PMCID: PMC8978263 DOI: 10.1117/1.jbo.27.8.083010] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/28/2022] [Indexed: 05/09/2023]
Abstract
SIGNIFICANCE Optical and acoustic imaging techniques enable noninvasive visualisation of structural and functional properties of tissue. The quantification of measurements, however, remains challenging due to the inverse problems that must be solved. Emerging data-driven approaches are promising, but they rely heavily on the presence of high-quality simulations across a range of wavelengths due to the lack of ground truth knowledge of tissue acoustical and optical properties in realistic settings. AIM To facilitate this process, we present the open-source simulation and image processing for photonics and acoustics (SIMPA) Python toolkit. SIMPA is being developed according to modern software design standards. APPROACH SIMPA enables the use of computational forward models, data processing algorithms, and digital device twins to simulate realistic images within a single pipeline. SIMPA's module implementations can be seamlessly exchanged as SIMPA abstracts from the concrete implementation of each forward model and builds the simulation pipeline in a modular fashion. Furthermore, SIMPA provides comprehensive libraries of biological structures, such as vessels, as well as optical and acoustic properties and other functionalities for the generation of realistic tissue models. RESULTS To showcase the capabilities of SIMPA, we show examples in the context of photoacoustic imaging: the diversity of creatable tissue models, the customisability of a simulation pipeline, and the degree of realism of the simulations. CONCLUSIONS SIMPA is an open-source toolkit that can be used to simulate optical and acoustic imaging modalities. The code is available at: https://github.com/IMSY-DKFZ/simpa, and all of the examples and experiments in this paper can be reproduced using the code available at: https://github.com/IMSY-DKFZ/simpa_paper_experiments.
Collapse
Affiliation(s)
- Janek Gröhl
- German Cancer Research Center (DKFZ), Division of Intelligent Medical Systems, Heidelberg, Germany
| | - Kris K. Dreher
- German Cancer Research Center (DKFZ), Division of Intelligent Medical Systems, Heidelberg, Germany
- Heidelberg University, Faculty of Physics and Astronomy, Heidelberg, Germany
| | - Melanie Schellenberg
- German Cancer Research Center (DKFZ), Division of Intelligent Medical Systems, Heidelberg, Germany
- Heidelberg University, Faculty of Mathematics and Computer Science, Heidelberg, Germany
- HIDSS4Health - Helmholtz Information and Data Science School for Health, Heidelberg, Germany
| | - Tom Rix
- German Cancer Research Center (DKFZ), Division of Intelligent Medical Systems, Heidelberg, Germany
- Heidelberg University, Faculty of Mathematics and Computer Science, Heidelberg, Germany
| | - Niklas Holzwarth
- German Cancer Research Center (DKFZ), Division of Intelligent Medical Systems, Heidelberg, Germany
| | - Patricia Vieten
- German Cancer Research Center (DKFZ), Division of Intelligent Medical Systems, Heidelberg, Germany
- Heidelberg University, Faculty of Physics and Astronomy, Heidelberg, Germany
| | - Leonardo Ayala
- German Cancer Research Center (DKFZ), Division of Intelligent Medical Systems, Heidelberg, Germany
- Heidelberg University, Medical Faculty, Heidelberg, Germany
| | - Sarah E. Bohndiek
- University of Cambridge, Cancer Research UK Cambridge Institute, Robinson Way, Cambridge, United Kingdom
- University of Cambridge, Department of Physics, Cambridge, United Kingdom
| | - Alexander Seitel
- German Cancer Research Center (DKFZ), Division of Intelligent Medical Systems, Heidelberg, Germany
| | - Lena Maier-Hein
- German Cancer Research Center (DKFZ), Division of Intelligent Medical Systems, Heidelberg, Germany
