151
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Asadollahi A, Latifi H, Pramanik M, Qazvini H, Rezaei A, Nikbakht H, Abedi A. Axial accuracy and signal enhancement in acoustic-resolution photoacoustic microscopy by laser jitter effect correction and pulse energy compensation. BIOMEDICAL OPTICS EXPRESS 2021; 12:1834-1845. [PMID: 33996201 PMCID: PMC8086458 DOI: 10.1364/boe.419564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/22/2021] [Accepted: 02/22/2021] [Indexed: 05/02/2023]
Abstract
In recent years, photoacoustic imaging has found vast applications in biomedical imaging. Photoacoustic imaging has high optical contrast and high ultrasound resolution allowing deep tissue non-invasive imaging beyond the optical diffusion limit. Q-switched lasers are extensively used in photoacoustic imaging due to the availability of high energy and short laser pulses, which are essential for high-resolution photoacoustic imaging. In most cases, this type of light source suffers from pulse peak-power energy variations and timing jitter noise, resulting in uncertainty in the output power and arrival time of the laser pulses. These problems cause intensity degradation and temporal displacement of generated photoacoustic signals which in turn deteriorate the quality of the acquired photoacoustic images. In this study, we used a high-speed data acquisition system in combination with a fast photodetector and a software-based approach to capture laser pulses precisely in order to reduce the effect of timing jitter and normalization of the photoacoustic signals based on pulse peak-powers simultaneously. In the experiments, maximum axial accuracy enhancement of 14 µm was achieved in maximum-amplitude projected images on XZ and YZ planes with ±13.5 ns laser timing jitter. Furthermore, photoacoustic signal enhancement of 77% was obtained for 75% laser pulses peak-power stability.
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Affiliation(s)
- Amir Asadollahi
- Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran
| | - Hamid Latifi
- Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran
- Department of Physics, Shahid Beheshti University, Tehran, Iran
| | - Manojit Pramanik
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
| | - Hamed Qazvini
- Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran
| | - Ali Rezaei
- Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran
- Physics of Fluids Group, University of Twente, Enschede, The Netherlands
| | - Hamed Nikbakht
- Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran
- LaserLaB, Department of Physics and Astronomy, VU Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Abolfazl Abedi
- Department of Electrical Engineering, Shahid Beheshti University, Tehran, Iran
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152
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Deng H, Qiao H, Dai Q, Ma C. Deep learning in photoacoustic imaging: a review. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-200374VRR. [PMID: 33837678 PMCID: PMC8033250 DOI: 10.1117/1.jbo.26.4.040901] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 03/18/2021] [Indexed: 05/18/2023]
Abstract
SIGNIFICANCE Photoacoustic (PA) imaging can provide structural, functional, and molecular information for preclinical and clinical studies. For PA imaging (PAI), non-ideal signal detection deteriorates image quality, and quantitative PAI (QPAI) remains challenging due to the unknown light fluence spectra in deep tissue. In recent years, deep learning (DL) has shown outstanding performance when implemented in PAI, with applications in image reconstruction, quantification, and understanding. AIM We provide (i) a comprehensive overview of the DL techniques that have been applied in PAI, (ii) references for designing DL models for various PAI tasks, and (iii) a summary of the future challenges and opportunities. APPROACH Papers published before November 2020 in the area of applying DL in PAI were reviewed. We categorized them into three types: image understanding, reconstruction of the initial pressure distribution, and QPAI. RESULTS When applied in PAI, DL can effectively process images, improve reconstruction quality, fuse information, and assist quantitative analysis. CONCLUSION DL has become a powerful tool in PAI. With the development of DL theory and technology, it will continue to boost the performance and facilitate the clinical translation of PAI.
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Affiliation(s)
- Handi Deng
- Tsinghua University, Department of Electronic Engineering, Haidian, Beijing, China
| | - Hui Qiao
- Tsinghua University, Department of Automation, Haidian, Beijing, China
- Tsinghua University, Institute for Brain and Cognitive Science, Beijing, China
- Tsinghua University, Beijing Laboratory of Brain and Cognitive Intelligence, Beijing, China
- Tsinghua University, Beijing Key Laboratory of Multi-Dimension and Multi-Scale Computational Photography, Beijing, China
| | - Qionghai Dai
- Tsinghua University, Department of Automation, Haidian, Beijing, China
- Tsinghua University, Institute for Brain and Cognitive Science, Beijing, China
- Tsinghua University, Beijing Laboratory of Brain and Cognitive Intelligence, Beijing, China
- Tsinghua University, Beijing Key Laboratory of Multi-Dimension and Multi-Scale Computational Photography, Beijing, China
| | - Cheng Ma
- Tsinghua University, Department of Electronic Engineering, Haidian, Beijing, China
- Beijing Innovation Center for Future Chip, Beijing, China
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153
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Banerjee S, Sarkar S, Karmakar S. Acquiring photoacoustic signature of hematocrit variation from plexus layer of in-silico human skin phantom. Biomed Phys Eng Express 2021; 7. [PMID: 33740772 DOI: 10.1088/2057-1976/abf052] [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: 12/11/2020] [Accepted: 03/19/2021] [Indexed: 11/11/2022]
Abstract
Optical penetration inside human skin is constrained by the wavelength dependent scattering and absorption losses by tissue microstructure and chromophores. This computational study investigates whether the signature of hematocrit variation from plexus i.e., the first skin layer having very small blood volume percentage distributed in capillary vessels, is retained by the detected photoacoustic response. Thein-silicoskin phantom is irradiated by a light source equivalent to a small footprint and low power (below 5 W) continuous wave LASER diode. As the low fluence can be compensated by exploiting strong absorption by targeted chromophores (hemoglobin molecules), an irradiation of wavelength 405 nm has been used to generate detectable pressure from capillary blood vessels of plexus. Optical energy deposition inside the tissue has been modelled using Monte Carlo technique and the pressure wave is computed using k-wave. It is found that with the increase in hematocrit from 10% to 50%, photoacoustic amplitude monotonically increases and gets almost doubled. The increment is about 30% in the range of hematocrit of physiological interest (from 30% to 50%).The variation follows a quadratic relationship for the entire hematocrit range. This photoacoustic signature of hematocrit variation has further been validated against minimum detectable pressure (800 Pa). This numerical model is expected to be an important basis to realize the idea of low cost small footprintin-vivophotoacoustic hematocrit measurement device.
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Affiliation(s)
- Soumyodeep Banerjee
- The University of Burdwan, USIC, Golapbag Campus, The University of Burdwan, Bardhaman, 713104, INDIA
| | - Sandip Sarkar
- Saha Institute of Nuclear Physics, Sector 1, AF Block, Bidhannagar, Kolkata, Kolkata, West Bengal, 700064, INDIA
| | - Subhajit Karmakar
- The University of Burdwan, USIC, Golapbag Campus, The University of Burdwan, Bardhaman, 713104, INDIA
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154
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Remote Photoacoustic Sensing Using Single Speckle Analysis by an Ultra-Fast Four Quadrant Photo-Detector. SENSORS 2021; 21:s21062109. [PMID: 33802885 PMCID: PMC8002695 DOI: 10.3390/s21062109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/09/2021] [Accepted: 03/11/2021] [Indexed: 12/15/2022]
Abstract
The need for tissue contact makes photoacoustic imaging not applicable for special medical applications like wound imaging, endoscopy, or laser surgery. An easy, stable, and contact-free sensing technique might thus help to broaden the applications of the medical imaging modality. In this work, it is demonstrated for the first time that remote photoacoustic sensing by speckle analysis can be performed in the MHz sampling range by tracking a single speckle using a four quadrant photo-detector. A single speckle, which is created by self-interference of surface back-reflection, is temporally analyzed using this photo-detector. Phantoms and skin samples are measured in transmission and reflection mode. The potential for miniaturization for endoscopic application is demonstrated by fiber bundle measurements. In addition, sensing parameters are discussed. Photoacoustic sensing in the MHz sampling range by single speckle analysis with the four quadrant detector is successfully demonstrated. Furthermore, the endoscopic applicability is proven, and the sensing parameters are convenient for photoacoustic sensing. It can be concluded that a single speckle contains all the relevant information for remote photoacoustic signal detection. Single speckle sensing is therefore an easy, robust, contact-free photoacoustic detection technique and holds the potential for economical, ultra-fast photoacoustic sensing. The new detection technique might thus help to broaden the field of photoacoustic imaging applications in the future.
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155
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Cebrecos A, García-Garrigós JJ, Descals A, Jiménez N, Benlloch JM, Camarena F. Beamforming for large-area scan and improved SNR in array-based photoacoustic microscopy. ULTRASONICS 2021; 111:106317. [PMID: 33310407 DOI: 10.1016/j.ultras.2020.106317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/19/2020] [Accepted: 11/24/2020] [Indexed: 05/11/2023]
Abstract
Beamforming enhances the performance of array-based photoacoustic microscopy (PAM) systems for large-area scan. In this study, we quantify the imaging performance of a large field-of-view optical-resolution photoacoustic-microscopy system using an phased-array detector. The system combines a low-cost pulsed-laser diode with a 128-element linear ultrasound probe. Signal-to-noise ratio (SNR) and generalized contrast-to-noise ratio (gCNR) are quantified using the phased-array detector and applying three beamforming strategies: a no-beamforming method equivalent to a single-element flat transducer, a fixed focus beamforming method that mimics a single-element focused transducer, and a dynamic focus beamforming using a delay-and-sum (DAS) algorithm. The imaging capabilities of the system are demonstrated generating high-resolution images of tissue-mimicking phantoms containing sub-millimetre ink tubes and an ex vivo rabbit's ear. The results show that dynamic focus DAS beamforming increases and homogenizes SNR along 1-cm2 images, reaching values up to 15 dB compared to an unfocused detector and up to 30 dB compared to out-of-focus regions of the fixed focus configuration. Moreover, the obtained values of gCNR using the DAS beamformer indicate an excellent target visibility, both on phantoms and ex vivo. This strategy makes it possible to scan larger surfaces compared to standard configurations using single-element detectors, paving the way for advanced array-based PAM systems.
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Affiliation(s)
- A Cebrecos
- Instituto de Instrumentación para Imagen Molecular (i3M), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Camino de Vera s/n, 46022, Valencia, Spain.
| | - J J García-Garrigós
- Instituto de Instrumentación para Imagen Molecular (i3M), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Camino de Vera s/n, 46022, Valencia, Spain
| | - A Descals
- Instituto de Instrumentación para Imagen Molecular (i3M), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Camino de Vera s/n, 46022, Valencia, Spain
| | - N Jiménez
- Instituto de Instrumentación para Imagen Molecular (i3M), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Camino de Vera s/n, 46022, Valencia, Spain
| | - J M Benlloch
- Instituto de Instrumentación para Imagen Molecular (i3M), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Camino de Vera s/n, 46022, Valencia, Spain
| | - F Camarena
- Instituto de Instrumentación para Imagen Molecular (i3M), Consejo Superior de Investigaciones Científicas (CSIC), Universitat Politècnica de València (UPV), Camino de Vera s/n, 46022, Valencia, Spain
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156
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Bai X, Li X, Ma J, Guan BO. Improvement in resolution of fiber-laser photoacoustic tomography based on a virtual-point concept. Vis Comput Ind Biomed Art 2021; 4:4. [PMID: 33620595 PMCID: PMC7902747 DOI: 10.1186/s42492-021-00070-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/04/2021] [Indexed: 12/20/2022] Open
Abstract
In this study, a virtual-point concept was introduced into fiber-laser photoacoustic tomography to improve the elevational image resolution. The flexible fiber laser was bent into an arc shape to conform to the ultrasound wavefront, which formed an ultrasound focus at the center of the arc. The synthetic aperture focusing technique was utilized to reconstruct the images; as a result, the elevational resolution particularly within the out-of-focus region was considerably improved compared to the resolution of an image retrieved by multiplexing the PA time-resolved signals with sound velocity. The all-optical fiber-laser photoacoustic tomography system with a high spatial resolution has potential for various applications, including biomedical research and preclinical/clinical diagnosis.
