1
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Valmaggia P, Cattin PC, Sandkühler R, Inglin N, Otto TP, Aumann S, Teussink MM, Spaide RF, Scholl HPN, Maloca PM. Time-Resolved Dynamic Optical Coherence Tomography for Retinal Blood Flow Analysis. Invest Ophthalmol Vis Sci 2024; 65:9. [PMID: 38837167 PMCID: PMC11160951 DOI: 10.1167/iovs.65.6.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 05/16/2024] [Indexed: 06/06/2024] Open
Abstract
Purpose Optical coherence tomography (OCT) representations in clinical practice are static and do not allow for a dynamic visualization and quantification of blood flow. This study aims to present a method to analyze retinal blood flow dynamics using time-resolved structural OCT. Methods We developed novel imaging protocols to acquire video-rate time-resolved OCT B-scans (1024 × 496 pixels, 10 degrees field of view) at four different sensor integration times (integration time of 44.8 µs at a nominal A-scan rate of 20 kHz, 22.4 µs at 40 kHz, 11.2 µs at 85 kHz, and 7.24 µs at 125 kHz). The vessel centers were manually annotated for each B-scan and surrounding subvolumes were extracted. We used a velocity model based on signal-to-noise ratio (SNR) drops due to fringe washout to calculate blood flow velocity profiles in vessels within five optic disc diameters of the optic disc rim. Results Time-resolved dynamic structural OCT revealed pulsatile SNR changes in the analyzed vessels and allowed the calculation of potential blood flow velocities at all integration times. Fringe washout was stronger in acquisitions with longer integration times; however, the ratio of the average SNR to the peak SNR inside the vessel was similar across all integration times. Conclusions We demonstrated the feasibility of estimating blood flow profiles based on fringe washout analysis, showing pulsatile dynamics in vessels close to the optic nerve head using structural OCT. Time-resolved dynamic OCT has the potential to uncover valuable blood flow information in clinical settings.
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Affiliation(s)
- Philippe Valmaggia
- Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Basel, Switzerland
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Philippe C. Cattin
- Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Robin Sandkühler
- Department of Biomedical Engineering, University of Basel, Allschwil, Switzerland
| | - Nadja Inglin
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Basel, Switzerland
| | | | - Silke Aumann
- Heidelberg Engineering GmbH, Heidelberg, Germany
| | | | - Richard F. Spaide
- Vitreous Retina Macula Consultants of New York, New York, United States
| | - Hendrik P. N. Scholl
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Basel, Switzerland
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Peter M. Maloca
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Basel, Switzerland
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
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2
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Giamberardino M, Krause TJH, Fraser JM. Artifact suppression and improved signal-to-noise ratio by phase-locked multiplexed coherent imaging. OPTICS LETTERS 2024; 49:738-741. [PMID: 38300103 DOI: 10.1364/ol.503939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/09/2024] [Indexed: 02/02/2024]
Abstract
Laser additive manufacturing (AM) promises direct metal 3D printing, but is held back by defects and process instabilities, giving rise to a need for in situ process monitoring. Inline coherent imaging (ICI) has proven effective for in situ, direct measurements of vapor depression depth and shape in AM and laser welding but struggles to track turbulent interfaces due to poor coupling back into a single-mode fiber and the presence of artifacts. By z-domain multiplexing, we achieve phase-sensitive image consolidation, automatically attenuating autocorrelation artifacts and improving interface tracking rates by 58% in signal-starved applications.
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3
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Feng X, Li GY, Yun SH. Ultra-wideband optical coherence elastography from acoustic to ultrasonic frequencies. Nat Commun 2023; 14:4949. [PMID: 37587178 PMCID: PMC10432526 DOI: 10.1038/s41467-023-40625-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 07/31/2023] [Indexed: 08/18/2023] Open
Abstract
Visualizing viscoelastic waves in materials and tissues through noninvasive imaging is valuable for analyzing their mechanical properties and detecting internal anomalies. However, traditional elastography techniques have been limited by a maximum wave frequency below 1-10 kHz, which hampers temporal and spatial resolution. Here, we introduce an optical coherence elastography technique that overcomes the limitation by extending the frequency range to MHz. Our system can measure the stiffness of hard materials including bones and extract viscoelastic shear moduli for polymers and hydrogels in conventionally inaccessible ranges between 100 Hz and 1 MHz. The dispersion of Rayleigh surface waves across the ultrawide band allowed us to profile depth-dependent shear modulus in cartilages ex vivo and human skin in vivo with sub-mm anatomical resolution. This technique holds immense potential as a noninvasive measurement tool for material sciences, tissue engineering, and medical diagnostics.
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Affiliation(s)
- Xu Feng
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St. BAR-8, Boston, MA, 02114, USA
| | - Guo-Yang Li
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St. BAR-8, Boston, MA, 02114, USA
| | - Seok-Hyun Yun
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St. BAR-8, Boston, MA, 02114, USA.
- Harvard-MIT Health Sciences and Technology, Cambridge, MA, 02139, USA.
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4
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Luo M, Xu Z, Ye Z, Liang Z, Xiao H, Li Y, Li Z, Zhu Y, He Y, Zhuo Y. Deep learning for anterior segment OCT angiography automated denoising and vascular quantitative measurement. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2023.104660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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5
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Britten A, Matten P, Weiss J, Niederleithner M, Roodaki H, Sorg B, Hecker-Denschlag N, Drexler W, Leitgeb RA, Schmoll T. Surgical microscope integrated MHz SS-OCT with live volumetric visualization. BIOMEDICAL OPTICS EXPRESS 2023; 14:846-865. [PMID: 36874504 PMCID: PMC9979659 DOI: 10.1364/boe.477386] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 01/05/2023] [Accepted: 01/07/2023] [Indexed: 06/18/2023]
Abstract
Intraoperative optical coherence tomography is still not overly pervasive in routine ophthalmic surgery, despite evident clinical benefits. That is because today's spectral-domain optical coherence tomography systems lack flexibility, acquisition speed, and imaging depth. We present to the best of our knowledge the most flexible swept-source optical coherence tomography (SS-OCT) engine coupled to an ophthalmic surgical microscope that operates at MHz A-scan rates. We use a MEMS tunable VCSEL to implement application-specific imaging modes, enabling diagnostic and documentary capture scans, live B-scan visualizations, and real-time 4D-OCT renderings. The technical design and implementation of the SS-OCT engine, as well as the reconstruction and rendering platform, are presented. All imaging modes are evaluated in surgical mock maneuvers using ex vivo bovine and porcine eye models. The applicability and limitations of MHz SS-OCT as a visualization tool for ophthalmic surgery are discussed.
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Affiliation(s)
- Anja Britten
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
- These authors contributed equally to this manuscript
| | - Philipp Matten
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
- These authors contributed equally to this manuscript
| | - Jakob Weiss
- Chair for Computer Aided Medical Procedures, Technical University of Munich, Boltzmannstrasse 385748 Munich, Germany
| | - Michael Niederleithner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
| | - Hessam Roodaki
- Carl Zeiss Meditec AG, Kistlerhofstrasse 75, 81379 Munich, Germany
| | - Benjamin Sorg
- Carl Zeiss Meditec AG, Rudolf-Eber-Strasse 11, 73447 Oberkochen, Germany
| | | | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
| | - Rainer A. Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
| | - Tilman Schmoll
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 4 L, 1090 Vienna, Austria
- Carl Zeiss Meditec, Inc., 5300 Central Pkwy, Dublin, CA 94568, USA
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Makita S, Azuma S, Mino T, Yamaguchi T, Miura M, Yasuno Y. Extending field-of-view of retinal imaging by optical coherence tomography using convolutional Lissajous and slow scan patterns. BIOMEDICAL OPTICS EXPRESS 2022; 13:5212-5230. [PMID: 36425618 PMCID: PMC9664899 DOI: 10.1364/boe.467563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 08/27/2022] [Accepted: 08/28/2022] [Indexed: 06/16/2023]
Abstract
Optical coherence tomography (OCT) is a high-speed non-invasive cross-sectional imaging technique. Although its imaging speed is high, three-dimensional high-spatial-sampling-density imaging of in vivo tissues with a wide field-of-view (FOV) is challenging. We employed convolved Lissajous and slow circular scanning patterns to extend the FOV of retinal OCT imaging with a 1-µm, 100-kHz-sweep-rate swept-source OCT prototype system. Displacements of sampling points due to eye movements are corrected by post-processing based on a Lissajous scan. Wide FOV three-dimensional retinal imaging with high sampling density and motion correction is achieved. Three-dimensional structures obtained using repeated imaging sessions of a healthy volunteer and two patients showed good agreement. The demonstrated technique will extend the FOV of simple point-scanning OCT, such as commercial ophthalmic OCT devices, without sacrificing sampling density.
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Affiliation(s)
- Shuichi Makita
- Computational Optics Group,
University of Tsukuba, 1–1–1 Tennodai, Tsukuba, Ibaraki 305–8573, Japan
| | - Shinnosuke Azuma
- Topcon Corporation, 75–1 Hasunumacho, Itabashi, Tokyo 174–8580, Japan
| | - Toshihiro Mino
- Topcon Corporation, 75–1 Hasunumacho, Itabashi, Tokyo 174–8580, Japan
| | - Tatsuo Yamaguchi
- Topcon Corporation, 75–1 Hasunumacho, Itabashi, Tokyo 174–8580, Japan
| | - Masahiro Miura
- Department of Ophthalmology, Tokyo Medical University Ibaraki Medical Center, 3–20–1 Chuo, Ami, Ibaraki 300–0395, Japan
| | - Yoshiaki Yasuno
- Computational Optics Group,
University of Tsukuba, 1–1–1 Tennodai, Tsukuba, Ibaraki 305–8573, Japan
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7
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Zhang Y, Gao W, Xie C. Fourier spatial transform-based method of suppressing motion noises in OCTA. OPTICS LETTERS 2022; 47:4544-4547. [PMID: 36048700 DOI: 10.1364/ol.464501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
A large amount of lateral noise will be generated in blood flow imaging with optical coherence tomography angiography (OCTA) due to the presence of muscle shaking, heartbeat, and respiration, resulting in the deterioration of images. In this paper, to the best of our knowledge, for the first time, the spatial frequency information of motion noise in the blood flow signal region is used to remove the motion noise and false connections in the blood flow signal region. The effectiveness of the proposed adaptive denoising algorithm is verified by the imaging of finger blood flow. It is found that OCTA with different projection methods has improved signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) after applying our algorithm. It is also found that the visual effect of the original blood flow image based on standard deviation projection is better, but mean projection is the most sensitive to the algorithm, and the average SNR and CNR are improved by 5.7 dB and 8.9 dB, respectively.
