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Tan KH, Ang JLY, Yong ASK, Lim SZE, Kng JSJ, Liang K. Non-destructive viability assessment of cancer cell spheroids using dynamic optical coherence tomography with trypan blue validation. BIOMEDICAL OPTICS EXPRESS 2024; 15:6370-6383. [PMID: 39553864 PMCID: PMC11563335 DOI: 10.1364/boe.533339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 08/22/2024] [Accepted: 09/05/2024] [Indexed: 11/19/2024]
Abstract
3D cell cultures are widely used in biomedical research for the recapitulation of in vivo microenvironments. Viability assessment and monitoring of these intricate conformations remain an open problem as standard cell viability protocols based on colorimetry or microscopy are not directly applicable to intact 3D samples. Optical coherence tomography (OCT) has been explored extensively for subsurface structural and quasi-functional analysis of 3D cell cultures and tissue. Recent studies of dynamic OCT as a source of cellular contrast have found qualitative associations with necrosis in cell spheroids, suggesting potential as a viability marker. We present empirical and validated evidence for dynamic OCT as a quantitative indicator of cell viability in 3D cultures. We analysed over 240 MCF-7 cancer cell spheroids with dynamic OCT and corresponding viability measurements using the trypan blue exclusion assay. Significant effects of common reagents dimethyl sulfoxide (DMSO) and phosphate-buffered saline (PBS) on OCT readouts were noted. We proposed a regression-based OCT brightness normalisation technique that removed reagent-induced OCT intensity biases and helped improve correspondence to the viability assay. These results offer a quantitative biological foundation for further advances of dynamic OCT as a novel non-invasive modality for 3D culture monitoring.
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Affiliation(s)
- Ko Hui Tan
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore
| | - Joel Lang Yi Ang
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore
| | - Alexander Si Kai Yong
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore
| | - Stefanie Zi En Lim
- Institute of Bioengineering and Bioimaging (IBB), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #07-01, Singapore 138669, Republic of Singapore
| | - Jessica Sze Jia Kng
- Institute of Bioengineering and Bioimaging (IBB), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #07-01, Singapore 138669, Republic of Singapore
| | - Kaicheng Liang
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore
- Institute of Microelectronics (IME), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-02, Singapore 138634, Republic of Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University (NTU), 11 Mandalay Rd, Singapore 308232, Republic of Singapore
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University (NTU), 62 Nanyang Drive, Singapore 637459, Republic of Singapore
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Ren Y, Hu Y, Li C, Zhong P, Liu H, Wang H, Kuang Y, Fu B, Wang Y, Zhao H, Zeng X, Kong H, Lawali DJAM, Yu D, Yu H, Yang X. Impaired retinal microcirculation in patients with non-obstructive coronary artery disease. Microvasc Res 2023; 148:104533. [PMID: 37004959 DOI: 10.1016/j.mvr.2023.104533] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/10/2023] [Accepted: 03/30/2023] [Indexed: 04/03/2023]
Abstract
PURPOSE To quantitatively investigate alterations of retinal microcirculation in patients with non-obstructive coronary artery disease (NOCAD) using optical coherence tomography angiography (OCTA), and to identify the ability of retinal microcirculation parameters in differentiating coronary artery disease (CAD) subtypes. METHODS All participants with angina pectoris underwent coronary computed tomography angiography. Patients with lumen diameter reduction of 20-50 % in all major coronary arteries were defined as NOCAD, while patients with at least one major coronary artery lumen diameter reduction ≥ 50 % were recruited as obstructive coronary artery disease (OCAD). Participants without a history of ophthalmic or systemic vascular disease were recruited as healthy controls. Retinal neural-vasculature was measured quantitatively by OCTA, including peripapillary retinal nerve fiber layer (RNFL) thickness and vessel density (VD) of the optic disc, superficial vessel plexus (SVP), deep vessel plexus (DVP), and foveal density (FD 300). p < 0.017 is considered significant in multiple comparisons. RESULTS A total of 185 participants (65 NOCAD, 62 OCAD, and 58 controls) were enrolled. Except for the DVP fovea (p = 0.069), significantly reduced VD in all other regions of SVP and DVP was detected in both the NOCAD and OCAD groups compared to control group (all p < 0.017), while a more significant decrease was found in OCAD compared to NOCAD. Multivariate regression analysis showed that lower VD in superior hemi part of whole SVP (OR: 0.582, 95 % CI: 0.451-0.752) was an independent risk factor for NOCAD compared to controls, while lower VD in the whole SVP (OR: 0.550, 95 % CI: 0.421-0.719) was an independent risk factor for OCAD compared to NOCAD. Using the integration of retinal microvascular parameters, the area under the receiver operating characteristic curve (AUC) for NOCAD versus control and OCAD versus NOCAD were 0.840 and 0.830, respectively. CONCLUSION Significant retinal microcirculation impairment, while milder than that in OCAD was observed in NOCAD patients, indicating retinal microvasculature assessment might provide a new systemic microcirculation observation window for NOCAD. Furthermore, retinal microvasculature may serve as a new indicator to assess the severity of CAD with good performance of retinal microvascular parameters in identifying different CAD subtypes.
