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Hong J, Zhu W, He K, Chen X, Lu J, Li P. Ergodic speckle contrast optical coherence tomography velocimetry of rapid blood flow. OPTICS LETTERS 2024; 49:3600-3603. [PMID: 38950219 DOI: 10.1364/ol.523063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 05/27/2024] [Indexed: 07/03/2024]
Abstract
Visualizing a 3D blood flow velocity field through noninvasive imaging is crucial for analyzing hemodynamic mechanisms in areas prone to disorders. However, traditional correlation-based optical coherence tomography (OCT) velocimetry techniques have a maximum measurable flow velocity depending on the A-line rate. We presented the ergodic speckle contrast OCT (ESCOCT) to break the bottleneck in measuring the rapid blood flow velocity. It achieved a measurement of blood flow velocity ranging from 9.5 to 280 mm/s using a 100 kHz swept-source (SS) OCT based on 100 A-repeats scanning mode. Addressing the non-ergodic problem of temporal OCT signals by integrating more consecutive A-scans, ESCOCT can enable the estimation for lower velocity flows by increasing A-repeats. ESCOCT provided a wide dynamic range with no upper limit on measuring blood flow velocity with an adequate signal-to-noise ratio and improved the sensitivity and accuracy of the hemodynamic assessment.
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2
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Lee M, Bang H, Lee E, Park S, Yoo H, Oh WY, Lee S. Imaging peritoneal blood vessels through optical coherence tomography angiography for laparoscopic surgery. JOURNAL OF BIOPHOTONICS 2024; 17:e202300221. [PMID: 37675626 DOI: 10.1002/jbio.202300221] [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: 06/09/2023] [Revised: 08/20/2023] [Accepted: 09/05/2023] [Indexed: 09/08/2023]
Abstract
Laparoscopic surgery presents challenges in identifying blood vessels due to lack of tactile feedback. The image-guided laparoscopic surgical tool (IGLaST) integrated with optical coherence tomography (OCT) has potential for in vivo blood vessel imaging; however, distinguishing vessels from surrounding tissue remains a challenge. In this study, we propose utilizing an inter-A-line intensity differentiation-based OCT angiography (OCTA) to improve visualization of blood vessels. By evaluating a tissue phantom with varying flow speeds, we optimized the system's blood flow imaging capabilities in terms of minimum detectable flow and contrast-to-noise ratio. In vivo experiments on rat and porcine models, successfully visualized previously unidentified blood vessels and concealed blood flows beneath the 1 mm depth peritoneum. Qualitative comparison of various OCTA algorithms indicated that the intensity differentiation-based algorithm performed best for our application. We believe that implementing IGLaST with OCTA can enhance surgical outcomes and reduce procedure time in laparoscopic surgeries.
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Affiliation(s)
- Minsuk Lee
- Medical Device Development Center, Osong Medical Innovation Foundation, Cheongju, Chungbuk, Korea
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Hyeonjin Bang
- Medical Device Development Center, Osong Medical Innovation Foundation, Cheongju, Chungbuk, Korea
| | - Eungjang Lee
- Medical Device Development Center, Osong Medical Innovation Foundation, Cheongju, Chungbuk, Korea
| | - Sungsoo Park
- Division of Foregut Surgery, Anam Hospital, Korea University College of Medicine, Seoul, Korea
- Department of Surgery, Anam Hospital, Korea University College of Medicine, Seoul, Korea
| | - Hongki Yoo
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Wang-Yuhl Oh
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Seungrag Lee
- Medical Device Development Center, Osong Medical Innovation Foundation, Cheongju, Chungbuk, Korea
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3
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Cheishvili K, Kalkman J. Scanning dynamic light scattering optical coherence tomography for measurement of high omnidirectional flow velocities. OPTICS EXPRESS 2022; 30:23382-23397. [PMID: 36225019 DOI: 10.1364/oe.456139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/16/2022] [Indexed: 06/16/2023]
Abstract
We show scanning dynamic light scattering optical coherence tomography (OCT) omnidirectional flow measurements. Our method improves the velocity measurement limit over conventional correlation-based or phase-resolved Doppler OCT by more than a factor of 2. Our technique is applicable without a-priori knowledge of the flow geometry as our method works both for non-zero Doppler angle and non-ideal scan alignment. In addition, the method improves the particle diffusion coefficient estimation for particles under flow.
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4
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Chen R, Yao L, Liu K, Cao T, Li H, Li P. Improvement of Decorrelation-Based OCT Angiography by an Adaptive Spatial-Temporal Kernel in Monitoring Stimulus-Evoked Hemodynamic Responses. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:4286-4296. [PMID: 32790625 DOI: 10.1109/tmi.2020.3016334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Complex decorrelation-based OCT angiography (OCTA) has the potential for monitoring hemodynamic activities in a label-free, high-resolution, and quantitative manner. To improve the measurement dynamic range and uncertainty of blood flow, an adaptive spatial-temporal (ST) kernel was proposed for decorrelation estimation and it was validated through a theoretical simulation and experimental measurements. The ensemble size in the decorrelation computation was effectively enlarged by collecting samples of the phasor pair in both the spatial and temporal dimensions. The spatial sub-kernel size was adaptively changed to suppress the influence of bulk motion in the temporal dimension by solving a maximum entropy model. Using the flow phantom, it was observed that the decorrelation dynamic range presented an increase of ~49% and the uncertainty exhibited a decrease of ~40% and ~38% in the saturation and background limits, respectively. In monitoring the stimulus-evoked hemodynamic response, the extended dynamic range enabled an improvement of ~180% in the separability between different stimulation modes. Furthermore, the suppressed uncertainty and motion artifacts allowed a reliable temporal analysis of the hemodynamic response. The proposed adaptive ST-kernel will greatly promote the development of decorrelation-based quantitative OCTA in hemodynamic studies.