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8
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Meleppat RK, Fortenbach CR, Jian Y, Martinez ES, Wagner K, Modjtahedi BS, Motta MJ, Ramamurthy DL, Schwab IR, Zawadzki RJ. In Vivo Imaging of Retinal and Choroidal Morphology and Vascular Plexuses of Vertebrates Using Swept-Source Optical Coherence Tomography. Transl Vis Sci Technol 2022; 11:11. [PMID: 35972433 PMCID: PMC9396679 DOI: 10.1167/tvst.11.8.11] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To perform in vivo evaluation of the structural morphology and vascular plexuses of the neurosensory retina and choroid across vertebrate species using swept-source optical coherence tomography (SS-OCT) and SS-OCT angiography (SS-OCTA) imaging. Methods A custom-built SS-OCT system with an incorporated flexible imaging arm was used to acquire the three-dimensional (3D) retinal OCT and vascular OCTA data of five different vertebrates: a mouse (C57BL/6J), a rat (Long Evans), a gray short-tailed opossum (Monodelphis domestica), a white sturgeon (Acipenser transmontanus), and a great horned owl (Bubo virginianus). Results In vivo structural morphology of the retina and choroid, as well as en face OCTA images of retinal and choroidal vasculature of all species were generated. The retinal morphology and vascular plexuses were similar between rat and mouse, whereas distinct choroidal and paired superficial vessels were observed in the opossum retina. The retinal and vascular structure of the sturgeon, as well as the pecten oculi and overlying the avascular and choroidal vasculature in the owl retina are reported in vivo. Conclusions A high-quality two-dimensional and 3D in vivo visualization of the retinal structures and en face visualization of the retina and choroidal vascular plexus of vertebrates was possible. Our studies affirm that SS-OCT and SS-OCTA are viable methods for evaluating the in vivo retinal and choroidal structure across terrestrial, aquatic, and aerial vertebrates. Translational Relevance In vivo characterization of retinal morphology and vasculature plexus of multiple species using SS-OCT and SS-OCTA imaging can increase the pool of species available as models of human retinal diseases.
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Affiliation(s)
- Ratheesh K Meleppat
- UC Davis Eyepod Imaging Laboratory, University of California Davis, Davis, CA, USA.,Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA, USA
| | - Christopher R Fortenbach
- Center for Neuroscience, University of California, Davis, Davis, CA, USA.,Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Yifan Jian
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Esteban Soto Martinez
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA
| | - Karen Wagner
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California Davis, Sacramento, CA, USA
| | - Bobeck S Modjtahedi
- Department of Research and Evaluation, Southern California Permanente Medical Group, Pasadena, CA, USA.,Department of Clinical Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA, USA
| | - Monica J Motta
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Deepa L Ramamurthy
- Center for Neuroscience, University of California, Davis, Davis, CA, USA
| | - Ivan R Schwab
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA, USA
| | - Robert J Zawadzki
- UC Davis Eyepod Imaging Laboratory, University of California Davis, Davis, CA, USA.,Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA, USA
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9
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Cheishvili K, Kalkman J. Scanning dynamic light scattering optical coherence tomography for measurement of high omnidirectional flow velocities. OPTICS EXPRESS 2022; 30:23382-23397. [PMID: 36225019 DOI: 10.1364/oe.456139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/16/2022] [Indexed: 06/16/2023]
Abstract
We show scanning dynamic light scattering optical coherence tomography (OCT) omnidirectional flow measurements. Our method improves the velocity measurement limit over conventional correlation-based or phase-resolved Doppler OCT by more than a factor of 2. Our technique is applicable without a-priori knowledge of the flow geometry as our method works both for non-zero Doppler angle and non-ideal scan alignment. In addition, the method improves the particle diffusion coefficient estimation for particles under flow.
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10
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Sampson DM, Dubis AM, Chen FK, Zawadzki RJ, Sampson DD. Towards standardizing retinal optical coherence tomography angiography: a review. LIGHT, SCIENCE & APPLICATIONS 2022; 11:63. [PMID: 35304441 PMCID: PMC8933532 DOI: 10.1038/s41377-022-00740-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 02/01/2022] [Accepted: 02/14/2022] [Indexed: 05/11/2023]
Abstract
The visualization and assessment of retinal microvasculature are important in the study, diagnosis, monitoring, and guidance of treatment of ocular and systemic diseases. With the introduction of optical coherence tomography angiography (OCTA), it has become possible to visualize the retinal microvasculature volumetrically and without a contrast agent. Many lab-based and commercial clinical instruments, imaging protocols and data analysis methods and metrics, have been applied, often inconsistently, resulting in a confusing picture that represents a major barrier to progress in applying OCTA to reduce the burden of disease. Open data and software sharing, and cross-comparison and pooling of data from different studies are rare. These inabilities have impeded building the large databases of annotated OCTA images of healthy and diseased retinas that are necessary to study and define characteristics of specific conditions. This paper addresses the steps needed to standardize OCTA imaging of the human retina to address these limitations. Through review of the OCTA literature, we identify issues and inconsistencies and propose minimum standards for imaging protocols, data analysis methods, metrics, reporting of findings, and clinical practice and, where this is not possible, we identify areas that require further investigation. We hope that this paper will encourage the unification of imaging protocols in OCTA, promote transparency in the process of data collection, analysis, and reporting, and facilitate increasing the impact of OCTA on retinal healthcare delivery and life science investigations.
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Affiliation(s)
- Danuta M Sampson
- Surrey Biophotonics, Centre for Vision, Speech and Signal Processing and School of Biosciences and Medicine, The University of Surrey, Guildford, GU2 7XH, UK.
| | - Adam M Dubis
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Trust and UCL Institute of Ophthalmology, London, EC1V 2PD, UK
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Nedlands, Western Australia, 6009, Australia
- Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, 6000, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, 3002, Australia
| | - Robert J Zawadzki
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA, 95817, USA
| | - David D Sampson
- Surrey Biophotonics, Advanced Technology Institute, School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, GU2 7XH, UK
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11
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Rico-Jimenez JJ, Hu D, Tang EM, Oguz I, Tao YK. Real-time OCT image denoising using a self-fusion neural network. BIOMEDICAL OPTICS EXPRESS 2022; 13:1398-1409. [PMID: 35415003 PMCID: PMC8973187 DOI: 10.1364/boe.451029] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/20/2022] [Accepted: 02/06/2022] [Indexed: 06/07/2023]
Abstract
Optical coherence tomography (OCT) has become the gold standard for ophthalmic diagnostic imaging. However, clinical OCT image-quality is highly variable and limited visualization can introduce errors in the quantitative analysis of anatomic and pathologic features-of-interest. Frame-averaging is a standard method for improving image-quality, however, frame-averaging in the presence of bulk-motion can degrade lateral resolution and prolongs total acquisition time. We recently introduced a method called self-fusion, which reduces speckle noise and enhances OCT signal-to-noise ratio (SNR) by using similarity between from adjacent frames and is more robust to motion-artifacts than frame-averaging. However, since self-fusion is based on deformable registration, it is computationally expensive. In this study a convolutional neural network was implemented to offset the computational overhead of self-fusion and perform OCT denoising in real-time. The self-fusion network was pretrained to fuse 3 frames to achieve near video-rate frame-rates. Our results showed a clear gain in peak SNR in the self-fused images over both the raw and frame-averaged OCT B-scans. This approach delivers a fast and robust OCT denoising alternative to frame-averaging without the need for repeated image acquisition. Real-time self-fusion image enhancement will enable improved localization of OCT field-of-view relative to features-of-interest and improved sensitivity for anatomic features of disease.
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Affiliation(s)
- Jose J. Rico-Jimenez
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, USA
| | - Dewei Hu
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN 37235 USA, USA
| | - Eric M. Tang
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, USA
| | - Ipek Oguz
- Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN 37235 USA, USA
| | - Yuankai K. Tao
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, USA
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Mazlin V, Xiao P, Irsch K, Scholler J, Groux K, Grieve K, Fink M, Boccara AC. Optical phase modulation by natural eye movements: application to time-domain FF-OCT image retrieval. BIOMEDICAL OPTICS EXPRESS 2022; 13:902-920. [PMID: 35284184 PMCID: PMC8884228 DOI: 10.1364/boe.445393] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/10/2021] [Accepted: 12/10/2021] [Indexed: 05/24/2023]
Abstract
Eye movements are commonly seen as an obstacle to high-resolution ophthalmic imaging. In this context we study the natural axial movements of the in vivo human eye and show that they can be used to modulate the optical phase and retrieve tomographic images via time-domain full-field optical coherence tomography (TD-FF-OCT). This approach opens a path to a simplified ophthalmic TD-FF-OCT device, operating without the usual piezo motor-camera synchronization. The device demonstrates in vivo human corneal images under the different image retrieval schemes (2-phase and 4-phase) and different exposure times (3.5 ms, 10 ms, 20 ms). Data on eye movements, acquired with a spectral-domain OCT with axial eye tracking (180 B-scans/s), are used to study the influence of ocular motion on the probability of capturing high-signal tomographic images without phase washout. The optimal combinations of camera acquisition speed and amplitude of piezo modulation are proposed and discussed.
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Affiliation(s)
- Viacheslav Mazlin
- ESPCI Paris, PSL University, CNRS, Langevin Institute, 1 Rue Jussieu, 75005 Paris, France
| | - Peng Xiao
- ESPCI Paris, PSL University, CNRS, Langevin Institute, 1 Rue Jussieu, 75005 Paris, France
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 510060, Guangzhou, China
| | - Kristina Irsch
- Vision Institute, Sorbonne University, CNRS, INSERM, 17 Rue Moreau, 75012 Paris, France
- Quinze-Vingts National Ophthalmology Hospital, 28 Rue de Charenton, 75012 Paris, France
| | - Jules Scholler
- ESPCI Paris, PSL University, CNRS, Langevin Institute, 1 Rue Jussieu, 75005 Paris, France
- Wyss Center for Bio and Neuroengineering, Chem. des Mines 9, 1202 Geneva, Switzerland
| | - Kassandra Groux
- ESPCI Paris, PSL University, CNRS, Langevin Institute, 1 Rue Jussieu, 75005 Paris, France
| | - Kate Grieve
- Vision Institute, Sorbonne University, CNRS, INSERM, 17 Rue Moreau, 75012 Paris, France
- Quinze-Vingts National Ophthalmology Hospital, 28 Rue de Charenton, 75012 Paris, France
| | - Mathias Fink
- ESPCI Paris, PSL University, CNRS, Langevin Institute, 1 Rue Jussieu, 75005 Paris, France
| | - A. Claude Boccara
- ESPCI Paris, PSL University, CNRS, Langevin Institute, 1 Rue Jussieu, 75005 Paris, France
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13
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Zvietcovich F, Larin KV. Wave-based optical coherence elastography: The 10-year perspective. PROGRESS IN BIOMEDICAL ENGINEERING (BRISTOL, ENGLAND) 2022; 4:012007. [PMID: 35187403 PMCID: PMC8856668 DOI: 10.1088/2516-1091/ac4512] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
After 10 years of progress and innovation, optical coherence elastography (OCE) based on the propagation of mechanical waves has become one of the major and the most studied OCE branches, producing a fundamental impact in the quantitative and nondestructive biomechanical characterization of tissues. Preceding previous progress made in ultrasound and magnetic resonance elastography; wave-based OCE has pushed to the limit the advance of three major pillars: (1) implementation of novel wave excitation methods in tissues, (2) understanding new types of mechanical waves in complex boundary conditions by proposing advance analytical and numerical models, and (3) the development of novel estimators capable of retrieving quantitative 2D/3D biomechanical information of tissues. This remarkable progress promoted a major advance in answering basic science questions and the improvement of medical disease diagnosis and treatment monitoring in several types of tissues leading, ultimately, to the first attempts of clinical trials and translational research aiming to have wave-based OCE working in clinical environments. This paper summarizes the fundamental up-to-date principles and categories of wave-based OCE, revises the timeline and the state-of-the-art techniques and applications lying in those categories, and concludes with a discussion on the current challenges and future directions, including clinical translation research.