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Affiliation(s)
- Xue Bai
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou, 511443, China
| | - Xu Li
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou, 511443, China
| | - Jun Ma
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou, 511443, China.
| | - Bai-Ou Guan
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou, 511443, China
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157
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DiSpirito A, Li D, Vu T, Chen M, Zhang D, Luo J, Horstmeyer R, Yao J. Reconstructing Undersampled Photoacoustic Microscopy Images Using Deep Learning. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:562-570. [PMID: 33064648 PMCID: PMC7858223 DOI: 10.1109/tmi.2020.3031541] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
One primary technical challenge in photoacoustic microscopy (PAM) is the necessary compromise between spatial resolution and imaging speed. In this study, we propose a novel application of deep learning principles to reconstruct undersampled PAM images and transcend the trade-off between spatial resolution and imaging speed. We compared various convolutional neural network (CNN) architectures, and selected a Fully Dense U-net (FD U-net) model that produced the best results. To mimic various undersampling conditions in practice, we artificially downsampled fully-sampled PAM images of mouse brain vasculature at different ratios. This allowed us to not only definitively establish the ground truth, but also train and test our deep learning model at various imaging conditions. Our results and numerical analysis have collectively demonstrated the robust performance of our model to reconstruct PAM images with as few as 2% of the original pixels, which can effectively shorten the imaging time without substantially sacrificing the image quality.
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158
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Jeong WY, Kang MS, Lee H, Lee JH, Kim J, Han DW, Kim KS. Recent Trends in Photoacoustic Imaging Techniques for 2D Nanomaterial-Based Phototherapy. Biomedicines 2021; 9:80. [PMID: 33467616 PMCID: PMC7830416 DOI: 10.3390/biomedicines9010080] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/13/2021] [Accepted: 01/13/2021] [Indexed: 02/06/2023] Open
Abstract
A variety of 2D materials have been developed for therapeutic biomedical studies. Because of their excellent physicochemical properties, 2D materials can be used as carriers for delivering therapeutic agents into a lesion, leading to phototherapy. Various optical imaging techniques have been used for the monitoring of the treatment process. Among these, photoacoustic imaging has unique advantages including relatively deep imaging depth and large field of view with high spatial resolution. In this review article, we summarize the types of photoacoustic imaging systems used for phototherapy monitoring, then we explore contrast-enhanced photoacoustic images using 2D materials. Finally, photoacoustic image-guided phototherapies are discussed. We conclude that 2D material-based phototherapy can be efficiently monitored by photoacoustic imaging techniques.
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Affiliation(s)
- Woo Yeup Jeong
- School of Chemical Engineering, College of Engineering, Pusan National University, Busan 46241, Korea;
| | - Moon Sung Kang
- Department of Cogno-Mechatronics Engineering, College of Nanoscience & Nanotechnology, Pusan National University, Busan 46241, Korea; (M.S.K.); (H.L.)
| | - Haeni Lee
- Department of Cogno-Mechatronics Engineering, College of Nanoscience & Nanotechnology, Pusan National University, Busan 46241, Korea; (M.S.K.); (H.L.)
| | - Jong Hun Lee
- Department of Food Science and Biotechnology, Gachon University, Seongnam, Gyeonggi 13120, Korea;
| | - Jeesu Kim
- Department of Cogno-Mechatronics Engineering, College of Nanoscience & Nanotechnology, Pusan National University, Busan 46241, Korea; (M.S.K.); (H.L.)
| | - Dong-Wook Han
- Department of Cogno-Mechatronics Engineering, College of Nanoscience & Nanotechnology, Pusan National University, Busan 46241, Korea; (M.S.K.); (H.L.)
| | - Ki Su Kim
- School of Chemical Engineering, College of Engineering, Pusan National University, Busan 46241, Korea;
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159
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Kim H, Baik JW, Jeon S, Kim JY, Kim C. PAExM: label-free hyper-resolution photoacoustic expansion microscopy. OPTICS LETTERS 2020; 45:6755-6758. [PMID: 33325889 DOI: 10.1364/ol.404041] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Reflection-mode ultraviolet photoacoustic microscopy (UV-PAM) is capable of imaging cell nuclei in thick tissue without complex preparation procedures, but it is challenging to distinguish adjacent nuclei due to the limited spatial resolution. Tissue expansion technology has recently been developed to exceed the diffraction-limited fluorescence microscopies, but it is accompanied by limitations including additional staining. Herein, photoacoustic expansion microscopy (PAExM) is presented, which is an advanced histologic imaging strategy combining advantages of fast label-free reflection-mode UV-PAM and the tissue expansion technology. Clustered cell nuclei in an enlarged volume of a mouse brain section can be visually resolved without staining, demonstrating a great potential of the system to be widely used for histologic applications throughout biomedical fields.
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160
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Benyamin M, Genish H, Califa R, Wolbromsky L, Ganani M, Wang Z, Zhou S, Xie Z, Zalevsky Z. Autoencoder based blind source separation for photoacoustic resolution enhancement. Sci Rep 2020; 10:21414. [PMID: 33293644 PMCID: PMC7722849 DOI: 10.1038/s41598-020-78310-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 11/24/2020] [Indexed: 11/08/2022] Open
Abstract
Photoacoustics is a promising technique for in-depth imaging of biological tissues. However, the lateral resolution of photoacoustic imaging is limited by size of the optical excitation spot, and therefore by light diffraction and scattering. Several super-resolution approaches, among which methods based on localization of labels and particles, have been suggested, presenting promising but limited solutions. This work demonstrates a novel concept for extended-resolution imaging based on separation and localization of multiple sub-pixel absorbers, each characterized by a distinct acoustic response. Sparse autoencoder algorithm is used to blindly decompose the acoustic signal into its various sources and resolve sub-pixel features. This method can be used independently or as a combination with other super-resolution techniques to gain further resolution enhancement and may also be extended to other imaging schemes. In this paper, the general idea is presented in details and experimentally demonstrated.
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Affiliation(s)
- Matan Benyamin
- Faculty of Engineering and the Nanotechnology Center, Bar Ilan University, 5290002, Ramat Gan, Israel.
- ContinUse Biometrics Ltd., Habarzel 32b Street, 6971048, Tel Aviv, Israel.
| | - Hadar Genish
- ContinUse Biometrics Ltd., Habarzel 32b Street, 6971048, Tel Aviv, Israel
| | - Ran Califa
- ContinUse Biometrics Ltd., Habarzel 32b Street, 6971048, Tel Aviv, Israel
| | - Lauren Wolbromsky
- Faculty of Engineering and the Nanotechnology Center, Bar Ilan University, 5290002, Ramat Gan, Israel
- ContinUse Biometrics Ltd., Habarzel 32b Street, 6971048, Tel Aviv, Israel
| | - Michal Ganani
- ContinUse Biometrics Ltd., Habarzel 32b Street, 6971048, Tel Aviv, Israel
| | - Zhen Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuyun Zhou
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Zheng Xie
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Zeev Zalevsky
- Faculty of Engineering and the Nanotechnology Center, Bar Ilan University, 5290002, Ramat Gan, Israel
- ContinUse Biometrics Ltd., Habarzel 32b Street, 6971048, Tel Aviv, Israel
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161
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Hosseinaee Z, Le M, Bell K, Reza PH. Towards non-contact photoacoustic imaging [review]. PHOTOACOUSTICS 2020; 20:100207. [PMID: 33024694 PMCID: PMC7530308 DOI: 10.1016/j.pacs.2020.100207] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/29/2020] [Accepted: 07/10/2020] [Indexed: 05/06/2023]
Abstract
Photoacoustic imaging (PAI) takes advantage of both optical and ultrasound imaging properties to visualize optical absorption with high resolution and contrast. Photoacoustic microscopy (PAM) is usually categorized with all-optical microscopy techniques such as optical coherence tomography or confocal microscopes. Despite offering high sensitivity, novel imaging contrast, and high resolution, PAM is not generally an all-optical imaging method unlike the other microscopy techniques. One of the significant limitations of photoacoustic microscopes arises from their need to be in physical contact with the sample through a coupling media. This physical contact, coupling, or immersion of the sample is undesirable or impractical for many clinical and pre-clinical applications. This also limits the flexibility of photoacoustic techniques to be integrated with other all-optical imaging microscopes for providing complementary imaging contrast. To overcome these limitations, several non-contact photoacoustic signal detection approaches have been proposed. This paper presents a brief overview of current non-contact photoacoustic detection techniques with an emphasis on all-optical detection methods and their associated physical mechanisms.
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Affiliation(s)
- Zohreh Hosseinaee
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, Ontario, N2L 3G1, Canada
| | - Martin Le
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, Ontario, N2L 3G1, Canada
| | - Kevan Bell
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, Ontario, N2L 3G1, Canada
- IllumiSonics Inc., Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
| | - Parsin Haji Reza
- PhotoMedicine Labs, Department of System Design Engineering, University of Waterloo, Ontario, N2L 3G1, Canada
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162
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Park SM, Kim DY, Cho SW, Kim BM, Lee TG, Kim CS, Lee SW. Quickly Alternating Green and Red Laser Source for Real-time Multispectral Photoacoustic Microscopy. PHOTOACOUSTICS 2020; 20:100204. [PMID: 33014706 PMCID: PMC7522855 DOI: 10.1016/j.pacs.2020.100204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 05/06/2023]
Abstract
Multispectral photoacoustic microscopy uses a wavelength-dependent absorption difference as a contrast mechanism to image the target molecule. In this paper, we present a novel multispectral pulsed fiber laser source, which selectively alternates the excitation wavelengths between green and red colors based on the stimulated Raman scattering (SRS) effect for imaging. This laser has a high pulse repetition rate (PRR) of 300 kHz and high pulse energy of more than 200 nJ meeting the real-time requirements of optical-resolution photoacoustic microscopy imaging. By switching the polarization state of the pump light and optical paths of the pump light, the operating wavelengths of the light source can be selectively alternated at the same fast PRR for any two SRS peak wavelengths between 545 and 655 nm. At 545 nm excitation wavelength, molecular photoacoustic signals from both blood vessels and gold nanorods were obtained simultaneously. However, at 655 nm, the photoacoustic signals of gold nanorods were dominant because the absorption of light by the blood vessels decreased drastically in the spectral region over 600 nm. Thus the multispectral photoacoustic system designed using the novel laser source implemented here could simultaneously monitor the time-dependent fast movement of two molecules independently, having different wavelength-dependent absorption properties at a high repetition rate of 0.49 frames per second (fps).
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Affiliation(s)
- Sang Min Park
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Do Yeon Kim
- Safety Measurement Institute, Korea Research Institute of Standards and Science, Daejeon 34113, Republic of Korea
- Department of Bio-Convergence Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Soon-Woo Cho
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Beop-Min Kim
- Department of Bio-Convergence Engineering, Korea University, Seoul 02841, Republic of Korea
- Department of Biomedical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Tae Geol Lee
- Safety Measurement Institute, Korea Research Institute of Standards and Science, Daejeon 34113, Republic of Korea
| | - Chang-Seok Kim
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 46241, Republic of Korea
- Corresponding author at: Department of Cogno-Mechatronics Engineering, Busan National University, 46241, Republic of Korea
| | - Sang-Won Lee
- Safety Measurement Institute, Korea Research Institute of Standards and Science, Daejeon 34113, Republic of Korea
- Department of Medical Physics, University of Science and Technology, Daejeon 34113, Republic of Korea
- Corresponding authors.
