1
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Label-free functional and structural imaging of liver microvascular complex in mice by Jones matrix optical coherence tomography. Sci Rep 2021; 11:20054. [PMID: 34625574 PMCID: PMC8501041 DOI: 10.1038/s41598-021-98909-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/16/2021] [Indexed: 12/21/2022] Open
Abstract
We demonstrate label-free imaging of the functional and structural properties of microvascular complex in mice liver. The imaging was performed by a custom-built Jones-matrix based polarization sensitive optical coherence tomography (JM-OCT), which is capable of measuring tissue's attenuation coefficient, birefringence, and tiny tissue dynamics. Two longitudinal studies comprising a healthy liver and an early fibrotic liver model were performed. In the healthy liver, we observed distinctive high dynamics beneath the vessel at the initial time point (0 h) and reappearance of high dynamics at 32-h time point. In the early fibrotic liver model, we observed high dynamics signal that reveals a clear network vascular structure by volume rendering. Longitudinal time-course imaging showed that these high dynamics signals faded and decreased over time.
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2
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Wei S, Kang JU. Stabilizing the phase of swept-source optical coherence tomography by a wrapped Gaussian mixture model. OPTICS LETTERS 2021; 46:2932-2935. [PMID: 34129577 PMCID: PMC9808914 DOI: 10.1364/ol.420898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 05/20/2021] [Indexed: 06/12/2023]
Abstract
The phase of an optical coherence tomography (OCT) signal carries critical information about particle micro-displacements. However, swept-source OCT (SSOCT) suffers from phase instability problems due to trigger jitters from the swept source. In this Letter, a wrapped Gaussian mixture model (WGMM) is proposed to stabilize the phase of SSOCT systems. A closed-form iteration solution of the WGMM is derived using the expectation-maximization algorithm. Necessary approximations are made for real-time graphic processing unit implementation. The performance of the proposed method is demonstrated through ex vivo, in vivo, and flow phantom experiments. The results show the robustness of the method in different application scenarios.
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3
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Liu X, Jiang L, Ke M, Schmetterer L, Barathi VA. Using image data to numerically correct the jitter in polarization depth encoding PS-OCT. OPTICS LETTERS 2021; 46:1692-1695. [PMID: 33793520 DOI: 10.1364/ol.420029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/06/2021] [Indexed: 06/12/2023]
Abstract
In swept source polarization depth encoding polarization sensitive optical coherence tomography (PS-OCT), the laser jitter induces additional noise to the polarization sensitive measurement. In this Letter, we developed a numerical algorithm to correct the jitter phases based on the image data using the Mueller matrix calculus. The algorithm was demonstrated on in vivo retina imaging of a guinea pig with a custom-built PS-OCT system. The performance of the proposed algorithm was almost comparable to the conventional method of using a physical calibration signal. By not requiring a hardware generated calibration signal and k-clock, the proposed algorithm is useful to reduce the complexity and the cost of a polarization depth encoding PS-OCT system.
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4
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Chen TH, Wu YC, Tsai TY, Chueh CB, Huang BH, Huang YP, Tsai MT, Yasuno Y, Lee HC. Effect of A-scan rate and interscan interval on optical coherence angiography. BIOMEDICAL OPTICS EXPRESS 2021; 12:722-736. [PMID: 33680538 PMCID: PMC7901325 DOI: 10.1364/boe.409636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 12/04/2020] [Accepted: 12/22/2020] [Indexed: 05/25/2023]
Abstract
Optical coherence tomography angiography (OCTA) can provide rapid, volumetric, and noninvasive imaging of tissue microvasculature without the requirement of exogenous contrast agents. To investigate how A-scan rate and interscan time affected the contrast and dynamic range of OCTA, we developed a 1.06-µm swept-source OCT system enabling 100-kHz or 200-kHz OCT using two light sources. After system settings were carefully adjusted, almost the same detection sensitivity was achieved between the 100-kHz and 200-kHz modalities. OCTA of ear skin was performed on five mice. We used the variable interscan time analysis algorithm (VISTA) and the designated scanning protocol with OCTA images reconstructed through the correlation mapping method. With a relatively long interscan time (e.g., 12.5 ms vs. 6.25 ms for 200-kHz OCT), OCTA can identify more intricate microvascular networks. OCTA image sets with the same interscan time (e.g., 12.5 ms) were compared. OCTA images acquired with a 100-kHz A-scan rate showed finer microvasculature than did other imaging modalities. We performed quantitative analysis on the contrast from OCTA images reconstructed with different A-scan rates and interscan time intervals in terms of vessel area, total vessel length, and junction density.
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Affiliation(s)
- Ting-Hao Chen
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Chun Wu
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Ting-Yen Tsai
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Chuan-Bor Chueh
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Bo-Huei Huang
- Department of Electrical Engineering, Chang Gung University, Taoyuan 33302, Taiwan
| | - Yin-Peng Huang
- Graduate Institute of Networking and Multimedia, National Taiwan University, Taipei 10617, Taiwan
| | - Meng-Tsan Tsai
- Department of Electrical Engineering, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Neurosurgery, Chang Gung Memorial Hospital, Linkou, Taoyuan 33306, Taiwan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8573, Japan
| | - Hsiang-Chieh Lee
- Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
- Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan
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5
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Zhu L, Miyazawa A, Mukherjee P, Abd El-Sadek I, Oikawa K, Oida D, Yasuno Y. Numerical jitter estimation for swept source optical coherence tomography. BIOMEDICAL IMAGING AND SENSING CONFERENCE 2020 2020. [DOI: 10.1117/12.2573281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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6
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Ferris NG, Cannon TM, Villiger M, Bouma BE, Uribe-Patarroyo N. Forward multiple scattering dominates speckle decorrelation in whole-blood flowmetry using optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2020; 11:1947-1966. [PMID: 32341859 PMCID: PMC7173878 DOI: 10.1364/boe.384539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 03/06/2020] [Accepted: 03/06/2020] [Indexed: 05/22/2023]
Abstract
Quantitative blood flow measurements using optical coherence tomography (OCT) have a wide potential range of medical research and clinical applications. Flowmetry based on the temporal dynamics of the OCT signal may have the ability to measure three-dimensional flow profiles regardless of the flow direction. State-of-the-art models describing the OCT signal temporal statistics are based on dynamic light scattering (DLS), a model which is inherently limited to single scattering regimes. DLS methods continue to be applied to OCT despite the knowledge that red blood cells produce strong forward multiple scattering. Here, we postulate that forward multiple scattering is the primary mechanism causing the rate of speckle-decorrelation derived from data acquired in vivo to deviate from the rate of decorrelation determined in phantom experiments. We also postulate that multiple scattering contributions to decorrelation are only present when the sample exhibits velocity field inhomogeneities larger than the scale of a resolution volume and are thus absent in rigid bulk motion. To test these hypotheses, we performed a systematic study of the effects of forward multiple scattering on OCT signal decorrelation with phantom experiments under physiologically relevant flow conditions and relative bulk motion. Our experimental results confirm that the amount of forward multiple scattering affects the proportionality between lateral flow and decorrelation. We propose that multiply scattered light carries information from different locations in the sample and each location imprints scattering dynamics on the scattered light causing increased decorrelation rates. Our analysis confirms that the detection of forward scattered light inside the vessel lumen causes an increase in the rate of decorrelation which results in an overestimation of blood flow velocities at depths as shallow as 40 µm into whole blood for OCT systems with typical numerical apertures used in retinal imaging.