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Affiliation(s)
- Yun Ren
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China; Shantou University Medical College, Shantou, China
| | - Yijun Hu
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Cong Li
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China; School of Medicine, South China University of Technology, Guangzhou, China
| | - Pingting Zhong
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China; State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Hui Liu
- Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Huimin Wang
- Department of Radiology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China; The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Yu Kuang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Bingqi Fu
- Shantou University Medical College, Shantou, China; Division of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yan Wang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China; School of Medicine, South China University of Technology, Guangzhou, China
| | - Hanpeng Zhao
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China; The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Xiaomin Zeng
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China; The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Huiqian Kong
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China; The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Dan Jouma Amadou Maman Lawali
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China; The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Danqing Yu
- Division of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.
| | - Honghua Yu
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China.
| | - Xiaohong Yang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China.
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Orduna-Hospital E, Arcas-Carbonell M, Sanchez-Cano A, Pinilla I, Consejo A. Speckle Contrast as Retinal Tissue Integrity Biomarker in Patients with Type 1 Diabetes Mellitus with No Retinopathy. J Pers Med 2022; 12:jpm12111807. [PMID: 36579516 PMCID: PMC9693211 DOI: 10.3390/jpm12111807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/25/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To study the retinal and choroidal layers in type 1 diabetes mellitus (DM1) without diabetic retinopathy (DR), using speckle contrast of optical coherence tomography (OCT) images as a tissue biomarker in comparison with healthy subjects. METHODS OCT Spectralis images of 148 eyes, 84 from DM1 patients without DR signs, and 64 belonging to the control group, were collected. The speckle contrast and thickness of the inner retinal layer (IRL), the outer retinal layer (ORL), and the choroidal layer in the nasal parafoveal area (N3), were prospectively analyzed. RESULTS A statistically significant difference (p = 0.001) in the IRL thickness between groups was observed, being thicker in the DM1 group. There were no differences in the ORL and choroidal thicknesses between groups. A statistically significant difference (p = 0.02) in the IRL speckle contrast was obtained, being lower in the DM1 group. The maximum speckle contrast was reached in the ORL for both groups, although in the DM1 group, it occurs closer to the choroid, at 64 ± 8 μm (p = 0.008). CONCLUSIONS Statistically significant differences were found in speckle contrast and thickness between the control and the DM1 group, suggesting an IRL alteration of DM1 patients, supporting the retinal neurodegeneration before DR signs are observed.