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163
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Guo H, Li Y, Qi W, Xi L. Photoacoustic endoscopy: A progress review. JOURNAL OF BIOPHOTONICS 2020; 13:e202000217. [PMID: 32935920 DOI: 10.1002/jbio.202000217] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/20/2020] [Accepted: 08/31/2020] [Indexed: 06/11/2023]
Abstract
Endoscopy has been widely used in biomedical imaging and integrated with various optical and acoustic imaging modalities. Photoacoustic imaging (PAI), one of the fastest growing biomedical imaging modalities, is a noninvasive and nonionizing method that owns rich optical contrast, deep acoustic penetration depth, multiscale and multiparametric imaging capability. Hence, it is preferred to miniaturize the volume of PAI and develop an emerged endoscopic imaging modality referred to as photoacoustic endoscopy (PAE). It has been developed for more than one decade since the first report of PAE. Unfortunately, until now, there is no mature photoacoustic endoscopic technique recognized in clinic due to various technical limitations. To address this concern, recent development of new scanning mechanisms, adoption of novel optical/acoustic devices, utilization of superior computation methods and exploration of multimodality strategies have significantly promoted the progress of PAE toward clinic. In this review, we comprehensively reviewed recent progresses in single- and multimodality PAE with new physics, mechanisms and strategies to achieve practical devices for potential applicable scenarios including esophageal, gastrointestinal, urogenital and intravascular imaging. We ended this review with challenges and prospects for future development of PAE.
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Affiliation(s)
- Heng Guo
- School of Physics, University of Electronic Science and Technology of China, Chengdu, China
| | - Ying Li
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Weizhi Qi
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Lei Xi
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, China
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164
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Chen J, Zhang Y, He L, Liang Y, Wang L. Wide-field polygon-scanning photoacoustic microscopy of oxygen saturation at 1-MHz A-line rate. PHOTOACOUSTICS 2020; 20:100195. [PMID: 32577378 PMCID: PMC7300162 DOI: 10.1016/j.pacs.2020.100195] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/25/2020] [Accepted: 06/03/2020] [Indexed: 05/06/2023]
Abstract
We report wide-field polygon-scanning functional OR-PAM that for the first time achieves 1-MHz A-line rate of oxygen saturation in vivo. We address two technical challenges. The first is a 1-MHz dual-wavelength pulsed laser that has sufficient pulse energy and ultrafast wavelength switching. The second is a polygon-scanning imaging probe that has a fast scanning speed, a large field of view, and great sensitivity. The OR-PAM system offers a B-scan rate of 477.5 Hz in a 12-mm range and a volumetric imaging rate of ∼1 Hz over a 12 × 5 mm2 scanning area. We image microvasculature and blood oxygen saturation in a 12 × 12 mm2 scanning area in 5 s. Dynamic imaging of oxygen saturation in the mouse ear is demonstrated to monitor fast response to epinephrine injection. The new wide-field fast functional imaging ability broadens the biomedical application of OR-PAM.
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Affiliation(s)
- Jiangbo Chen
- Department of Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon, Hong Kong SAR, China
| | - Yachao Zhang
- Department of Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon, Hong Kong SAR, China
| | - Linyun He
- Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangzhou, 510282, China
| | - Yizhi Liang
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou, 510632, China
| | - Lidai Wang
- Department of Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon, Hong Kong SAR, China
- City University of Hong Kong Shenzhen Research Institute, Yuexing Yi Dao, Shenzhen, Guang Dong, 518057, China
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165
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Retinal safety evaluation of photoacoustic microscopy. Exp Eye Res 2020; 202:108368. [PMID: 33242491 DOI: 10.1016/j.exer.2020.108368] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/31/2020] [Accepted: 11/20/2020] [Indexed: 11/22/2022]
Abstract
Photoacoustic microscopy (PAM) has significant potential as a promising diagnostic method for eye diseases and can provide anatomic and functional information of the retinal and choroidal vasculature. However, there are no FDA-approved PAM systems for ophthalmic imaging. In this study, a comprehensive safety evaluation was performed to evaluate the safety of PAM retinal imaging and whether PAM causes damage to retinal structure or function in rabbit eyes. 12 Dutch-Belted pigmented rabbits received photoacoustic imaging to 57% of the retinal surface area with a laser energy of 5% of the ANSI safety limit for five consecutive days and followed before imaging and 3 days, 1, 2, 3, and 4 weeks post imaging. Retinal morphologic analyses using slit lamp examination, fundus photography, red free, FA, FAF, ICGA, and OCT showed no retinal hemorrhage, edema, detachment, vascular abnormalities, or pigmentary abnormalities in the retina or choroid after PAM imaging. Full-field ERG analysis showed no significant difference in scotopic or photopic a- and b-wave amplitudes or implicit times between the control and experimental eyes over time (n = 6, P values > 0.05). Retinal ultrastructural evaluation using TEM showed normal structure of organelles and nuclei, and no significant loss of cells after PAM. TUNEL assay showed no evidence of cells apoptosis in retina. Retinal histopathology indicated that the architecture and thickness of the retinal layers was well preserved in all experimental eyes. A positive control at 500% of the ANSI limit demonstrated significant damage. The comprehensive retinal safety evaluation demonstrated no damage to retinal structure or function for 4 weeks after PAM imaging in rabbits.
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166
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Newsome IG, Dayton PA. Visualization of Microvascular Angiogenesis Using Dual-Frequency Contrast-Enhanced Acoustic Angiography: A Review. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:2625-2635. [PMID: 32703659 PMCID: PMC7608693 DOI: 10.1016/j.ultrasmedbio.2020.06.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 05/25/2020] [Accepted: 06/14/2020] [Indexed: 05/07/2023]
Abstract
Cancerous tumor growth is associated with the development of tortuous, chaotic microvasculature, and this aberrant microvascular morphology can act as a biomarker of malignant disease. Acoustic angiography is a contrast-enhanced ultrasound technique that relies on superharmonic imaging to form high-resolution 3-D maps of the microvasculature. To date, acoustic angiography has been performed with dual-element transducers that can achieve high contrast-to-tissue ratio and resolution in pre-clinical small animal models. In this review, we first describe the development of acoustic angiography, including the principle, transducer design, and optimization of superharmonic imaging techniques. We then detail several preclinical applications of this microvascular imaging method, as well as the current and future development of acoustic angiography as a pre-clinical and clinical diagnostic tool.
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Affiliation(s)
- Isabel G Newsome
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Paul A Dayton
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, USA.
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167
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Li X, Kang L, Zhang Y, Wong TTW. High-speed label-free ultraviolet photoacoustic microscopy for histology-like imaging of unprocessed biological tissues. OPTICS LETTERS 2020; 45:5401-5404. [PMID: 33001904 DOI: 10.1364/ol.401643] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Ultraviolet photoacoustic microscopy (UV-PAM) has recently been demonstrated as a potential imaging tool for surgical margin analysis (SMA). UV-PAM does not require staining or micrometer-thick slicing, which is inevitable in conventional histological imaging. To promote UV-PAM as a practical intraoperative diagnostic tool, the imaging speed should be improved while preserving the high-resolution imaging capability and simplistic system design. In this Letter, we developed a galvanometer mirror-based UV-PAM (GM-UV-PAM) system for high-speed histology-like imaging. By using a UV laser with a high repetition rate (55 kHz) and a one-dimensional galvanometer mirror, our GM-UV-PAM system can generate subcellular images in less than 15 min for a typical brain biopsy (5mm×5mm), with a lateral resolution of ∼1.0µm. The images of mouse brain slices obtained by our GM-UV-PAM system show that it can provide histological information for SMA.
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168
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Chalklen T, Jing Q, Kar-Narayan S. Biosensors Based on Mechanical and Electrical Detection Techniques. SENSORS (BASEL, SWITZERLAND) 2020; 20:E5605. [PMID: 33007906 PMCID: PMC7584018 DOI: 10.3390/s20195605] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/18/2020] [Accepted: 09/23/2020] [Indexed: 12/20/2022]
Abstract
Biosensors are powerful analytical tools for biology and biomedicine, with applications ranging from drug discovery to medical diagnostics, food safety, and agricultural and environmental monitoring. Typically, biological recognition receptors, such as enzymes, antibodies, and nucleic acids, are immobilized on a surface, and used to interact with one or more specific analytes to produce a physical or chemical change, which can be captured and converted to an optical or electrical signal by a transducer. However, many existing biosensing methods rely on chemical, electrochemical and optical methods of identification and detection of specific targets, and are often: complex, expensive, time consuming, suffer from a lack of portability, or may require centralised testing by qualified personnel. Given the general dependence of most optical and electrochemical techniques on labelling molecules, this review will instead focus on mechanical and electrical detection techniques that can provide information on a broad range of species without the requirement of labelling. These techniques are often able to provide data in real time, with good temporal sensitivity. This review will cover the advances in the development of mechanical and electrical biosensors, highlighting the challenges and opportunities therein.
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Affiliation(s)
| | - Qingshen Jing
- Department of Materials Science, University of Cambridge, Cambridge CB3 0FS, UK;
| | - Sohini Kar-Narayan
- Department of Materials Science, University of Cambridge, Cambridge CB3 0FS, UK;
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169
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Endoscopic Optical Imaging Technologies and Devices for Medical Purposes: State of the Art. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10196865] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The growth and development of optical components and, in particular, the miniaturization of micro-electro-mechanical systems (MEMSs), has motivated and enabled researchers to design smaller and smaller endoscopes. The overarching goal of this work has been to image smaller previously inaccessible luminal organs in real time, at high resolution, in a minimally invasive manner that does not compromise the comfort of the subject, nor introduce additional risk. Thus, an initial diagnosis can be made, or a small precancerous lesion may be detected, in a small-diameter luminal organ that would not have otherwise been possible. Continuous advancement in the field has enabled a wide range of optical scanners. Different scanning techniques, working principles, and the applications of endoscopic scanners are summarized in this review.
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170
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Manwar R, Kratkiewicz K, Avanaki K. Overview of Ultrasound Detection Technologies for Photoacoustic Imaging. MICROMACHINES 2020; 11:E692. [PMID: 32708869 PMCID: PMC7407969 DOI: 10.3390/mi11070692] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/14/2020] [Accepted: 07/14/2020] [Indexed: 12/15/2022]
Abstract
Ultrasound detection is one of the major components of photoacoustic imaging systems. Advancement in ultrasound transducer technology has a significant impact on the translation of photoacoustic imaging to the clinic. Here, we present an overview on various ultrasound transducer technologies including conventional piezoelectric and micromachined transducers, as well as optical ultrasound detection technology. We explain the core components of each technology, their working principle, and describe their manufacturing process. We then quantitatively compare their performance when they are used in the receive mode of a photoacoustic imaging system.
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Affiliation(s)
- Rayyan Manwar
- Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA;
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48201, USA;
| | - Karl Kratkiewicz
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48201, USA;
| | - Kamran Avanaki
- Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA;
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48201, USA;
- Department of Dermatology, University of Illinois at Chicago, Chicago, IL 60607, USA
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171
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Seeger M, Soliman D, Aguirre J, Diot G, Wierzbowski J, Ntziachristos V. Pushing the boundaries of optoacoustic microscopy by total impulse response characterization. Nat Commun 2020; 11:2910. [PMID: 32518250 PMCID: PMC7283257 DOI: 10.1038/s41467-020-16565-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 04/22/2020] [Indexed: 11/19/2022] Open
Abstract
Optical microscopy improves in resolution and signal-to-noise ratio by correcting for the system’s point spread function; a measure of how a point source is resolved, typically determined by imaging nanospheres. Optical-resolution optoacoustic (photoacoustic) microscopy could be similarly corrected, especially to account for the spatially-dependent signal distortions induced by the acoustic detection and the time-resolved and bi-polar nature of optoacoustic signals. Correction algorithms must therefore include the spatial dependence of signals’ origins and profiles in time, i.e. the four-dimensional total impulse response (TIR). However, such corrections have been so far impeded by a lack of efficient TIR-characterization methods. We introduce high-quality TIR determination based on spatially-distributed optoacoustic point sources (SOAPs), produced by scanning an optical focus on an axially-translatable 250 nm gold layer. Using a spatially-dependent TIR-correction improves the signal-to-noise ratio by >10 dB and the axial resolution by ~30%. This accomplishment displays a new performance paradigm for optoacoustic microscopy. Characterizing the total impulse response (TIR) of photoacoustic microscopes has been challenging due to difficulties distributing appropriate point sources. Here, the authors present a method for 3D generation of spatially-distributed optoacoustic point sources and show that subsequent TIR correction results in improved image quality.