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5
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Braaf B, Donner S, Uribe-Patarroyo N, Bouma BE, Vakoc BJ. A Neural Network Approach to Quantify Blood Flow from Retinal OCT Intensity Time-Series Measurements. Sci Rep 2020; 10:9611. [PMID: 32541887 PMCID: PMC7295995 DOI: 10.1038/s41598-020-66158-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 05/12/2020] [Indexed: 12/31/2022] Open
Abstract
Many diseases of the eye are associated with alterations in the retinal vasculature that are possibly preceded by undetected changes in blood flow. In this work, a robust blood flow quantification framework is presented based on optical coherence tomography (OCT) angiography imaging and deep learning. The analysis used a forward signal model to simulate OCT blood flow data for training of a neural network (NN). The NN was combined with pre- and post-processing steps to create an analysis framework for measuring flow rates from individual blood vessels. The framework’s accuracy was validated using both blood flow phantoms and human subject imaging, and across flow speed, vessel angle, hematocrit levels, and signal-to-noise ratio. The reported flow rate of the calibrated NN framework was measured to be largely independent of vessel angle, hematocrit levels, and measurement signal-to-noise ratio. In vivo retinal flow rate measurements were self-consistent across vascular branch points, and approximately followed a predicted power-law dependence on the vessel diameter. The presented OCT-based NN flow rate estimation framework addresses the need for a robust, deployable, and label-free quantitative retinal blood flow mapping technique.
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Affiliation(s)
- Boy Braaf
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | | | - Néstor Uribe-Patarroyo
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Brett E Bouma
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Benjamin J Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA. .,Harvard Medical School, Boston, MA, USA.
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6
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Wang T, Pfeiffer T, Daemen J, Mastik F, Wieser W, van der Steen AFW, Huber R, van Soest G. Simultaneous Morphological and Flow Imaging Enabled by Megahertz Intravascular Doppler Optical Coherence Tomography. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:1535-1544. [PMID: 31725370 DOI: 10.1109/tmi.2019.2948258] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We demonstrate three-dimensional intravascular flow imaging compatible with routine clinical image acquisition workflow by means of megahertz (MHz) intravascular Doppler Optical Coherence Tomography (OCT). The OCT system relies on a 1.1 mm diameter motorized imaging catheter and a 1.5 MHz Fourier Domain Mode Locked (FDML) laser. Using a post processing method to compensate the drift of the FDML laser output, we can resolve the Doppler phase shift between two adjoining OCT A-line datasets. By interpretation of the velocity field as measured around the zero phase shift, the flow direction at specific angles can be qualitatively estimated. Imaging experiments were carried out in phantoms, micro channels, and swine coronary artery in vitro at a speed of 600 frames/s. The MHz wavelength sweep rate of the OCT system allows us to directly investigate flow velocity of up to 37.5 cm/s while computationally expensive phase-unwrapping has to be applied to measure such high speed using conventional OCT system. The MHz sweep rate also enables a volumetric Doppler imaging even with a fast pullback at 40 mm/s. We present the first simultaneously recorded 3D morphological images and Doppler flow profiles. Flow pattern estimation and three-dimensional structural reconstruction of entire coronary artery are achieved using a single OCT pullback dataset.
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7
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Uribe-Patarroyo N, Post AL, Ruiz-Lopera S, Faber DJ, Bouma BE. Noise and bias in optical coherence tomography intensity signal decorrelation. OSA CONTINUUM 2020; 3:709-741. [PMID: 34085035 PMCID: PMC8171193 DOI: 10.1364/osac.385431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Functional optical coherence tomography (OCT) imaging based on the decorrelation of the intensity signal has been used extensively in angiography and is finding use in flowmetry and therapy monitoring. In this work, we present a rigorous analysis of the autocorrelation function, introduce the concepts of contrast bias, statistical bias and variability, and identify the optimal definition of the second-order autocorrelation function (ACF) g (2) to improve its estimation from limited data. We benchmark different averaging strategies in reducing statistical bias and variability. We also developed an analytical correction for the noise contributions to the decorrelation of the ACF in OCT that extends the signal-to-noise ratio range in which ACF analysis can be used. We demonstrate the use of all the tools developed in the experimental determination of the lateral speckle size depth dependence in a rotational endoscopic probe with low NA, and we show the ability to more accurately determine the rotational speed of an endoscopic probe to implement NURD detection. We finally present g (2)-based angiography of the finger nailbed, demonstrating the improved results from noise correction and the optimal bias mitigation strategies.