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Affiliation(s)
- Natalie G. Ferris
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Harvard-MIT Program in Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
- Harvard Graduate Program in Biophysics, Harvard University Cambridge, Massachusetts 02139, USA
| | - Taylor M. Cannon
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Harvard-MIT Program in Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
| | - Martin Villiger
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
| | - Brett E. Bouma
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Harvard-MIT Program in Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
- Institute for Medical Engineering and Science, MIT, Massachusetts 02139, USA
| | - Néstor Uribe-Patarroyo
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
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7
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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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8
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Yamanari M, Uematsu S, Ishihara K, Ikuno Y. Parallel detection of Jones-matrix elements in polarization-sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2019; 10:2318-2336. [PMID: 31149375 PMCID: PMC6524579 DOI: 10.1364/boe.10.002318] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/16/2019] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
The polarization properties of a sample can be characterized using a Jones matrix. To measure the Jones matrix without assumptions of the sample, two different incident states of polarization are usually used. This requirement often causes certain drawbacks in polarization-sensitive optical coherence tomography (PS-OCT), e.g., a decrease in the effective A-scan rate or axial depth range, if a multiplexing scheme is used. Because both the A-scan rate and axial depth range are important for clinical applications, including the imaging of an anterior eye segment, a new PS-OCT method that does not have these drawbacks is desired. Here, we present a parallel-detection approach that maintains the same A-scan rate and axial measurement range as conventional OCT. The interferometer consists of fiber-optic components, most of which are polarization-maintaining components with fast-axis blocking free from polarization management. When a parallel detection is implemented using swept-source OCT (SS-OCT), synchronization between the A-scans and synchronization between the detection channels have critical effects on the Jones-matrix measurement. Because it is difficult to achieve perfect synchronization using only hardware, we developed a solution using a numerical correction with signals from a static mirror. Using the developed system, we demonstrate the imaging of an anterior eye segment from the cornea to the back surface of the crystalline lens.
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Affiliation(s)
- Masahiro Yamanari
- Engineering Department, Tomey Corporation, 2-11-33 Noritakeshinmachi, Nishiku, Nagoya, Aichi, 451-0051, Japan
| | - Sato Uematsu
- Department of Ophthalmology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Kenji Ishihara
- Engineering Department, Tomey Corporation, 2-11-33 Noritakeshinmachi, Nishiku, Nagoya, Aichi, 451-0051, Japan
| | - Yasushi Ikuno
- Ikuno Eye Center, 2-9-10 3F Juso-Higashi, Yodogawaku, Osaka, Osaka, 532-0023, Japan
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Singh SR, Vupparaboina KK, Goud A, Dansingani KK, Chhablani J. Choroidal imaging biomarkers. Surv Ophthalmol 2018; 64:312-333. [PMID: 30496750 DOI: 10.1016/j.survophthal.2018.11.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 11/18/2018] [Accepted: 11/19/2018] [Indexed: 12/22/2022]
Abstract
The choroid is the vascular coat of the eye, and its role has been studied in multiple chorioretinal disorders. Recent advancements in choroidal imaging techniques, including enhanced depth imaging optical coherence tomography, swept source optical coherence tomography, en face optical coherence tomography, and optical coherence tomography angiography have facilitated an in-depth analysis of the choroid. The gradual shift from manual to automated segmentation and binarization methods have led to precise and reproducible measurements of choroidal parameters. These qualitative and quantitative parameters, called choroidal imaging biomarkers, have evolved over the past decade from a simple linear subfoveal choroidal thickness to more complex 3D choroidal reconstruction, thus widening the spectrum encompassing multiple parameters. These biomarkers have provided a better understanding of the pathogenesis, are helpful in diagnostic dilemmas, and, in the future may also help to devise treatment options. The lack of normative data, absence of standardized parameters, and limitations of the imaging techniques, however, have led to ambiguity and difficulty in the interpretation of these variables. We attempt to address these lacunae in the literature and provide a basic understanding of the choroid in both health and disease using these choroidal biomarkers.
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Affiliation(s)
- Sumit Randhir Singh
- Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases, LV Prasad Eye Institute, Hyderabad, India; Retina and Uveitis Department, GMR Varalakshmi Campus, LV Prasad Eye Institute, Visakhapatnam, Andhra Pradesh, India
| | - Kiran Kumar Vupparaboina
- Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases, LV Prasad Eye Institute, Hyderabad, India
| | - Abhilash Goud
- Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases, LV Prasad Eye Institute, Hyderabad, India
| | - Kunal K Dansingani
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Jay Chhablani
- Smt. Kanuri Santhamma Centre for Vitreo-Retinal Diseases, LV Prasad Eye Institute, Hyderabad, India.
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10
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Urs R, Ketterling JA, Yu ACH, Lloyd HO, Yiu BYS, Silverman RH. Ultrasound Imaging and Measurement of Choroidal Blood Flow. Transl Vis Sci Technol 2018; 7:5. [PMID: 30197837 PMCID: PMC6126950 DOI: 10.1167/tvst.7.5.5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 07/30/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose The choroid is a vascular network providing the bulk of the oxygen and nutrient supply to the retina and may play a pivotal role in retinal disease pathogenesis. While optical coherence tomography angiography provides an en face depiction of the choroidal vasculature, it does not reveal flow dynamics. In this report, we describe the use of plane-wave ultrasound to image and characterize choroidal blood flow. Methods We scanned both eyes of 12 healthy subjects in a horizontal plane superior to the optic nerve head using an 18-MHz linear array. Plane-wave data were acquired over 10 transmission angles that were coherently compounded to produce 1000 images/sec for 3 seconds. These data were processed to produce a time series of power Doppler images and spectrograms depicting choroidal flow velocity. Analysis of variance was used to characterize peak systolic, and end diastolic velocities and resistive index, and their variability between scans, eyes, and subjects. Results Power Doppler images showed distinct arterioles within a more diffuse background. Choroidal flow was moderately pulsatile, with peak systolic velocity averaging approximately 10 mm/sec and resistive index of 0.55. There was no significant difference between left and right eyes, but significant variation among subjects. Conclusions Plane-wave ultrasound visualized individual arterioles and allowed measurement of flow over the cardiac cycle. Characterization of choroidal flow dynamics offers a novel means for assessment of the choroid's role in ocular disease. Translational Relevance Characterization of choroidal flow dynamics offers a novel means for assessment of the choroid's role in ocular disease.