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Affiliation(s)
- Markus Seeger
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany.,Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Dominik Soliman
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany.,Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Juan Aguirre
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany.,Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Gael Diot
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany.,Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Jakob Wierzbowski
- Walter Schottky Institute, Physics Department, Technical University of Munich, Am Coulombwall 4, 85748, Garching, Germany
| | - Vasilis Ntziachristos
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Ismaninger Straße 22, 81675, Munich, Germany. .,Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany.
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172
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Dasa MK, Nteroli G, Bowen P, Messa G, Feng Y, Petersen CR, Koutsikou S, Bondu M, Moselund PM, Podoleanu A, Bradu A, Markos C, Bang O. All-fibre supercontinuum laser for in vivo multispectral photoacoustic microscopy of lipids in the extended near-infrared region. PHOTOACOUSTICS 2020; 18:100163. [PMID: 32042589 PMCID: PMC6997905 DOI: 10.1016/j.pacs.2020.100163] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/15/2020] [Accepted: 01/22/2020] [Indexed: 05/06/2023]
Abstract
Among the numerous endogenous biological molecules, information on lipids is highly coveted for understanding both aspects of developmental biology and research in fatal chronic diseases. Due to the pronounced absorption features of lipids in the extended near-infrared region (1650-1850 nm), visualisation and identification of lipids become possible using multi-spectral photoacoustic (optoacoustic) microscopy. However, the spectroscopic studies in this spectral region require lasers that can produce high pulse energies over a broad spectral bandwidth to efficiently excite strong photoacoustic signals. The most well-known laser sources capable of satisfying the multi-spectral photoacoustic microscopy requirements (tunability and pulse energy) are tunable nanosecond optical parametric oscillators. However, these lasers have an inherently large footprint, thus preventing their use in compact microscopy systems. Besides, they exhibit low-repetition rates. Here, we demonstrate a compact all-fibre, high pulse energy supercontinuum laser that covers a spectral range from 1440 to 1870 nm with a 7 ns pulse duration and total energy of 18.3 μJ at a repetition rate of 100 kHz. Using the developed high-pulse energy source, we perform multi-spectral photoacoustic microscopy imaging of lipids, both ex vivo on adipose tissue and in vivo to study the development of Xenopus laevis tadpoles, using six different excitation bands over the first overtone transition of C-H vibration bonds (1650-1850 nm).
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Affiliation(s)
- Manoj K. Dasa
- DTU Fotonik, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Gianni Nteroli
- Applied Optics Group, University of Kent, Canterbury, UK
| | - Patrick Bowen
- NKT Photonics A/S, Blokken 84, 3460 Birkerød, Denmark
| | - Giulia Messa
- Medway School of Pharmacy, University of Kent, Chatham, UK
| | - Yuyang Feng
- COPAC A/S, Diplomvej 381, 2800 Kongens Lyngby, Denmark
| | - Christian R. Petersen
- DTU Fotonik, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
- NORBLIS IVS, Virumgade 35D, 2830 Virum, Denmark
| | | | - Magalie Bondu
- NKT Photonics A/S, Blokken 84, 3460 Birkerød, Denmark
| | | | | | - Adrian Bradu
- Applied Optics Group, University of Kent, Canterbury, UK
| | - Christos Markos
- DTU Fotonik, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
- NORBLIS IVS, Virumgade 35D, 2830 Virum, Denmark
| | - Ole Bang
- DTU Fotonik, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
- NORBLIS IVS, Virumgade 35D, 2830 Virum, Denmark
- NKT Photonics A/S, Blokken 84, 3460 Birkerød, Denmark
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173
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Zhou Y, Liang S, Li M, Liu C, Lai P, Wang L. Optical-resolution photoacoustic microscopy with ultrafast dual-wavelength excitation. JOURNAL OF BIOPHOTONICS 2020; 13:e201960229. [PMID: 32049415 DOI: 10.1002/jbio.201960229] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/30/2020] [Accepted: 02/04/2020] [Indexed: 05/07/2023]
Abstract
Fast functional and molecular photoacoustic microscopy requires pulsed laser excitations at multiple wavelengths with enough pulse energy and short wavelength-switching time. Recent development of stimulated Raman scattering in optical fiber offers a low-cost laser source for multiwavelength photoacoustic imaging. In this approach, long fibers temporally separate different wavelengths via optical delay. The time delay between adjacent wavelengths may eventually limits the highest A-line rate. In addition, a long-time delay in fiber may limit the highest pulse energy, leading to poor image quality. In order to achieve high pulse energy and ultrafast dual-wavelength excitation, we present optical-resolution photoacoustic microscopy with ultrafast dual-wavelength excitation and a signal separation method. The signal separation method is validated in numerical simulation and phantom experiments. We show that when two photoacoustic signals are partially overlapped with a 50-ns delay, they can be recovered with 98% accuracy. We apply this ultrafast dual-wavelength excitation technique to in vivo OR-PAM. Results demonstrate that A-lines at two wavelengths can be successfully separated, and sO2 values can be reliably computed from the separated data. The ultrafast dual-wavelength excitation enables fast functional photoacoustic microscopy with negligible misalignment among different wavelengths and high pulse energy, which is important for in vivo imaging of microvascular dynamics.
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Affiliation(s)
- Yingying Zhou
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Kowloon, Hong Kong
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong
- Department of Biomedical Engineering, The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Siyi Liang
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong
| | - Mingsheng Li
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong
| | - Chengbo Liu
- Research Laboratory for Biomedical Optics and Molecular Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Puxiang Lai
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Kowloon, Hong Kong
- Department of Biomedical Engineering, The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Lidai Wang
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong
- Department of Biomedical Engineering, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
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174
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Zhang W, Li Y, Nguyen VP, Derouin K, Xia X, Paulus YM, Wang X. Ultralow energy photoacoustic microscopy for ocular imaging in vivo. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-8. [PMID: 32519521 PMCID: PMC7282506 DOI: 10.1117/1.jbo.25.6.066003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 06/01/2020] [Indexed: 06/11/2023]
Abstract
SIGNIFICANCE The development of ultralow energy photoacoustic microscopy (PAM) on the clinically relevant pigmented rabbit eye model paves a road toward translation of the emerging PAM technology in ophthalmology clinics. AIM Since the eye is particularly vulnerable to laser damage, we aim to develop an ultralow energy PAM system to significantly improve the laser safety of PAM by increasing the sensitivity of the system and reducing the incident laser energy for imaging. APPROACH A multichannel data acquisition circuit with two-stage signal amplification was specially designed, which, in combination with the application of 3 by 3 median filter in the spatial domain, significantly improved the signal-to-noise ratio of the PAM system. The safety of this system was validated by histopathology, fluorescein angiography, and fundus photography. RESULTS Experiments performed on pigmented rabbits demonstrated that, when using this ultralow energy PAM system, satisfactory image quality can be achieved in the eye with an incident laser fluence that is only 1% of the American National Standards Institute safety limit. Fundus photography, fluorescein angiography, and histopathology were performed after the imaging procedure, and no retinal or ocular damage was observed. CONCLUSIONS The proposed ultralow energy PAM system has excellent safety and holds potential to be developed into a clinical tool for ocular imaging.
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Affiliation(s)
- Wei Zhang
- University of Michigan, Department of Biomedical Engineering, Ann Arbor, Michigan, United States
| | - Yanxiu Li
- University of Michigan, Department of Ophthalmology and Visual Sciences, Ann Arbor, Michigan, United States
- Central South University, Eye Center of Xiangya Hospital, Changsha, China
- Central South University, Hunan Key Laboratory of Ophthalmology, Changsha, China
| | - Van Phuc Nguyen
- University of Michigan, Department of Ophthalmology and Visual Sciences, Ann Arbor, Michigan, United States
| | - Katherine Derouin
- University of Michigan, Department of Ophthalmology and Visual Sciences, Ann Arbor, Michigan, United States
| | - Xiaobo Xia
- Central South University, Eye Center of Xiangya Hospital, Changsha, China
- Central South University, Hunan Key Laboratory of Ophthalmology, Changsha, China
| | - Yannis M. Paulus
- University of Michigan, Department of Biomedical Engineering, Ann Arbor, Michigan, United States
- University of Michigan, Department of Ophthalmology and Visual Sciences, Ann Arbor, Michigan, United States
| | - Xueding Wang
- University of Michigan, Department of Biomedical Engineering, Ann Arbor, Michigan, United States
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175
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Torke PR, Nuster R, Paltauf G. Conical ring array detector for large depth of field photoacoustic macroscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:2461-2475. [PMID: 32499937 PMCID: PMC7249821 DOI: 10.1364/boe.386585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/31/2020] [Accepted: 02/26/2020] [Indexed: 05/07/2023]
Abstract
Photoacoustic microscopy and macroscopy (PAM) using focused detector scanning are emerging imaging methods for biological tissue, providing high resolution and high sensitivity for structures with optical absorption contrast. However, achieving a constant lateral resolution over a large depth of field for deeply penetrating photoacoustic macroscopy is still a challenge. In this work, a detector design for scanning photoacoustic macroscopy is presented. Based on simulation results, a sensor array geometry is developed and fabricated that consists of concentric ring elements made of polyvinylidene fluoride (PVDF) film in a geometry that combines a centered planar ring with several inclined outer ring elements. The reconstruction algorithm, which uses dynamic focusing and coherence weighting, is explained and its capability to reduce artefacts occurring for single element conical sensors is demonstrated. Several phantoms are manufactured to evaluate the performance of the array in experimental measurements. The sensor array provides a constant axial and lateral resolution of 95 µm and 285 µm, respectively, over a depth of field of 20 mm. The depth of field corresponds approximately to the maximum imaging depth in biological tissue, estimated from the sensitivity of the array. With its ability to achieve the maximum resolution even with a very small scanning range, the array is believed to have applications in the imaging of limited regions of interest buried in biological tissue.
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176
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Ilkhechi AK, Ceroici C, Li Z, Zemp R. Transparent capacitive micromachined ultrasonic transducer (CMUT) arrays for real-time photoacoustic applications. OPTICS EXPRESS 2020; 28:13750-13760. [PMID: 32403843 DOI: 10.1364/oe.390612] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 03/30/2020] [Indexed: 05/26/2023]
Abstract
Photoacoustic imaging has shown great potential for non-invasive high-resolution deep-tissue imaging. Minimizing the optical and acoustic paths for excitation and detection could significantly increase the signal-to-noise ratio. This could be accomplished by transparent transducers permitting through-transducer illumination. However, most ultrasound transducers are not optically transparent. Capacitive micromachined ultrasound transducer (CMUT) technology has compelling properties compared to piezoelectric transducers such as wide bandwidth and high receive sensitivity. Here, we introduce transparent CMUT linear arrays with high transparency in the visible and near-infrared range. To fabricate the devices, we used an adhesive wafer bonding technique using photosensitive benzocyclobutene (BCB) as both a structural and adhesive layer with a glass-indium-tin-oxide (ITO) substrate. Silicon nitride is used as the membrane material ensuring hermiticity and optical transparency. Our fabricated transducer arrays consist of 64 and 128 elements with immersion operation frequency of 8 MHz, enabling high-resolution imaging. ITO, along with thin metal strips, are used as a conductive layer for the top electrodes with minimal impact on device transparency. Fabricated devices have shown average transparency of 70% in the visible wavelength range that goes up to 90% in the near-infrared range. Arrays are wire-bonded to interfacing electronics and connected to a research ultrasound platform for phantom imaging. Arrays exhibited signal-to-noise (SNR) of 40 dB with 30V bias voltage and laser fluence of 13.5 mJ/cm2. Arrays with 128 channels provided lateral and axial resolutions of 234 µm and 220 µm, respectively.