- Heidelberg University, Faculty of Mathematics and Computer Science, Heidelberg, Germany
- Heidelberg University, Medical Faculty, Heidelberg, Germany
| |
Collapse
|
12
|
Yan X, Qi Y, Wang Y, Wang Y. Regional-Lag Signed Delay Multiply and Sum Beamforming in Ultrafast Ultrasound Imaging. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:580-591. [PMID: 34767507 DOI: 10.1109/tuffc.2021.3127878] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Ultrafast ultrasound imaging provides very high frame rates but provides poor imaging quality due to unfocused beams. The delay multiply and sum (DMAS) beamformer has been used to improve ultrafast ultrasound imaging contrast but is always accompanied by oversuppression, which produces low-quality speckle images and degrades the contrast performance. A smaller maximum lag in the signed DMAS (sDMAS) contributes better speckle preservation but lower resolution for hyperechoic scatters. To overcome this tradeoff, a regional-lag signed delay multiply and sum (rsDMAS) beamformer is proposed in this article. Innovatively, a region discrimination tool realized by the generalized coherence factor (GCF) is used to limit the maximum lag for spatial coherence estimation. Subaperture coherence smoothing estimates the short-lag coherence instead of multiplication in pairs, thereby reducing calculation complexity and smoothing the speckle texture. Normalization and sign correction are also introduced to achieve better beamforming output. The simulated, phantom, and in vivo data are adopted to evaluate the effectiveness of the proposed beamformer. Numerical results show that the proposed method achieves improvements of the contrast ratio (CR) by 9%, contrast-to-noise ratio (CNR) by 41%, speckle signal-to-noise ratio (sSNR) by 41%, and generalized contrast-to-noise ratio (gCNR) by 0.0004 compared with DMAS (in simulation). Resolution experiments show that the proposed method obtains a loss of 0.07 mm in the full width at half maximum (FWHM) and the same separability of close point scatters as DMAS. These findings indicate that the proposed method achieves higher contrast performance at less obvious sacrifice of the lateral resolution than DMAS.
Collapse
|
13
|
Vayyeti A, Thittai AK. Optimally-weighted non-linear beamformer for conventional focused beam ultrasound imaging systems. Sci Rep 2021; 11:21622. [PMID: 34732736 PMCID: PMC8566575 DOI: 10.1038/s41598-021-00741-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 10/14/2021] [Indexed: 11/09/2022] Open
Abstract
A novel non-linear beamforming method, namely, filtered delay optimally-weighted multiply and sum (F-DowMAS) beamforming is reported for conventional focused beamforming (CFB) technique. The performance of F-DowMAS was compared against delay and sum (DAS), filtered delay multiply and sum (F-DMAS), filtered delay weight multiply and sum (F-DwMAS) and filter delay Euclidian weighted multiply and sum (F-DewMAS) methods. Notably, in the proposed method the optimal adaptive weights are computed for each imaging point to compensate for the effects due to spatial variations in beam pattern in CFB technique. F-DowMAS, F-DMAS, and DAS were compared in terms of the resulting image quality metrics, Lateral resolution (LR), axial resolution (AR), contrast ratio (CR) and contrast-to-noise ratio (CNR), estimated from experiments on a commercially available tissue-mimicking phantom. The results demonstrate that F-DowMAS improved the AR by 57.04% and 46.95%, LR by 58.21% and 53.40%, CR by 67.35% and 39.25%, and CNR by 44.04% and 30.57% compared to those obtained using DAS and F-DMAS, respectively. Thus, it can be concluded that the newly proposed F-DowMAS outperforms DAS and F-DMAS. As an aside, we also show that the optimal weighting strategy can be extended to benefit DAS.