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Affiliation(s)
- Raksha Urs
- Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA
| | | | - Alfred C H Yu
- Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Harriet O Lloyd
- Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA
| | - Billy Y S Yiu
- Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Ronald H Silverman
- Department of Ophthalmology, Columbia University Medical Center, New York, NY, USA
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11
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Gao W. Quantitative depth-resolved microcirculation imaging with optical coherence tomography angiography (Part ΙΙ): Microvascular network imaging. Microcirculation 2018; 25:e12376. [DOI: 10.1111/micc.12376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 04/11/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Wanrong Gao
- Department of Optical Engineering; Nanjing University of Science and Technology; Nanjing Jiangsu China
- MIIT Key Laboratory of Advanced Solid Laser; Nanjing University of Science and Technology; Nanjing Jiangsu China
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12
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Ju MJ, Heisler M, Athwal A, Sarunic MV, Jian Y. Effective bidirectional scanning pattern for optical coherence tomography angiography. BIOMEDICAL OPTICS EXPRESS 2018; 9:2336-2350. [PMID: 29760992 PMCID: PMC5946793 DOI: 10.1364/boe.9.002336] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/17/2018] [Accepted: 04/17/2018] [Indexed: 05/18/2023]
Abstract
We demonstrate the utility of a novel scanning method for optical coherence tomography angiography (OCTA). Although raster scanning is commonly used for OCTA imaging, a bidirectional approach would lessen the distortion caused by galvanometer-based scanners as sources continue to increase sweep rates. As shown, a unidirectional raster scan approach has a lower effective scanning time than bidirectional approaches; however, a strictly bidirectional approach causes contrast variation along the B-scan direction due to the non-uniform time interval between B-scans. Therefore, a stepped bidirectional approach is introduced and successfully applied to retinal imaging in normal controls and in a pathological subject with diabetic retinopathy.
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13
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Braaf B, Donner S, Nam AS, Bouma BE, Vakoc BJ. Complex differential variance angiography with noise-bias correction for optical coherence tomography of the retina. BIOMEDICAL OPTICS EXPRESS 2018; 9:486-506. [PMID: 29552388 PMCID: PMC5854053 DOI: 10.1364/boe.9.000486] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/03/2018] [Accepted: 01/03/2018] [Indexed: 05/05/2023]
Abstract
Complex differential variance (CDV) provides phase-sensitive angiographic imaging for optical coherence tomography (OCT) with immunity to phase-instabilities of the imaging system and small-scale axial bulk motion. However, like all angiographic methods, measurement noise can result in erroneous indications of blood flow that confuse the interpretation of angiographic images. In this paper, a modified CDV algorithm that corrects for this noise-bias is presented. This is achieved by normalizing the CDV signal by analytically derived upper and lower limits. The noise-bias corrected CDV algorithm was implemented into an experimental 1 μm wavelength OCT system for retinal imaging that used an eye tracking scanner laser ophthalmoscope at 815 nm for compensation of lateral eye motions. The noise-bias correction improved the CDV imaging of the blood flow in tissue layers with a low signal-to-noise ratio and suppressed false indications of blood flow outside the tissue. In addition, the CDV signal normalization suppressed noise induced by galvanometer scanning errors and small-scale lateral motion. High quality cross-section and motion-corrected en face angiograms of the retina and choroid are presented.
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Affiliation(s)
- Boy Braaf
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Sabine Donner
- Heidelberg Engineering GmbH, Max-Jarecki-Straße 8, 69115 Heidelberg, Germany
| | - Ahhyun S. Nam
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Brett E. Bouma
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
| | - Benjamin J. Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
- Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
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14
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Song S, Xu J, Men S, Shen TT, Wang RK. Robust numerical phase stabilization for long-range swept-source optical coherence tomography. JOURNAL OF BIOPHOTONICS 2017; 10:1398-1410. [PMID: 28485132 PMCID: PMC5831409 DOI: 10.1002/jbio.201700034] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 03/28/2017] [Accepted: 04/03/2017] [Indexed: 05/03/2023]
Abstract
A novel phase stabilization technique is demonstrated with significant improvement in the phase stability of a micro-electromechanical (MEMS) vertical cavity surface-emitting laser (VCSEL) based swept-source optical coherence tomography (SS-OCT) system. Without any requirements of hardware modifications, the new fully numerical phase stabilization technique features high tolerance to acquisition jitter, and significantly reduced budget in computational effort. We demonstrate that when measured with biological tissue, this technique enables a phase sensitivity of 89 mrad in highly scattering tissue, with image ranging distance of up to 12.5 mm at A-line scan rate of 100.3 kHz. We further compare the performances delivered by the phase-stabilization approach with conventional numerical approach for accuracy and computational efficiency. Imaging result of complex signal-based optical coherence tomography angiography (OCTA) and Doppler OCTA indicate that the proposed phase stabilization technique is robust, and efficient in improving the image contrast-to-noise ratio and extending OCTA depth range. The proposed technique can be universally applied to improve phase-stability in generic SS-OCT with different scale of scan rates without a need for special treatment.
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Affiliation(s)
- Shaozhen Song
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
| | - Jingjiang Xu
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
| | - Shaojie Men
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
| | - Tueng T Shen
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
- University of Washington, Department of Ophthalmology, Seattle, WA 98195, USA
| | - Ruikang K Wang
- University of Washington, Department of Bioengineering, Seattle, WA 98195, USA
- University of Washington, Department of Ophthalmology, Seattle, WA 98195, USA
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15
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Ju MJ, Heisler M, Wahl D, Jian Y, Sarunic MV. Multiscale sensorless adaptive optics OCT angiography system for in vivo human retinal imaging. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-10. [PMID: 29094524 DOI: 10.1117/1.jbo.22.12.121703] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 10/05/2017] [Indexed: 05/25/2023]
Abstract
We present a multiscale sensorless adaptive optics (SAO) OCT system capable of imaging retinal structure and vasculature with various fields-of-view (FOV) and resolutions. Using a single deformable mirror and exploiting the polarization properties of light, the SAO-OCT-A was implemented in a compact and easy to operate system. With the ability to adjust the beam diameter at the pupil, retinal imaging was demonstrated at two different numerical apertures with the same system. The general morphological structure and retinal vasculature could be observed with a few tens of micrometer-scale lateral resolution with conventional OCT and OCT-A scanning protocols with a 1.7-mm-diameter beam incident at the pupil and a large FOV (15 deg× 15 deg). Changing the system to a higher numerical aperture with a 5.0-mm-diameter beam incident at the pupil and the SAO aberration correction, the FOV was reduced to 3 deg× 3 deg for fine detailed imaging of morphological structure and microvasculature such as the photoreceptor mosaic and capillaries. Multiscale functional SAO-OCT imaging was performed on four healthy subjects, demonstrating its functionality and potential for clinical utility.