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177
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Dahlstrand U, Sheikh R, Berggren J, Hult J, Albinsson J, Cinthio M, Malmsjö M. Spectral Signatures in the Different Layers of the Human Eyelid by Photoacoustic Imaging. Lasers Surg Med 2020; 52:341-346. [DOI: 10.1002/lsm.23148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Ulf Dahlstrand
- Department of Clinical Sciences Lund, Ophthalmology, Skåne University HospitalLund UniversityLund SE‐221 85 Sweden
| | - Rafi Sheikh
- Department of Clinical Sciences Lund, Ophthalmology, Skåne University HospitalLund UniversityLund SE‐221 85 Sweden
| | - Johanna Berggren
- Department of Clinical Sciences Lund, Ophthalmology, Skåne University HospitalLund UniversityLund SE‐221 85 Sweden
| | - Jenny Hult
- Department of Clinical Sciences Lund, Ophthalmology, Skåne University HospitalLund UniversityLund SE‐221 85 Sweden
| | - John Albinsson
- Department of Clinical Sciences Lund, Ophthalmology, Skåne University HospitalLund UniversityLund SE‐221 85 Sweden
| | - Magnus Cinthio
- Department of Biomedical Engineering, Faculty of EngineeringLund UniversityLund SE‐221 00 Sweden
| | - Malin Malmsjö
- Department of Clinical Sciences Lund, Ophthalmology, Skåne University HospitalLund UniversityLund SE‐221 85 Sweden
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178
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Li G, Ye Z, Liang S, Chen SL. Miniature probe for dual-modality photoacoustic microscopy and white-light microscopy for image guidance: A prototype toward an endoscope. JOURNAL OF BIOPHOTONICS 2020; 13:e201960200. [PMID: 31920005 DOI: 10.1002/jbio.201960200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/22/2019] [Accepted: 12/23/2019] [Indexed: 05/11/2023]
Abstract
In this study, a novel photoacoustic microscopy (PAM) probe integrating white-light microscopy (WLM) modality that provides guidance for PAM imaging and complementary information is implemented. One single core of an imaging fiber bundle is employed to deliver a pulsed laser for photoacoustic excitation for PAM mode, which provides high resolution with deep penetration. Meanwhile, for WLM mode, the imaging fiber bundle is used to transmit two-dimensional superficial images. Lateral resolution of 7.2 μm for PAM is achieved. Since miniature components are used, the probe diameter is only 1.7 mm. Imaging of phantom and animals in vivo is conducted to show the imaging capability of the probe. The probe has several advantages by introducing the WLM mode, such as being able to conveniently identify regions of interest and align the focus for PAM mode. The prototype of an endoscope shows potential to facilitate clinical photoacoustic endoscopic applications.
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Affiliation(s)
- Guangyao Li
- University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Zhanhong Ye
- University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Siqi Liang
- University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Sung-Liang Chen
- University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai, China
- State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Jiao Tong University, Shanghai, China
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179
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Abbasi S, Bell K, Ecclestone B, Haji Reza P. Live feedback and 3D photoacoustic remote sensing. Quant Imaging Med Surg 2020; 11:1033-1045. [PMID: 33654675 DOI: 10.21037/qims-20-758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background As photoacoustic (PA) techniques progress towards clinical adoption, providing a high-speed live feedback becomes a high priority. To keep up with the instantaneous optical feedback of conventional light microscopes, PA imaging would need to provide a high-resolution video-rate live feed to the user. However, conventional PA microscopy typically trades resolution, sensitivity and imaging speed when optically scanning due to the difficult opto-acoustic confocal geometry. Here, we employ photoacoustic remote sensing (PARS), an all-optical technique that relies on optical confocal geometry, to provide a high-resolution live display in a reflection-mode PA architecture. Methods Employing a conventional x-y galvanometer scanner and a 600 KHz pulse repetition rate laser we implement a system capable of acquiring 2.5 frames per second in 2D. To complement this fast scanning optical system, we implement a computationally inexpensive image reconstruction method that is able to render the frames with minimal overhead, providing a live display. Results Employing the proposed method, we demonstrate a live feedback with frame rates as high as 2.5 Hz in 2D and also report the first results of 3D imaging with a non-contact label-free reflection-mode technique. The method is validated with phantom studies and in-vivo imaging. Employing a repetition rate of 600 KHz, a live feed of carbon fibers is realized with a C-scan rate of 2.5 Hz. The imaging resolution was measured to be 1.2 µm, the highest reported for a real-time reflection-mode architecture. The mean and peak SNR were measured to be 44 and 62 dB respectively in-vivo. 3D visualizations of carbon fiber phantoms and mouse ear microvasculature structure are also demonstrated. Conclusions In summary, we present a method that has a small computational overhead for image rendering, resulting in a live display capable of real-time frame rates. We also report the first 3D imaging with a non-contact label-free reflection-mode PA technique. The all-optical confocal geometry required by PARS is significantly easier to implement and maintain than the opto-acoustic geometry of conventional PA microscopy techniques. This results in a system capable of high resolution and sensitivity, imaging at real-time rates. The authors believe this work represents a vital step towards a clinical high-resolution reflection-mode video-rate PA imaging system.
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Affiliation(s)
- Saad Abbasi
- PhotoMedicine Labs, Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Kevan Bell
- PhotoMedicine Labs, Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada.,IllumiSonics, Inc., Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Benjamin Ecclestone
- PhotoMedicine Labs, Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Parsin Haji Reza
- PhotoMedicine Labs, Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
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180
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Rapid High-Resolution Mosaic Acquisition for Photoacoustic Remote Sensing. SENSORS 2020; 20:s20041027. [PMID: 32075006 PMCID: PMC7071083 DOI: 10.3390/s20041027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/10/2020] [Accepted: 02/10/2020] [Indexed: 12/13/2022]
Abstract
Mechanical stages are routinely used to scan large expanses of biological specimens in photoacoustic imaging. This is primarily due to the limited field of view (FOV) provided by optical scanning. However, stage scanning becomes impractical at higher scanning speeds, or potentially unfeasible with heavier samples. Also, the slow scan-rate of the stages makes high resolution scanning a time-consuming process. Some clinical applications such as microsurgery require submicron resolution in a reflection-mode configuration necessitating a method that can acquire large field of views with a small raster scanning step size. In this study, we describe a method that combines mechanical stages with optical scanning for the rapid acquisition of high-resolution large FOVs. Optical scanning is used to acquire small frames in a two-dimensional grid formed by the mechanical stages. These frames are captured with specific overlap for effective image registration. Using a step size of 200 nm, we demonstrate mosaics of carbon fiber networks with FOVs of 0.8 × 0.8 mm2 captured in under 70 s with 1.2 µm image resolution. Larger mosaics yielding an imaging area of 3 × 3 mm2 are also shown. The method is validated by imaging a 1 × 1 mm2 section of unstained histopathological human tissue.
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181
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Shrestha B, DeLuna F, Anastasio MA, Yong Ye J, Brey EM. Photoacoustic Imaging in Tissue Engineering and Regenerative Medicine. TISSUE ENGINEERING. PART B, REVIEWS 2020; 26:79-102. [PMID: 31854242 PMCID: PMC7041335 DOI: 10.1089/ten.teb.2019.0296] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 12/13/2019] [Indexed: 12/16/2022]
Abstract
Several imaging modalities are available for investigation of the morphological, functional, and molecular features of engineered tissues in small animal models. While research in tissue engineering and regenerative medicine (TERM) would benefit from a comprehensive longitudinal analysis of new strategies, researchers have not always applied the most advanced methods. Photoacoustic imaging (PAI) is a rapidly emerging modality that has received significant attention due to its ability to exploit the strong endogenous contrast of optical methods with the high spatial resolution of ultrasound methods. Exogenous contrast agents can also be used in PAI for targeted imaging. Applications of PAI relevant to TERM include stem cell tracking, longitudinal monitoring of scaffolds in vivo, and evaluation of vascularization. In addition, the emerging capabilities of PAI applied to the detection and monitoring of cancer and other inflammatory diseases could be exploited by tissue engineers. This article provides an overview of the operating principles of PAI and its broad potential for application in TERM. Impact statement Photoacoustic imaging, a new hybrid imaging technique, has demonstrated high potential in the clinical diagnostic applications. The optical and acoustic aspect of the photoacoustic imaging system works in harmony to provide better resolution at greater tissue depth. Label-free imaging of vasculature with this imaging can be used to track and monitor disease, as well as the therapeutic progression of treatment. Photoacoustic imaging has been utilized in tissue engineering to some extent; however, the full benefit of this technique is yet to be explored. The increasing availability of commercial photoacoustic systems will make application as an imaging tool for tissue engineering application more feasible. This review first provides a brief description of photoacoustic imaging and summarizes its current and potential application in tissue engineering.
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Affiliation(s)
- Binita Shrestha
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas
| | - Frank DeLuna
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas
| | - Mark A. Anastasio
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Jing Yong Ye
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas
| | - Eric M. Brey
- Department of Biomedical Engineering, University of Texas at San Antonio, San Antonio, Texas
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182
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Tanabe M, Wu TC, Kobayashi M, Yang CH. Fabrication of Coaxial and Confocal Transducer Based on Sol-Gel Composite Material for Optical Resolution Photoacoustic Microscopy. Diagnostics (Basel) 2019; 10:diagnostics10010006. [PMID: 31877790 PMCID: PMC7168185 DOI: 10.3390/diagnostics10010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/18/2019] [Accepted: 12/19/2019] [Indexed: 11/16/2022] Open
Abstract
We have newly developed coaxial and confocal optical-resolution photoacoustic microscopy based on sol-gel composite materials. This transducer contains a concave-shaped piezoelectric layer with a focus depth of 5 mm and a hole with a diameter of 3 mm at the center to pass a laser beam into a phantom. Therefore, this system can directly detect an excited photoacoustic signal without prisms or acoustic lenses. We demonstrate the capability of the system through pulse-echo and photoacoustic imaging experiments. The center frequency of the fabricated transducer is approximately 7 MHz, and its relative bandwidth is 86%. An ex-vivo experiment is conducted, and photoacoustic signals are clearly obtained. As a result, 2- and 3-dimensional maximum amplitude projection images are reconstructed.
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Affiliation(s)
- Masayuki Tanabe
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto 8608555, Japan
- Correspondence:
| | - Tai Chieh Wu
- College of Mechanical and Electrical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan
| | - Makiko Kobayashi
- Faculty of Advanced Science and Technology, Kumamoto University, Kumamoto 8608555, Japan
| | - Che Hua Yang
- College of Mechanical and Electrical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan
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183
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Zhao T, Desjardins AE, Ourselin S, Vercauteren T, Xia W. Minimally invasive photoacoustic imaging: Current status and future perspectives. PHOTOACOUSTICS 2019; 16:100146. [PMID: 31871889 PMCID: PMC6909166 DOI: 10.1016/j.pacs.2019.100146] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/26/2019] [Accepted: 09/30/2019] [Indexed: 05/09/2023]
Abstract
Photoacoustic imaging (PAI) is an emerging biomedical imaging modality that is based on optical absorption contrast, capable of revealing distinct spectroscopic signatures of tissue at high spatial resolution and large imaging depths. However, clinical applications of conventional non-invasive PAI systems have been restricted to examinations of tissues at depths less than a few cm due to strong light attenuation. Minimally invasive photoacoustic imaging (miPAI) has greatly extended the landscape of PAI by delivering excitation light within tissue through miniature fibre-optic probes. In the past decade, various miPAI systems have been developed with demonstrated applicability in several clinical fields. In this article, we present an overview of the current status of miPAI and our thoughts on future perspectives.