Collapse
Affiliation(s)
- Anudeep Vayyeti
- Biomedical Ultrasound Laboratory, Department of Applied Mechanics, Indian Institute of Technology, Madras, Chennai, India
| | - Arun K Thittai
- Biomedical Ultrasound Laboratory, Department of Applied Mechanics, Indian Institute of Technology, Madras, Chennai, India.
| |
Collapse
|
14
|
Al Mukaddim R, Ahmed R, Varghese T. Improving Minimum Variance Beamforming with Sub-Aperture Processing for Photoacoustic Imaging. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:2879-2882. [PMID: 34891848 PMCID: PMC8908882 DOI: 10.1109/embc46164.2021.9630278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Minimum variance (MV) beamforming improves resolution and reduces sidelobes when compared to delay-and-sum (DAS) beamforming for photoacoustic imaging (PAI). However, some level of sidelobe signal and incoherent clutter persist degrading MV PAI quality. Here, an adaptive beamforming algorithm (PSAPMV) combining MV formulation and sub-aperture processing is proposed. In PSAPMV, the received channel data are split into two complementary nonoverlapping sub-apertures and beamformed using MV. A weighting matrix based on similarity between sub-aperture beamformed images was derived and multiplied with the full aperture MV image resulting in suppression of sidelobe and incoherent clutter in the PA image. Numerical simulation experiments with point targets, diffuse inclusions and microvasculature networks are used to validate PSAPMV. Quantitative evaluation was done in terms of main-lobe-to-side-lobe ratio, full width at half maximum (FWHM), contrast ratio (CR) and generalized contrast-to-noise ratio (gCNR). PSAPMV demonstrated improved beamforming performance both qualitatively and quantitatively. PSAPMV had higher resolution (FWHM =0.19 mm) than MV (0.21 mm) and DAS (0.22mm) in point target simulations, better target detectability (gCNR =0.99) than MV (0.89) and DAS (0.84) for diffuse inclusions and improved contrast (CR in microvasculature simulation, DAS = 15.38, MV = 22.42, PSAPMV = 51.74 dB).
Collapse
|
15
|
Vayyeti A, Thittai AK. Euclidian-Weighted Non-linear Beamformer for Conventional Focused Beam Ultrasound Imaging Systems. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:3684-3687. [PMID: 34892036 DOI: 10.1109/embc46164.2021.9630076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this paper, the recently developed method of, Filtered Delay Euclidian-Weighted Multiply and Sum (F-DewMAS), is newly investigated for Conventional Focused Beamforming (CFB) technique. The performance of F-DewMAS method was compared with the established Delay and Sum (DAS) method and the popular non-linear beamforming method of F-DMAS. The different methods of F-DewMAS, F-DMAS, and DAS were compared in terms of the resulting image quality metrics, Lateral Resolution (LR), Axial Resolution (AR), Contrast Ratio (CR) and contrast-to-noise ratio (CNR), in experiments on Nylon point scatterer and CIRS Triple modality Abdominal phantoms. Experimental results show that F-DewMAS resulted in improvements of AR by 35.56% and 25.33%, LR by 42.97 % and 31.05 % and CR by 119.94% and 61.46% compared to those obtained using DAS and F-DMAS, respectively. The CNR of F-DewMAS is 46.33 % more compared to F-DMAS. Hence, it can be concluded that the image quality is improved appreciably by F-DewMAS compared to DAS and F-DMAS.Clinical Relevance-The developed method can improve the resolution and contrast of the image, which results in better visualization of finer details and thus may aid in better diagnosis.
