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Han L, Bizheva K. Correcting spatial-spectral crosstalk and chromatic aberrations in broadband line-scan spectral-domain OCT images. BIOMEDICAL OPTICS EXPRESS 2023; 14:3344-3361. [PMID: 37497512 PMCID: PMC10368066 DOI: 10.1364/boe.488881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/30/2023] [Accepted: 06/02/2023] [Indexed: 07/28/2023]
Abstract
Digital correction of optical aberrations allows for high-resolution imaging across the full depth range in optical coherence tomography (OCT). Many digital aberration correction (DAC) methods have been proposed in the past to evaluate and correct monochromatic error in OCT images. However, other factors that deteriorate the image quality have not been fully investigated. Specifically, in a broadband line-scan spectral-domain OCT system (LS-SD-OCT), photons with different wavelengths scattered from the same transverse location and in the imaged object will be projected onto different spatial coordinates onto the 2D camera sensor, which in this work is defined as spatial-spectral crosstalk. In addition, chromatic aberrations in both axial and lateral directions are not negligible for broad spectral bandwidths. Here we present a novel approach to digital recovery of the spatial resolution in images acquired with a broadband LS-SD-OCT, which addresses these two main factors that limit the effectiveness of DAC for restoring diffraction-limited resolution in LS-SD-OCT images. In the proposed approach, spatial-spectral crosstalk and chromatic aberrations are suppressed by the registration of monochromatic sub-band tomograms that are digitally corrected for aberrations. The new method was validated by imaging a standard resolution target, a microspheres phantom, and different biological tissues. LS-SD-OCT technology combined with the proposed novel image reconstruction method could be a valuable research tool for various biomedical and clinical applications.
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Affiliation(s)
- Le Han
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Kostadinka Bizheva
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
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2
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de Wit J, Glentis GO, Kalkman J. Computational 3D resolution enhancement for optical coherence tomography with a narrowband visible light source. BIOMEDICAL OPTICS EXPRESS 2023; 14:3532-3554. [PMID: 37497501 PMCID: PMC10368068 DOI: 10.1364/boe.487345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 05/22/2023] [Accepted: 05/26/2023] [Indexed: 07/28/2023]
Abstract
Phase-preserving spectral estimation optical coherence tomography (SE-OCT) enables combining axial resolution improvement with computational depth of field (DOF) extension. We show that the combination of SE-OCT with interferometric synthetic aperture microscopy (ISAM) and computational adaptive optics (CAO) results in high 3D resolution over a large depth range for an OCT system with a narrow bandwidth visible light super-luminescent diode (SLD). SE-OCT results in up to five times axial resolution improvement from 8 µm to 1.5 µm. The combination with ISAM gives a sub-micron lateral resolution over a 400 µm axial range, which is at least 16 times the conventional depth of field. CAO can be successfully applied after SE and ISAM and removes residual aberrations, resulting in high quality images. The results show that phase-preserving SE-OCT is sufficiently accurate for coherent post-processing, enabling the use of cost-effective SLDs in the visible light range for high spatial resolution OCT.
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Affiliation(s)
- Jos de Wit
- Department of Imaging Physics, Lorentzweg 1, 2628 CJ, Delft, The Netherlands
| | - George-Othon Glentis
- Department of Informatics and Telecommunications, University of Peloponnese, Tripolis, 22100, Greece
| | - Jeroen Kalkman
- Department of Imaging Physics, Lorentzweg 1, 2628 CJ, Delft, The Netherlands
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3
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Lee B, Jeong S, Lee J, Kim TS, Braaf B, Vakoc BJ, Oh WY. Wide-Field Three-Dimensional Depth-Invariant Cellular-Resolution Imaging of the Human Retina. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2203357. [PMID: 36642824 PMCID: PMC10023497 DOI: 10.1002/smll.202203357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Three-dimensional (3D) cellular-resolution imaging of the living human retina over a large field of view will bring a great impact in clinical ophthalmology, potentially finding new biomarkers for early diagnosis and improving the pathophysiological understanding of ocular diseases. While hardware-based and computational adaptive optics (AO) optical coherence tomography (OCT) have been developed to achieve cellular-resolution retinal imaging, these approaches support limited 3D imaging fields, and their high cost and intrinsic hardware complexity limit their practical utility. Here, this work demonstrates 3D depth-invariant cellular-resolution imaging of the living human retina over a 3 × 3 mm field of view using the first intrinsically phase-stable multi-MHz retinal swept-source OCT and novel computational defocus and aberration correction methods. Single-acquisition imaging of photoreceptor cells, retinal nerve fiber layer, and retinal capillaries is presented across unprecedented imaging fields. By providing wide-field 3D cellular-resolution imaging in the human retina using a standard point-scan architecture routinely used in the clinic, this platform proposes a strategy for expanded utilization of high-resolution retinal imaging in both research and clinical settings.