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Affiliation(s)
- Tianrui Zhao
- School of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor, Lambeth Wing St Thomas’ Hospital London, London SE1 7EH, United Kingdom
| | - Adrien E. Desjardins
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, Charles Bell House, 67-73 Riding House Street, London W1W 7EJ, United Kingdom
| | - Sebastien Ourselin
- School of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor, Lambeth Wing St Thomas’ Hospital London, London SE1 7EH, United Kingdom
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Tom Vercauteren
- School of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor, Lambeth Wing St Thomas’ Hospital London, London SE1 7EH, United Kingdom
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Wenfeng Xia
- School of Biomedical Engineering and Imaging Sciences, King’s College London, 4th Floor, Lambeth Wing St Thomas’ Hospital London, London SE1 7EH, United Kingdom
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London WC1E 6BT, United Kingdom
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184
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Hochuli R, An L, Beard PC, Cox BT. Estimating blood oxygenation from photoacoustic images: can a simple linear spectroscopic inversion ever work? JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-13. [PMID: 31849203 PMCID: PMC7005536 DOI: 10.1117/1.jbo.24.12.121914] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 11/21/2019] [Indexed: 05/07/2023]
Abstract
Linear spectroscopic inversions, in which photoacoustic amplitudes are assumed to be directly proportional to absorption coefficients, are widely used in photoacoustic imaging to estimate blood oxygen saturation because of their simplicity. Unfortunately, they do not account for the spatially varying wavelength-dependence of the light fluence within the tissue, which introduces "spectral coloring," a potentially significant source of error. However, accurately correcting for spectral coloring is challenging, so we investigated whether there are conditions, e.g., sets of wavelengths, where it is possible to ignore the spectral coloring and still obtain accurate oxygenation measurements using linear inversions. Accurate estimates of oxygenation can be obtained when the wavelengths are chosen to (i) minimize spectral coloring, (ii) avoid ill-conditioning, and (iii) maintain a sufficiently high signal-to-noise ratio (SNR) for the estimates to be meaningful. It is not obvious which wavelengths will satisfy these conditions, and they are very likely to vary for different imaging scenarios, making it difficult to find general rules. Through the use of numerical simulations, we isolated the effect of spectral coloring from sources of experimental error. It was shown that using wavelengths between 500 nm and 1000 nm yields inaccurate estimates of oxygenation and that careful selection of wavelengths in the 620- to 920-nm range can yield more accurate oxygenation values. However, this is only achievable with a good prior estimate of the true oxygenation. Even in this idealized case, it was shown that considerable care must be exercised over the choice of wavelengths when using linear spectroscopic inversions to obtain accurate estimates of blood oxygenation. This suggests that for a particular imaging scenario, obtaining accurate and reliable oxygenation estimates using linear spectroscopic inversions requires careful modeling or experimental studies of that scenario, taking account of the instrumentation, tissue anatomy, likely sO2 range, and image formation process.
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Affiliation(s)
- Roman Hochuli
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Lu An
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Paul C. Beard
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Benjamin T. Cox
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
- Address all correspondence to Benjamin T. Cox, E-mail:
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185
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Mozaffarzadeh M, Varnosfaderani MHH, Sharma A, Pramanik M, de Jong N, Verweij MD. Enhanced contrast acoustic-resolution photoacoustic microscopy using double-stage delay-multiply-and-sum beamformer for vasculature imaging. JOURNAL OF BIOPHOTONICS 2019; 12:e201900133. [PMID: 31353839 PMCID: PMC7065614 DOI: 10.1002/jbio.201900133] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/14/2019] [Accepted: 07/17/2019] [Indexed: 05/18/2023]
Abstract
In acoustic-resolution photoacoustic microscopy (AR-PAM) systems, the lateral resolution in the focal zone of the ultrasound (US) transducer is determined by the numerical aperture (NA) of the transducer. To have a high lateral resolution, a large NA is used. However, the larger the NA, the smaller the depth of focus [DOF]. As a result, the lateral resolution is deteriorated at depths out of the focal region. The synthetic aperture focusing technique (SAFT) along with a beamformer can be used to improve the resolution outside the focal region. In this work, for image formation in AR-PAM, we propose the double-stage delay-multiply-and-sum (DS_DMAS) algorithm to be combined with SAFT. The proposed method is evaluated experimentally using hair targets and in vivo vasculature imaging. It is shown that DS_DMAS provides a higher resolution and contrast compared to other methods. For the B-mode images obtained using the hair phantom, the proposed method reduces the average noise level for all the depths by about 134%, 57% and 23%, compared to the original low- resolution, SAFT+DAS and SAFT+DMAS methods, respectively. All the results indicate that the proposed method can be an appropriate algorithm for image formation in AR-PAM systems.
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Affiliation(s)
- Moein Mozaffarzadeh
- Department of Imaging Physics, Laboratory of Acoustical Wavefield ImagingDelft University of TechnologyDelftThe Netherlands
| | | | - Arunima Sharma
- School of Chemical and Biomedical EngineeringNanyang Technological UniversitySingaporeSingapore
| | - Manojit Pramanik
- School of Chemical and Biomedical EngineeringNanyang Technological UniversitySingaporeSingapore
| | - Nico de Jong
- Department of Imaging Physics, Laboratory of Acoustical Wavefield ImagingDelft University of TechnologyDelftThe Netherlands
- Department Biomedical EngineeringThoraxcenter, Erasmus MCRotterdamThe Netherlands
| | - Martin D. Verweij
- Department of Imaging Physics, Laboratory of Acoustical Wavefield ImagingDelft University of TechnologyDelftThe Netherlands
- Department Biomedical EngineeringThoraxcenter, Erasmus MCRotterdamThe Netherlands
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186
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Xiao M, Dai C, Li L, Zhou C, Wang F. Evaluation of Retinal Pigment Epithelium and Choroidal Neovascularization in Rats Using Laser-Scanning Optical-Resolution Photoacoustic Microscopy. Ophthalmic Res 2019; 63:271-283. [PMID: 31665740 DOI: 10.1159/000502800] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 08/19/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE To demonstrate the value of the laser-scanning optical-resolution (LSOR)-photoacoustic (PA) microscopy (PAM) system and the conventional multimodal imaging techniques in the evaluation of laser-induced retinal injury and choroidal neovascularization (CNV) in rats. METHODS Different degrees of retinal injury were induced using laser photocoagulation. We compared the LSOR-PAM system with conventional imaging techniques in evaluating retinal injury with or without CNV. Six additional rats, treated with an anti-VEGF antibody or immunoglobulin G immediately after photocoagulation, were imaged 7 and 14 days after injection, and CNV lesion areas were compared. RESULTS In the retinal injury model, fundus autofluorescence showed well-defined hyperreflection, while the lesion displayed abundant PA signals demonstrating nonuniform melanin distribution in retinal pigment epithelium (RPE). RPE was detected with higher contrast in the PAM B-scan image than optical coherence tomography (OCT). Additionally, the CNV lesion was present with multiple PA signal intensities which distinctly characterized the location and area of CNV as found in fundus fluorescein angiography. Furthermore, the decreased PA signals extending from the CNV lesion were similar to those of the vascular bud in ex vivo imaging, which was invisible in other in vivo images. When treated with anti-VEGF agents, statistically significant differences can be demonstrated by PAM similar to other modalities. CONCLUSIONS LSOR-PAM can detect the melanin distribution of RPE in laser-induced retinal injury and CNV in rats. PAM imaging provides a potential new tool to evaluate the vitality and functionality of RPE in vivo as well as to monitor the development and treatment of CNV.
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Affiliation(s)
- Meichun Xiao
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Cuixia Dai
- College of Science, Shanghai Institute of Technology, Shanghai, China
| | - Lin Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Chuanqing Zhou
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Fenghua Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai, China, .,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai, China,
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187
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Development of a Stationary 3D Photoacoustic Imaging System Using Sparse Single-Element Transducers: Phantom Study. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9214505] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Photoacoustic imaging (PAI) is an emerging label-free and non-invasive modality for imaging biological tissues. PAI has been implemented in different configurations, one of which is photoacoustic computed tomography (PACT) with a potential wide range of applications, including brain and breast imaging. Hemispherical Array PACT (HA-PACT) is a variation of PACT that has solved the limited detection-view problem. Here, we designed an HA-PACT system consisting of 50 single element transducers. For implementation, we initially performed a simulation study, with parameters close to those in practice, to determine the relationship between the number of transducers and the quality of the reconstructed image. We then used the greatest number of transducers possible on the hemisphere and imaged copper wire phantoms coated with a light absorbing material to evaluate the performance of the system. Several practical issues such as light illumination, arrangement of the transducers, and an image reconstruction algorithm have been comprehensively studied.
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188
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Deán-Ben XL, Razansky D. Optoacoustic image formation approaches-a clinical perspective. Phys Med Biol 2019; 64:18TR01. [PMID: 31342913 DOI: 10.1088/1361-6560/ab3522] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Clinical translation of optoacoustic imaging is fostered by the rapid technical advances in imaging performance as well as the growing number of clinicians recognizing the immense diagnostic potential of this technology. Clinical optoacoustic systems are available in multiple configurations, including hand-held and endoscopic probes as well as raster-scan approaches. The hardware design must be adapted to the accessible portion of the imaged region and other application-specific requirements pertaining the achievable depth, field of view or spatio-temporal resolution. Equally important is the adequate choice of the signal and image processing approach, which is largely responsible for the resulting imaging performance. Thus, new image reconstruction algorithms are constantly evolving in parallel to the newly-developed set-ups. This review focuses on recent progress on optoacoustic image formation algorithms and processing methods in the clinical setting. Major reconstruction challenges include real-time image rendering in two and three dimensions, efficient hybridization with other imaging modalitites as well as accurate interpretation and quantification of bio-markers, herein discussed in the context of ongoing progress in clinical translation.
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Affiliation(s)
- Xosé Luís Deán-Ben
- Faculty of Medicine and Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland. Department of Information Technology and Electrical Engineering and Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland
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189
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All-optical Reflection-mode Microscopic Histology of Unstained Human Tissues. Sci Rep 2019; 9:13392. [PMID: 31527734 PMCID: PMC6746717 DOI: 10.1038/s41598-019-49849-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 09/02/2019] [Indexed: 01/28/2023] Open
Abstract
Surgical oncologists depend heavily on visual field acuity during cancer resection surgeries for in-situ margin assessment. Clinicians must wait up to two weeks for results from a pathology lab to confirm a post-operative diagnosis, potentially resulting in subsequent treatments. Currently, there are no clinical tools that can visualize diagnostically pertinent tissue information in-situ. Here, we present the first microscopy capable of non-contact label-free visualization of human cellular morphology in a reflection-mode apparatus. This is possible with the recently reported imaging modality called photoacoustic remote sensing microscopy which enables non-contact detection of optical absorption contrast. By taking advantage of the 266-nanometer optical absorption peak of DNA, photoacoustic remote sensing is efficacious in recovering qualitatively similar nuclear information in comparison to that provided by the hematoxylin stain in the gold-standard hematoxylin and eosin (H&E) prepared samples. A photoacoustic remote sensing system was employed utilizing a 266-nanometer pulsed excitation beam to induce photoacoustic pressures within the sample resulting in refractive index modulation of the optical absorber. A 1310-nanometer continuous-wave interrogation beam detects these perturbed regions as back reflected intensity variations due to the changes in the local optical properties. Using this technique, clinically useful histologic images of human tissue samples including breast cancer (invasive ductal carcinoma), tonsil, gastrointestinal, and pancreatic tissue images were formed. These were qualitatively comparable to standard H&E prepared samples.