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Affiliation(s)
- Myeong Jin Ju
- Simon Fraser University, Department of Engineering Science, Burnaby, British Columbia, Canada
| | - Morgan Heisler
- Simon Fraser University, Department of Engineering Science, Burnaby, British Columbia, Canada
| | - Daniel Wahl
- Simon Fraser University, Department of Engineering Science, Burnaby, British Columbia, Canada
| | - Yifan Jian
- Simon Fraser University, Department of Engineering Science, Burnaby, British Columbia, Canada
| | - Marinko V Sarunic
- Simon Fraser University, Department of Engineering Science, Burnaby, British Columbia, Canada
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Poddar R, Migacz JV, Schwartz DM, Werner JS, Gorczynska I. Challenges and advantages in wide-field optical coherence tomography angiography imaging of the human retinal and choroidal vasculature at 1.7-MHz A-scan rate. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-14. [PMID: 29090534 PMCID: PMC9062069 DOI: 10.1117/1.jbo.22.10.106018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 10/04/2017] [Indexed: 05/08/2023]
Abstract
We present noninvasive, three-dimensional, depth-resolved imaging of human retinal and choroidal blood circulation with a swept-source optical coherence tomography (OCT) system at 1065-nm center wavelength. Motion contrast OCT imaging was performed with the phase-variance OCT angiography method. A Fourier-domain mode-locked light source was used to enable an imaging rate of 1.7 MHz. We experimentally demonstrate the challenges and advantages of wide-field OCT angiography (OCTA). In the discussion, we consider acquisition time, scanning area, scanning density, and their influence on visualization of selected features of the retinal and choroidal vascular networks. The OCTA imaging was performed with a field of view of 16 deg (5 mm×5 mm) and 30 deg (9 mm×9 mm). Data were presented in en face projections generated from single volumes and in en face projection mosaics generated from up to 4 datasets. OCTA imaging at 1.7 MHz A-scan rate was compared with results obtained from a commercial OCTA instrument and with conventional ophthalmic diagnostic methods: fundus photography, fluorescein, and indocyanine green angiography. Comparison of images obtained from all methods is demonstrated using the same eye of a healthy volunteer. For example, imaging of retinal pathology is presented in three cases of advanced age-related macular degeneration.
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Affiliation(s)
- Raju Poddar
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, Sacramento, California, United States
- Birla Institute of Technology, Department of Bio-Engineering, Mesra, Ranchi, Jharkhand, India
| | - Justin V. Migacz
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, Sacramento, California, United States
| | - Daniel M. Schwartz
- University of California San Francisco, Department of Ophthalmology and Vision Science, San Francisco, California, United States
| | - John S. Werner
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, Sacramento, California, United States
| | - Iwona Gorczynska
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, Sacramento, California, United States
- Nicolaus Copernicus University, Institute of Physics, Toruń, Poland
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17
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Gao SS, Jia Y, Zhang M, Su JP, Liu G, Hwang TS, Bailey ST, Huang D. Optical Coherence Tomography Angiography. Invest Ophthalmol Vis Sci 2017; 57:OCT27-36. [PMID: 27409483 PMCID: PMC4968919 DOI: 10.1167/iovs.15-19043] [Citation(s) in RCA: 239] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Optical coherence tomography angiography (OCTA) is a noninvasive approach that can visualize blood vessels down to the capillary level. With the advent of high-speed OCT and efficient algorithms, practical OCTA of ocular circulation is now available to ophthalmologists. Clinical investigations that used OCTA have increased exponentially in the past few years. This review will cover the history of OCTA and survey its most important clinical applications. The salient problems in the interpretation and analysis of OCTA are described, and recent advances are highlighted.
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18
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Bai Y, Nichols JJ. Advances in thickness measurements and dynamic visualization of the tear film using non-invasive optical approaches. Prog Retin Eye Res 2017; 58:28-44. [DOI: 10.1016/j.preteyeres.2017.02.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/09/2017] [Accepted: 02/20/2017] [Indexed: 12/13/2022]
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19
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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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20
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Chen W, You J, Gu X, Du C, Pan Y. High-speed swept source optical coherence Doppler tomography for deep brain microvascular imaging. Sci Rep 2016; 6:38786. [PMID: 27934907 PMCID: PMC5146972 DOI: 10.1038/srep38786] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 11/14/2016] [Indexed: 11/29/2022] Open
Abstract
Noninvasive microvascular imaging using optical coherence Doppler tomography (ODT) has shown great promise in brain studies; however, high-speed microcirculatory imaging in deep brain remains an open quest. A high-speed 1.3 μm swept-source ODT (SS-ODT) system is reported which was based on a 200 kHz vertical-cavity-surface-emitting laser. Phase errors induced by sweep-trigger desynchronization were effectively reduced by spectral phase encoding and instantaneous correlation among the A-scans. Phantom studies have revealed a significant reduction in phase noise, thus an enhancement of minimally detectable flow down to 268.2 μm/s. Further in vivo validation was performed, in which 3D cerebral-blood-flow (CBF) networks in mouse brain over a large field-of-view (FOV: 8.5 × 5 × 3.2 mm3) was scanned through thinned skull. Results showed that fast flows up to 3 cm/s in pial vessels and minute flows down to 0.3 mm/s in arterioles or venules were readily detectable at depths down to 3.2 mm. Moreover, the dynamic changes of the CBF networks elicited by acute cocaine such as heterogeneous responses in various vessel compartments and at different cortical layers as well as transient ischemic events were tracked, suggesting the potential of SS-ODT for brain functional imaging that requires high flow sensitivity and dynamic range, fast frame rate and a large FOV to cover different brain regions.