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Affiliation(s)
- Fernando Zvietcovich
- University of Houston, Biomedical Engineering, Houston, TX, United States, 77204
| | - Kirill V. Larin
- University of Houston, Biomedical Engineering, Houston, TX, United States, 77204,
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14
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Cereda MG, Parrulli S, Douven Y, Faridpooya K, van Romunde S, Hüttmann G, Eixmann T, Schulz-Hildebrandt H, Kronreif G, Beelen M, de Smet MD. Clinical Evaluation of an Instrument-Integrated OCT-Based Distance Sensor for Robotic Vitreoretinal Surgery. OPHTHALMOLOGY SCIENCE 2021; 1:100085. [PMID: 36246942 PMCID: PMC9560530 DOI: 10.1016/j.xops.2021.100085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 10/11/2021] [Accepted: 11/08/2021] [Indexed: 04/29/2023]
Abstract
PURPOSE To assess the efficacy of an instrument-integrated OCT (iiOCT)-based distance sensor during robotic vitreoretinal surgery using the Preceyes Surgical System (PSS; Preceyes B.V.). DESIGN Single-center interventional study. PARTICIPANTS Patients requiring vitreoretinal surgery. METHODS Five patients were enrolled. Standard preoperative OCT images were obtained. After vitrectomy, a predefined set of actions was performed using the iiOCT-based sensor. Images then were processed to assess the signal-to-noise ratio (SNR) at various angles to the retina and at different distances between the instrument tip and the retinal surface. Preoperative and intraoperative OCT images were compared qualitatively and quantitatively. MAIN OUTCOMES MEASURES The feasibility in performing surgical tasks using the iiOCT-based sensor during vitreoretinal surgery, the SNR when imaging the retina, differences among intraoperative and preoperative OCT images, and characteristics of intraoperative retinal movements detected with the iiOCT-based probe. RESULTS Surgeons were able to perform all the tasks but one. The PSS was able to maintain a fixed distance. The SNR of the iiOCT-based sensor signal was adequate to determine the distance to the retina and to control the PSS. Analysis of iiOCT-based sensor A-scans identified 3 clearly distinguishable retinal layers, including the inner retinal boundary and the interface at the retinal pigment epithelium-Bruch's membrane. Thickness values differed by less than 5% from that measured by preoperative OCT, indicating its accuracy. The Fourier analysis of iiOCT-based sensor recordings identified anteroposterior retinal movements attributed to heartbeat and respiration. CONCLUSIONS This iiOCT-based sensor was tested successfully and promises reliable use during robot-assisted surgery. An iiOCT-based sensor is a promising step toward OCT-guided robotic retinal surgery.
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Affiliation(s)
- Matteo Giuseppe Cereda
- Eye Clinic, Department of Biomedical and Clinical Science “Luigi Sacco,” Sacco Hospital, University of Milan, Milan, Italy
| | - Salvatore Parrulli
- Eye Clinic, Department of Biomedical and Clinical Science “Luigi Sacco,” Sacco Hospital, University of Milan, Milan, Italy
- Correspondence: Salvatore Parrulli, MD, Eye Clinic, Department of Biomedical and Clinical Science “Luigi Sacco,” Sacco Hospital, University of Milan, via G.B. Grassi 74, Milan, 20157, Italy.
| | - Y.G.M. Douven
- Department of Mechanical Engineering, University of Technology, Eindhoven, The Netherlands
| | | | | | - Gereon Hüttmann
- Medical Laser Center Lübeck GmbH, Lübeck, Germany
- Airway Research Center North, Member of the German Center for Lung Research (DZL), Grosshansdorf, Germany
| | - Tim Eixmann
- Medical Laser Center Lübeck GmbH, Lübeck, Germany
| | | | | | | | - Marc D. de Smet
- Preceyes B.V., Eindhoven, The Netherlands
- MIOS sa, Lausanne, Switzerland
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15
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Matveyev AL, Matveev LA, Moiseev AA, Sovetsky AA, Gelikonov GV, Zaitsev VY. Simulating scan formation in multimodal optical coherence tomography: angular-spectrum formulation based on ballistic scattering of arbitrary-form beams. BIOMEDICAL OPTICS EXPRESS 2021; 12:7599-7615. [PMID: 35003855 PMCID: PMC8713662 DOI: 10.1364/boe.440739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 06/14/2023]
Abstract
We present a computationally highly efficient full-wave spectral model of OCT-scan formation with the following features: allowance of arbitrary phase-amplitude profile of illuminating beams; absence of paraxial approximation; utilization of broadly used approximation of ballistic scattering by discrete scatterers without limitations on their density/location and scattering strength. The model can easily incorporate the wave decay, dispersion, measurement noises with given signal-to-noise ratios and arbitrary inter-scan displacements of scatterers. We illustrate several of such abilities, including comparative simulations of OCT-scans for Bessel versus Gaussian beams, presence of arbitrary aberrations at the tissue boundary and various scatterer motions. The model flexibility and computational efficiency allow one to accurately study various properties of OCT-scans for developing new methods of their processing in various biomedical applications.
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Affiliation(s)
- Alexander L. Matveyev
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
| | - Lev A. Matveev
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
| | - Aleksandr A. Moiseev
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
| | - Alexander A. Sovetsky
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
| | - Grigory V. Gelikonov
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
| | - Vladimir Y. Zaitsev
- Federal Research Center Institute of Applied Physics of the Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod, 603950, Russia
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16
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Nagib K, Mezgebo B, Fernando N, Kordi B, Sherif SS. Generalized Image Reconstruction in Optical Coherence Tomography Using Redundant and Non-Uniformly-Spaced Samples. SENSORS 2021; 21:s21217057. [PMID: 34770364 PMCID: PMC8587445 DOI: 10.3390/s21217057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/10/2021] [Accepted: 10/19/2021] [Indexed: 11/22/2022]
Abstract
In this paper, we use Frame Theory to develop a generalized OCT image reconstruction method using redundant and non-uniformly spaced frequency domain samples that includes using non-redundant and uniformly spaced samples as special cases. We also correct an important theoretical error in the previously reported results related to OCT image reconstruction using the Non-uniform Discrete Fourier Transform (NDFT). Moreover, we describe an efficient method to compute our corrected reconstruction transform, i.e., a scaled NDFT, using the Fast Fourier Transform (FFT). Finally, we demonstrate different advantages of our generalized OCT image reconstruction method by achieving (1) theoretically corrected OCT image reconstruction directly from non-uniformly spaced frequency domain samples; (2) a novel OCT image reconstruction method with a higher signal-to-noise ratio (SNR) using redundant frequency domain samples. Our new image reconstruction method is an improvement of OCT technology, so it could benefit all OCT applications.
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Affiliation(s)
- Karim Nagib
- Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada; (K.N.); (B.M.); (B.K.)
| | - Biniyam Mezgebo
- Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada; (K.N.); (B.M.); (B.K.)
| | - Namal Fernando
- Manitoba Hydro High Voltage Test Facility, Manitoba Hydro, Winnipeg, MB R3T 1Y6, Canada;
| | - Behzad Kordi
- Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada; (K.N.); (B.M.); (B.K.)
| | - Sherif S. Sherif
- Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada; (K.N.); (B.M.); (B.K.)
- Correspondence:
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17
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Das V, Dandapat S, Bora PK. A diagnostic information based framework for super-resolution and quality assessment of retinal OCT images. Comput Med Imaging Graph 2021; 94:101997. [PMID: 34678643 DOI: 10.1016/j.compmedimag.2021.101997] [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: 12/12/2019] [Revised: 10/20/2020] [Accepted: 09/06/2021] [Indexed: 10/20/2022]
Abstract
High-resolution (HR) retinal optical coherence tomography (OCT) images are preferred by the ophthalmologists to diagnose retinal diseases. These images can be obtained by dense scanning of the target retinal region during acquisition. However, a dense scanning increases the image acquisition time and introduces motion artefacts, which corrupt diagnostic information. Therefore, researchers have a growing interest in developing image processing techniques to recover HR images from low-resolution (LR) OCT images. In this paper, we present an automated super-resolution (SR) scheme using diagnostic information weighted sparse representation framework to reconstruct HR images from LR OCT images. The proposed method performs fast and reliable reconstruction of the LR images. We also propose a 2D- variational mode decomposition (VMD) based OCT diagnostic distortion measure (QOCT) to quantify diagnostic distortion in the reconstructed OCT images. The SR method is evaluated on clinical grade OCT images with the proposed diagnostic distortion measure along with the conventional non-diagnostic measures like the contrast to noise ratio (CNR), the equivalent number of looks (ENL) and the peak signal to noise ratio (PSNR). The results show an average CNR of 4.07, ENL of 58.96 and PSNR of 27.72 dB. An average score of 1.53 is obtained using the proposed diagnostic distortion measure. Experimental results quantify that the proposed QOCT metric can effectively capture diagnostic distortion.
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Affiliation(s)
- Vineeta Das
- Electro Medical and Speech Technology Lab, Department of Electronics and Electrical Engineering, Indian Institute of Technology, Guwahati 781039, India
| | - Samarendra Dandapat
- Electro Medical and Speech Technology Lab, Department of Electronics and Electrical Engineering, Indian Institute of Technology, Guwahati 781039, India
| | - Prabin Kumar Bora
- Electro Medical and Speech Technology Lab, Department of Electronics and Electrical Engineering, Indian Institute of Technology, Guwahati 781039, India
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18
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Kufcsák A, Bagnaninchi P, Erdogan AT, Henderson RK, Krstajić N. Time-resolved spectral-domain optical coherence tomography with CMOS SPAD sensors. OPTICS EXPRESS 2021; 29:18720-18733. [PMID: 34154122 DOI: 10.1364/oe.422648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/14/2021] [Indexed: 06/13/2023]
Abstract
We present a first spectral-domain optical coherence tomography (SD-OCT) system deploying a complementary metal-oxide-semiconductor (CMOS) single-photon avalanche diode (SPAD) based, time-resolved line sensor. The sensor with 1024 pixels achieves a sensitivity of 87 dB at an A-scan rate of 1 kHz using a supercontinuum laser source with a repetition rate of 20 MHz, 38 nm bandwidth, and 2 mW power at 850 nm centre wavelength. In the time-resolved mode of the sensor, the system combines low-coherence interferometry (LCI) and massively parallel time-resolved single-photon counting to control the detection of interference spectra on the single-photon level based on the time-of-arrival of photons. For proof of concept demonstration of the combined detection scheme we show the acquisition of time-resolved interference spectra and the reconstruction of OCT images from selected time bins. Then, we exemplify the temporal discrimination feature with 50 ps time resolution and 249 ps timing uncertainty by removing unwanted reflections from along the optical path at a 30 mm distance from the sample. The current limitations of the proposed technique in terms of sensor parameters are analysed and potential improvements are identified for advanced photonic applications.
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19
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Kiseleva E, Ryabkov M, Baleev M, Bederina E, Shilyagin P, Moiseev A, Beschastnov V, Romanov I, Gelikonov G, Gladkova N. Prospects of Intraoperative Multimodal OCT Application in Patients with Acute Mesenteric Ischemia. Diagnostics (Basel) 2021; 11:705. [PMID: 33920827 PMCID: PMC8071199 DOI: 10.3390/diagnostics11040705] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/11/2021] [Accepted: 04/13/2021] [Indexed: 01/02/2023] Open
Abstract
INTRODUCTION Despite the introduction of increasingly multifaceted diagnostic techniques and the general advances in emergency abdominal and vascular surgery, the outcome of treatment of patients with acute impaired intestinal circulation remains unsatisfactory. The non-invasive and high-resolution technique of optical coherence tomography (OCT) can be used intraoperatively to assess intestine viability and associated conditions that frequently emerge under conditions of impaired blood circulation. This study aims to demonstrate the effectiveness of multimodal (MM) OCT for intraoperative diagnostics of both the microstructure (cross-polarization OCT mode) and microcirculation (OCT angiography mode) of the small intestine wall in patients with acute mesenteric ischemia (AMI). METHODS AND PARTICIPANTS A total of 18 patients were enrolled in the study. Nine of them suffered from AMI in segments II-III of the superior mesenteric artery (AMI group), whereby the ischemic segments of the intestine were examined. Nine others were operated on for adenocarcinoma of the colon (control group), thus allowing areas of their normal small intestine to be examined for comparison. Data on the microstructure and microcirculation in the walls of the small intestine were obtained intraoperatively from the side of the serous membrane using the MM OCT system (IAP RAS, Russia) before bowel resection. The MM OCT data were compared with the results of histological examination. RESULTS The study finds that MM OCT visualized the damage to serosa, muscularis externa, and blood vessels localized in these layers in 100% of AMI cases. It also visualized the submucosa in 33.3% of AMI cases. The MM OCT images of non-ischemic (control group), viable ischemic, and necrotic small intestines (AMI group) differed significantly across stratification of the distinguishable layers, the severity of intermuscular fluid accumulations, and the type and density of the vasculature. CONCLUSION The MM OCT diagnostic procedure optimally meets the requirements of emergency surgery. Data on the microstructure and microcirculation of the intestinal wall can be obtained simultaneously in real time without requiring contrast agent injections. The depth of visualization of the intestinal wall from the side of the serous membrane is sufficient to assess the volume of the affected tissues. However, the methodology for obtaining MM OCT data needs to be improved to minimize the motion artefacts generated in actual clinical conditions.