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Affiliation(s)
- Néstor Uribe-Patarroyo
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, MA 02114, USA
| | - Anouk L. Post
- Amsterdam UMC, University of Amsterdam, Department of Biomedical Engineering and Physics, Cancer Center Amsterdam, Amsterdam Cardiovascular Sciences, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- These authors contributed equally to this work and are listed in alphabetical order
| | - Sebastián Ruiz-Lopera
- Applied Optics Group, Universidad EAFIT, Carrera 49 # 7 Sur-50, Medellín, Colombia
- These authors contributed equally to this work and are listed in alphabetical order
| | - Dirk J. Faber
- Amsterdam UMC, University of Amsterdam, Department of Biomedical Engineering and Physics, Cancer Center Amsterdam, Amsterdam Cardiovascular Sciences, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Brett E. Bouma
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, MA 02114, USA
- Institute for Medical Engineering and Science, Massachussets Institute of Technology, Cambridge, MA 02142, USA
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8
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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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9
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Leedumrongwatthanakun S, Thavarungkul P, Kanatharana P, Buranachai C. Wavelet analysis on time-frequency plane of optical coherence tomography: simultaneous signal quality improvement in structural and velocity images. OPTICS LETTERS 2018; 43:3730-3733. [PMID: 30067666 DOI: 10.1364/ol.43.003730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 07/09/2018] [Indexed: 06/08/2023]
Abstract
In this Letter, we utilize one-dimensional wavelet analysis to improve the quality of morphology images and velocity profiles of optical coherence tomography simultaneously, by performing analysis on the complex time-frequency plane of raw interferograms, prior to image construction. The results indicate a robust signal improvement that also preserves accuracy for both morphology and velocity information and has been demonstrated on a variety of samples with diverse flow speeds and morphologies.
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10
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Zhu J, Zhang B, Qi L, Wang L, Yang Q, Zhu Z, Huo T, Chen Z. Quantitative angle-insensitive flow measurement using relative standard deviation OCT. APPLIED PHYSICS LETTERS 2017; 111:181101. [PMID: 29151604 PMCID: PMC5663647 DOI: 10.1063/1.5009200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 10/13/2017] [Indexed: 05/09/2023]
Abstract
Incorporating different data processing methods, optical coherence tomography (OCT) has the ability for high-resolution angiography and quantitative flow velocity measurements. However, OCT angiography cannot provide quantitative information of flow velocities, and the velocity measurement based on Doppler OCT requires the determination of Doppler angles, which is a challenge in a complex vascular network. In this study, we report on a relative standard deviation OCT (RSD-OCT) method which provides both vascular network mapping and quantitative information for flow velocities within a wide range of Doppler angles. The RSD values are angle-insensitive within a wide range of angles, and a nearly linear relationship was found between the RSD values and the flow velocities. The RSD-OCT measurement in a rat cortex shows that it can quantify the blood flow velocities as well as map the vascular network in vivo.
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Affiliation(s)
- Jiang Zhu
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
| | | | - Li Qi
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
| | | | - Qiang Yang
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
| | | | - Tiancheng Huo
- Beckman Laser Institute, University of California, Irvine, Irvine, California 92612, USA
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11
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Fu L, Su Y, Wang Y, Chen L, Li W, Wang H, Li Z, Steve Yao X. Rapid measurement of transversal flow velocity vector with high spatial resolution using speckle decorrelation optical coherence tomography. OPTICS LETTERS 2017; 42:3545-3548. [PMID: 28914896 DOI: 10.1364/ol.42.003545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 08/14/2017] [Indexed: 06/07/2023]
Abstract
We propose and demonstrate a novel method that uses only three sets of B-scans to accurately determine both the direction and the speed of a transversal flow using speckle decorrelation optical coherence tomography. Our tri-scan method has the advantages of high measurement speed, high spatial resolution, and insensitivity to the flow speed. By introducing error maps, we show that the flow angle inaccuracy can be minimized by choosing the measurement result with a lesser error between results obtained from the x- and y-scans. Finally, we demonstrate that the flow angle measurement accuracy can be further improved for the high-speed flows by increasing the speed of the x- and y-scans.
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12
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Grishina OA, Wang S, Larina IV. Speckle variance optical coherence tomography of blood flow in the beating mouse embryonic heart. JOURNAL OF BIOPHOTONICS 2017; 10:735-743. [PMID: 28417585 PMCID: PMC5565627 DOI: 10.1002/jbio.201600293] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 01/25/2017] [Accepted: 01/31/2017] [Indexed: 05/19/2023]
Abstract
Efficient separation of blood and cardiac wall in the beating embryonic heart is essential and critical for experiment-based computational modelling and analysis of early-stage cardiac biomechanics. Although speckle variance optical coherence tomography (SV-OCT) relying on calculation of intensity variance over consecutively acquired frames is a powerful approach for segmentation of fluid flow from static tissue, application of this method in the beating embryonic heart remains challenging because moving structures generate SV signal indistinguishable from the blood. Here, we demonstrate a modified four-dimensional SV-OCT approach that effectively separates the blood flow from the dynamic heart wall in the beating mouse embryonic heart. The method takes advantage of the periodic motion of the cardiac wall and is based on calculation of the SV signal over the frames corresponding to the same phase of the heartbeat cycle. Through comparison with Doppler OCT imaging, we validate this speckle-based approach and show advantages in its insensitiveness to the flow direction and velocity as well as reduced influence from the heart wall movement. This approach has a potential in variety of applications relying on visualization and segmentation of blood flow in periodically moving structures, such as mechanical simulation studies and finite element modelling. Picture: Four-dimensional speckle variance OCT imaging shows the blood flow inside the beating heart of an E8.5 mouse embryo.