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Affiliation(s)
- Wei Chen
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Jiang You
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Xiaochun Gu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA.,Key Laboratory of Developmental Genes and Human Diseases, Department of Anatomy and Neuroscience, School of Medicine, Southeast University, Nanjing 210009, China
| | - Congwu Du
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Yingtian Pan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
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21
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In vivo label-free measurement of lymph flow velocity and volumetric flow rates using Doppler optical coherence tomography. Sci Rep 2016; 6:29035. [PMID: 27377852 PMCID: PMC4932526 DOI: 10.1038/srep29035] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 06/09/2016] [Indexed: 01/08/2023] Open
Abstract
Direct in vivo imaging of lymph flow is key to understanding lymphatic system function in normal and disease states. Optical microscopy techniques provide the resolution required for these measurements, but existing optical techniques for measuring lymph flow require complex protocols and provide limited temporal resolution. Here, we describe a Doppler optical coherence tomography platform that allows direct, label-free quantification of lymph velocity and volumetric flow rates. We overcome the challenge of very low scattering by employing a Doppler algorithm that operates on low signal-to-noise measurements. We show that this technique can measure lymph velocity at sufficiently high temporal resolution to resolve the dynamic pulsatile flow in collecting lymphatic vessels.
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22
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Song S, Wei W, Hsieh BY, Pelivanov I, Shen TT, O'Donnell M, Wang RK. Strategies to improve phase-stability of ultrafast swept source optical coherence tomography for single shot imaging of transient mechanical waves at 16 kHz frame rate. APPLIED PHYSICS LETTERS 2016; 108:191104. [PMID: 27375295 PMCID: PMC4866944 DOI: 10.1063/1.4949469] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 04/25/2016] [Indexed: 05/17/2023]
Abstract
We present single-shot phase-sensitive imaging of propagating mechanical waves within tissue, enabled by an ultrafast optical coherence tomography (OCT) system powered by a 1.628 MHz Fourier domain mode-locked (FDML) swept laser source. We propose a practical strategy for phase-sensitive measurement by comparing the phases between adjacent OCT B-scans, where the B-scan contains a number of A-scans equaling an integer number of FDML buffers. With this approach, we show that micro-strain fields can be mapped with ∼3.0 nm sensitivity at ∼16 000 fps. The system's capabilities are demonstrated on porcine cornea by imaging mechanical wave propagation launched by a pulsed UV laser beam, promising non-contact, real-time, and high-resolution optical coherence elastography.
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Affiliation(s)
- Shaozhen Song
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | - Wei Wei
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | - Bao-Yu Hsieh
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | - Ivan Pelivanov
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
| | | | - Matthew O'Donnell
- Department of Bioengineering, University of Washington , Seattle, Washington 98195, USA
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23
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Makita S, Kurokawa K, Hong YJ, Miura M, Yasuno Y. Noise-immune complex correlation for optical coherence angiography based on standard and Jones matrix optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2016; 7:1525-48. [PMID: 27446673 PMCID: PMC4929659 DOI: 10.1364/boe.7.001525] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/24/2016] [Accepted: 03/24/2016] [Indexed: 05/18/2023]
Abstract
This paper describes a complex correlation mapping algorithm for optical coherence angiography (cmOCA). The proposed algorithm avoids the signal-to-noise ratio dependence and exhibits low noise in vasculature imaging. The complex correlation coefficient of the signals, rather than that of the measured data are estimated, and two-step averaging is introduced. Algorithms of motion artifact removal based on non perfusing tissue detection using correlation are developed. The algorithms are implemented with Jones-matrix OCT. Simultaneous imaging of pigmented tissue and vasculature is also achieved using degree of polarization uniformity imaging with cmOCA. An application of cmOCA to in vivo posterior human eyes is presented to demonstrate that high-contrast images of patients' eyes can be obtained.
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Affiliation(s)
- Shuichi Makita
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
| | - Kazuhiro Kurokawa
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
| | - Young-Joo Hong
- Computational Optics Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573,
Japan
| | - Masahiro Miura
- Department of Ophthalmology, Tokyo Medical University Ibaraki Medical Center, 3-20-1 Chuo, Ami, Inashiki, 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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24
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Makita S, Yasuno Y. In vivo photothermal optical coherence tomography for non-invasive imaging of endogenous absorption agents. BIOMEDICAL OPTICS EXPRESS 2015; 6:1707-25. [PMID: 26137374 PMCID: PMC4467701 DOI: 10.1364/boe.6.001707] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 04/04/2015] [Indexed: 05/19/2023]
Abstract
In vivo photothermal optical coherence tomography (OCT) is demonstrated for cross-sectional imaging of endogenous absorption agents. In order to compromise the sensitivity, imaging speed, and sample motion immunity, a new photothermal detection scheme and phase processing method are developed. Phase-resolved swept-source OCT and fiber-pigtailed laser diode (providing excitation at 406 nm) are combined to construct a high-sensitivity photothermal OCT system. OCT probe and excitation beam coaxially illuminate and are focused on tissues. The photothermal excitation and detection procedure is designed to obtain high efficiency of photothermal effect measurement. The principle and method of depth-resolved cross-sectional imaging of absorption agents with photothermal OCT has been derived. The phase-resolved thermal expansion detection algorithm without motion artifact enables in vivo detection of photothermal effect. Phantom imaging with a blood phantom and in vivo human skin imaging are conducted. A phantom with guinea-pig blood as absorber has been scanned by the photothermal OCT system to prove the concept of cross-sectional absorption agent imaging. An in vivo human skin measurement is also performed with endogenous absorption agents.
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Affiliation(s)
- Shuichi Makita
- Computational Optics Group, University of Tsukuba, Tsukuba, 305-8573,
Japan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tsukuba, 305-8573,
Japan
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25
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Liu G, Tan O, Gao SS, Pechauer AD, Lee B, Lu CD, Fujimoto JG, Huang D. Postprocessing algorithms to minimize fixed-pattern artifact and reduce trigger jitter in swept source optical coherence tomography. OPTICS EXPRESS 2015; 23:9824-34. [PMID: 25969023 PMCID: PMC4523376 DOI: 10.1364/oe.23.009824] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/19/2015] [Accepted: 03/26/2015] [Indexed: 05/19/2023]
Abstract
We propose methods to align interferograms affected by trigger jitter to a reference interferogram based on the information (amplitude/phase) at a fixed-pattern noise location to reduce residual fixed-pattern noise and improve the phase stability of swept source optical coherence tomography (SS-OCT) systems. One proposed method achieved this by introducing a wavenumber shift (k-shift) in the interferograms of interest and searching for the k-shift that minimized the fixed-pattern noise amplitude. The other method calculated the relative k-shift using the phase information at the residual fixed-pattern noise location. Repeating this wavenumber alignment procedure for all A-lines of interest produced fixed-pattern noise free and phase stable OCT images. A system incorporating these correction routines was used for human retina OCT and Doppler OCT imaging. The results from the two methods were compared, and it was found that the intensity-based method provided better results.