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190
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Xu Z, Wang Y, Sun N, Li Z, Hu S, Liu Q. Parallel Computing for Quantitative Blood Flow Imaging in Photoacoustic Microscopy. SENSORS 2019; 19:s19184000. [PMID: 31527505 PMCID: PMC6767147 DOI: 10.3390/s19184000] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/30/2019] [Accepted: 09/14/2019] [Indexed: 02/07/2023]
Abstract
Photoacoustic microscopy (PAM) is an emerging biomedical imaging technology capable of quantitative measurement of the microvascular blood flow by correlation analysis. However, the computational cost is high, limiting its applications. Here, we report a parallel computation design based on graphics processing unit (GPU) for high-speed quantification of blood flow in PAM. Two strategies were utilized to improve the computational efficiency. First, the correlation method in the algorithm was optimized to avoid redundant computation and a parallel computing structure was designed. Second, the parallel design was realized on GPU and optimized by maximizing the utilization of computing resource in GPU. The detailed timings and speedup for each calculation step were given and the MATLAB and C/C++ code versions based on CPU were presented as a comparison. Full performance test shows that a stable speedup of ~80-fold could be achieved with the same calculation accuracy and the computation time could be reduced from minutes to just several seconds with the imaging size ranging from 1 × 1 mm2 to 2 × 2 mm2. Our design accelerates PAM-based blood flow measurement and paves the way for real-time PAM imaging and processing by significantly improving the computational efficiency.
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Affiliation(s)
- Zhiqiang Xu
- School of Information Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
- Department of Biomedical Engineering, University of Virginia, 415 Lane Road, Charlottesville, VA 22908, USA.
| | - Yiming Wang
- School of Information Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
- Department of Biomedical Engineering, University of Virginia, 415 Lane Road, Charlottesville, VA 22908, USA.
| | - Naidi Sun
- Department of Biomedical Engineering, University of Virginia, 415 Lane Road, Charlottesville, VA 22908, USA.
| | - Zhengying Li
- School of Information Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
| | - Song Hu
- Department of Biomedical Engineering, University of Virginia, 415 Lane Road, Charlottesville, VA 22908, USA.
| | - Quan Liu
- School of Information Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070, China.
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191
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Tserevelakis GJ, Siozos P, Papanikolaou A, Melessanaki K, Zacharakis G. Non-invasive photoacoustic detection of hidden underdrawings in paintings using air-coupled transducers. ULTRASONICS 2019; 98:94-98. [PMID: 31233981 DOI: 10.1016/j.ultras.2019.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/26/2019] [Accepted: 06/11/2019] [Indexed: 06/09/2023]
Abstract
We demonstrate the application of a fully non-contact and non-invasive photoacoustic (PA) imaging system integrating a high sensitivity spherically focused air-coupled ultrasonic transducer, for the uncovering of hidden underdrawings in paintings. By selectively transforming optical absorption information into ultrasonic waves which propagate virtually unobstructed through the paint layers, PA signals provide specific imaging of underlying pencil sketches even for paints presenting high optical scattering and absorption properties. The developed system could be employed for case studies involving the investigation of paintings with historical significance, considerably complementing the capabilities of existing methods.
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Affiliation(s)
- George J Tserevelakis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete GR-70013, Greece.
| | - Panagiotis Siozos
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete GR-70013, Greece
| | - Athanasia Papanikolaou
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete GR-70013, Greece
| | - Kristalia Melessanaki
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete GR-70013, Greece
| | - Giannis Zacharakis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete GR-70013, Greece
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192
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Chan J, Zheng Z, Bell K, Le M, Reza PH, Yeow JTW. Photoacoustic Imaging with Capacitive Micromachined Ultrasound Transducers: Principles and Developments. SENSORS (BASEL, SWITZERLAND) 2019; 19:E3617. [PMID: 31434241 PMCID: PMC6720758 DOI: 10.3390/s19163617] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/15/2019] [Accepted: 08/18/2019] [Indexed: 12/14/2022]
Abstract
Photoacoustic imaging (PAI) is an emerging imaging technique that bridges the gap between pure optical and acoustic techniques to provide images with optical contrast at the acoustic penetration depth. The two key components that have allowed PAI to attain high-resolution images at deeper penetration depths are the photoacoustic signal generator, which is typically implemented as a pulsed laser and the detector to receive the generated acoustic signals. Many types of acoustic sensors have been explored as a detector for the PAI including Fabry-Perot interferometers (FPIs), micro ring resonators (MRRs), piezoelectric transducers, and capacitive micromachined ultrasound transducers (CMUTs). The fabrication technique of CMUTs has given it an edge over the other detectors. First, CMUTs can be easily fabricated into given shapes and sizes to fit the design specifications. Moreover, they can be made into an array to increase the imaging speed and reduce motion artifacts. With a fabrication technique that is similar to complementary metal-oxide-semiconductor (CMOS), CMUTs can be integrated with electronics to reduce the parasitic capacitance and improve the signal to noise ratio. The numerous benefits of CMUTs have enticed researchers to develop it for various PAI purposes such as photoacoustic computed tomography (PACT) and photoacoustic endoscopy applications. For PACT applications, the main areas of research are in designing two-dimensional array, transparent, and multi-frequency CMUTs. Moving from the table top approach to endoscopes, some of the different configurations that are being investigated are phased and ring arrays. In this paper, an overview of the development of CMUTs for PAI is presented.
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Affiliation(s)
- Jasmine Chan
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Zhou Zheng
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Kevan Bell
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Martin Le
- Department of Physics, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Parsin Haji Reza
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
| | - John T W Yeow
- Department of Systems Design Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
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193
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Ratto F, Cavigli L, Borri C, Centi S, Magni G, Mazzoni M, Pini R. Hybrid organosilicon/polyol phantom for photoacoustic imaging. BIOMEDICAL OPTICS EXPRESS 2019; 10:3719-3730. [PMID: 31452970 PMCID: PMC6701555 DOI: 10.1364/boe.10.003719] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/17/2019] [Accepted: 05/18/2019] [Indexed: 05/15/2023]
Abstract
The rapid development of hardware and software for photoacoustic technologies is urging the establishment of dedicated tools for standardization and performance assessment. In particular, the fabrication of anatomical phantoms for photoacoustic imaging remains an open question, as current solutions have not yet gained unanimous support. Here, we propose that a hybrid material made of a water-in-oil emulsion of glycerol and polydimethylsiloxane may represent a versatile platform to host a broad taxonomy of hydrophobic and hydrophilic dyes and recapitulate the optical and acoustic features of bio tissue. For a full optical parameterization, we refer to Wróbel, et al. [ Biomed. Opt. Express7, 2088 (2016)], where this material was first presented for optical imaging. Instead, here, we complete the picture and find that its speed of sound and acoustic attenuation resemble those of pure polydimethylsiloxane, i.e. respectively 1150 ± 30 m/s and 3.5 ± 0.4 dB/(MHz·cm). We demonstrate its use under a commercial B-mode scanner and a home-made A-mode stage for photoacoustic analysis to retrieve the ground-truth encoded in a multilayer architecture containing indocyanine green, plasmonic particles and red blood cells. Finally, we verify the stability of its acoustic, optical and geometric features over a time span of three months.
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Affiliation(s)
- Fulvio Ratto
- Istituto di Fisica Applicata ‘Nello Carrara’ IFAC-CNR, Via Madonna del Piano, 10, 50019 Sesto Fiorentino (FI), Italy
| | - Lucia Cavigli
- Istituto di Fisica Applicata ‘Nello Carrara’ IFAC-CNR, Via Madonna del Piano, 10, 50019 Sesto Fiorentino (FI), Italy
| | - Claudia Borri
- Istituto di Fisica Applicata ‘Nello Carrara’ IFAC-CNR, Via Madonna del Piano, 10, 50019 Sesto Fiorentino (FI), Italy
| | - Sonia Centi
- Istituto di Fisica Applicata ‘Nello Carrara’ IFAC-CNR, Via Madonna del Piano, 10, 50019 Sesto Fiorentino (FI), Italy
| | - Giada Magni
- Istituto di Fisica Applicata ‘Nello Carrara’ IFAC-CNR, Via Madonna del Piano, 10, 50019 Sesto Fiorentino (FI), Italy
| | - Marina Mazzoni
- Istituto di Fisica Applicata ‘Nello Carrara’ IFAC-CNR, Via Madonna del Piano, 10, 50019 Sesto Fiorentino (FI), Italy
| | - Roberto Pini
- Istituto di Fisica Applicata ‘Nello Carrara’ IFAC-CNR, Via Madonna del Piano, 10, 50019 Sesto Fiorentino (FI), Italy
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194
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Liu T, Sun M, Liu Y, Hu D, Ma Y, Ma L, Feng N. ADMM based low-rank and sparse matrix recovery method for sparse photoacoustic microscopy. Biomed Signal Process Control 2019. [DOI: 10.1016/j.bspc.2019.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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195
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Arandian A, Bagheri Z, Ehtesabi H, Najafi Nobar S, Aminoroaya N, Samimi A, Latifi H. Optical Imaging Approaches to Monitor Static and Dynamic Cell-on-Chip Platforms: A Tutorial Review. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1900737. [PMID: 31087503 DOI: 10.1002/smll.201900737] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 04/14/2019] [Indexed: 06/09/2023]
Abstract
Miniaturized laboratories on chip platforms play an important role in handling life sciences studies. The platforms may contain static or dynamic biological cells. Examples are a fixed medium of an organ-on-a-chip and individual cells moving in a microfluidic channel, respectively. Due to feasibility of control or investigation and ethical implications of live targets, both static and dynamic cell-on-chip platforms promise various applications in biology. To extract necessary information from the experiments, the demand for direct monitoring is rapidly increasing. Among different microscopy methods, optical imaging is a straightforward choice. Considering light interaction with biological agents, imaging signals may be generated as a result of scattering or emission effects from a sample. Thus, optical imaging techniques could be categorized into scattering-based and emission-based techniques. In this review, various optical imaging approaches used in monitoring static and dynamic platforms are introduced along with their optical systems, advantages, challenges, and applications. This review may help biologists to find a suitable imaging technique for different cell-on-chip studies and might also be useful for the people who are going to develop optical imaging systems in life sciences studies.
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Affiliation(s)
- Alireza Arandian
- Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, 1983969411, Iran
| | - Zeinab Bagheri
- Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, 1983969411, Iran
| | - Hamide Ehtesabi
- Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, 1983969411, Iran
| | - Shima Najafi Nobar
- Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, 1969764499, Iran
| | - Neda Aminoroaya
- Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, 1983969411, Iran
| | - Ashkan Samimi
- Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, 1983969411, Iran
| | - Hamid Latifi
- Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, 1983969411, Iran
- Department of Physics, Shahid Beheshti University, Tehran, 1983969411, Iran
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196
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Bi R, Dinish US, Goh CC, Imai T, Moothanchery M, Li X, Kim JY, Jeon S, Pu Y, Kim C, Ng LG, Wang LV, Olivo M. In vivo label-free functional photoacoustic monitoring of ischemic reperfusion. JOURNAL OF BIOPHOTONICS 2019; 12:e201800454. [PMID: 30865386 DOI: 10.1002/jbio.201800454] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/30/2019] [Accepted: 03/03/2019] [Indexed: 05/18/2023]
Abstract
Pressure ulcer formation is a common problem among patients confined to bed or restricted to wheelchairs. The ulcer forms when the affected skin and underlying tissues go through repeated cycles of ischemia and reperfusion, leading to inflammation. This theory is evident by intravital imaging studies performed in immune cell-specific, fluorescent reporter mouse skin with induced ischemia-reperfusion (I-R) injuries. However, traditional confocal or multiphoton microscopy cannot accurately monitor the progression of vascular reperfusion by contrast agents, which leaks into the interstitium under inflammatory conditions. Here, we develop a dual-wavelength micro electro mechanical system (MEMS) scanning-based optical resolution photoacoustic microscopy (OR-PAM) system for continuous label-free functional imaging of vascular reperfusion in an IR mouse model. This MEMS-OR-PAM system provides fast scanning speed for concurrent dual-wavelength imaging, which enables continuous monitoring of the reperfusion process. During reperfusion, the revascularization of blood vessels and the oxygen saturation (sO2 ) changes in both arteries and veins are recorded, from which the local oxygen extraction ratios of the ischemic tissue and the unaffected tissue can be quantified. Our MEMS-OR-PAM system provides novel perspectives to understand the I-R injuries. It solves the problem of dynamic label-free functional monitoring of the vascular reperfusion at high spatial resolution.