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Affiliation(s)
- ByungKun Lee
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Sunhong Jeong
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Joosung Lee
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Tae Shik Kim
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston 02140, USA
| | - Boy Braaf
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston 02140, USA
| | - Benjamin J. Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston 02140, USA
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
- KI for Health Science and Technology, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
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4
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Glandorf L, Marchand PJ, Lasser T, Razansky D. Digital aberration correction enhances field of view in visible-light optical coherence microscopy. OPTICS LETTERS 2022; 47:5088-5091. [PMID: 36181193 DOI: 10.1364/ol.464405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 09/08/2022] [Indexed: 06/16/2023]
Abstract
In optical coherence microscopy, optical aberrations commonly result in astigmatism-dominated wavefront errors in the peripheral regions of the optical objective, primarily elongating the microscope's point-spread function along the radial direction in the vicinity of the focal plane. We report on enhanced-field-of-view optical coherence microscopy through computational aberration correction in the visible-light range. An isotropic spatial resolution of 2.5 µm was achieved over an enhanced lateral field of view spanning 1.3 mm × 1.6 mm, as experimentally verified in a micro-bead phantom and further demonstrated in ex vivo tissue samples. The extended field of view achieved by the digital aberration correction facilitates the use of low-cost systems by averting the need for high-quality objectives.
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5
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Pfäffle C, Spahr H, Gercke K, Puyo L, Höhl S, Melenberg D, Miura Y, Hüttmann G, Hillmann D. Phase-Sensitive Measurements of Depth-Dependent Signal Transduction in the Inner Plexiform Layer. Front Med (Lausanne) 2022; 9:885187. [PMID: 35721092 PMCID: PMC9198552 DOI: 10.3389/fmed.2022.885187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 05/10/2022] [Indexed: 12/01/2022] Open
Abstract
Non-invasive spatially resolved functional imaging in the human retina has recently attracted considerable attention. Particularly functional imaging of bipolar and ganglion cells could aid in studying neuronal activity in humans, including an investigation of processes of the central nervous system. Recently, we imaged the activity of the inner neuronal layers by measuring nanometer-size changes of the cells within the inner plexiform layer (IPL) using phase-sensitive optical coherence tomography (OCT). In the IPL, there are connections between the neuronal cells that are dedicated to the processing of different aspects of the visual information, such as edges in the image or temporal changes. Still, so far, it was not possible to assign functional changes to single cells or cell classes in living humans, which is essential for studying the vision process. One characteristic of signal processing in the IPL is that different aspects of the visual impression are only processed in specific sub-layers (strata). Here, we present an investigation of these functional signals for three different sub-layers in the IPL with the aim to separate different properties of the visual signal processing. Whereas the inner depth-layer, closest to the ganglion cells, exhibits an increase in the optical path length, the outer depth-layer, closest to the bipolar cell layer, exhibits a decrease in the optical path length. Additionally, we found that the central depth is sensitive to temporal changes, showing a maximum response at a stimulation frequency of around 12.5 Hz. The results demonstrate that the signals from different cell types can be distinguished by phase-sensitive OCT.