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Affiliation(s)
- Gangjun Liu
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Ou Tan
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Simon S. Gao
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Alex D. Pechauer
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - ByungKun Lee
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Chen D. Lu
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - James G. Fujimoto
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
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26
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Miura M, Hong YJ, Yasuno Y, Muramatsu D, Iwasaki T, Goto H. Three-dimensional vascular imaging of proliferative diabetic retinopathy by Doppler optical coherence tomography. Am J Ophthalmol 2015; 159:528-38.e3. [PMID: 25498353 DOI: 10.1016/j.ajo.2014.12.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 11/27/2014] [Accepted: 12/01/2014] [Indexed: 11/15/2022]
Abstract
PURPOSE To evaluate the 3-dimensional architecture of neovascularization in proliferative diabetic retinopathy using Doppler optical coherence tomography (OCT). DESIGN Prospective, nonrandomized clinical trial. METHODS Seventeen eyes of 14 patients with proliferative diabetic retinopathy were prospectively studied. Prototype Doppler OCT was used to evaluate the 3-dimensional vascular architecture at vitreoretinal adhesions. RESULTS Proliferative membranes were detected in all eyes with proliferative diabetic retinopathy by standard OCT images. Doppler OCT images detected blood flow by neovascularization of the disc in 12 eyes and neovascularization elsewhere in 11 eyes. Doppler OCT images showed the 3-dimensional extent of new vessels at various stages of neovascularization, and the extent of new vessels could be clearly confirmed at vitreoretinal adhesions. CONCLUSIONS Doppler OCT is useful for the detection and evaluation of the 3-dimensional vascular structure of neovascularization, and can assist in the noninvasive assessment of proliferative diabetic retinopathy.
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Affiliation(s)
- Masahiro Miura
- Department of Ophthalmology, Tokyo Medical University, Ibaraki Medical Center, Ibaraki, Japan; Department of Ophthalmology, Tokyo Medical University, Tokyo, Japan.
| | - Young-Joo Hong
- Computational Optics Group, University of Tsukuba, Ibaraki, Japan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Ibaraki, Japan
| | - Daisuke Muramatsu
- Department of Ophthalmology, Tokyo Medical University, Ibaraki Medical Center, Ibaraki, Japan; Department of Ophthalmology, Tokyo Medical University, Tokyo, Japan
| | - Takuya Iwasaki
- Department of Ophthalmology, Tokyo Medical University, Ibaraki Medical Center, Ibaraki, Japan; Department of Ophthalmology, Tokyo Medical University, Tokyo, Japan
| | - Hiroshi Goto
- Department of Ophthalmology, Tokyo Medical University, Tokyo, Japan
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27
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Poddar R, Kim DY, Werner JS, Zawadzki RJ. In vivo imaging of human vasculature in the chorioretinal complex using phase-variance contrast method with phase-stabilized 1-μm swept-source optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:126010. [PMID: 25517255 PMCID: PMC4269528 DOI: 10.1117/1.jbo.19.12.126010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 07/17/2014] [Accepted: 10/08/2014] [Indexed: 05/22/2023]
Abstract
We present a noninvasive phase-variance (pv)–based motion contrast method for depth-resolved imaging of the human chorioretinal complex microcirculation with a newly developed phase-stabilized high speed (100-kHz A-scans/s) 1-μm swept- ource optical coherence tomography (SSOCT) system. Compared to our previous spectral-domain (spectrometer based) pv-spectral domain OCT (SDOCT) system, this system has the advantages of higher sensitivity, reduced fringe wash-out for high blood flow speeds and deeper penetration in choroid. High phase stability SSOCT imaging was achieved by using a computationally efficient phase stabilization approach. This process does not require additional calibration hardware and complex numerical procedures. Our phase stabilization method is simple and can be employed in a variety of SSOCT systems. Examples of vasculature in the chorioretinal complex imaged by pv-SSOCT from normal as well as diseased eyes are presented and compared to retinal images of the same subjects acquired with fluorescein angiography and indocyanine green angiography. Observations of morphology of vascular perfusion in chorioretinal complex visualized by our method are listed.
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Affiliation(s)
- Raju Poddar
- University of California Davis, Department of Ophthalmology and Vision Science, Vision Science and Advanced Retinal Imaging Laboratory, Sacramento, California 95817, United States
- Birla Institute of Technology, Department of Biotechnology, Mesra, Ranchi, Jharkhand 835215, India
| | - Dae Yu Kim
- University of California Davis, Department of Ophthalmology and Vision Science, Vision Science and Advanced Retinal Imaging Laboratory, Sacramento, California 95817, United States
- Dankook University, Beckman Laser Institute Korea, Cheonan, Chungnam 330-715, Republic of Korea
| | - John S. Werner
- University of California Davis, Department of Ophthalmology and Vision Science, Vision Science and Advanced Retinal Imaging Laboratory, Sacramento, California 95817, United States
| | - Robert J. Zawadzki
- University of California Davis, Department of Ophthalmology and Vision Science, Vision Science and Advanced Retinal Imaging Laboratory, Sacramento, California 95817, United States
- Address all correspondence to: Robert J. Zawadzki, E-mail:
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28
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Vuong B, Lee AMD, Luk TWH, Sun C, Lam S, Lane P, Yang VXD. High speed, wide velocity dynamic range Doppler optical coherence tomography (Part IV): split spectrum processing in rotary catheter probes. OPTICS EXPRESS 2014; 22:7399-415. [PMID: 24718115 DOI: 10.1364/oe.22.007399] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report a technique for blood flow detection using split spectrum Doppler optical coherence tomography (ssDOCT) that shows improved sensitivity over existing Doppler OCT methods. In ssDOCT, the Doppler signal is averaged over multiple sub-bands of the interferogram, increasing the SNR of the Doppler signal. We explore the parameterization of this technique in terms of number of sub-band windows, width and overlap of the windows, and their effect on the Doppler signal to noise in a flow phantom. Compared to conventional DOCT, ssDOCT processing has increased flow sensitivity. We demonstrate the effectiveness of ssDOCT in-vivo for intravascular flow detection within a porcine carotid artery and for microvascular vessel detection in human pulmonary imaging, using rotary catheter probes. To our knowledge, this is the first report of visualizing in-vivo Doppler flow patterns adjacent to stent struts in the carotid artery.