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Affiliation(s)
- Elvira Orduna-Hospital
- Department of Applied Physics, University of Zaragoza, 50009 Zaragoza, Spain
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain
- Correspondence:
| | | | - Ana Sanchez-Cano
- Department of Applied Physics, University of Zaragoza, 50009 Zaragoza, Spain
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain
| | - Isabel Pinilla
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain
- Department of Ophthalmology, Lozano Blesa University Hospital, 50009 Zaragoza, Spain
- Department of Surgery, University of Zaragoza, 50009 Zaragoza, Spain
| | - Alejandra Consejo
- Department of Applied Physics, University of Zaragoza, 50009 Zaragoza, Spain
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Zhong P, Qin J, Li Z, Jiang L, Peng Q, Huang M, Lin Y, Liu B, Li C, Wu Q, Kuang Y, Cui S, Yu H, Liu Z, Yang X. Development and Validation of Retinal Vasculature Nomogram in Suspected Angina Due to Coronary Artery Disease. J Atheroscler Thromb 2022; 29:579-596. [PMID: 33746138 PMCID: PMC9135645 DOI: 10.5551/jat.62059] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/02/2021] [Indexed: 02/05/2023] Open
Abstract
AIMS To develop and validate a nomogram using retinal vasculature features and clinical variables to predict coronary artery disease (CAD) in patients with suspected angina. METHODS The prediction model consisting of 795 participants was developed in a training set of 508 participants with suspected angina due to CAD, and data were collected from January 2018 to June 2019. The held-out validation was conducted with 287 consecutive patients from July 2019 to November 2019. All patients with suspected CAD received optical coherence tomography angiography (OCTA) examination before undergoing coronary CT angiography. LASSO regression model was used for data reduction and feature selection. Multivariable logistic regression analysis was used to develop the retinal vasculature model for predicting the probability of the presence of CAD. RESULTS Three potential OCTA parameters including vessel density of the nasal and temporal perifovea in the superficial capillary plexus and vessel density of the inferior parafovea in the deep capillary plexus were further selected as independent retinal vasculature predictors. Model clinical electrocardiogram (ECG) OCTA (clinical variables+ECG+OCTA) was presented as the individual prediction nomogram, with good discrimination (AUC of 0.942 [95% CI, 0.923-0.961] and 0.897 [95% CI, 0.861-0.933] in the training and held-out validation sets, respectively) and good calibration. Decision curve analysis indicated the clinical applicability of this retinal vasculature nomogram. CONCLUSIONS The presented retinal vasculature nomogram based on individual probability can accurately identify the presence of CAD, which could improve patient selection and diagnostic yield of aggressive testing before determining a diagnosis.
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Affiliation(s)
- Pingting Zhong
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Shantou University Medical College, Shantou, China
| | - Jie Qin
- School of Automation Science and Engineering, South China University of Technology, Guangzhou, China
| | - Zhixi Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Lei Jiang
- Guangdong Geriatrics Institute, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Qingsheng Peng
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Shantou University Medical College, Shantou, China
| | - Manqing Huang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yingwen Lin
- Shantou University Medical College, Shantou, China
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Baoyi Liu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Southern Medical University, Guangzhou, China
| | - Cong Li
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- School of Medicine, South China University of Technology, Guangzhou, China
| | - Qiaowei Wu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Southern Medical University, Guangzhou, China
| | - Yu Kuang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Shirong Cui
- Department of Statistics, University of California, Davis, CA, USA
| | - Honghua Yu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Zaiyi Liu
- Department of Radiology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xiaohong Yang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
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Zhong P, Li Z, Lin Y, Peng Q, Huang M, Jiang L, Li C, Kuang Y, Cui S, Yu D, Yu H, Yang X. Retinal microvasculature impairments in patients with coronary artery disease: An optical coherence tomography angiography study. Acta Ophthalmol 2022; 100:225-233. [PMID: 33629471 DOI: 10.1111/aos.14806] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/15/2021] [Accepted: 02/02/2021] [Indexed: 02/05/2023]