Collapse
|
16
|
Mukaddim RA, Ahmed R, Varghese T. Subaperture Processing-Based Adaptive Beamforming for Photoacoustic Imaging. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:2336-2350. [PMID: 33606629 PMCID: PMC8330397 DOI: 10.1109/tuffc.2021.3060371] [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: 05/07/2023]
Abstract
Delay-and-sum (DAS) beamformers, when applied to photoacoustic (PA) image reconstruction, produce strong sidelobes due to the absence of transmit focusing. Consequently, DAS PA images are often severely degraded by strong off-axis clutter. For preclinical in vivo cardiac PA imaging, the presence of these noise artifacts hampers the detectability and interpretation of PA signals from the myocardial wall, crucial for studying blood-dominated cardiac pathological information and to complement functional information derived from ultrasound imaging. In this article, we present PA subaperture processing (PSAP), an adaptive beamforming method, to mitigate these image degrading effects. In PSAP, a pair of DAS reconstructed images is formed by splitting the received channel data into two complementary nonoverlapping subapertures. Then, a weighting matrix is derived by analyzing the correlation between subaperture beamformed images and multiplied with the full-aperture DAS PA image to reduce sidelobes and incoherent clutter. We validated PSAP using numerical simulation studies using point target, diffuse inclusion and microvasculature imaging, and in vivo feasibility studies on five healthy murine models. Qualitative and quantitative analysis demonstrate improvements in PAI image quality with PSAP compared to DAS and coherence factor weighted DAS (DAS CF ). PSAP demonstrated improved target detectability with a higher generalized contrast-to-noise (gCNR) ratio in vasculature simulations where PSAP produces 19.61% and 19.53% higher gCNRs than DAS and DAS CF , respectively. Furthermore, PSAP provided higher image contrast quantified using contrast ratio (CR) (e.g., PSAP produces 89.26% and 11.90% higher CR than DAS and DAS CF in vasculature simulations) and improved clutter suppression.
Collapse
|
17
|
Gröhl J, Schellenberg M, Dreher K, Maier-Hein L. Deep learning for biomedical photoacoustic imaging: A review. PHOTOACOUSTICS 2021; 22:100241. [PMID: 33717977 PMCID: PMC7932894 DOI: 10.1016/j.pacs.2021.100241] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 05/04/2023]
Abstract
Photoacoustic imaging (PAI) is a promising emerging imaging modality that enables spatially resolved imaging of optical tissue properties up to several centimeters deep in tissue, creating the potential for numerous exciting clinical applications. However, extraction of relevant tissue parameters from the raw data requires the solving of inverse image reconstruction problems, which have proven extremely difficult to solve. The application of deep learning methods has recently exploded in popularity, leading to impressive successes in the context of medical imaging and also finding first use in the field of PAI. Deep learning methods possess unique advantages that can facilitate the clinical translation of PAI, such as extremely fast computation times and the fact that they can be adapted to any given problem. In this review, we examine the current state of the art regarding deep learning in PAI and identify potential directions of research that will help to reach the goal of clinical applicability.
Collapse
Affiliation(s)
- Janek Gröhl
- German Cancer Research Center, Computer Assisted Medical Interventions, Heidelberg, Germany
- Heidelberg University, Medical Faculty, Heidelberg, Germany
| | - Melanie Schellenberg
- German Cancer Research Center, Computer Assisted Medical Interventions, Heidelberg, Germany
| | - Kris Dreher
- German Cancer Research Center, Computer Assisted Medical Interventions, Heidelberg, Germany
- Heidelberg University, Faculty of Physics and Astronomy, Heidelberg, Germany
| | - Lena Maier-Hein
- German Cancer Research Center, Computer Assisted Medical Interventions, Heidelberg, Germany
- Heidelberg University, Medical Faculty, Heidelberg, Germany
- Heidelberg University, Faculty of Mathematics and Computer Science, Heidelberg, Germany
| |
Collapse
|
18
|