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Affiliation(s)
- Elena Kiseleva
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603950 Nizhny Novgorod, Russia;
| | - Maxim Ryabkov
- Thermal Injury Group, University Clinic, Privolzhsky Research Medical University, 18/1 Verkhnevolzhskaya Naberezhnaja, 603155 Nizhny Novgorod, Russia;
| | - Mikhail Baleev
- City Clinical Hospital No.30, 85A Berezovskaya St., 605157 Nizhny Novgorod, Russia; (M.B.); (V.B.); (I.R.)
| | - Evgeniya Bederina
- The Department of Pathology, University Clinic, Privolzhsky Research Medical University, 18/1 Verkhnevolzhskaya Naberezhnaja, 603155 Nizhny Novgorod, Russia;
| | - Pavel Shilyagin
- Institute of Applied Physics of the RAS, 46 Ulyanova St., 603950 Nizhny Novgorod, Russia; (P.S.); (A.M.); (G.G.)
| | - Alexander Moiseev
- Institute of Applied Physics of the RAS, 46 Ulyanova St., 603950 Nizhny Novgorod, Russia; (P.S.); (A.M.); (G.G.)
| | - Vladimir Beschastnov
- City Clinical Hospital No.30, 85A Berezovskaya St., 605157 Nizhny Novgorod, Russia; (M.B.); (V.B.); (I.R.)
| | - Ivan Romanov
- City Clinical Hospital No.30, 85A Berezovskaya St., 605157 Nizhny Novgorod, Russia; (M.B.); (V.B.); (I.R.)
| | - Grigory Gelikonov
- Institute of Applied Physics of the RAS, 46 Ulyanova St., 603950 Nizhny Novgorod, Russia; (P.S.); (A.M.); (G.G.)
| | - Natalia Gladkova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, 10/1 Minin and Pozharsky Sq., 603950 Nizhny Novgorod, Russia;
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20
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Cheong H, Krishna Devalla S, Chuangsuwanich T, Tun TA, Wang X, Aung T, Schmetterer L, Buist ML, Boote C, Thiéry AH, Girard MJA. OCT-GAN: single step shadow and noise removal from optical coherence tomography images of the human optic nerve head. BIOMEDICAL OPTICS EXPRESS 2021; 12:1482-1498. [PMID: 33796367 PMCID: PMC7984803 DOI: 10.1364/boe.412156] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/12/2021] [Accepted: 01/15/2021] [Indexed: 06/12/2023]
Abstract
Speckle noise and retinal shadows within OCT B-scans occlude important edges, fine textures and deep tissues, preventing accurate and robust diagnosis by algorithms and clinicians. We developed a single process that successfully removed both noise and retinal shadows from unseen single-frame B-scans within 10.4ms. Mean average gradient magnitude (AGM) for the proposed algorithm was 57.2% higher than current state-of-the-art, while mean peak signal to noise ratio (PSNR), contrast to noise ratio (CNR), and structural similarity index metric (SSIM) increased by 11.1%, 154% and 187% respectively compared to single-frame B-scans. Mean intralayer contrast (ILC) improvement for the retinal nerve fiber layer (RNFL), photoreceptor layer (PR) and retinal pigment epithelium (RPE) layers decreased from 0.362 ± 0.133 to 0.142 ± 0.102, 0.449 ± 0.116 to 0.0904 ± 0.0769, 0.381 ± 0.100 to 0.0590 ± 0.0451 respectively. The proposed algorithm reduces the necessity for long image acquisition times, minimizes expensive hardware requirements and reduces motion artifacts in OCT images.
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Affiliation(s)
- Haris Cheong
- Ophthalmic Engineering and Innovation Laboratory (OEIL), Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore
| | - Sripad Krishna Devalla
- Ophthalmic Engineering and Innovation Laboratory (OEIL), Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Thanadet Chuangsuwanich
- Ophthalmic Engineering and Innovation Laboratory (OEIL), Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore
| | - Tin A. Tun
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Xiaofei Wang
- Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Tin Aung
- Ophthalmic Engineering and Innovation Laboratory (OEIL), Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Leopold Schmetterer
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- School of Clinical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore
- SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
- Institute of Molecular and Clinical Ophthalmology, Basel, Switzerland
| | - Martin L. Buist
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore
| | - Craig Boote
- Ophthalmic Engineering and Innovation Laboratory (OEIL), Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, UK
| | - Alexandre H. Thiéry
- Department of Statistics and Applied Probability, National University of Singapore, Singapore, Singapore
| | - Michaël J. A. Girard
- Ophthalmic Engineering and Innovation Laboratory (OEIL), Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
- Duke-NUS Medical School, Singapore
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21
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Laíns I, Wang JC, Cui Y, Katz R, Vingopoulos F, Staurenghi G, Vavvas DG, Miller JW, Miller JB. Retinal applications of swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). Prog Retin Eye Res 2021; 84:100951. [PMID: 33516833 DOI: 10.1016/j.preteyeres.2021.100951] [Citation(s) in RCA: 110] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 01/17/2021] [Accepted: 01/20/2021] [Indexed: 02/08/2023]
Abstract
The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited. In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.
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Affiliation(s)
- Inês Laíns
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Harvard Retinal Imaging Lab, Boston, MA, USA
| | - Jay C Wang
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Harvard Retinal Imaging Lab, Boston, MA, USA
| | - Ying Cui
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Harvard Retinal Imaging Lab, Boston, MA, USA; Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Raviv Katz
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Harvard Retinal Imaging Lab, Boston, MA, USA
| | - Filippos Vingopoulos
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Harvard Retinal Imaging Lab, Boston, MA, USA
| | - Giovanni Staurenghi
- Eye Clinic, Department of Biomedical and Clinical Science "Luigi Sacco", University of Milan, Italy
| | - Demetrios G Vavvas
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Joan W Miller
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - John B Miller
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA; Harvard Retinal Imaging Lab, Boston, MA, USA.
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22
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Moreira-Neto CA, Lima LH, Zett C, Pereira R, Moreira C. En-face OCT and OCT angiography analysis of macular choroidal macrovessel. Am J Ophthalmol Case Rep 2021; 21:101012. [PMID: 33490717 PMCID: PMC7811033 DOI: 10.1016/j.ajoc.2021.101012] [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: 07/11/2020] [Revised: 11/02/2020] [Accepted: 01/06/2021] [Indexed: 12/19/2022] Open
Abstract
Purpose To analyze en-face optical coherence tomography (OCT) and decorrelation signals on OCT angiography (OCTA) in two cases of macular choroidal macrovessel (MCM). Observations Case report. Both the 64-year-old and 71-year-old females presented for a routine evaluation, and multimodal imaging analysis, including color fundus photography, indocyanine green angiography (ICG), spectral-domain optical coherence tomography (SD-OCT) and OCTA, was performed to diagnose a MCM. En-face OCT, en-face OCTA and decorrelation signals were analyzed through the MCM. In both reported cases, color fundus photograph revealed a serpiginoid lesion in the temporal macula. Red-free imaging enhanced the appearance of this lesion resembling a dilated choroidal vessel. Cross-sectional OCT showed an enlarged choroidal vessel causing elevation of the retinal pigment epithelium (RPE) within the fovea. En-face OCTA with segmentation below the choriocapillaris enhanced the MCM delineation. En-face OCT with segmentation below the choriocapillaris showed MCM with a greater distinctness than the en-face OCTA imaging. Decorrelation signals were not observed within MCM on cross-sectional OCTA. Conclusion and importance En-face OCT and decorrelation signals on OCTA may have diagnostic value in distinguishing macular choroidal macrovessel from other choroidal vascular diseases.
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Affiliation(s)
| | - Luiz H Lima
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
| | - Claudio Zett
- Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
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Imaging Motion: A Comprehensive Review of Optical Coherence Tomography Angiography. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1310:343-365. [PMID: 33834441 DOI: 10.1007/978-981-33-6064-8_12] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Optical coherence tomography (OCT) is a three-dimensional (3-D) optical imaging technology that provides noninvasive, micrometer resolution images of structural interiors within biological samples with an approximately 1 ~ 2 mm penetration depth. Over the last decades, advances in OCT have revolutionized biomedical imaging by demonstrating a potential of optical biopsy in preclinical and clinical settings. Recently, functional OCT imaging has shown a promise as angiography to visualize cell-perfused vasculatures in the tissue bed in vivo without requiring any exogenous contrast agents. This new technology termed OCT angiography (OCTA) possesses a unique imaging capability of delineating tissue morphology and blood or lymphatic vessels down to capillaries at real-time acquisition rates. For the past 10 years since 2007, OCTA has been proven to be a useful tool to identify disorder or dysfunction in tissue microcirculation from both experimental animal studies and clinical studies in ophthalmology and dermatology. In this section, we overview about OCTA including a basic principle of OCTA explained with simple optical physics, and its scan protocols and post-processing algorithms for acquisition of angiography. Then, potential and challenge of OCTA for clinical settings are shown with outcomes of human studies.
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24
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Pfeiffer T, Göb M, Draxinger W, Karpf S, Kolb JP, Huber R. Flexible A-scan rate MHz-OCT: efficient computational downscaling by coherent averaging. BIOMEDICAL OPTICS EXPRESS 2020; 11:6799-6811. [PMID: 33282524 PMCID: PMC7687947 DOI: 10.1364/boe.402477] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/18/2020] [Accepted: 09/28/2020] [Indexed: 05/29/2023]
Abstract
In order to realize adjustable A-scan rates of fast optical coherence tomography (OCT) systems, we investigate averaging of OCT image data acquired with a MHz-OCT system based on a Fourier Domain Mode Locked (FDML) laser. Increased system sensitivity and image quality can be achieved with the same system at the cost of lower imaging speed. Effectively, the A-scan rate can be reduced in software by a freely selectable factor. We demonstrate a detailed technical layout of the strategies necessary to achieve efficient coherent averaging. Since there are many new challenges specific to coherent averaging in swept source MHz-OCT, we analyze them point by point and describe the appropriate solutions. We prove that coherent averaging is possible at MHz OCT-speed without special interferometer designs or digital phase stabilization. We find, that in our system up to ∼100x coherent averaging is possible while achieving a sensitivity increase close to the ideal values. This corresponds to a speed reduction from 3.3 MHz to 33 kHz and a sensitivity gain of 20 dB. We show an imaging comparison between coherent and magnitude averaging of a human finger knuckle joint in vivo with 121 dB sensitivity for the coherent case. Further, the benefits of computational downscaling in low sensitivity MHz-OCT systems are analyzed.