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Affiliation(s)
| | | | - Irina V. Larina
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas, 77030, USA
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13
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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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14
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Choi WJ, Li Y, Qin W, Wang RK. Cerebral capillary velocimetry based on temporal OCT speckle contrast. BIOMEDICAL OPTICS EXPRESS 2016; 7:4859-4873. [PMID: 28018711 PMCID: PMC5175537 DOI: 10.1364/boe.7.004859] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 10/21/2016] [Accepted: 10/27/2016] [Indexed: 05/15/2023]
Abstract
We propose a new optical coherence tomography (OCT) based method to measure red blood cell (RBC) velocities of single capillaries in the cortex of rodent brain. This OCT capillary velocimetry exploits quantitative laser speckle contrast analysis to estimate speckle decorrelation rate from the measured temporal OCT speckle signals, which is related to microcirculatory flow velocity. We hypothesize that OCT signal due to sub-surface capillary flow can be treated as the speckle signal in the single scattering regime and thus its time scale of speckle fluctuations can be subjected to single scattering laser speckle contrast analysis to derive characteristic decorrelation time. To validate this hypothesis, OCT measurements are conducted on a single capillary flow phantom operating at preset velocities, in which M-mode B-frames are acquired using a high-speed OCT system. Analysis is then performed on the time-varying OCT signals extracted at the capillary flow, exhibiting a typical inverse relationship between the estimated decorrelation time and absolute RBC velocity, which is then used to deduce the capillary velocities. We apply the method to in vivo measurements of mouse brain, demonstrating that the proposed approach provides additional useful information in the quantitative assessment of capillary hemodynamics, complementary to that of OCT angiography.
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15
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Uribe-Patarroyo N, Bouma BE. Velocity gradients in spatially resolved laser Doppler flowmetry and dynamic light scattering with confocal and coherence gating. Phys Rev E 2016; 94:022604. [PMID: 27627357 PMCID: PMC5059111 DOI: 10.1103/physreve.94.022604] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Indexed: 11/07/2022]
Abstract
Dynamic light scattering (DLS) is widely used to characterize diffusive motion to obtain precise information on colloidal suspensions by calculating the autocorrelation function of the signal from a heterodyne optical system. DLS can also be used to determine the flow velocity field in systems that exhibit mass transport by incorporating the effects of the deterministic motion of scatterers on the autocorrelation function, a technique commonly known as laser Doppler flowmetry. DLS measurements can be localized with confocal and coherence gating techniques such as confocal microscopy and optical coherence tomography, thereby enabling the determination of the spatially resolved velocity field in three dimensions. It has been thought that spatially resolved DLS can determine the axial velocity as well as the lateral speed in a single measurement. We demonstrate, however, that gradients in the axial velocity of scatterers exert a fundamental influence on the autocorrelation function even in well-behaved, nonturbulent flow. By obtaining the explicit functional relation between axial-velocity gradients and the autocorrelation function, we show that the velocity field and its derivatives are intimately related and their contributions cannot be separated. Therefore, a single DLS measurement cannot univocally determine the velocity field. Our extended theoretical model was found to be in good agreement with experimental measurements.
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Affiliation(s)
- Néstor Uribe-Patarroyo
- 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 and Harvard-MIT Program in Health Sciences and Technology, Cambridge, Massachusetts 02139, USA
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16
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Son T, Wang B, Thapa D, Lu Y, Chen Y, Cao D, Yao X. Optical coherence tomography angiography of stimulus evoked hemodynamic responses in individual retinal layers. BIOMEDICAL OPTICS EXPRESS 2016; 7:3151-62. [PMID: 27570706 PMCID: PMC4986822 DOI: 10.1364/boe.7.003151] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/08/2016] [Accepted: 06/10/2016] [Indexed: 05/05/2023]
Abstract
Blood flow changes are highly related to neural activities in the retina. It has been reported that neural activity increases when flickering light stimulation of the retina is used. It is known that blood flow changes with flickering light stimulation can be altered in patients with vascular disease and that measurement of flicker-induced vasodilatation is an easily applied tool for monitoring functional microvascular alterations. However, details of distortions in retinal neurovascular coupling associated with major eye diseases are not well understood due to the limitation of existing techniques. In this study, flickering light stimulation was applied to mouse retinas to investigate stimulus evoked hemodynamic responses in individual retinal layers. A spectral domain optical coherence tomography (OCT) angiography imaging system was developed to provide dynamic mapping of hemodynamic responses in the ganglion cell layer, inner plexiform layer, outer plexiform layer and choroid layer before, during and after flickering light stimulation. Experimental results showed hemodynamic responses with different magnitudes and time courses in individual retinal layers. We anticipate that the dynamic OCT angiography of stimulus evoked hemodynamic responses can greatly foster the study of neurovascular coupling mechanisms in the retina, promising new biomarkers for retinal disease detection and diagnosis.