Al Mukaddim R, Weichmann AM, Mitchell CC, Varghese T. Enhancement of in vivo cardiac photoacoustic signal specificity using spatiotemporal singular value decomposition. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210037RR. [PMID: 33876591 PMCID: PMC8054608 DOI: 10.1117/1.jbo.26.4.046001] [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: 01/31/2021] [Accepted: 03/29/2021] [Indexed: 05/07/2023]
Abstract
SIGNIFICANCE Photoacoustic imaging (PAI) can be used to infer molecular information about myocardial health non-invasively in vivo using optical excitation at ultrasonic spatial resolution. For clinical and preclinical linear array imaging systems, conventional delay-and-sum (DAS) beamforming is typically used. However, DAS cardiac PA images are prone to artifacts such as diffuse quasi-static clutter with temporally varying noise-reducing myocardial signal specificity. Typically, multiple frame averaging schemes are utilized to improve the quality of cardiac PAI, which affects the spatial and temporal resolution and reduces sensitivity to subtle PA signal variation. Furthermore, frame averaging might corrupt myocardial oxygen saturation quantification due to the presence of natural cardiac wall motion. In this paper, a spatiotemporal singular value decomposition (SVD) processing algorithm is proposed to reduce DAS PAI artifacts and subsequent enhancement of myocardial signal specificity. AIM Demonstrate enhancement of PA signals from myocardial tissue compared to surrounding tissues and blood inside the left-ventricular (LV) chamber using spatiotemporal SVD processing with electrocardiogram (ECG) and respiratory signal (ECG-R) gated in vivo murine cardiac PAI. APPROACH In vivo murine cardiac PAI was performed by collecting single wavelength (850 nm) photoacoustic channel data on eight healthy mice. A three-dimensional (3D) volume of complex PAI data over a cardiac cycle was reconstructed using a custom ECG-R gating algorithm and DAS beamforming. Spatiotemporal SVD was applied on a two-dimensional Casorati matrix generated using the 3D volume of PAI data. The singular value spectrum (SVS) was then filtered to remove contributions from diffuse quasi-static clutter and random noise. Finally, SVD processed beamformed images were derived using filtered SVS and inverse SVD computations. RESULTS Qualitative comparison with DAS and minimum variance (MV) beamforming shows that SVD processed images had better myocardial signal specificity, contrast, and target detectability. DAS, MV, and SVD images were quantitatively evaluated by calculating contrast ratio (CR), generalized contrast-to-noise ratio (gCNR), and signal-to-noise ratio (SNR). Quantitative evaluations were done at three cardiac time points (during systole, at end-systole (ES), and during diastole) identified from co-registered ultrasound M-Mode image. Mean CR, gCNR, and SNR values of SVD images at ES were 245, 115.15, and 258.17 times higher than DAS images with statistical significance evaluated with one-way analysis of variance. CONCLUSIONS Our results suggest that significantly better-quality images can be realized using spatiotemporal SVD processing for in vivo murine cardiac PAI.
Collapse
Affiliation(s)
- Rashid Al Mukaddim
- University of Wisconsin–Madison, Department of ECE, Madison, Wisconsin, United States
- University of Wisconsin–Madison, School of Medicine and Public Health, Department of Medical Physics, Madison, Wisconsin, United States
- Address all correspondence to Rashid Al Mukaddim,
| | - Ashley M. Weichmann
- Small Animal Imaging and Radiotherapy Facility, UW Carbone Cancer Center, Wisconsin, United States
| | - Carol C. Mitchell
- University of Wisconsin School of Medicine and Public Health, Department of Medicine/Division of Cardiovascular Medicine, Madison, Wisconsin, United States
| | - Tomy Varghese
- University of Wisconsin–Madison, Department of ECE, Madison, Wisconsin, United States
- University of Wisconsin–Madison, School of Medicine and Public Health, Department of Medical Physics, Madison, Wisconsin, United States
| |
Collapse
|
19
|