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Affiliation(s)
- Tom Pfeiffer
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Optores GmbH, Gollierstr. 70, 80339 Munich, Germany
| | - Madita Göb
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Wolfgang Draxinger
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Sebastian Karpf
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Jan Philip Kolb
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Medizinisches Laserzentrum Lübeck GmbH, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Robert Huber
- Institut für Biomedizinische Optik, Universität zu Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
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25
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Lee B, Chen S, Moult EM, Yu Y, Alibhai AY, Mehta N, Baumal CR, Waheed NK, Fujimoto JG. High-Speed, Ultrahigh-Resolution Spectral-Domain OCT with Extended Imaging Range Using Reference Arm Length Matching. Transl Vis Sci Technol 2020; 9:12. [PMID: 32832219 PMCID: PMC7414734 DOI: 10.1167/tvst.9.7.12] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 04/02/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose To develop high-speed, extended-range, ultrahigh-resolution spectral-domain optical coherence tomography (UHR SD-OCT) and demonstrate scan protocols for clinical retinal imaging. Methods A UHR SD-OCT operating at 840-nm with 150-nm bandwidths was developed. The axial imaging range was extended by dynamically matching reference arm length to the retinal contour during acquisition. Two scan protocols were demonstrated for imaging healthy participants and patients with dry age-related macular degeneration. A high-definition raster protocol with intra–B-scan reference arm length matching (ReALM) was used for high-quality cross-sectional imaging. A cube volume scan using horizontal and vertical rasters with inter–B-scan ReALM and software motion correction was used for en face and cross-sectional imaging. Linear OCT signal display enhanced visualization of outer retinal features. Results UHR SD-OCT was demonstrated at 128- and 250-kHz A-scan rates with 2.7 µm axial resolution and a 1.2-mm, 6-dB imaging range in the eye. Dynamic ReALM was used to maintain the retina within the 6-dB imaging range over wider fields of view. Outer retinal features, including the rod and cone interdigitation zones, retinal pigment epithelium, and Bruch's membrane were visualized and alterations observed in age-related macular degeneration eyes. Conclusions Technological advances and dynamic ReALM improve the imaging performance and clinical usability of UHR SD-OCT. Translational Relevance These advances should simplify clinical imaging workflow, reduce imaging session times, and improve yield of high quality images. Improved visualization of photoreceptors, retinal pigment epithelium, and Bruch's membrane may facilitate diagnosis and monitoring of age-related macular degeneration and other retinal diseases.
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Affiliation(s)
- ByungKun Lee
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Siyu Chen
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Eric M Moult
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yue Yu
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - A Yasin Alibhai
- New England Eye Center, Tufts University School of Medicine, Boston, MA, USA
| | - Nihaal Mehta
- New England Eye Center, Tufts University School of Medicine, Boston, MA, USA
| | - Caroline R Baumal
- New England Eye Center, Tufts University School of Medicine, Boston, MA, USA
| | - Nadia K Waheed
- New England Eye Center, Tufts University School of Medicine, Boston, MA, USA
| | - James G Fujimoto
- Department of Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
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26
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Pan CT, Chang WH, Kumar A, Singh SP, Kaushik AC, Sharma J, Long ZJ, Wen ZH, Mishra SK, Yen CK, Chaudhary RK, Shiue YL. Nanoparticles-mediated Brain Imaging and Disease Prognosis by Conventional as well as Modern Modal Imaging Techniques: a Comparison. Curr Pharm Des 2020; 25:2637-2649. [PMID: 31603057 DOI: 10.2174/1381612825666190709220139] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Accepted: 07/02/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Multimodal imaging plays an important role in the diagnosis of brain disorders. Neurological disorders need to be diagnosed at an early stage for their effective treatment as later, it is very difficult to treat them. If possible, diagnosing at an early stage can be much helpful in curing the disease with less harm to the body. There is a need for advanced and multimodal imaging techniques for the same. This paper provides an overview of conventional as well as modern imaging techniques for brain diseases, specifically for tumor imaging. In this paper, different imaging modalities are discussed for tumor detection in the brain along with their advantages and disadvantages. Conjugation of two and more than two modalities provides more accurate information rather than a single modality. They can monitor and differentiate the cellular processes of normal and diseased condition with more clarity. The advent of molecular imaging, including reporter gene imaging, has opened the door of more advanced noninvasive detection of brain tumors. Due to specific optical properties, semiconducting polymer-based nanoparticles also play a pivotal role in imaging tumors. OBJECTIVE The objective of this paper is to review nanoparticles-mediated brain imaging and disease prognosis by conventional as well as modern modal imaging techniques. CONCLUSION We reviewed in detail various medical imaging techniques. This paper covers recent developments in detail and elaborates a possible research aspect for the readers in the field.
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Affiliation(s)
- Cheng-Tang Pan
- Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung City 804, Taiwan.,Institute of Medical Science and Technology, National Sun Yat-Sen University, Kaohsiung City 804, Taiwan
| | - Wei-Hsi Chang
- Department of Emergency Medicine, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan
| | - Ajay Kumar
- Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung City 804, Taiwan.,Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung City 804, Taiwan
| | - Satya P Singh
- School of EEE, Nanyang Technological University, Nanyang Ave, Singapore
| | - Aman Chandra Kaushik
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, ShanghaiJia Tong University, Shanghai 200240, China
| | - Jyotsna Sharma
- Amity School of Applied Sciences, Amity University Haryana, Gurugram-122413, Manesai, Panchgaon, Haryana, India
| | - Zheng-Jing Long
- Department of Emergency Medicine, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan
| | - Zhi-Hong Wen
- Department of Marine Biotechnology and Resources, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Sunil Kumar Mishra
- Patronage Institute of Management Studies, Greater Noida, Uttar Pradesh, India
| | - Chung-Kun Yen
- Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung City 804, Taiwan
| | - Ravi Kumar Chaudhary
- School of Biotechnology, Gautam Buddha University, Greater Noida, Uttar Pardesh, India, India
| | - Yow-Ling Shiue
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung City 804, Taiwan
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27
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Jerwick J, Huang Y, Dong Z, Slaudades A, Brucker AJ, Zhou C. Wide-field Ophthalmic Space-Division Multiplexing Optical Coherence Tomography. PHOTONICS RESEARCH 2020; 8:539-547. [PMID: 34222553 PMCID: PMC8248931 DOI: 10.1364/prj.383034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
High-speed ophthalmic optical coherence tomography systems are of interest because they allow rapid, motion-free, and wide-field retinal imaging. Space-division multiplexing optical coherence tomography (SDM-OCT) is a high-speed imaging technology which takes advantage of the long coherence length of microelectromechanical vertical cavity surface emitting laser (MEMs VCSEL) sources to multiplex multiple images along a single imaging depth. We demonstrate wide-field retinal OCT imaging, acquired at an effective A-scan rate of 800,000 A-scans/sec with volumetric images covering up to 12.5 mm × 7.4 mm on the retina acquired in less than 1 second. A clinical feasibility study was conducted to compare the ophthalmic SDM-OCT with commercial OCT systems, illustrating the high-speed capability of SDM-OCT in a clinical setting.
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Affiliation(s)
- Jason Jerwick
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO, 63130
| | - Yongyang Huang
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Zhao Dong
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO, 63130
| | - Adrienne Slaudades
- Scheie Eye Institute, Penn Presbyterian Medical Center, University of Pennsylvania, Philadelphia PA, 19104
| | - Alexander J. Brucker
- Scheie Eye Institute, Penn Presbyterian Medical Center, University of Pennsylvania, Philadelphia PA, 19104
| | - Chao Zhou
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO, 63130
- Department of Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
- Corresponding author:
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28
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Almog IF, Chen F, Senova S, Fomenko A, Gondard E, Sacher WD, Lozano AM, Poon JKS. Full-field swept-source optical coherence tomography and neural tissue classification for deep brain imaging. JOURNAL OF BIOPHOTONICS 2020; 13:e201960083. [PMID: 31710771 PMCID: PMC7065632 DOI: 10.1002/jbio.201960083] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 10/19/2019] [Accepted: 11/06/2019] [Indexed: 05/28/2023]
Abstract
Optical coherence tomography can differentiate brain regions with intrinsic contrast and at a micron scale resolution. Such a device can be particularly useful as a real-time neurosurgical guidance tool. We present, to our knowledge, the first full-field swept-source optical coherence tomography system operating near a wavelength of 1310 nm. The proof-of-concept system was integrated with an endoscopic probe tip, which is compatible with deep brain stimulation keyhole neurosurgery. Neuroimaging experiments were performed on ex vivo brain tissues and in vivo in rat brains. Using classification algorithms involving texture features and optical attenuation, images were successfully classified into three brain tissue types.
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Affiliation(s)
- Ilan Felts Almog
- Edward S. Rogers Sr. Department of Electrical and Computer EngineeringUniversity of TorontoTorontoOntarioCanada
- Krembil Research InstituteToronto Western HospitalTorontoOntarioCanada
| | - Fu‐Der Chen
- Edward S. Rogers Sr. Department of Electrical and Computer EngineeringUniversity of TorontoTorontoOntarioCanada
- Krembil Research InstituteToronto Western HospitalTorontoOntarioCanada
| | - Suhan Senova
- Krembil Research InstituteToronto Western HospitalTorontoOntarioCanada
- Department of NeurosurgeryCentre Hospitalier Universitaire Henri‐Mondor, APHPCréteilFrance
- INSERM Unit 955, Institut Mondor de Recherche Biomédicale, Université Paris‐EstCréteilFrance
| | - Anton Fomenko
- Krembil Research InstituteToronto Western HospitalTorontoOntarioCanada
| | - Elise Gondard
- Krembil Research InstituteToronto Western HospitalTorontoOntarioCanada
| | - Wesley D. Sacher
- Edward S. Rogers Sr. Department of Electrical and Computer EngineeringUniversity of TorontoTorontoOntarioCanada
- Max Planck Institute of Microstructure PhysicsHalleGermany
| | - Andres M. Lozano
- Krembil Research InstituteToronto Western HospitalTorontoOntarioCanada
- Division of Neurosurgery, Department of SurgeryToronto Western HospitalTorontoOntarioCanada
| | - Joyce K. S. Poon
- Edward S. Rogers Sr. Department of Electrical and Computer EngineeringUniversity of TorontoTorontoOntarioCanada
- Krembil Research InstituteToronto Western HospitalTorontoOntarioCanada
- Max Planck Institute of Microstructure PhysicsHalleGermany
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29
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Rubinoff I, Beckmann L, Wang Y, Fawzi AA, Liu X, Tauber J, Jones K, Ishikawa H, Schuman JS, Kuranov R, Zhang HF. Speckle reduction in visible-light optical coherence tomography using scan modulation. NEUROPHOTONICS 2019; 6:041107. [PMID: 31482105 PMCID: PMC6718816 DOI: 10.1117/1.nph.6.4.041107] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/08/2019] [Indexed: 05/25/2023]
Abstract
We present a technique to reduce speckle in visible-light optical coherence tomography (vis-OCT) that preserves fine structural details and is robust against sample motion. Specifically, we locally modulate B-scans orthogonally to their axis of acquisition. Such modulation enables acquisition of uncorrelated speckle patterns from similar anatomical locations, which can be averaged to reduce speckle. To verify the effectiveness of speckle reduction, we performed in-vivo retinal imaging using modulated raster and circular scans in both mice and humans. We compared speckle-reduced vis-OCT images with the images acquired with unmodulated B-scans from the same anatomical locations. We compared contrast-to-noise ratio (CNR) and equivalent number of looks (ENL) to quantify the image quality enhancement. Speckle-reduced images showed up to a 2.35-dB improvement in CNR and up to a 3.1-fold improvement in ENL with more discernable anatomical features using eight modulated A-line averages at a 25-kHz A-line rate.