Abstract
PURPOSE To investigate the association between retinal microvasculature and the presence and severity of coronary artery disease (CAD) using optical coherence tomography angiography (OCTA). METHODS The cross-sectional study was conducted in Guangdong Provincial People's Hospital, China. Retinal microvasculature parameters were measured by OCTA of the optic disc, including the vessel density (VD) and retinal nerve fibre thickness of the radial peripapillary capillary. In terms of the entire macula, VD of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and foveal density (FD-300) were included. The Gensini score was used to evaluate the severity of coronary artery obstructive lesions in CAD patients. RESULTS A total of 410 participants (270 CAD patients and 140 controls) were included. Overall, participants showed significantly greater odds of having CAD in the lower versus higher VD for mean SCP, OR = 2.33 (95% CI 1.49-3.65); in the parafoveal SCP, OR = 2.68 (95% CI 1.70-4.23); and in the perifoveal SCP, OR = 2.36 (95% CI 1.49-3.72). Additionally, participants showed significantly greater odds of having CAD in the lower versus higher VD for mean DCP, OR = 4.04 (95% CI 2.53-6.45); in the parafoveal DCP, OR = 4.08 (95% CI 2.54-6.55); and in the perifoveal DCP, OR = 3.88 (95% CI 2.43-6.19). Among CAD patients, lower VD of DCP was associated with significantly greater adjusted Gensini scores (p = 0.004 for mean DCP; p = 0.035 for parafoveal DCP; p = 0.006 for perifoveal DCP). CONCLUSIONS SCP and DCP were found to be associated with the presence of CAD among the whole population, while DCP was found to be associated with Gensini scores in CAD patients. Retinal microvasculature was associated with the presence and severity of coronary artery stenosis in CAD patients.
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Affiliation(s)
- Pingting Zhong
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Shantou University Medical College, Shantou, China
| | - Zhixi Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yingwen Lin
- Shantou University Medical College, Shantou, China
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Qingsheng Peng
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- Shantou University Medical College, Shantou, China
| | - Manqing Huang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Lei Jiang
- Guangdong Geriatrics Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Cong Li
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
- School of Medicine, South China University of Technology, Guangzhou, China
| | - Yu Kuang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Shirong Cui
- Department of Statistics, University of California, Davis, CA, USA
| | - Danqing Yu
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Honghua Yu
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xiaohong Yang
- Guangdong Eye Institute, Department of Ophthalmology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
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Silva VB, Andrade De Jesus D, Klein S, van Walsum T, Cardoso J, Brea LS, Vaz PG. Signal-carrying speckle in optical coherence tomography: a methodological review on biomedical applications. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:030901. [PMID: 35289154 PMCID: PMC8919025 DOI: 10.1117/1.jbo.27.3.030901] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 02/22/2022] [Indexed: 06/14/2023]
Abstract
SIGNIFICANCE Speckle has historically been considered a source of noise in coherent light imaging. However, a number of works in optical coherence tomography (OCT) imaging have shown that speckle patterns may contain relevant information regarding subresolution and structural properties of the tissues from which it is originated. AIM The objective of this work is to provide a comprehensive overview of the methods developed for retrieving speckle information in biomedical OCT applications. APPROACH PubMed and Scopus databases were used to perform a systematic review on studies published until December 9, 2021. From 146 screened studies, 40 were eligible for this review. RESULTS The studies were clustered according to the nature of their analysis, namely static or dynamic, and all features were described and analyzed. The results show that features retrieved from speckle can be used successfully in different applications, such as classification and segmentation. However, the results also show that speckle analysis is highly application-dependant, and the best approach varies between applications. CONCLUSIONS Several of the reviewed analyses were only performed in a theoretical context or using phantoms, showing that signal-carrying speckle analysis in OCT imaging is still in its early stage, and further work is needed to validate its applicability and reproducibility in a clinical context.