Shen CC. Computationally efficient minimum-variance baseband delay-multiply-and-sum beamforming for adjustable enhancement of ultrasound image resolution. ULTRASONICS 2021; 112:106345. [PMID: 33465594 DOI: 10.1016/j.ultras.2020.106345] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 11/22/2020] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
Baseband Delay-Multiply-and-Sum (BB-DMAS) beamforming takes advantage of the baseband spatial coherence of receiving aperture to improve image resolution and contrast. Meanwhile, the side-lobe clutter and noise level can also be effectively suppressed in BB-DMAS beamforming due to their low coherence when being detected by channels in different spatial locations. BB-DMAS scales the magnitude of channel signal by p-th root and restores the output dimensionality by p-th power after channel summation. Higher p value introduces more spatial coherence into DMAS beamforming and provides higher image resolution at the cost of background speckle quality. In this study, a computationally efficient integration of BB-DMAS with minimum-variance (MV) beamforming is developed so that the image resolution can be drastically improved with low p value (e.g. p < 2) while maintaining the speckle quality. For each image pixel, the proposed MV-DMAS only requires single MV estimation to optimize the aperture apodization for DMAS beamforming. Our simulation results show that, with p = 1.5, the -6-dB lateral width of wire reflector noticeably improves from 0.22 mm to 0.13 mm by adopting MV estimation in BB-DMAS beamforming. In MV-DMAS, the suppression of uncorrelated random noises also remains effective. Experimental results not only confirm the superior resolution in MV-DMAS beamforming but also demonstrates comparable image contrast and speckle quality to BB-DMAS counterpart. In conclusion, MV-DMAS beamforming can provide improvement in image resolution while maintaining the other image quality metrics using an efficient combination of moderate spatial coherence and MV estimation of receiving aperture apodization in ultrasonic imaging.
Collapse
Affiliation(s)
- Che-Chou Shen
- Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan.
| |
Collapse
|
20
|
Vayyeti A, Thittai AK. Weighted non-linear beamformers for low cost 2-element receive ultrasound imaging system. ULTRASONICS 2021; 110:106293. [PMID: 33130360 DOI: 10.1016/j.ultras.2020.106293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 10/01/2020] [Accepted: 10/22/2020] [Indexed: 06/11/2023]
Abstract
In this paper, the development of modified beamforming methods, Filtered Delay Weight Multiply and Sum (F-DwMAS) and Filtered Delay Euclidian-Weighted Multiply and Sum (F-DewMAS), are reported. These methods were investigated on a minimum-redundancy synthetic aperture technique, called as 2 element Receive Synthetic Aperture Focusing Technique (2R-SAFT), which uses one element on transmit and two consecutive elements on receive, for reducing hardware complexity without compromising much on the image quality. The performance of the developed F-DwMAS and F-DewMAS methods were compared with Delay and Sum (DAS) and recently introduced F-DMAS beamforming methods. Notably, in the proposed methods, an additional aperture window function is designed and incorporated to the F-DMAS method. The different methods of F-DwMAS, F-DewMAS, F-DMAS and DAS were compared in terms of the resulting image quality metrics, Lateral Resolution (LR), Axial Resolution (AR), Contrast Ratio (CR) and contrast-to-noise ratio (CNR), in simulation and experiments on tissue-mimicking phantoms. Experimental results show that (F-DwMAS) and {F-DewMAS} resulted in improvements of AR by (46.32% and 23.51%), {43.56% and 17.78%}, LR by (47.81% and 30.27%), {44.26% and 26.14%} and CR by (45.68% and 17.15%), {42.16% and 9.87%} compared to those obtained using DAS and F-DMAS, respectively. However, CNR of F-DwMAS and F-DewMAS was found to be 31.19% and 21.16% less compared to DAS, but 4.89% and 18.64% more than F-DMAS, respectively. Hence, it can be concluded that the image quality improved by both F-DwMAS and F-DewMAS compared to DAS and F-DMAS. Also, between F-DwMAS and F-DewMAS, the later has the advantage of ready applicability to different acquisition schemes and settings compared to the former also having an additional advantage of better CNR compared to both F-DMAS and F-DewMAS.