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Affiliation(s)
- Taeyoon Son
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Benquan Wang
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Damber Thapa
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Yiming Lu
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Yanjun Chen
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Dingcai Cao
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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17
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Zhou KC, Huang BK, Tagare H, Choma MA. Improved velocimetry in optical coherence tomography using Bayesian analysis. BIOMEDICAL OPTICS EXPRESS 2015; 6:4796-811. [PMID: 26713195 PMCID: PMC4679255 DOI: 10.1364/boe.6.004796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 10/14/2015] [Accepted: 10/20/2015] [Indexed: 05/10/2023]
Abstract
OCT is a popular cross-sectional microscale imaging modality in medicine and biology. While structural imaging using OCT is a mature technology in many respects, flow and motion estimation using OCT remains an intense area of research. In particular, there is keen interest in maximizing information extraction from the complex-valued OCT signal. Here, we introduce a Bayesian framework into the data workflow in OCT-based velocimetry. We demonstrate that using prior information in this Bayesian framework can significantly improve velocity estimate precision in a correlation-based, model-based framework for Doppler and transverse velocimetry. We show results in calibrated flow phantoms as well as in vivo in a Drosophila melanogaster (fruit fly) heart. Thus, our work improves upon the current approaches in terms of improved information extraction from the complex-valued OCT signal.
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Affiliation(s)
- Kevin C. Zhou
- Department of Biomedical Engineering, Yale University, 55 Prospect St., New Haven, Connecticut 06520,
USA
| | - Brendan K. Huang
- Department of Biomedical Engineering, Yale University, 55 Prospect St., New Haven, Connecticut 06520,
USA
| | - Hemant Tagare
- Department of Biomedical Engineering, Yale University, 55 Prospect St., New Haven, Connecticut 06520,
USA
- Department of Diagnostic Radiology, Yale University, 333 Cedar St., New Haven, Connecticut 06510,
USA
- Department of Electrical Engineering, Yale University, 10 Hillhouse Ave., New Haven, Connecticut 06520,
USA
| | - Michael A. Choma
- Department of Biomedical Engineering, Yale University, 55 Prospect St., New Haven, Connecticut 06520,
USA
- Department of Diagnostic Radiology, Yale University, 333 Cedar St., New Haven, Connecticut 06510,
USA
- Department of Pediatrics, Yale University, 333 Cedar St., New Haven, Connecticut 06510,
USA
- Department of Applied Physics, Yale University, P.O. Box 208267, New Haven, Connecticut 06520,
USA
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18
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Wang Y, Wang Y, Akansu A, Belfield KD, Hubbi B, Liu X. Robust motion tracking based on adaptive speckle decorrelation analysis of OCT signal. BIOMEDICAL OPTICS EXPRESS 2015; 6:4302-16. [PMID: 26600996 PMCID: PMC4646540 DOI: 10.1364/boe.6.004302] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 09/22/2015] [Accepted: 09/24/2015] [Indexed: 05/19/2023]
Abstract
Speckle decorrelation analysis of optical coherence tomography (OCT) signal has been used in motion tracking. In our previous study, we demonstrated that cross-correlation coefficient (XCC) between Ascans had an explicit functional dependency on the magnitude of lateral displacement (δx). In this study, we evaluated the sensitivity of speckle motion tracking using the derivative of function XCC(δx) on variable δx. We demonstrated the magnitude of the derivative can be maximized. In other words, the sensitivity of OCT speckle tracking can be optimized by using signals with appropriate amount of decorrelation for XCC calculation. Based on this finding, we developed an adaptive speckle decorrelation analysis strategy to achieve motion tracking with optimized sensitivity. Briefly, we used subsequently acquired Ascans and Ascans obtained with larger time intervals to obtain multiple values of XCC and chose the XCC value that maximized motion tracking sensitivity for displacement calculation. Instantaneous motion speed can be calculated by dividing the obtained displacement with time interval between Ascans involved in XCC calculation. We implemented the above-described algorithm in real-time using graphic processing unit (GPU) and demonstrated its effectiveness in reconstructing distortion-free OCT images using data obtained from a manually scanned OCT probe. The adaptive speckle tracking method was validated in manually scanned OCT imaging, on phantom as well as in vivo skin tissue.
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Affiliation(s)
- Yuewen Wang
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Yahui Wang
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Ali Akansu
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Kevin D. Belfield
- College of Science and Liberal Arts, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Basil Hubbi
- Department of Radiology, New Jersey Medical School, Newark, NJ, 07103, USA
| | - Xuan Liu
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA
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19
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Sakadžić S, Lee J, Boas DA, Ayata C. High-resolution in vivo optical imaging of stroke injury and repair. Brain Res 2015; 1623:174-92. [PMID: 25960347 PMCID: PMC4569527 DOI: 10.1016/j.brainres.2015.04.044] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 12/15/2022]
Abstract
Central nervous system (CNS) function and dysfunction are best understood within a framework of interactions between neuronal, glial and vascular compartments comprising the neurovascular unit (NVU), all of which contribute to stroke-induced CNS injury, plasticity, repair, and recovery. Recent advances in in vivo optical microscopy have enabled us to observe and interrogate cells and their processes with high spatial resolution in real time and in their natural environment deep in the brain tissue. Here, we review some of these state-of-the-art imaging techniques with an emphasis on imaging the interactions among the constituents of the NVU during ischemic injury and repair in small animal models. This article is part of a Special Issue entitled SI: Cell Interactions In Stroke.