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Affiliation(s)
- Ian Rubinoff
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Lisa Beckmann
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
| | - Yuanbo Wang
- Opticent Health, Evanston, Illinois, United States
| | - Amani A. Fawzi
- Northwestern University, Department of Ophthalmology, Chicago, Illinois, United States
| | - Xiaorong Liu
- University of Virginia, Department of Biology and Psychology, Charlottesville, Virginia, United States
| | - Jenna Tauber
- New York University, Department of Ophthalmology, New York, United States
| | - Katie Jones
- New York University, Department of Ophthalmology, New York, United States
| | - Hiroshi Ishikawa
- New York University, Department of Ophthalmology, New York, United States
| | - Joel S. Schuman
- New York University, Department of Ophthalmology, New York, United States
| | - Roman Kuranov
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Opticent Health, Evanston, Illinois, United States
| | - Hao F. Zhang
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois, United States
- Northwestern University, Department of Ophthalmology, Chicago, Illinois, United States
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30
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Optical coherence tomography angiography in preclinical neuroimaging. Biomed Eng Lett 2019; 9:311-325. [PMID: 31456891 DOI: 10.1007/s13534-019-00118-8] [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: 01/16/2019] [Revised: 04/29/2019] [Accepted: 06/27/2019] [Indexed: 01/22/2023] Open
Abstract
Preclinical neuroimaging allows for the assessment of brain anatomy, connectivity, and function in laboratory animals, such as mice and this imaging field has been a rapidly growing aimed at bridging the translation gap between animal and human research. The progress in the animal research could be accelerated by high-resolution in vivo optical imaging technologies. Optical coherence tomography-based angiography (OCTA) estimates the scattering from moving red blood cells, providing the visualization of functional micro-vessel networks within tissue beds in vivo without a need for exogenous contrast agents. Recent advancement of OCTA methods have expanded its application to neuroimaging of small animal models of brain disorders. In this paper, we overview the recent development of OCTA techniques for blood flow imaging and its preclinical applications in neuroimaging. In specific, a summary of preclinical OCTA studies for traumatic brain injury, cerebral stroke, and aging brain on mice is reviewed.
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31
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Leitgeb RA. En face optical coherence tomography: a technology review [Invited]. BIOMEDICAL OPTICS EXPRESS 2019; 10:2177-2201. [PMID: 31143489 PMCID: PMC6524600 DOI: 10.1364/boe.10.002177] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/01/2019] [Accepted: 03/05/2019] [Indexed: 05/20/2023]
Abstract
A review on the technological development of en face optical coherence tomography (OCT) and optical coherence microscopy (OCM) is provided. The terminology originally referred to time domain OCT, where the preferential scanning was performed in the en face plane. Potentially the fastest realization of en face image recording is full-field OCT, where the full en face plane is illuminated and recorded simultaneously. The term has nowadays been adopted for high-speed Fourier domain approaches, where the en face image is reconstructed from full 3D volumes either by direct slicing or through axial projection in post processing. The success of modern en face OCT lies in its immediate and easy image interpretation, which is in particular of advantage for OCM or OCT angiography. Applications of en face OCT with a focus on ophthalmology are presented. The review concludes by outlining exciting technological prospects of en face OCT based both on time as well as on Fourier domain OCT.
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Affiliation(s)
- R A Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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32
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Kolb JP, Draxinger W, Klee J, Pfeiffer T, Eibl M, Klein T, Wieser W, Huber R. Live video rate volumetric OCT imaging of the retina with multi-MHz A-scan rates. PLoS One 2019; 14:e0213144. [PMID: 30921342 PMCID: PMC6438632 DOI: 10.1371/journal.pone.0213144] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 02/18/2019] [Indexed: 12/17/2022] Open
Abstract
Surgical microscopes are vital tools for ophthalmic surgeons. The recent development of an integrated OCT system for the first time allows to look at tissue features below the surface. Hence, these systems can drastically improve the quality and reduce the risk of surgical interventions. However, current commercial OCT-enhanced ophthalmic surgical microscopes provide only one additional cross sectional view to the standard microscope image and feature a low update rate. To present volumetric data at a high update rate, much faster OCT systems than the ones applied in today's surgical microscopes need to be developed. We demonstrate live volumetric retinal OCT imaging, which may provide a sufficiently large volume size (330x330x595 Voxel) and high update frequency (24.2 Hz) such that the surgeon may even purely rely on the OCT for certain surgical maneuvers. It represents a major technological step towards the possible application of OCT-only surgical microscopes in the future which would be much more compact thus enabling many additional minimal invasive applications. We show that multi-MHz A-scan rates are essential for such a device. Additionally, advanced phase-based OCT techniques require 3D OCT volumes to be detected with a stable optical phase. These techniques can provide additional functional information of the retina. Up to now, classical OCT was to slow for this, so our system can pave the way to holographic OCT with a traditional confocal flying spot approach. For the first time, we present point scanning volumetric OCT imaging of the posterior eye with up to 191.2 Hz volume rate. We show that this volume rate is high enough to enable a sufficiently stable optical phase to a level, where remaining phase errors can be corrected. Applying advanced post processing concepts for numerical refocusing or computational adaptive optics should be possible in future with such a system.
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Affiliation(s)
- Jan Philip Kolb
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | - Wolfgang Draxinger
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | - Julian Klee
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | - Tom Pfeiffer
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | - Matthias Eibl
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | | | | | - Robert Huber
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
- * E-mail:
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33
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Kolb JP, Draxinger W, Klee J, Pfeiffer T, Eibl M, Klein T, Wieser W, Huber R. Live video rate volumetric OCT imaging of the retina with multi-MHz A-scan rates. PLoS One 2019; 14:e0213144. [PMID: 30921342 DOI: 10.1371/journals.phone.0213144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 02/18/2019] [Indexed: 05/25/2023] Open
Abstract
Surgical microscopes are vital tools for ophthalmic surgeons. The recent development of an integrated OCT system for the first time allows to look at tissue features below the surface. Hence, these systems can drastically improve the quality and reduce the risk of surgical interventions. However, current commercial OCT-enhanced ophthalmic surgical microscopes provide only one additional cross sectional view to the standard microscope image and feature a low update rate. To present volumetric data at a high update rate, much faster OCT systems than the ones applied in today's surgical microscopes need to be developed. We demonstrate live volumetric retinal OCT imaging, which may provide a sufficiently large volume size (330x330x595 Voxel) and high update frequency (24.2 Hz) such that the surgeon may even purely rely on the OCT for certain surgical maneuvers. It represents a major technological step towards the possible application of OCT-only surgical microscopes in the future which would be much more compact thus enabling many additional minimal invasive applications. We show that multi-MHz A-scan rates are essential for such a device. Additionally, advanced phase-based OCT techniques require 3D OCT volumes to be detected with a stable optical phase. These techniques can provide additional functional information of the retina. Up to now, classical OCT was to slow for this, so our system can pave the way to holographic OCT with a traditional confocal flying spot approach. For the first time, we present point scanning volumetric OCT imaging of the posterior eye with up to 191.2 Hz volume rate. We show that this volume rate is high enough to enable a sufficiently stable optical phase to a level, where remaining phase errors can be corrected. Applying advanced post processing concepts for numerical refocusing or computational adaptive optics should be possible in future with such a system.
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Affiliation(s)
- Jan Philip Kolb
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | - Wolfgang Draxinger
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | - Julian Klee
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | - Tom Pfeiffer
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | - Matthias Eibl
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | | | | | - Robert Huber
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
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Pijewska E, Gorczynska I, Szkulmowski M. Computationally effective 2D and 3D fast phase unwrapping algorithms and their applications to Doppler optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2019; 10:1365-1382. [PMID: 30891352 PMCID: PMC6420292 DOI: 10.1364/boe.10.001365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/20/2019] [Accepted: 01/22/2019] [Indexed: 05/07/2023]
Abstract
We propose a simplification for a robust and easy to implement fast phase unwrapping (FPU) algorithm that is used to solve the phase wrapping problem encountered in various fields of optical imaging and metrology. We show that the number of necessary computations using the algorithm can be reduced compared to its original version. FPU can be easily extended from two to three spatial dimensions. We demonstrate the applicability of the two- and three-dimensional FPU algorithm for Doppler optical coherence tomography (DOCT) in numerical simulations, and in the imaging of a flow phantom and blood flow in the human retina in vivo. We introduce an FPU applicability plot for use as a guide in the selection of the most suitable version of the algorithm depending on the phase noise in the acquired data. This plot uses the circular standard deviation of the wrapped phase distribution as a measure of noise and relates it to the root-mean-square error of the recovered, unwrapped phase.
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35
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Napoli PE, Nioi M, d'Aloja E, Fossarello M. The Bull's Eye Pattern of the Tear Film in Humans during Visual Fixation on En-Face Optical Coherence Tomography. Sci Rep 2019; 9:1413. [PMID: 30723239 PMCID: PMC6363734 DOI: 10.1038/s41598-018-38260-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 12/19/2018] [Indexed: 12/31/2022] Open
Abstract
The aim of the study was to define and characterize the optical behavior of the tear film during visual fixation in humans on en-face optical coherence tomography (OCT). We included 20 healthy participants, 60% female, aged from 25 to 42 years (33.05 ± 4.97 [mean ± SD]) and ten patients with severe dry eye, 50% female, aged from 26 to 42 years (33.7 ± 5.31). To perform high-resolution tear film imaging, participants were asked to gaze at the internal fixation point in the spectral-domain anterior segment OCT device, and meanwhile scanning session was executed at the following time-points after blinking: at the 2nd, 3rd, 4th, 5th, and 6th second. After one hour, OCT imaging was repeated (second session) by a different operator masked to the study to verify the reliability of results. During each measuring session, a pulse oximetry was used for continuously measuring the heart rate and oxygen saturation (SpO2%). A preliminary experiment was also performed to test the absence of geometric patterns from the anterior surface of a motionless artificial eye. OCT imaging showed a motionless, stable anterior surface of the artificial eye and in dry eye patients. Conversely, in the healthy participants of the study, a bull's eye pattern of the tear film was detected by OCT at the 2nd, 3rd, 4th, 5th, and 6th second after blinking, respectively, in 45%, 60%, 45%, 60%, and 40% of OCT scans during the first session, and in 35%, 65%, 65%, 60%, and 35% of cases in the second session. Overall, a total of 200 OCT scans were performed in normal human population. A significant correlation was found between the novel tear film pattern and heart rate during the first and the second session (p < 0.01) in healthy eyes. Conversely, no correlation was revealed with SpO2%. Intraclass correlation (ICC) analysis for OCT imaging of the tear film revealed a statistically significant reproducibility of the results (ICC = 0.838; p < 0.01), indicating the high level of reliability of the method, independently of heart rate and SpO2% variables. There exists a novel, geometric pattern of the tear film during visual fixation detectable by en-face OCT, which is mainly evident as heart rate increases. Its discovery implies in turn the presence of a specific vibration (or imperceptible motion) of the tear film that, at present, is not recognized and corrected by the OCT software (in image postprocessing) unlike other eyeball movements.
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Affiliation(s)
- Pietro Emanuele Napoli
- From the San Giovanni di Dio hospital, Clinica Oculistica, Azienda Ospedaliera Universitaria di Cagliari, Cagliari, Italy.