Collapse
Affiliation(s)
- Anudeep Vayyeti
- Biomedical Ultrasound Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Arun K Thittai
- Biomedical Ultrasound Laboratory, Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India.
| |
Collapse
|
21
|
Yan X, Qi Y, Wang Y, Wang Y. High Resolution, High Contrast Beamformer Using Minimum Variance and Plane Wave Nonlinear Compounding with Low Complexity. SENSORS 2021; 21:s21020394. [PMID: 33429947 PMCID: PMC7826701 DOI: 10.3390/s21020394] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/31/2020] [Accepted: 01/05/2021] [Indexed: 12/05/2022]
Abstract
The plane wave compounding (PWC) is a promising modality to improve the imaging quality and maintain the high frame rate for ultrafast ultrasound imaging. In this paper, a novel beamforming method is proposed to achieve higher resolution and contrast with low complexity. A minimum variance (MV) weight calculated by the partial generalized sidelobe canceler is adopted to beamform the receiving array signals. The dimension reduction technique is introduced to project the data into lower dimensional space, which also contributes to a large subarray length. Estimation of multi-wave receiving covariance matrix is performed and then utilized to determine only one weight. Afterwards, a fast second-order reformulation of the delay multiply and sum (DMAS) is developed as nonlinear compounding to composite the beamforming output of multiple transmissions. Simulations, phantom, in vivo, and robustness experiments were carried out to evaluate the performance of the proposed method. Compared with the delay and sum (DAS) beamformer, the proposed method achieved 86.3% narrower main lobe width and 112% higher contrast ratio in simulations. The robustness to the channel noise of the proposed method is effectively enhanced at the same time. Furthermore, it maintains a linear computational complexity, which means that it has the potential to be implemented for real-time response.
Collapse
Affiliation(s)
- Xin Yan
- Department of Electronic Engineering, Fudan University, Shanghai 200433, China; (X.Y.); (Y.Q.); (Y.W.)
| | - Yanxing Qi
- Department of Electronic Engineering, Fudan University, Shanghai 200433, China; (X.Y.); (Y.Q.); (Y.W.)
| | - Yinmeng Wang
- Department of Electronic Engineering, Fudan University, Shanghai 200433, China; (X.Y.); (Y.Q.); (Y.W.)
| | - Yuanyuan Wang
- Department of Electronic Engineering, Fudan University, Shanghai 200433, China; (X.Y.); (Y.Q.); (Y.W.)
- Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai, Shanghai 200032, China
- Correspondence:
| |
Collapse
|
22
|
Kim M, Jeng GS, Pelivanov I, O'Donnell M. Deep-Learning Image Reconstruction for Real-Time Photoacoustic System. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:3379-3390. [PMID: 32396076 PMCID: PMC8594135 DOI: 10.1109/tmi.2020.2993835] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Recent advances in photoacoustic (PA) imaging have enabled detailed images of microvascular structure and quantitative measurement of blood oxygenation or perfusion. Standard reconstruction methods for PA imaging are based on solving an inverse problem using appropriate signal and system models. For handheld scanners, however, the ill-posed conditions of limited detection view and bandwidth yield low image contrast and severe structure loss in most instances. In this paper, we propose a practical reconstruction method based on a deep convolutional neural network (CNN) to overcome those problems. It is designed for real-time clinical applications and trained by large-scale synthetic data mimicking typical microvessel networks. Experimental results using synthetic and real datasets confirm that the deep-learning approach provides superior reconstructions compared to conventional methods.
