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Two-Dimensional Photoacoustic/Ultrasonic Endoscopic Imaging Based on a Line-Focused Transducer

Existing acoustic-resolution photoacoustic/ultrasonic endoscopy (PA/USE) generally employs a point-focused transducer for ultrasound detection, which is only sensitive in its focal region, thus the lateral resolution and sensitivity drop dramatically when the targets move far from its focus. Even if...

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Autores principales: Pang, Weiran, Wang, Yongjun, Guo, Lili, Wang, Bo, Lai, Puxiang, Xiao, Jiaying
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8770734/
https://www.ncbi.nlm.nih.gov/pubmed/35071214
http://dx.doi.org/10.3389/fbioe.2021.807633
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author Pang, Weiran
Wang, Yongjun
Guo, Lili
Wang, Bo
Lai, Puxiang
Xiao, Jiaying
author_facet Pang, Weiran
Wang, Yongjun
Guo, Lili
Wang, Bo
Lai, Puxiang
Xiao, Jiaying
author_sort Pang, Weiran
collection PubMed
description Existing acoustic-resolution photoacoustic/ultrasonic endoscopy (PA/USE) generally employs a point-focused transducer for ultrasound detection, which is only sensitive in its focal region, thus the lateral resolution and sensitivity drop dramatically when the targets move far from its focus. Even if a dynamic focusing algorithm is applied, the sensitivity out of the transducer focus is still much lower than that in the focus in ultrasonic imaging mode. In this work, we propose an acoustic-resolution PA/USE with a line-focused transducer to realize automatic focusing for the first time. In comparison to a point-focused transducer, the line-focused transducer emits a more uniform sound field, causing the original signal intensity and signal-to-noise ratio (SNR) of the front and rear targets to be closer in the radial direction, which is beneficial for improving target signal uniformity in ultrasonic imaging. Simultaneously, we improved the resolution of the defocus area by modifying a prior work of back-projection (BP) reconstruction algorithm typically used in point-focused transducer based PAE and applying it to line-focused PA/USE. This combined approach may significantly enhance the depth of field of ultrasonic imaging and the resolution of the defocus zone in PA/US imaging, compared to the conventional method. Sufficient numerical simulations and phantom experiments were performed to verify this method. The results show that our method can effectively improve the lateral resolution in the image’s defocused region to achieve automatic focusing and perfectly solve the defect of the target signal difference in the far-focus region in ultrasonic imaging, while also enhancing the image SNR and contrast. The proposed method in this paper lays foundations for the realization of photoacoustic/ultrasonic combined endoscopy with enhanced lateral resolution and depth of field, which can potentially benefit a many of biomedical applications.
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spelling pubmed-87707342022-01-21 Two-Dimensional Photoacoustic/Ultrasonic Endoscopic Imaging Based on a Line-Focused Transducer Pang, Weiran Wang, Yongjun Guo, Lili Wang, Bo Lai, Puxiang Xiao, Jiaying Front Bioeng Biotechnol Bioengineering and Biotechnology Existing acoustic-resolution photoacoustic/ultrasonic endoscopy (PA/USE) generally employs a point-focused transducer for ultrasound detection, which is only sensitive in its focal region, thus the lateral resolution and sensitivity drop dramatically when the targets move far from its focus. Even if a dynamic focusing algorithm is applied, the sensitivity out of the transducer focus is still much lower than that in the focus in ultrasonic imaging mode. In this work, we propose an acoustic-resolution PA/USE with a line-focused transducer to realize automatic focusing for the first time. In comparison to a point-focused transducer, the line-focused transducer emits a more uniform sound field, causing the original signal intensity and signal-to-noise ratio (SNR) of the front and rear targets to be closer in the radial direction, which is beneficial for improving target signal uniformity in ultrasonic imaging. Simultaneously, we improved the resolution of the defocus area by modifying a prior work of back-projection (BP) reconstruction algorithm typically used in point-focused transducer based PAE and applying it to line-focused PA/USE. This combined approach may significantly enhance the depth of field of ultrasonic imaging and the resolution of the defocus zone in PA/US imaging, compared to the conventional method. Sufficient numerical simulations and phantom experiments were performed to verify this method. The results show that our method can effectively improve the lateral resolution in the image’s defocused region to achieve automatic focusing and perfectly solve the defect of the target signal difference in the far-focus region in ultrasonic imaging, while also enhancing the image SNR and contrast. The proposed method in this paper lays foundations for the realization of photoacoustic/ultrasonic combined endoscopy with enhanced lateral resolution and depth of field, which can potentially benefit a many of biomedical applications. Frontiers Media S.A. 2022-01-06 /pmc/articles/PMC8770734/ /pubmed/35071214 http://dx.doi.org/10.3389/fbioe.2021.807633 Text en Copyright © 2022 Pang, Wang, Guo, Wang, Lai and Xiao. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Bioengineering and Biotechnology
Pang, Weiran
Wang, Yongjun
Guo, Lili
Wang, Bo
Lai, Puxiang
Xiao, Jiaying
Two-Dimensional Photoacoustic/Ultrasonic Endoscopic Imaging Based on a Line-Focused Transducer
title Two-Dimensional Photoacoustic/Ultrasonic Endoscopic Imaging Based on a Line-Focused Transducer
title_full Two-Dimensional Photoacoustic/Ultrasonic Endoscopic Imaging Based on a Line-Focused Transducer
title_fullStr Two-Dimensional Photoacoustic/Ultrasonic Endoscopic Imaging Based on a Line-Focused Transducer
title_full_unstemmed Two-Dimensional Photoacoustic/Ultrasonic Endoscopic Imaging Based on a Line-Focused Transducer
title_short Two-Dimensional Photoacoustic/Ultrasonic Endoscopic Imaging Based on a Line-Focused Transducer
title_sort two-dimensional photoacoustic/ultrasonic endoscopic imaging based on a line-focused transducer
topic Bioengineering and Biotechnology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8770734/
https://www.ncbi.nlm.nih.gov/pubmed/35071214
http://dx.doi.org/10.3389/fbioe.2021.807633
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