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29
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Quantitative optical coherence tomography angiography of choroidal neovascularization in age-related macular degeneration. Ophthalmology 2014; 121:1435-44. [PMID: 24679442 DOI: 10.1016/j.ophtha.2014.01.034] [Citation(s) in RCA: 532] [Impact Index Per Article: 53.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 01/04/2014] [Accepted: 01/24/2014] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To detect and quantify choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD) using optical coherence tomography (OCT) angiography. DESIGN Observational, cross-sectional study. PARTICIPANTS A total of 5 normal subjects and 5 subjects with neovascular AMD were included. METHODS A total of 5 eyes with neovascular AMD and 5 normal age-matched controls were scanned by a high-speed (100 000 A-scans/seconds) 1050-nm wavelength swept-source OCT. The macular angiography scan covered a 3 × 3-mm area and comprised 200 × 200 × 8 A-scans acquired in 3.5 seconds. Flow was detected using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm. Motion artifacts were removed by 3-dimensional (3D) orthogonal registration and merging of 4 scans. The 3D angiography was segmented into 3 layers: inner retina (to show retinal vasculature), outer retina (to identify CNV), and choroid. En face maximum projection was used to obtain 2-dimensional angiograms from the 3 layers. The CNV area and flow index were computed from the en face OCT angiogram of the outer retinal layer. Flow (decorrelation) and structural data were combined in composite color angiograms for both en face and cross-sectional views. MAIN OUTCOME MEASURES The CNV angiogram, CNV area, and CNV flow index. RESULTS En face OCT angiograms of CNV showed sizes and locations that were confirmed by fluorescein angiography (FA). Optical coherence tomography angiography provided more distinct vascular network patterns that were less obscured by subretinal hemorrhage. The en face angiograms also showed areas of reduced choroidal flow adjacent to the CNV in all cases and significantly reduced retinal flow in 1 case. Cross-sectional angiograms were used to visualize CNV location relative to the retinal pigment epithelium and Bruch's layer and classify type I and type II CNV. A feeder vessel could be identified in 1 case. Higher flow indexes were associated with larger CNV and type II CNV. CONCLUSIONS Optical coherence tomography angiography provides depth-resolved information and detailed images of CNV in neovascular AMD. Quantitative information regarding CNV flow and area can be obtained. Further studies are needed to assess the role of quantitative OCT angiography in the evaluation and treatment of neovascular AMD.
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30
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Tokayer J, Jia Y, Dhalla AH, Huang D. Blood flow velocity quantification using split-spectrum amplitude-decorrelation angiography with optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2013; 4:1909-24. [PMID: 24156053 PMCID: PMC3799655 DOI: 10.1364/boe.4.001909] [Citation(s) in RCA: 168] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 08/22/2013] [Accepted: 08/27/2013] [Indexed: 05/05/2023]
Abstract
The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was recently developed as a method for imaging blood flow in the human retina without the use of phase information. In order to enable absolute blood velocity quantification, in vitro phantom experiments are performed to correlate the SSADA signal at multiple time scales with various preset velocities. A linear model relating SSADA measurements to absolute flow velocities is derived using the phantom data. The operating range for the linear model is discussed along with its implication for velocity quantification with SSADA in a clinical setting.
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Affiliation(s)
- Jason Tokayer
- Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
| | - Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Al-Hafeez Dhalla
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- New England Eye Center, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
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31
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Ju MJ, Hong YJ, Makita S, Lim Y, Kurokawa K, Duan L, Miura M, Tang S, Yasuno Y. Advanced multi-contrast Jones matrix optical coherence tomography for Doppler and polarization sensitive imaging. OPTICS EXPRESS 2013; 21:19412-36. [PMID: 23938857 DOI: 10.1364/oe.21.019412] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
An advanced version of Jones matrix optical coherence tomography (JMT) is demonstrated for Doppler and polarization sensitive imaging of the posterior eye. JMT is capable of providing localized flow tomography by Doppler detection and investigating the birefringence property of tissue through a three-dimensional (3-D) Jones matrix measurement. Owing to an incident polarization multiplexing scheme based on passive optical components, this system is stable, safe in a clinical environment, and cost effective. Since the properties of this version of JMT provide intrinsic compensation for system imperfection, the system is easy to calibrate. Compared with the previous version of JMT, this advanced JMT achieves a sufficiently long depth measurement range for clinical cases of posterior eye disease. Furthermore, a fine spectral shift compensation method based on the cross-correlation of calibration signals was devised for stabilizing the phase of OCT, which enables a high sensitivity Doppler OCT measurement. In addition, a new theory of JMT which integrates the Jones matrix measurement, Doppler measurement, and scattering measurement is presented. This theory enables a sensitivity-enhanced scattering OCT and high-sensitivity Doppler OCT. These new features enable the application of this system to clinical cases. A healthy subject and a geographic atrophy patient were measured in vivo, and simultaneous imaging of choroidal vasculature and birefringence structures are demonstrated.
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Affiliation(s)
- Myeong Jin Ju
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
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32
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Poddar R, Cortés DE, Werner JS, Mannis MJ, Zawadzki RJ. Three-dimensional anterior segment imaging in patients with type 1 Boston Keratoprosthesis with switchable full depth range swept source optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:86002. [PMID: 23912759 PMCID: PMC3731227 DOI: 10.1117/1.jbo.18.8.086002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 06/17/2013] [Accepted: 06/27/2013] [Indexed: 05/22/2023]
Abstract
A high-speed (100 kHz A-scans/s) complex conjugate resolved 1 μm swept source optical coherence tomography (SS-OCT) system using coherence revival of the light source is suitable for dense three-dimensional (3-D) imaging of the anterior segment. The short acquisition time helps to minimize the influence of motion artifacts. The extended depth range of the SS-OCT system allows topographic analysis of clinically relevant images of the entire depth of the anterior segment of the eye. Patients with the type 1 Boston Keratoprosthesis (KPro) require evaluation of the full anterior segment depth. Current commercially available OCT systems are not suitable for this application due to limited acquisition speed, resolution, and axial imaging range. Moreover, most commonly used research grade and some clinical OCT systems implement a commercially available SS (Axsun) that offers only 3.7 mm imaging range (in air) in its standard configuration. We describe implementation of a common swept laser with built-in k-clock to allow phase stable imaging in both low range and high range, 3.7 and 11.5 mm in air, respectively, without the need to build an external MZI k-clock. As a result, 3-D morphology of the KPro position with respect to the surrounding tissue could be investigated in vivo both at high resolution and with large depth range to achieve noninvasive and precise evaluation of success of the surgical procedure.