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Affiliation(s)
- Renzhe Bi
- Singapore Bioimaging Consortium, Singapore
| | - U S Dinish
- Singapore Bioimaging Consortium, Singapore
| | | | - Toru Imai
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering and Department of Electrical Engineering, California Institute of Technology, Pasadena, California
| | | | - Xiuting Li
- Singapore Bioimaging Consortium, Singapore
| | - Jin Young Kim
- Department of Creative IT Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Seungwan Jeon
- Department of Creative IT Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Yang Pu
- MicroPhotoAcoustics Inc., Ronkonkoma, New York
| | - Chulhong Kim
- Department of Creative IT Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | | | - Lihong V Wang
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering and Department of Electrical Engineering, California Institute of Technology, Pasadena, California
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197
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Karlas A, Fasoula NA, Paul-Yuan K, Reber J, Kallmayer M, Bozhko D, Seeger M, Eckstein HH, Wildgruber M, Ntziachristos V. Cardiovascular optoacoustics: From mice to men - A review. PHOTOACOUSTICS 2019; 14:19-30. [PMID: 31024796 PMCID: PMC6476795 DOI: 10.1016/j.pacs.2019.03.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 03/18/2019] [Indexed: 05/04/2023]
Abstract
Imaging has become an indispensable tool in the research and clinical management of cardiovascular disease (CVD). An array of imaging technologies is considered for CVD diagnostics and therapeutic assessment, ranging from ultrasonography, X-ray computed tomography and magnetic resonance imaging to nuclear and optical imaging methods. Each method has different operational characteristics and assesses different aspects of CVD pathophysiology; nevertheless, more information is desirable for achieving a comprehensive view of the disease. Optoacoustic (photoacoustic) imaging is an emerging modality promising to offer novel information on CVD parameters by allowing high-resolution imaging of optical contrast several centimeters deep inside tissue. Implemented with illumination at several wavelengths, multi-spectral optoacoustic tomography (MSOT) in particular, is sensitive to oxygenated and deoxygenated hemoglobin, water and lipids allowing imaging of the vasculature, tissue oxygen saturation and metabolic or inflammatory parameters. Progress with fast-tuning lasers, parallel detection and advanced image reconstruction and data-processing algorithms have recently transformed optoacoustics from a laboratory tool to a promising modality for small animal and clinical imaging. We review progress with optoacoustic CVD imaging, highlight the research and diagnostic potential and current applications and discuss the advantages, limitations and possibilities for integration into clinical routine.
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Affiliation(s)
- Angelos Karlas
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- Clinic for Vascular and Endovascular Surgery, University Hospital rechts der Isar, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Nikolina-Alexia Fasoula
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Korbinian Paul-Yuan
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Josefine Reber
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Michael Kallmayer
- Clinic for Vascular and Endovascular Surgery, University Hospital rechts der Isar, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Dmitry Bozhko
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Markus Seeger
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
| | - Hans-Henning Eckstein
- Clinic for Vascular and Endovascular Surgery, University Hospital rechts der Isar, Munich, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
| | - Moritz Wildgruber
- Institute for Diagnostic and Interventional Radiology, University Hospital rechts der Isar, Munich, Germany
- Institute for Clinical Radiology, University Hospital Muenster, Muenster, Germany
| | - Vasilis Ntziachristos
- Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Munich, Germany
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Cardiovascular Research (DZHK), partner site Munich Heart Alliance, Munich, Germany
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198
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Ding N, Liu X, Chen N, Jiang J, Zhao H, Li Z, Zhang J, Liu C. Lack of association between acupoint sensitization and microcirculatory structural changes in a mouse model of knee osteoarthritis: A pilot study. JOURNAL OF BIOPHOTONICS 2019; 12:e201800458. [PMID: 30740905 PMCID: PMC7065615 DOI: 10.1002/jbio.201800458] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 02/01/2019] [Accepted: 02/06/2019] [Indexed: 05/05/2023]
Abstract
As a stimulating point in acupuncture, acupoint has unique microcirculatory features, and its dynamics vary greatly depending on health status. Acupoint sensitization is defined as the transformation of an acupoint from a "silenced status" (healthy) to an "activated status" (disease). Our previous study demonstrated that acupoint sensitization is associated with an increase in the level of local blood perfusion. However, the structural changes in microcirculation during acupoint sensitization have yet to be elucidated because the high-resolution microcirculation imaging of acupoints has been difficult to obtain. In this study, the structural changes in microcirculation at the Zusanli (ST36), Yanglingquan (GB34) and nonacupoint sites on days 0, 7 and 21 were dynamically observed during acupoint sensitization in an experimental knee osteoarthritis mouse model by using optical-resolution photoacoustic microscopy. The results showed that no significant differences in microvessel density, the distribution of vessel diameters or vascular tortuosity were observed at the GB34, ST36 or nonacupoint sites among days 0, 7 and 21. We proposed that acupoint sensitization may not be associated with the structural changes in microcirculation and that the microcirculatory changes during acupoint sensitization are more likely to be functional. The functional characteristics of the sensitized acupoints warrant further investigation.
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Affiliation(s)
- Ning Ding
- School of Acupuncture, Moxibustion and TuinaBeijing University of Chinese MedicineBeijingChina
| | - Xiaoxiao Liu
- School of Acupuncture, Moxibustion and TuinaBeijing University of Chinese MedicineBeijingChina
| | - Ningbo Chen
- Research Laboratory for Biomedical Optics and Molecular ImagingShenzhen Institutes of Advanced Technology, Chinese Academy of SciencesShenzhenChina
- School of Mechanical and Electrical EngineeringGuangzhou UniversityGuangzhouChina
| | - Jing Jiang
- School of NursingBeijing University of Chinese MedicineBeijingChina
| | - Huangxuan Zhao
- Research Laboratory for Biomedical Optics and Molecular ImagingShenzhen Institutes of Advanced Technology, Chinese Academy of SciencesShenzhenChina
- School of Biomedical EngineeringCapital Medical UniversityBeijingChina
| | - Zhigang Li
- School of Acupuncture, Moxibustion and TuinaBeijing University of Chinese MedicineBeijingChina
| | - Jianhui Zhang
- School of Mechanical and Electrical EngineeringGuangzhou UniversityGuangzhouChina
| | - Chengbo Liu
- Research Laboratory for Biomedical Optics and Molecular ImagingShenzhen Institutes of Advanced Technology, Chinese Academy of SciencesShenzhenChina
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199
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Steinberg I, Huland DM, Vermesh O, Frostig HE, Tummers WS, Gambhir SS. Photoacoustic clinical imaging. PHOTOACOUSTICS 2019; 14:77-98. [PMID: 31293884 PMCID: PMC6595011 DOI: 10.1016/j.pacs.2019.05.001] [Citation(s) in RCA: 277] [Impact Index Per Article: 55.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 04/09/2019] [Accepted: 05/30/2019] [Indexed: 05/18/2023]
Abstract
Photoacoustic is an emerging biomedical imaging modality, which allows imaging optical absorbers in the tissue by acoustic detectors (light in - sound out). Such a technique has an immense potential for clinical translation since it allows high resolution, sufficient imaging depth, with diverse endogenous and exogenous contrast, and is free from ionizing radiation. In recent years, tremendous developments in both the instrumentation and imaging agents have been achieved. These opened avenues for clinical imaging of various sites allowed applications such as brain functional imaging, breast cancer screening, diagnosis of psoriasis and skin lesions, biopsy and surgery guidance, the guidance of tumor therapies at the reproductive and urological systems, as well as imaging tumor metastases at the sentinel lymph nodes. Here we survey the various clinical and pre-clinical literature and discuss the potential applications and hurdles that still need to be overcome.
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Affiliation(s)
- Idan Steinberg
- Department of Radiology, At Stanford University, School of Medicine, Stanford, CA, United States
- Department of Bioengineering, At Stanford University, School of Medicine, Stanford, CA, United States
| | - David M. Huland
- Department of Radiology, At Stanford University, School of Medicine, Stanford, CA, United States
- Molecular Imaging Program at Stanford, Canary Center at Stanford for Cancer Early Detection, At Stanford University, School of Medicine, Stanford, CA, United States
| | - Ophir Vermesh
- Department of Radiology, At Stanford University, School of Medicine, Stanford, CA, United States
- Molecular Imaging Program at Stanford, Canary Center at Stanford for Cancer Early Detection, At Stanford University, School of Medicine, Stanford, CA, United States
| | - Hadas E. Frostig
- Department of Radiology, At Stanford University, School of Medicine, Stanford, CA, United States
- Molecular Imaging Program at Stanford, Canary Center at Stanford for Cancer Early Detection, At Stanford University, School of Medicine, Stanford, CA, United States
| | - Willemieke S. Tummers
- Department of Radiology, At Stanford University, School of Medicine, Stanford, CA, United States
- Molecular Imaging Program at Stanford, Canary Center at Stanford for Cancer Early Detection, At Stanford University, School of Medicine, Stanford, CA, United States
| | - Sanjiv S. Gambhir
- Department of Radiology, At Stanford University, School of Medicine, Stanford, CA, United States
- Department of Bioengineering, At Stanford University, School of Medicine, Stanford, CA, United States
- Department of Materials Science & Engineering, At Stanford University, School of Medicine, Stanford, CA, United States
- Molecular Imaging Program at Stanford, Canary Center at Stanford for Cancer Early Detection, At Stanford University, School of Medicine, Stanford, CA, United States
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200
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Liu C, Liang Y, Wang L. Optical-resolution photoacoustic microscopy of oxygen saturation with nonlinear compensation. BIOMEDICAL OPTICS EXPRESS 2019; 10:3061-3069. [PMID: 31259074 PMCID: PMC6583336 DOI: 10.1364/boe.10.003061] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/16/2019] [Accepted: 05/19/2019] [Indexed: 05/02/2023]
Abstract
Optical-resolution photoacoustic microscopy (OR-PAM) of oxygen saturation (sO2) offers high-resolution functional information on living tissue. Limited by the availability of high-speed multi-wavelength lasers, most OR-PAM systems use wavelengths around 532nm. Blood has high absorption coefficients in this spectrum, which may cause absorption saturation and induce systematic errors in sO2 imaging. Here, we present nonlinear OR-PAM that compensates for the absorption saturation in sO2 imaging. We model the absorption saturation at different absorption coefficients and ultrasonic bandwidths. To compensate for the absorption saturation, we develop an OR-PAM system with three optical wavelengths and implement a nonlinear algorithm to compute sO2. Phantom experiments on bovine blood validate that the nonlinear OR-PAM can improve the sO2 accuracy by up to 0.13 for fully oxygenated blood. In vivo sO2 imaging has been conducted in the mouse ear. The nonlinear sO2 results agree with the normal physiological values. These results show that the absorption saturation effect can be compensated for in nonlinear OR-PAM, which improves the accuracy of functional photoacoustic imaging.
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Affiliation(s)
- Chao Liu
- Department of Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon, Hong Kong SAR, China
- City University of Hong Kong Shenzhen Research Institute, Yuexing Yi Dao, Nanshan District, China
| | - Yizhi Liang
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China
| | - Lidai Wang
- Department of Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon, Hong Kong SAR, China
- City University of Hong Kong Shenzhen Research Institute, Yuexing Yi Dao, Nanshan District, China
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