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Affiliation(s)
- Clara Pfäffle
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany
| | - Hendrik Spahr
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany
| | - Katharina Gercke
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany
| | - Léo Puyo
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany.,Medical Laser Center Lübeck GmbH, Lübeck, Germany
| | - Svea Höhl
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany
| | - David Melenberg
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany
| | - Yoko Miura
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany.,Department of Ophthalmology, University of Lübeck, Lübeck, Germany
| | - Gereon Hüttmann
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany.,Airway Research Center North, Member of the German Center for Lung Research, Grosshansdorf, Germany.,Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, Lübeck, Germany
| | - Dierck Hillmann
- Institute of Biomedical Optic, University of Lübeck, Lübeck, Germany.,Thorlabs GmbH, Lübeck, Germany.,Department of Physics, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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6
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Amplitude Zone Plate in Adaptive Optics: Proposal of the Principle. PHOTONICS 2022. [DOI: 10.3390/photonics9030163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
One of the main elements in hardware-based adaptive optics systems is a deformable mirror. There is quite a large number of such mirrors based on different principles and exhibiting varying performance. They constitute a significant portion of the cost of the final optical devices. In this study, we consider the possibility of replacing an adaptive mirror with the adaptive amplitude Fresnel zone plate, implemented using a digital light-processing matrix. Since such matrices are widely used in mass industry products (light projectors), their costs in large batches are 1–2 orders of magnitude lower than the cost of inexpensive deformable mirrors. Numerical modeling for scanning an optical coherence tomography system with adaptive optics is presented. It is shown that wavefront distortions with high spatial frequencies and large amplitudes can be corrected using an amplitude Fresnel zone plate. The results are compared with piezoelectric and microelectromechanical system mirrors.
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7
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Puyo L, Spahr H, Pfäffle C, Hüttmann G, Hillmann D. Retinal blood flow imaging with combined full-field swept-source optical coherence tomography and laser Doppler holography. OPTICS LETTERS 2022; 47:1198-1201. [PMID: 35230326 DOI: 10.1364/ol.449739] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Full-field swept-source optical coherence tomography (FF-SS-OCT) and laser Doppler holography (LDH) are two holographic imaging techniques presenting unique capabilities for ophthalmology. We report on interlaced FF-SS-OCT and LDH imaging with a single instrument. Effectively, retinal blood flow and pulsation could be quasi-simultaneously monitored. This instrument holds potential for a wide scope of ophthalmic applications.
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8
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Leartprapun N, Adie SG. Resolution-enhanced OCT and expanded framework of information capacity and resolution in coherent imaging. Sci Rep 2021; 11:20541. [PMID: 34654877 PMCID: PMC8521598 DOI: 10.1038/s41598-021-99889-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 09/17/2021] [Indexed: 11/09/2022] Open
Abstract
Spatial resolution in conventional optical microscopy has traditionally been treated as a fixed parameter of the optical system. Here, we present an approach to enhance transverse resolution in beam-scanned optical coherence tomography (OCT) beyond its aberration-free resolution limit, without any modification to the optical system. Based on the theorem of invariance of information capacity, resolution-enhanced (RE)-OCT navigates the exchange of information between resolution and signal-to-noise ratio (SNR) by exploiting efficient noise suppression via coherent averaging and a simple computational bandwidth expansion procedure. We demonstrate a resolution enhancement of 1.5 × relative to the aberration-free limit while maintaining comparable SNR in silicone phantom. We show that RE-OCT can significantly enhance the visualization of fine microstructural features in collagen gel and ex vivo mouse brain. Beyond RE-OCT, our analysis in the spatial-frequency domain leads to an expanded framework of information capacity and resolution in coherent imaging that contributes new implications to the theory of coherent imaging. RE-OCT can be readily implemented on most OCT systems worldwide, immediately unlocking information that is beyond their current imaging capabilities, and so has the potential for widespread impact in the numerous areas in which OCT is utilized, including the basic sciences and translational medicine.
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Affiliation(s)
- Nichaluk Leartprapun
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Steven G Adie
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA.
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9
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Liu S, Xia F, Yang X, Wu M, Bizimana LA, Xu C, Adie SG. Closed-loop wavefront sensing and correction in the mouse brain with computed optical coherence microscopy. BIOMEDICAL OPTICS EXPRESS 2021; 12:4934-4954. [PMID: 34513234 PMCID: PMC8407825 DOI: 10.1364/boe.427979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 05/18/2023]
Abstract
Optical coherence microscopy (OCM) uses interferometric detection to capture the complex optical field with high sensitivity, which enables computational wavefront retrieval using back-scattered light from the sample. Compared to a conventional wavefront sensor, aberration sensing with OCM via computational adaptive optics (CAO) leverages coherence and confocal gating to obtain signals from the focus with less cross-talk from other depths or transverse locations within the field-of-view. Here, we present an investigation of the performance of CAO-based aberration sensing in simulation, bead phantoms, and ex vivo mouse brain tissue. We demonstrate that, due to the influence of the double-pass confocal OCM imaging geometry on the shape of computed pupil functions, computational sensing of high-order aberrations can suffer from signal attenuation in certain spatial-frequency bands and shape similarity with lower order counterparts. However, by sensing and correcting only low-order aberrations (astigmatism, coma, and trefoil), we still successfully corrected tissue-induced aberrations, leading to 3× increase in OCM signal intensity at a depth of ∼0.9 mm in a freshly dissected ex vivo mouse brain.