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Affiliation(s)
- Raju Poddar
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Sacramento, California 95817
- University of California Davis, Department of Ophthalmology & Vision Science, Sacramento, California 95817
| | - Dennis E. Cortés
- University of California Davis, Department of Ophthalmology & Vision Science, Sacramento, California 95817
| | - John S. Werner
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Sacramento, California 95817
- University of California Davis, Department of Ophthalmology & Vision Science, Sacramento, California 95817
| | - Mark J. Mannis
- University of California Davis, Department of Ophthalmology & Vision Science, Sacramento, California 95817
| | - Robert J. Zawadzki
- University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Sacramento, California 95817
- University of California Davis, Department of Ophthalmology & Vision Science, Sacramento, California 95817
- Address all correspondence to: Robert J. Zawadzki, University of California Davis, Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Sacramento, California 95817. Tel: 916-734-4541; Fax: 916-734-4543; E-mail:
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33
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Duan L, Hong YJ, Yasuno Y. Automated segmentation and characterization of choroidal vessels in high-penetration optical coherence tomography. OPTICS EXPRESS 2013; 21:15787-808. [PMID: 23842365 DOI: 10.1364/oe.21.015787] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
An automated choroidal vessel segmentation and quantification method for high-penetration optical coherence tomography (OCT) was developed for advanced visualization and evaluation of the choroidal vasculature. This method uses scattering OCT volumes for the segmentation of choroidal vessels by using a multi-scale adaptive threshold. The segmented choroidal vessels are then processed by multi-scale morphological analysis to quantify the vessel diameters. The three-dimensional structure and the diameter distribution of the choroidal vasculature were then obtained. The usefulness of the method was then evaluated by analyzing the OCT volumes of normal subjects.
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Affiliation(s)
- Lian Duan
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
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An L, Li P, Lan G, Malchow D, Wang RK. High-resolution 1050 nm spectral domain retinal optical coherence tomography at 120 kHz A-scan rate with 6.1 mm imaging depth. BIOMEDICAL OPTICS EXPRESS 2013; 4:245-59. [PMID: 23411636 PMCID: PMC3567712 DOI: 10.1364/boe.4.000245] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 01/09/2013] [Accepted: 01/09/2013] [Indexed: 05/23/2023]
Abstract
We report a newly developed high speed 1050nm spectral domain optical coherence tomography (SD-OCT) system for imaging posterior segment of human eye. The system is capable of an axial resolution at ~10 µm in air, an imaging depth of 6.1 mm in air, a system sensitivity fall-off at ~6 dB/3mm and an imaging speed of 120,000 A-scans per second. We experimentally demonstrate the system's capability to perform phase-resolved imaging of dynamic blood flow within retina, indicating high phase stability of the SDOCT system. Finally, we show an example that uses this newly developed system to image posterior segment of human eye with a large view of view (10 × 9 mm(2)), providing detailed visualization of microstructural features from anterior retina to posterior choroid. The demonstrated system parameters and imaging performances are comparable to those that a typical 1 µm swept source OCT would deliver for retinal imaging.
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Affiliation(s)
- Lin An
- Department of Bioengineering, University of Washington, Seattle, WA
98195, USA
| | - Peng Li
- Department of Bioengineering, University of Washington, Seattle, WA
98195, USA
| | - Gongpu Lan
- Department of Bioengineering, University of Washington, Seattle, WA
98195, USA
| | - Doug Malchow
- Sensors Unlimited Inc (SUI), Princeton, NJ 08540,
USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, WA
98195, USA
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35
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Kurokawa K, Sasaki K, Makita S, Hong YJ, Yasuno Y. Three-dimensional retinal and choroidal capillary imaging by power Doppler optical coherence angiography with adaptive optics. OPTICS EXPRESS 2012; 20:22796-812. [PMID: 23037430 DOI: 10.1364/oe.20.022796] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Retinal and choroidal vascular imaging is a key to the better understanding and diagnosis of eye diseases. To achieve comprehensive three-dimensional capillary imaging, we used an enhanced vascular imaging technique, so called adaptive optics optical coherence angiography (AO-OCA). AO-OCA enables in vivo high-resolution and high-contrast micro-vascular imaging by detecting Doppler frequency shifts. Using this technique, the retinal and choroidal vasculatures of healthy subjects were imaged. The results show that both intensity and Doppler power images have sufficient contrast to discriminate almost all vasculatures from the static tissue. However, the choriocapillaris, pre-arterioles, and post-venules in the Sattler layer were more contrasted by the Doppler technique. In conclusion, AO-OCA enables three-dimensional capillary imaging, and is especially useful for the detection of the choriocapillaris and choroidal capillary network.
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36
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Li P, Yin X, Shi L, Rugonyi S, Wang RK. In vivo functional imaging of blood flow and wall strain rate in outflow tract of embryonic chick heart using ultrafast spectral domain optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:96006-1. [PMID: 23085907 PMCID: PMC3434623 DOI: 10.1117/1.jbo.17.9.096006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 08/06/2012] [Accepted: 08/08/2012] [Indexed: 05/22/2023]
Abstract
During cardiac development, the cardiac wall and flowing blood are two important cardiac tissues that constantly interact with each other. This dynamic interaction defines appropriate biomechanical environment to which the embryonic heart is exposed. Quantitative assessment of the dynamic parameters of wall tissues and blood flow is required to further our understanding of cardiac development. We report the use of an ultrafast 1310-nm dual-camera spectral domain optical coherence tomography (SDOCT) system to characterize/image, in parallel, the dynamic radial strain rate of the myocardial wall and the Doppler velocity of the underlying flowing blood within an in vivo beating chick embryo. The OCT system operates at 184-kHz line scan rate, providing the flexibility of imaging the fast blood flow and the slow tissue deformation within one scan. The ability to simultaneously characterize tissue motion and blood flow provides a useful approach to better understand cardiac dynamics during early developmental stages.
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Affiliation(s)
- Peng Li
- University of Washington, Department of Bioengineering, Seattle, Washington 98195
| | - Xin Yin
- Oregon Health & Science University, Department of Biomedical Engineering, Portland, Oregon 97239
| | - Liang Shi
- Oregon Health & Science University, Department of Biomedical Engineering, Portland, Oregon 97239
| | - Sandra Rugonyi
- Oregon Health & Science University, Department of Biomedical Engineering, Portland, Oregon 97239
| | - Ruikang K. Wang
- University of Washington, Department of Bioengineering, Seattle, Washington 98195
- Address all correspondence to: Ruikang K. Wang, University of Washington, Department of Bioengineering, Seattle, Washington 98195. E-mail:
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37
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Lim Y, Hong YJ, Duan L, Yamanari M, Yasuno Y. Passive component based multifunctional Jones matrix swept source optical coherence tomography for Doppler and polarization imaging. OPTICS LETTERS 2012; 37:1958-60. [PMID: 22660086 DOI: 10.1364/ol.37.001958] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present a fiber based multifunctional Jones matrix swept source optical coherence tomography (SS-OCT) system for Doppler and polarization imaging. Jones matrix measurement without using active components such as electro-optic modulators is realized by incident polarization multiplexing based on independent delay of two orthogonal polarization states and polarization diversity detection. In addition to polarization sensitivity, this system measures Doppler flow without extra hardware for phase stabilized SS-OCT detection. An eighth-wave plate was measured to demonstrate the polarization detection accuracy. The optic nerve head of a retina was measured in vivo. Detailed vasculature and birefringent structures were investigated simultaneously.
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Affiliation(s)
- Yiheng Lim
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
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