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Affiliation(s)
- Vania B. Silva
- University of Coimbra, Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UC), Department of Physics, Coimbra, Portugal
- University Medical Center Rotterdam, Department of Radiology and Nuclear Medicine, Erasmus MC, Biomedical Imaging Group Rotterdam, Rotterdam, The Netherlands
| | - Danilo Andrade De Jesus
- University Medical Center Rotterdam, Department of Radiology and Nuclear Medicine, Erasmus MC, Biomedical Imaging Group Rotterdam, Rotterdam, The Netherlands
| | - Stefan Klein
- University Medical Center Rotterdam, Department of Radiology and Nuclear Medicine, Erasmus MC, Biomedical Imaging Group Rotterdam, Rotterdam, The Netherlands
| | - Theo van Walsum
- University Medical Center Rotterdam, Department of Radiology and Nuclear Medicine, Erasmus MC, Biomedical Imaging Group Rotterdam, Rotterdam, The Netherlands
| | - João Cardoso
- University of Coimbra, Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UC), Department of Physics, Coimbra, Portugal
| | - Luisa Sánchez Brea
- University Medical Center Rotterdam, Department of Radiology and Nuclear Medicine, Erasmus MC, Biomedical Imaging Group Rotterdam, Rotterdam, The Netherlands
| | - Pedro G. Vaz
- University of Coimbra, Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UC), Department of Physics, Coimbra, Portugal
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Zhong P, Hu Y, Jiang L, Peng Q, Huang M, Li C, Kuang Y, Tan N, Yu H, Yang X. Retinal Microvasculature Changes in Patients With Coronary Total Occlusion on Optical Coherence Tomography Angiography. Front Med (Lausanne) 2022; 8:708491. [PMID: 34977052 PMCID: PMC8716542 DOI: 10.3389/fmed.2021.708491] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 11/29/2021] [Indexed: 12/19/2022] Open
Abstract
Background: Retinal microvasculature has been associated with coronary artery disease (CAD), but the exact contributory role in coronary total occlusion (CTO) is unclear. We aimed to investigate whether retinal vasculature is associated with CTO and could provide incremental value in the assessment of CTO. Methods: A total of 218 CAD patients including 102 CTO and 116 non-CTO were enrolled. Retinal vasculature was measured by optical coherence tomography angiography (OCTA) for all patients. Receiver operating characteristic (ROC) curve was used to assess the performance of retinal vasculature in differentiating CTO from non-CTO patients. Results: In non-CTO CAD patients, vessel density (VD) of mean superficial capillary plexus (SCP) and parafovea SCP were 49.85 and 52.56%, respectively; in CTO patients, VD of mean SCP and parafovea SCP were 47.77, and 49.58%, respectively. After multiple adjustment, VD in the SCP was significantly lower in CTO patients compared to non-CTO patients. VD of superior hemi in the parafovea SCP combined with the clinical variates showed the best ability to predict CTO from CAD with an area under the curve (AUC) of 0.812 (specificity of 89.0% and sensitivity of 65.9%). Conclusions: In CTO patients, retinal VD was significantly decreased, and microvascular damage might specifically target to arterioles than capillaries. Retinal vasculature could thus be a surrogate for detecting the microvascular damage and assist in the assessment of CTO patients. OCTA examination could be suggested to monitor the process of coronary arteries lesions.
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Affiliation(s)
- Pingting Zhong
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yijun Hu
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Aier School of Ophthalmology, Central South University, Changsha, China.,Aier Institute of Refractive Surgery, Refractive Surgery Center, Guangzhou Aier Eye Hospital, Guangzhou, China
| | - Lei Jiang
- Guangdong Geriatrics Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Qingsheng Peng
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Manqing Huang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Cong Li
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,School of Medicine, South China University of Technology, Guangzhou, China
| | - Yu Kuang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Ning Tan
- Guangdong Provincial Key Laboratory of Coronary Heart Disease Prevention, Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Honghua Yu
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xiaohong Yang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
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8
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Liu B, Hu Y, Ma G, Xiao Y, Zhang B, Liang Y, Zhong P, Zeng X, Lin Z, Kong H, Wu G, Du Z, Fang Y, Huang M, Wang L, Yang X, Yu H. Reduced Retinal Microvascular Perfusion in Patients With Stroke Detected by Optical Coherence Tomography Angiography. Front Aging Neurosci 2021; 13:628336. [PMID: 33927607 PMCID: PMC8078175 DOI: 10.3389/fnagi.2021.628336] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 02/16/2021] [Indexed: 12/20/2022] Open
Abstract