Collapse
|
23
|
Zaffino P, Moccia S, De Momi E, Spadea MF. A Review on Advances in Intra-operative Imaging for Surgery and Therapy: Imagining the Operating Room of the Future. Ann Biomed Eng 2020; 48:2171-2191. [PMID: 32601951 DOI: 10.1007/s10439-020-02553-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 06/17/2020] [Indexed: 12/19/2022]
Abstract
With the advent of Minimally Invasive Surgery (MIS), intra-operative imaging has become crucial for surgery and therapy guidance, allowing to partially compensate for the lack of information typical of MIS. This paper reviews the advancements in both classical (i.e. ultrasounds, X-ray, optical coherence tomography and magnetic resonance imaging) and more recent (i.e. multispectral, photoacoustic and Raman imaging) intra-operative imaging modalities. Each imaging modality was analyzed, focusing on benefits and disadvantages in terms of compatibility with the operating room, costs, acquisition time and image characteristics. Tables are included to summarize this information. New generation of hybrid surgical room and algorithms for real time/in room image processing were also investigated. Each imaging modality has its own (site- and procedure-specific) peculiarities in terms of spatial and temporal resolution, field of view and contrasted tissues. Besides the benefits that each technique offers for guidance, considerations about operators and patient risk, costs, and extra time required for surgical procedures have to be considered. The current trend is to equip surgical rooms with multimodal imaging systems, so as to integrate multiple information for real-time data extraction and computer-assisted processing. The future of surgery is to enhance surgeons eye to minimize intra- and after-surgery adverse events and provide surgeons with all possible support to objectify and optimize the care-delivery process.
Collapse
Affiliation(s)
- Paolo Zaffino
- Department of Experimental and Clinical Medicine, Universitá della Magna Graecia, Catanzaro, Italy
| | - Sara Moccia
- Department of Information Engineering (DII), Universitá Politecnica delle Marche, via Brecce Bianche, 12, 60131, Ancona, AN, Italy.
| | - Elena De Momi
- Department of Electronics, Information and Bioengineering (DEIB), Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milano, MI, Italy
| | - Maria Francesca Spadea
- Department of Experimental and Clinical Medicine, Universitá della Magna Graecia, Catanzaro, Italy
| |
Collapse
|
24
|
Kirchner T, Gröhl J, Herrera MA, Adler T, Hernández-Aguilera A, Santos E, Maier-Hein L. Photoacoustics can image spreading depolarization deep in gyrencephalic brain. Sci Rep 2019; 9:8661. [PMID: 31209253 PMCID: PMC6572820 DOI: 10.1038/s41598-019-44935-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 05/29/2019] [Indexed: 11/09/2022] Open
Abstract
Spreading depolarization (SD) is a self-propagating wave of near-complete neuronal depolarization that is abundant in a wide range of neurological conditions, including stroke. SD was only recently documented in humans and is now considered a therapeutic target for brain injury, but the mechanisms related to SD in complex brains are not well understood. While there are numerous approaches to interventional imaging of SD on the exposed brain surface, measuring SD deep in brain is so far only possible with low spatiotemporal resolution and poor contrast. Here, we show that photoacoustic imaging enables the study of SD and its hemodynamics deep in the gyrencephalic brain with high spatiotemporal resolution. As rapid neuronal depolarization causes tissue hypoxia, we achieve this by continuously estimating blood oxygenation with an intraoperative hybrid photoacoustic and ultrasonic imaging system. Due to its high resolution, promising imaging depth and high contrast, this novel approach to SD imaging can yield new insights into SD and thereby lead to advances in stroke, and brain injury research.
Collapse
Affiliation(s)
- Thomas Kirchner
- Division of Computer Assisted Medical Interventions, German Cancer Research Center, Heidelberg, Germany.
- Faculty of Physics and Astronomy, Heidelberg University, Heidelberg, Germany.
| | - Janek Gröhl
- Division of Computer Assisted Medical Interventions, German Cancer Research Center, Heidelberg, Germany
- Medical Faculty, Heidelberg University, Heidelberg, Germany
| | - Mildred A Herrera
- Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Tim Adler
- Division of Computer Assisted Medical Interventions, German Cancer Research Center, Heidelberg, Germany
- Faculty of Mathematics and Computer Science, Heidelberg University, Heidelberg, Germany
| | | | - Edgar Santos
- Department of Neurosurgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Lena Maier-Hein
- Division of Computer Assisted Medical Interventions, German Cancer Research Center, Heidelberg, Germany.
- Medical Faculty, Heidelberg University, Heidelberg, Germany.
| |
Collapse
|