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Affiliation(s)
- Siyang Liu
- School of Electrical and Computer Engineering, Cornell University, Ithaca, NY 14853, USA
- These authors contribute equally to this work
| | - Fei Xia
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
- These authors contribute equally to this work
| | - Xusan Yang
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
| | - Meiqi Wu
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Laurie A. Bizimana
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Chris Xu
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
| | - Steven G. Adie
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
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10
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Matkivsky V, Moiseev A, Shilyagin P, Rodionov A, Spahr H, Pfäffle C, Hüttmann G, Hillmann D, Gelikonov G. Determination and correction of aberrations in full field optical coherence tomography using phase gradient autofocus by maximizing the likelihood function. JOURNAL OF BIOPHOTONICS 2020; 13:e202000112. [PMID: 32639647 DOI: 10.1002/jbio.202000112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 07/03/2020] [Accepted: 07/04/2020] [Indexed: 06/11/2023]
Abstract
A method for numerical estimation and correction of aberrations of the eye in fundus imaging with optical coherence tomography (OCT) is presented. Aberrations are determined statistically by using the estimate based on likelihood function maximization. The method can be considered as an extension of the phase gradient autofocusing algorithm in synthetic aperture radar imaging to 2D optical aberration correction. The efficacy of the proposed method has been demonstrated in OCT fundus imaging with 6λ aberrations. After correction, single photoreceptors were resolved. It is also shown that wave front distortions with high spatial frequencies can be determined and corrected.
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Affiliation(s)
| | | | | | | | - Hendrik Spahr
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
| | - Clara Pfäffle
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
| | - Gereon Hüttmann
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
- Airway Research Center North (ARCN), Member of the German Center for Lung Research (DZL), Germany
| | - Dierck Hillmann
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany
- Thorlabs GmbH, Lübeck, Germany
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Zhu D, Wang R, Žurauskas M, Pande P, Bi J, Yuan Q, Wang L, Gao Z, Boppart SA. Automated fast computational adaptive optics for optical coherence tomography based on a stochastic parallel gradient descent algorithm. OPTICS EXPRESS 2020; 28:23306-23319. [PMID: 32752329 PMCID: PMC7470677 DOI: 10.1364/oe.395523] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The transverse resolution of optical coherence tomography is decreased by aberrations introduced from optical components and the tested samples. In this paper, an automated fast computational aberration correction method based on a stochastic parallel gradient descent (SPGD) algorithm is proposed for aberration-corrected imaging without adopting extra adaptive optics hardware components. A virtual phase filter constructed through combination of Zernike polynomials is adopted to eliminate the wavefront aberration, and their coefficients are stochastically estimated in parallel through the optimization of the image metrics. The feasibility of the proposed method is validated by a simulated resolution target image, in which the introduced aberration wavefront is estimated accurately and with fast convergence. The computation time for the aberration correction of a 512 × 512 pixel image from 7 terms to 12 terms requires little change, from 2.13 s to 2.35 s. The proposed method is then applied for samples with different scattering properties including a particle-based phantom, ex-vivo rabbit adipose tissue, and in-vivo human retina photoreceptors, respectively. Results indicate that diffraction-limited optical performance is recovered, and the maximum intensity increased nearly 3-fold for out-of-focus plane in particle-based tissue phantom. The SPGD algorithm shows great potential for aberration correction and improved run-time performance compared to our previous Resilient backpropagation (Rprop) algorithm when correcting for complex wavefront distortions. The fast computational aberration correction suggests that after further optimization our method can be integrated for future applications in real-time clinical imaging.
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Affiliation(s)
- Dan Zhu
- School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Ruoyan Wang
- School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Mantas Žurauskas
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Paritosh Pande
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jinci Bi
- School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Qun Yuan
- School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Lingjie Wang
- Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Zhishan Gao
- School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Stephen A. Boppart
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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