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Affiliation(s)
- Sava Sakadžić
- Optics Division, MHG/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
| | - Jonghwan Lee
- Optics Division, MHG/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - David A Boas
- Optics Division, MHG/MIT/HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA; Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
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20
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Kang D, Wang A, Volgger V, Chen Z, Wong BJF. Spatiotemporal correlation of optical coherence tomography in-vivo images of rabbit airway for the diagnosis of edema. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:076015. [PMID: 26222962 PMCID: PMC4518273 DOI: 10.1117/1.jbo.20.7.076015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 06/30/2015] [Indexed: 03/28/2024]
Abstract
Detection of an early stage of subglottic edema is vital for airway management and prevention of stenosis, a life-threatening condition in critically ill neonates. As an observer for the task of diagnosing edema in vivo, we investigated spatiotemporal correlation (STC) of full-range optical coherence tomography (OCT) images acquired in the rabbit airway with experimentally simulated edema. Operating the STC observer on OCT images generates STC coefficients as test statistics for the statistical decision task. Resulting from this, the receiver operating characteristic (ROC) curves for the diagnosis of airway edema with full-range OCT in-vivo images were extracted and areas under ROC curves were calculated. These statistically quantified results demonstrated the potential clinical feasibility of the STC method as a means to identify early airway edema.
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Affiliation(s)
- DongYel Kang
- Hanbat National University, College of Engineering, School of Basic Sciences, 125 DogSeoDaeRo, YuSeong-Gu, Daejeon 305-719, Republic of Korea
| | - Alex Wang
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California 92617, United States
| | - Veronika Volgger
- Ludwig-Maximilians-University Munich, Department of Otolaryngology-Head and Neck Surgery, Marchioninistr. 15, Munich 81377, Germany
| | - Zhongping Chen
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California 92617, United States
- University of California Irvine, Department of Biomedical Engineering, Irvine, California 92617, United States
- University of California Irvine, Department of Otolaryngology-Head and Neck Surgery, Irvine, California 92617, United States
| | - Brian J. F. Wong
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California 92617, United States
- University of California Irvine, Department of Biomedical Engineering, Irvine, California 92617, United States
- University of California Irvine, Department of Otolaryngology-Head and Neck Surgery, Irvine, California 92617, United States
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21
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Joseph S, Adnan A, Subhash HM, Leahy M, Adlam D. Developing cross-correlation as a method for microvessel imaging using clinical intravascular optical coherence tomography systems. BIOMEDICAL OPTICS EXPRESS 2015; 6:668-89. [PMID: 25798295 PMCID: PMC4361425 DOI: 10.1364/boe.6.000668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/17/2015] [Accepted: 01/21/2015] [Indexed: 06/04/2023]
Abstract
Current clinical intravascular optical coherence tomography (IV-OCT) imaging systems have limited in-vivo flow imaging capability because of non-uniform catheter rotation and inadequate A-line scan density. Thus any flow-localisation method that seeks to identify sites of variation within the OCT image data-sets, whether that is in amplitude or phase, produces non-representative correlation (or variance) maps. In this study, both mean and the variation within a set of cross-correlation maps, for static OCT imaging was used to differentiate flow from nonflow regions. Variation was quantified by use of standard deviation. The advantage of this approach is its ability to image flow, even in the presence of motion artifacts. The ability of this technique to suppress noise and capture flow maps was demonstrated by imaging microflow in an ex-vivo porcine coronary artery model, by nailfold capillary imaging and in-vivo microvessel imaging from within the human coronary sinus.
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Affiliation(s)
- Shiju Joseph
- Department of Cardiovascular Sciences, University of Leicester, Leicester,
United Kingdom
- Tissue optics and microcirculation imaging Facility, National University of Ireland, Galway,
Ireland
| | - Asif Adnan
- Department of Cardiovascular Sciences, University of Leicester, Leicester,
United Kingdom
| | - Hrebesh M. Subhash
- Tissue optics and microcirculation imaging Facility, National University of Ireland, Galway,
Ireland
| | - Martin Leahy
- Tissue optics and microcirculation imaging Facility, National University of Ireland, Galway,
Ireland
| | - David Adlam
- Department of Cardiovascular Sciences, University of Leicester, Leicester,
United Kingdom
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22
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Liu X, Kirby M, Zhao F. Motion analysis and removal in intensity variation based OCT angiography. BIOMEDICAL OPTICS EXPRESS 2014; 5:3833-47. [PMID: 25426314 PMCID: PMC4242021 DOI: 10.1364/boe.5.003833] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 09/18/2014] [Accepted: 09/19/2014] [Indexed: 05/18/2023]
Abstract
In this work, we investigated how bulk motion degraded the quality of optical coherence tomography (OCT) angiography that was obtained through calculating interframe signal variation, i.e., interframe signal variation based optical coherence angiography (isvOCA). We demonstrated theoretically and experimentally that the spatial average of isvOCA signal had an explicit functional dependency on bulk motion. Our result suggested that the bulk motion could lead to an increased background in angiography image. Based on our motion analysis, we proposed to reduce image artifact induced by transient bulk motion in isvOCA through adaptive thresholding. The motion artifact reduced angiography was demonstrated in a 1.3μm spectral domain OCT system. We implemented signal processing using graphic processing unit for real-time imaging and conducted in vivo microvasculature imaging on human skin. Our results clearly showed that the adaptive thresholding method was highly effective in the motion artifact removal for OCT angiography.