- From the Department of Surgical Sciences, Eye Clinic, University of Cagliari, Cagliari, Italy.
| | - Matteo Nioi
- From the Department of Medical Sciences and Public Health - Forensic Science Unit -University of Cagliari, Cagliari, Italy
| | - Ernesto d'Aloja
- From the Department of Medical Sciences and Public Health - Forensic Science Unit -University of Cagliari, Cagliari, Italy
| | - Maurizio Fossarello
- From the San Giovanni di Dio hospital, Clinica Oculistica, Azienda Ospedaliera Universitaria di Cagliari, Cagliari, Italy
- From the Department of Surgical Sciences, Eye Clinic, University of Cagliari, Cagliari, Italy
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36
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Dubois A, Levecq O, Azimani H, Davis A, Ogien J, Siret D, Barut A. Line-field confocal time-domain optical coherence tomography with dynamic focusing. OPTICS EXPRESS 2018; 26:33534-33542. [PMID: 30650800 DOI: 10.1364/oe.26.033534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A time-domain optical coherence tomography technique is introduced for high-resolution B-scan imaging in real-time. The technique is based on a two-beam interference microscope with line illumination and line detection using a broadband spatially coherent light source and a line-scan camera. Multiple (2048) A-scans are acquired in parallel by scanning the sample depth while adjusting the focus. Quasi-isotropic spatial resolution of 1.3 µm × 1.1 µm (lateral × axial) is achieved. In vivo cellular-level resolution imaging of human skin is demonstrated at 10 frames per second with a penetration depth of ∼500 µm.
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Dubois A, Levecq O, Azimani H, Siret D, Barut A, Suppa M, Del Marmol V, Malvehy J, Cinotti E, Rubegni P, Perrot JL. Line-field confocal optical coherence tomography for high-resolution noninvasive imaging of skin tumors. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-9. [PMID: 30353716 DOI: 10.1117/1.jbo.23.10.106007] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/01/2018] [Indexed: 05/06/2023]
Abstract
An optical technique called line-field confocal optical coherence tomography (LC-OCT) is introduced for high-resolution, noninvasive imaging of human skin in vivo. LC-OCT combines the principles of time-domain optical coherence tomography and confocal microscopy with line illumination and detection using a broadband laser and a line-scan camera. LC-OCT measures the echo-time delay and amplitude of light backscattered from cutaneous microstructures through low-coherence interferometry associated with confocal spatial filtering. Multiple A-scans are acquired simultaneously while dynamically adjusting the focus. The resulting cross-sectional B-scan image is produced in real time at 10 frame / s. With an isotropic spatial resolution of ∼1 μm, the LC-OCT images reveal a comprehensive structural mapping of skin at the cellular level down to a depth of ∼500 μm. LC-OCT has been applied to the imaging of various skin lesions, in vivo, including carcinomas and melanomas. LC-OCT images are found to strongly correlate with conventional histopathological images. The use of LC-OCT as an adjunct tool in medical practice could significantly improve clinical diagnostic accuracy while reducing the number of biopsies of benign lesions.
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Affiliation(s)
- Arnaud Dubois
- Université Paris-Saclay, Institut d'Optique Graduate School, Laboratoire Charles Fabry, Palaiseau, France
| | | | | | | | | | - Mariano Suppa
- Hôpital Erasme, Université Libre de Bruxelles, Department of Dermatology, Brussels, Belgium
| | - Véronique Del Marmol
- Hôpital Erasme, Université Libre de Bruxelles, Department of Dermatology, Brussels, Belgium
| | - Josep Malvehy
- University Hospital Clinic of Barcelona, Barcelona, Spain
| | - Elisa Cinotti
- University of Siena, Department of Medical, Surgical and Neurological Sciences, Dermatology Unit, Si, Italy
| | - Pietro Rubegni
- University of Siena, Department of Medical, Surgical and Neurological Sciences, Dermatology Unit, Si, Italy
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Spahr H, Pfäffle C, Koch P, Sudkamp H, Hüttmann G, Hillmann D. Interferometric detection of 3D motion using computational subapertures in optical coherence tomography. OPTICS EXPRESS 2018; 26:18803-18816. [PMID: 30114142 DOI: 10.1364/oe.26.018803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Doppler optical coherence tomography (OCT) quantifies axial motion with high precision, whereas lateral motion cannot be detected by a mere evaluation of phase changes. This problem was solved by the introduction of three-beam Doppler OCT, which, however, entails a high experimental effort. Here, we present the numerical analogue to this experimental approach. Phase-stable complex-valued OCT datasets, recorded with full-field swept-source OCT, are filtered in the Fourier domain to limit imaging to different computational subapertures. These are used to calculate all three components of the motion vector with interferometric precision. As known from conventional Doppler OCT for axial motion only, the achievable accuracy exceeds the actual imaging resolution by orders of magnitude in all three dimensions. The feasibility of this method is first demonstrated by quantifying micro-rotation of a scattering sample. Subsequently, a potential application is explored by recording the 3D motion vector field of tissue during laser photocoagulation in ex-vivo porcine retina.
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Spaide RF, Fujimoto JG, Waheed NK, Sadda SR, Staurenghi G. Optical coherence tomography angiography. Prog Retin Eye Res 2018; 64:1-55. [PMID: 29229445 PMCID: PMC6404988 DOI: 10.1016/j.preteyeres.2017.11.003] [Citation(s) in RCA: 985] [Impact Index Per Article: 164.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 11/20/2017] [Accepted: 11/22/2017] [Indexed: 02/07/2023]
Abstract
Optical coherence tomography (OCT) was one of the biggest advances in ophthalmic imaging. Building on that platform, OCT angiography (OCTA) provides depth resolved images of blood flow in the retina and choroid with levels of detail far exceeding that obtained with older forms of imaging. This new modality is challenging because of the need for new equipment and processing techniques, current limitations of imaging capability, and rapid advancements in both imaging and in our understanding of the imaging and applicable pathophysiology of the retina and choroid. These factors lead to a steep learning curve, even for those with a working understanding dye-based ocular angiography. All for a method of imaging that is a little more than 10 years old. This review begins with a historical account of the development of OCTA, and the methods used in OCTA, including signal processing, image generation, and display techniques. This forms the basis to understand what OCTA images show as well as how image artifacts arise. The anatomy and imaging of specific vascular layers of the eye are reviewed. The integration of OCTA in multimodal imaging in the evaluation of retinal vascular occlusive diseases, diabetic retinopathy, uveitis, inherited diseases, age-related macular degeneration, and disorders of the optic nerve is presented. OCTA is an exciting, disruptive technology. Its use is rapidly expanding in clinical practice as well as for research into the pathophysiology of diseases of the posterior pole.
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Affiliation(s)
- Richard F Spaide
- Vitreous, Retina, Macula Consultants of New York, New York, NY, United States.
| | - James G Fujimoto
- Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA, United States
| | - Nadia K Waheed
- The Department of Ophthalmology, Tufts University School of Medicine, Boston MA, United States
| | - Srinivas R Sadda
- Doheny Eye Institute, University of California - Los Angeles, Los Angeles, CA, United States
| | - Giovanni Staurenghi
- Eye Clinic, Department of Biomedical and Clinical Sciences "Luigi Sacco", Luigi Sacco Hospital, University of Milan, Milan, Italy
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Bernucci MT, Merkle CW, Srinivasan VJ. Investigation of artifacts in retinal and choroidal OCT angiography with a contrast agent. BIOMEDICAL OPTICS EXPRESS 2018; 9:1020-1040. [PMID: 29541501 PMCID: PMC5846511 DOI: 10.1364/boe.9.001020] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 01/22/2018] [Accepted: 01/24/2018] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography angiography (OCTA) has recently emerged for imaging vasculature in clinical ophthalmology. Yet, OCTA images contain artifacts that remain challenging to interpret. To help explain these artifacts, we perform contrast-enhanced OCTA with a custom-designed wide-field ophthalmoscope in rats in vivo. We choose an intravascular contrast agent (Intralipid) with particles that are more isotropically scattering and more symmetrically shaped than red blood cells (RBCs). Then, by examining how OCTA artifacts change after contrast agent injection, we attribute OCTA artifacts to RBC-specific properties. In this work, we investigate retinal and choroidal OCTA in rats with or without melanosomes, both before and after contrast agent injection, at a wavelength at which scattering dominates the image contrast (1300 nm). First, baseline images suggest that high backscattering of choroidal melanosomes accounts for the relatively dark appearance of choroidal vessel lumens in OCTA. Second, Intralipid injection tends to eliminate the hourglass pattern artifact in OCTA images of vessel lumens and highlights vertical capillaries that were previously faint in OCTA, showing that RBC orientation is important in determining OCTA signal. Third, Intralipid injection increases lumen signal without significantly affecting the tails, suggesting that projection artifacts, or tails, are due to RBC multiple scattering. Fourth, Intralipid injection increases the side-to-top signal ratio less in choroidal vessel lumens of pigmented rats, suggesting that melanosome multiple scattering makes the hourglass artifact less prominent. This study provides the first direct experimental in vivo evidence to explain light scattering-related artifacts in OCTA.
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Affiliation(s)
- Marcel T. Bernucci
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Conrad W. Merkle
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
| | - Vivek J. Srinivasan
- Department of Biomedical Engineering, University of California Davis, Davis, California, USA
- Department of Ophthalmology and Vision Science, University of California Davis School of Medicine, Sacramento, California, USA
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Sugita M, Brown RA, Popov I, Vitkin A. K-distribution three-dimensional mapping of biological tissues in optical coherence tomography. JOURNAL OF BIOPHOTONICS 2018; 11. [PMID: 28700119 DOI: 10.1002/jbio.201700055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 04/22/2017] [Accepted: 05/19/2017] [Indexed: 05/05/2023]
Abstract
Probability density function (PDF) analysis with K-distribution model of optical coherence tomography (OCT) intensity signals has previously yielded a good representation of the average number of scatterers in a coherence volume for microspheres-in-water systems, and has shown initial promise for biological tissue characterization. In this work, we extend these previous findings, based on single point M-mode or two-dimenstional slice analysis, to full three-dimensional (3D) imaging maps of the shape parameter α of the K-distribution PDF. After selecting a suitably sized 3D evaluation window, and verifying methodology in phantoms, the resultant parametric α images obtained in different animal tissues (rat liver and brain) show new contrasting ability not seen in conventional OCT intensity images.
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Affiliation(s)
- Mitsuro Sugita
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Robert A Brown
- Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Ivan Popov
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Alex Vitkin
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
- Department of Radiation Oncology, University of Toronto, Toronto, Canada
- Division of Biophysics and Bioimaging, Ontario Cancer Institute/University Health Network, Toronto, Canada
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Lan G, Singh M, Larin KV, Twa MD. Common-path phase-sensitive optical coherence tomography provides enhanced phase stability and detection sensitivity for dynamic elastography. BIOMEDICAL OPTICS EXPRESS 2017; 8:5253-5266. [PMID: 29188118 PMCID: PMC5695968 DOI: 10.1364/boe.8.005253] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/16/2017] [Accepted: 10/23/2017] [Indexed: 05/08/2023]
Abstract
Phase-sensitive optical coherence elastography (PhS-OCE) is an emerging optical technique to quantify soft-tissue biomechanical properties. We implemented a common-path OCT design to enhance displacement sensitivity and optical phase stability for dynamic elastography imaging. The background phase stability was greater in common-path PhS-OCE (0.24 ± 0.07nm) than conventional PhS-OCE (1.60 ± 0.11μm). The coefficient of variation for surface displacement measurements using conventional PhS-OCE averaged 11% versus 2% for common-path PhS-OCE. Young's modulus estimates showed good precision (95% CIs) for tissue phantoms: 24.96 ± 2.18kPa (1% agar), 49.69 ± 4.87kPa (1.5% agar), and 116.08 ± 12.14kPa (2% agar), respectively. Common-path PhS-OCE effectively reduced the amplitude of background dynamic optical phase instability to a sub-nanometer level, which provided a larger dynamic detection range and higher detection sensitivity for surface displacement measurements than conventional PhS-OCE.