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Affiliation(s)
- Xuan Liu
- Department of Electrical and Computer Engineering, New Jersey Institute of Technology, 323 Dr Martin Luther King Jr Blvd, Newark, NJ USA
| | - Mitchell Kirby
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI USA
| | - Feng Zhao
- Department of Biomedical Engineering, Michigan Technological University, 1400 Townsend Dr., Houghton, MI USA
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23
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Uribe-Patarroyo N, Villiger M, Bouma BE. Quantitative technique for robust and noise-tolerant speed measurements based on speckle decorrelation in optical coherence tomography. OPTICS EXPRESS 2014; 22:24411-29. [PMID: 25322018 PMCID: PMC4247190 DOI: 10.1364/oe.22.024411] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 08/27/2014] [Indexed: 05/18/2023]
Abstract
Intensity-based techniques in optical coherence tomography (OCT), such as those based on speckle decorrelation, have attracted great interest for biomedical and industrial applications requiring speed or flow information. In this work we present a rigorous analysis of the effects of noise on speckle decorrelation, demonstrate that these effects frustrate accurate speed quantitation, and propose new techniques that achieve quantitative and repeatable measurements. First, we derive the effect of background noise on the speckle autocorrelation function, finding two detrimental effects of noise. We propose a new autocorrelation function that is immune to the main effect of background noise and permits quantitative measurements at high and moderate signal-to-noise ratios. At the same time, this autocorrelation function is able to provide motion contrast information that accurately identifies areas with movement, similar to speckle variance techniques. In order to extend the SNR range, we quantify and model the second effect of background noise on the autocorrelation function through a calibration. By obtaining an explicit expression for the decorrelation time as a function of speed and diffusion, we show how to use our autocorrelation function and noise calibration to measure a flowing liquid. We obtain accurate results, which are validated by Doppler OCT, and demonstrate a very high dynamic range (> 600 mm/s) compared to that of Doppler OCT (±25 mm/s). We also derive the behavior for low flows, and show that there is an inherent non-linearity in speed measurements in the presence of diffusion due to statistical fluctuations of speckle. Our technique allows quantitative and robust measurements of speeds using OCT, and this work delimits precisely the conditions in which it is accurate.
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Affiliation(s)
- Néstor Uribe-Patarroyo
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114,
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
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24
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Cheng KHY, Mariampillai A, Lee KKC, Vuong B, Luk TWH, Ramjist J, Curtis A, Jakubovic H, Kertes P, Letarte M, Faughnan ME, HHT Investigator Group BVMC, Yang VXD. Histogram flow mapping with optical coherence tomography for in vivo skin angiography of hereditary hemorrhagic telangiectasia. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:086015. [PMID: 25140883 PMCID: PMC4407667 DOI: 10.1117/1.jbo.19.8.086015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 07/09/2014] [Accepted: 07/21/2014] [Indexed: 05/24/2023]
Abstract
Speckle statistics of flowing scatterers have been well documented in the literature. Speckle variance optical coherence tomography exploits the large variance values of intensity changes in time caused mainly by the random backscattering of light resulting from translational activity of red blood cells to map out the microvascular networks. A method to map out the microvasculature malformation of skin based on the time-domain histograms of individual pixels is presented with results obtained from both normal skin and skin containing vascular malformation. Results demonstrated that this method can potentially map out deeper blood vessels and enhance the visualization of microvasculature in low signal regions, while being resistant against motion (e.g., patient tremor or internal reflex movements). The overall results are manifested as more uniform en face projection maps of microvessels. Potential applications include clinical imaging of skin vascular abnormalities and wide-field skin angiography for the study of complex vascular networks.