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Affiliation(s)
- Gongpu Lan
- School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Manmohan Singh
- Biomedical Engineering, University of Houston, Houston, TX, USA
| | - Kirill V. Larin
- Biomedical Engineering, University of Houston, Houston, TX, USA
- Interdisciplinary Laboratory of Biophotonics, Tomsk State University, Tomsk, Russia
| | - Michael D. Twa
- School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
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de Boer JF, Leitgeb R, Wojtkowski M. Twenty-five years of optical coherence tomography: the paradigm shift in sensitivity and speed provided by Fourier domain OCT [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:3248-3280. [PMID: 28717565 PMCID: PMC5508826 DOI: 10.1364/boe.8.003248] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 04/26/2017] [Accepted: 05/22/2017] [Indexed: 05/19/2023]
Abstract
Optical coherence tomography (OCT) has become one of the most successful optical technologies implemented in medicine and clinical practice mostly due to the possibility of non-invasive and non-contact imaging by detecting back-scattered light. OCT has gone through a tremendous development over the past 25 years. From its initial inception in 1991 [Science254, 1178 (1991)] it has become an indispensable medical imaging technology in ophthalmology. Also in fields like cardiology and gastro-enterology the technology is envisioned to become a standard of care. A key contributor to the success of OCT has been the sensitivity and speed advantage offered by Fourier domain OCT. In this review paper the development of FD-OCT will be revisited, providing a single comprehensive framework to derive the sensitivity advantage of both SD- and SS-OCT. We point out the key aspects of the physics and the technology that has enabled a more than 2 orders of magnitude increase in sensitivity, and as a consequence an increase in the imaging speed without loss of image quality. This speed increase provided a paradigm shift from point sampling to comprehensive 3D in vivo imaging, whose clinical impact is still actively explored by a large number of researchers worldwide.
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Affiliation(s)
- Johannes F. de Boer
- Department of Physics and Astronomy and LaserLaB Amsterdam, VU University, De Boelelaan 1105, 1081 HV Amsterdam, Department of Ophthalmology, VU Medical Center, Amsterdam, The Netherlands
- Authors are listed in alphabetical order and contributed equally
| | - Rainer Leitgeb
- Christian Doppler Laboratory OPTRAMED, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
- Authors are listed in alphabetical order and contributed equally
| | - Maciej Wojtkowski
- Physical Optics and Biophotonics Group, Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52 01-224 Warsaw, Poland
- Authors are listed in alphabetical order and contributed equally
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Adabi S, Turani Z, Fatemizadeh E, Clayton A, Nasiriavanaki M. Optical Coherence Tomography Technology and Quality Improvement Methods for Optical Coherence Tomography Images of Skin: A Short Review. Biomed Eng Comput Biol 2017; 8:1179597217713475. [PMID: 28638245 PMCID: PMC5470862 DOI: 10.1177/1179597217713475] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/03/2017] [Indexed: 12/11/2022] Open
Abstract
Optical coherence tomography (OCT) delivers 3-dimensional images of tissue microstructures. Although OCT imaging offers a promising high-resolution method, OCT images experience some artifacts that lead to misapprehension of tissue structures. Speckle, intensity decay, and blurring are 3 major artifacts in OCT images. Speckle is due to the low coherent light source used in the configuration of OCT. Intensity decay is a deterioration of light with respect to depth, and blurring is the consequence of deficiencies of optical components. In this short review, we summarize some of the image enhancement algorithms for OCT images which address the abovementioned artifacts.
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Affiliation(s)
- Saba Adabi
- Department of Biomedical Engineering, College of Engineering and School of Medicine, Wayne State University, Detroit, MI, USA
- Department of Applied Electronics, Engineering Faculty, Roma Tre University, Roma, Italy
| | - Zahra Turani
- Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran
| | - Emad Fatemizadeh
- Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran
| | - Anne Clayton
- Department of Biomedical Engineering, College of Engineering and School of Medicine, Wayne State University, Detroit, MI, USA
| | - Mohammadreza Nasiriavanaki
- Department of Biomedical Engineering, College of Engineering and School of Medicine, Wayne State University, Detroit, MI, USA
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Bouma BE, Villiger M, Otsuka K, Oh WY. Intravascular optical coherence tomography [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:2660-2686. [PMID: 28663897 PMCID: PMC5480504 DOI: 10.1364/boe.8.002660] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 05/03/2023]
Abstract
Shortly after the first demonstration of optical coherence tomography for imaging the microstructure of the human eye, work began on developing systems and catheters suitable for intravascular imaging in order to diagnose and investigate atherosclerosis and potentially to monitor therapy. This review covers the driving considerations of the clinical application and its constraints, the major engineering milestones that enabled the current, high-performance commercial imaging systems, the key studies that laid the groundwork for image interpretation, and the clinical research that traces intravascular optical coherence tomography (OCT) from early human pilot studies to current clinical trials.
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Affiliation(s)
- Brett E Bouma
- Harvard Medical School and Massachusetts General Hospital, Boston, MA 02171, USA
- Institute for Medical Engineering and Science, Cambridge, MA, 02139, USA
| | - Martin Villiger
- Harvard Medical School and Massachusetts General Hospital, Boston, MA 02171, USA
| | - Kenichiro Otsuka
- Harvard Medical School and Massachusetts General Hospital, Boston, MA 02171, USA
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, South Korea
- KI for Health Science and Technology, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, South Korea
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46
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Gao W. Quantitative depth-resolved microcirculation imaging with optical coherence tomography angiography (Part Ι): Blood flow velocity imaging. Microcirculation 2017; 25:e12375. [PMID: 28419622 DOI: 10.1111/micc.12375] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/11/2017] [Indexed: 12/20/2022]
Abstract
The research goal of the microvascular network imaging with OCT angiography is to achieve depth-resolved blood flow and vessel imaging in vivo in the clinical management of patents. In this review, we review the main phenomena that have been explored in OCT to image the blood flow velocity vector and the vessels of the microcirculation within living tissues. Parameters that limit the accurate measurements of blood flow velocity are then considered. Finally, initial clinical diagnosis applications and future developments of OCT flow images are discussed.
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Affiliation(s)
- Wanrong Gao
- Department of Optical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, China.,MIIT Key Laboratory of Advanced soIid Laser, Nanjing University of science and Technology, Nanjing, Jiangsu, China
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Kassani SH, Villiger M, Uribe-Patarroyo N, Jun C, Khazaeinezhad R, Lippok N, Bouma BE. Extended bandwidth wavelength swept laser source for high resolution optical frequency domain imaging. OPTICS EXPRESS 2017; 25:8255-8266. [PMID: 28380940 PMCID: PMC5810910 DOI: 10.1364/oe.25.008255] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Improving the axial resolution by providing wider bandwidth wavelength swept lasers remains an important issue for optical frequency domain imaging (OFDI). Here, we demonstrate a wide tuning range, all-fiber wavelength swept laser at a center wavelength of 1250 nm by combining two ring cavities that share a single Fabry-Perot tunable filter. The two cavities contain semiconductor optical amplifiers with central wavelengths of 1190 nm and 1292 nm, respectively. To avoid disturbing interference effects in the overlapping spectral region, we modulated the amplifiers in order to obtain consecutive wavelength sweeps in the two spectral regions. The two sweeps were fused together in post-processing to achieve a total scanning range of 223 nm, corresponding to 3.3 µm axial resolution in air. We confirm improved image quality and reduced speckle size in tomograms of swine esophagus ex vivo, and human skin and nailbed in vivo.
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48
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Apostolopoulos S, Sznitman R. Efficient OCT Volume Reconstruction From Slitlamp Microscopes. IEEE Trans Biomed Eng 2017; 64:2403-2410. [PMID: 28141513 DOI: 10.1109/tbme.2017.2657884] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Since its introduction 25 years ago, Optical Coherence Tomography (OCT) has contributed tremendously to diagnostic and monitoring capabilities of pathologies in the field of ophthalmology. Despite rapid progress in hardware and software technology however, the price of OCT devices has remained high, limiting their use in private practice, and in screening examinations. In this paper, we present a slitlamp-integrated OCT device, built with off-the-shelf components, which can generate high-quality volumetric images of the posterior eye segment. To do so, we present a novel strategy for 3D image reconstruction in this challenging domain that allows us for state-of-the-art OCT volumes to be generated at fast speeds. The result is an OCT device that can match current systems in clinical practice, at a significantly lower cost.
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Zang P, Liu G, Zhang M, Wang J, Hwang TS, Wilson DJ, Huang D, Li D, Jia Y. Automated three-dimensional registration and volume rebuilding for wide-field angiographic and structural optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:26001. [PMID: 28144683 PMCID: PMC5285731 DOI: 10.1117/1.jbo.22.2.026001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/09/2017] [Indexed: 05/05/2023]
Abstract
We propose a three-dimensional (3-D) registration method to correct motion artifacts and construct the volume structure for angiographic and structural optical coherence tomography (OCT). This algorithm is particularly suitable for the nonorthogonal wide-field OCT scan acquired by a ultrahigh-speed swept-source system ( > 200 ?? kHz A-scan rate). First, the transverse motion artifacts are corrected by the between-frame registration based on en face OCT angiography (OCTA). After A-scan transverse translation between B-frames, the axial motions are corrected based on the rebuilt boundary of inner limiting membrane. Finally, a within-frame registration is performed for local optimization based on cross-sectional OCTA. We evaluated this algorithm on retinal volumes of six normal subjects. The results showed significantly improved retinal smoothness in 3-D-registered structural OCT and image contrast on en face OCTA.
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Affiliation(s)
- Pengxiao Zang
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
- Shandong Normal University, Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Biomedical Sciences, School of Physics and Electronics, Jinan, Shandong, China
| | - Gangjun Liu
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Miao Zhang
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Jie Wang
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Thomas S. Hwang
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - David J. Wilson
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - David Huang
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
| | - Dengwang Li
- Shandong Normal University, Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Biomedical Sciences, School of Physics and Electronics, Jinan, Shandong, China
- Address all correspondence to: Dengwang Li, E-mail: ; Yali Jia, E-mail:
| | - Yali Jia
- Oregon Health and Science University, Casey Eye Institute, Portland, Oregon, United States
- Address all correspondence to: Dengwang Li, E-mail: ; Yali Jia, E-mail:
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50
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Walther J, Koch E. Impact of a detector dead time in phase-resolved Doppler analysis using spectral domain optical coherence tomography. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2017; 34:241-251. [PMID: 28157850 DOI: 10.1364/josaa.34.000241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
For any oblique sample movement containing a transverse velocity component, the commonly used linear relationship between the phase shift and the axial velocity component is erroneous for spectrometer-based optical coherence tomography (spectral domain OCT, SD-OCT). We recently proposed a new Doppler model that assumes a continuous integration of the photocurrent. In this research, we extend the model for detectors with a shutter control by taking detector dead time into account. We present the new relation between phase shift and oblique sample displacement as well as the correlation of the phases of consecutive depth scans, in dependency on the detector dead times ranging from 5% to 90%, as numerically calculated universal contour plots, which are valid for any center wavelength and sample beam size. We found that detector dead time is recommended, especially for oblique sample motion. The reason for this recommendation is the achieved linear relation between the phase shift and the axial velocity component in the velocity range relevant for in vivo measurements, despite the signal damping due to shorter exposure time of the line detector. The theoretical Doppler model is verified using a 1% Intralipid flow phantom model. Because of the results of this research, we believe future measurements in Doppler SD-OCT can be more simple and more accurate by setting a shutter control for the line detector used.
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