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Affiliation(s)
- Kyle H. Y. Cheng
- University of Toronto, Edward S. Rogers Sr. Department of Electrical and Computer Engineering, Toronto M5S 3G4, Canada
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
| | - Adrian Mariampillai
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
- Ryerson University, Department of Electrical and Computer Engineering, Toronto M5B 2K3, Canada
| | - Kenneth K. C. Lee
- University of Toronto, Edward S. Rogers Sr. Department of Electrical and Computer Engineering, Toronto M5S 3G4, Canada
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
| | - Barry Vuong
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
- Ryerson University, Department of Electrical and Computer Engineering, Toronto M5B 2K3, Canada
| | - Timothy W. H. Luk
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
- Ryerson University, Department of Electrical and Computer Engineering, Toronto M5B 2K3, Canada
| | - Joel Ramjist
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
| | - Anne Curtis
- University of Toronto, Department of Medicine, Toronto M5S 1A8, Canada
| | - Henry Jakubovic
- University of Toronto, St. Michael’s Hospital, Dermatopathology, Department of Laboratory Medicine, Toronto M5B 1W8, Canada
| | - Peter Kertes
- University of Toronto, John and Liz Tory Eye Centre, Sunnybrook Health Sciences Centre, Department of Ophthalmology and Vision Sciences, Toronto M4N 3M5, Canada
| | - Michelle Letarte
- SickKids Research Institute, Hospital for Sick Children, Toronto M5G 1X8, Canada
- University of Toronto, Department of Immunology, Toronto M5S 1A8, Canada
| | - Marie E. Faughnan
- University of Toronto, St. Michael’s Hospital, Toronto HHT Program, Division of Respirology, Department of Medicine, Toronto M5B 1W8, Canada
- St. Michaels Hospital, Li Ka Shing Knowledge Institute, Toronto M5B 1W8, Canada
| | | | - Victor X. D. Yang
- Ryerson University, Biophotonics and Bioengineering Laboratory, Toronto M5B 2K3, Canada
- Ryerson University, Department of Electrical and Computer Engineering, Toronto M5B 2K3, Canada
- Sunnybrook Health Science Centre, Division of Neurosurgery, Toronto M4N 3M5, Canada
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25
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Lee J, Jiang JY, Wu W, Lesage F, Boas DA. Statistical intensity variation analysis for rapid volumetric imaging of capillary network flux. BIOMEDICAL OPTICS EXPRESS 2014; 5:1160-72. [PMID: 24761298 PMCID: PMC3986000 DOI: 10.1364/boe.5.001160] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 02/12/2014] [Accepted: 02/19/2014] [Indexed: 05/18/2023]
Abstract
We present a novel optical coherence tomography (OCT)-based technique for rapid volumetric imaging of red blood cell (RBC) flux in capillary networks. Previously we reported that OCT can capture individual RBC passage within a capillary, where the OCT intensity signal at a voxel fluctuates when an RBC passes the voxel. Based on this finding, we defined a metric of statistical intensity variation (SIV) and validated that the mean SIV is proportional to the RBC flux [RBC/s] through simulations and measurements. From rapidly scanned volume data, we used Hessian matrix analysis to vectorize a segment path of each capillary and estimate its flux from the mean of the SIVs gathered along the path. Repeating this process led to a 3D flux map of the capillary network. The present technique enabled us to trace the RBC flux changes over hundreds of capillaries with a temporal resolution of ~1 s during functional activation.
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Affiliation(s)
- Jonghwan Lee
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
| | | | - Weicheng Wu
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
| | - Frederic Lesage
- Department of Electrical Engineering, Polytechnique Montreal, Canada
| | - David A. Boas
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA
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26
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Huang BK, Choma MA. Resolving directional ambiguity in dynamic light scattering-based transverse motion velocimetry in optical coherence tomography. OPTICS LETTERS 2014; 39:521-4. [PMID: 24487855 PMCID: PMC4174353 DOI: 10.1364/ol.39.000521] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Dynamic light scattering-based optical coherence tomography approaches have been successfully implemented to measure total transverse (xy) flow speed, but are unable to resolve directionality. We propose a method to extract directional velocity in the transverse plane by introducing a variable scan bias to our system. Our velocity estimation, which yields the directional velocity component along the scan axis, is also independent of any point-spread function calibration. By combining our approach with Doppler velocimetry, we show three-component velocimetry that is appropriately dependent on latitudinal and longitudinal angle.
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Affiliation(s)
- Brendan K. Huang
- Deptartment of Biomedical Engineering, Yale University, 300 Cedar St., PO Box 208043, New Haven, CT USA 06520
| | - Michael A. Choma
- Deptartment of Biomedical Engineering, Yale University, 300 Cedar St., PO Box 208043, New Haven, CT USA 06520
- Dept. of Diagnostic Radiology, Yale University, 300 Cedar St., PO Box 208043, New Haven, CT USA 06520
- Dept. of Pediatrics, Yale University, 300 Cedar St., PO Box 208043, New Haven, CT USA 06520
- Corresponding author:
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27
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Huang Y, Ibrahim Z, Tong D, Zhu S, Mao Q, Pang J, Andree Lee WP, Brandacher G, Kang JU. Microvascular anastomosis guidance and evaluation using real-time three-dimensional Fourier-domain Doppler optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:111404. [PMID: 23856833 PMCID: PMC3710915 DOI: 10.1117/1.jbo.18.11.111404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Vascular and microvascular anastomoses are critical components of reconstructive microsurgery, vascular surgery, and transplant surgery. Intraoperative surgical guidance using a surgical imaging modality that provides an in-depth view and three-dimensional (3-D) imaging can potentially improve outcome following both conventional and innovative anastomosis techniques. Objective postoperative imaging of the anastomosed vessel can potentially improve the salvage rate when combined with other clinical assessment tools, such as capillary refill, temperature, blanching, and skin turgor. Compared to other contemporary postoperative monitoring modalities--computed tomography angiograms, magnetic resonance (MR) angiograms, and ultrasound Doppler--optical coherence tomography (OCT) is a noninvasive high-resolution (micron-level), high-speed, 3-D imaging modality that has been adopted widely in biomedical and clinical applications. For the first time, to the best of our knowledge, the feasibility of real-time 3-D phase-resolved Doppler OCT (PRDOCT) as an assisted intra- and postoperative imaging modality for microvascular anastomosis of rodent femoral vessels is demonstrated, which will provide new insights and a potential breakthrough to microvascular and supermicrovascular surgery.
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Affiliation(s)
- Yong Huang
- Johns Hopkins University, Department of Electrical and Computer Engineering, 3400 N. Charles Street, Baltimore, MD 21218, USA.
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