Currently there is a shortage of biomarkers for stroke, one of the leading causes of death and disability in aging populations. Retinal vessels offer a unique and accessible “window” to study the microvasculature in vivo. However, the relationship between the retinal microvasculature and stroke is not entirely clear. To investigate the retinal microvascular characteristics in stroke, we recruited patients with stroke and age-matched control subjects from a tertiary hospital in China. The macular vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), foveal avascular zone (FAZ) metrics, and optical coherence tomography angiography (OCTA) measured optic disc VD were recorded for analysis. A total of 189 patients with stroke and 195 control subjects were included. After adjusting for sex, visual acuity, systolic and diastolic blood pressure, a history of smoking, levels of hemoglobulin (HbA1c), cholesterol, and high-density lipoprotein (HDL), the macular VD of SCP and DCP in all sectors was decreased in patients with stroke. In the stroke group, the VD around the FAZ and the VD of the optic disk were lower. Logistic regression found the parafovea-superior-hemi VD of DCP > 54.53% [odds ratio (OR): 0.169] as a protective factor of stroke. Using the integration of all OCTA parameters and traditional risk factors, the area under the receiver operating characteristic (AUC) curve of distinguishing patients with stroke was 0.962, with a sensitivity of 0.944 and a specificity of 0.871. Our study demonstrates that the retinal VD is decreased in patients with stroke independently of the traditional risk factors of stroke, which may shed light on the monitoring of stroke using the retinal microvascular parameters.
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Affiliation(s)
- Baoyi Liu
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Yijun Hu
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China.,Refractive Surgery Center, Aier Institute of Refractive Surgery, Guangzhou Aier Eye Hospital, Guangzhou, China.,Aier School of Ophthalmology, Central South University, Changsha, China
| | - Guixian Ma
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yu Xiao
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Bin Zhang
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Yingying Liang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Pingting Zhong
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Xiaomin Zeng
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Zhanjie Lin
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Huiqian Kong
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Guanrong Wu
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Zijing Du
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Ying Fang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Manqing Huang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Lijuan Wang
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xiaohong Yang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Honghua Yu
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China
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9
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Abd El-Sadek I, Miyazawa A, Tzu-Wei Shen L, Makita S, Fukuda S, Yamashita T, Oka Y, Mukherjee P, Matsusaka S, Oshika T, Kano H, Yasuno Y. Optical coherence tomography-based tissue dynamics imaging for longitudinal and drug response evaluation of tumor spheroids. BIOMEDICAL OPTICS EXPRESS 2020; 11:6231-6248. [PMID: 33282486 PMCID: PMC7687946 DOI: 10.1364/boe.404336] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/30/2020] [Accepted: 10/01/2020] [Indexed: 05/18/2023]
Abstract
We present optical coherence tomography (OCT)-based tissue dynamics imaging method to visualize and quantify tissue dynamics such as subcellular motion based on statistical analysis of rapid-time-sequence OCT signals at the same location. The analyses include logarithmic intensity variance (LIV) method and two types of OCT correlation decay speed analysis (OCDS). LIV is sensitive to the magnitude of the signal fluctuations, while OCDSs including early- and late-OCDS (OCDS e and OCDS l , respectively) are sensitive to the fast and slow tissue dynamics, respectively. These methods were able to visualize and quantify the longitudinal necrotic process of a human breast adenocarcinoma spheroid and its anti-cancer drug response. Additionally, the effects of the number of OCT signals and the total acquisition time on dynamics imaging are examined. Small number of OCT signals, e.g., five or nine suffice for dynamics imaging when the total acquisition time is suitably long.
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Affiliation(s)
| | - Arata Miyazawa
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Larina Tzu-Wei Shen
- Clinical Research and Regional Innovation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Shuichi Makita
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Shinichi Fukuda
- Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Department of Advanced Vision Science, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Toshiharu Yamashita
- Laboratory of Regenerative Medicine and Stem Cell Biology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yuki Oka
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Pradipta Mukherjee
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Satoshi Matsusaka
- Clinical Research and Regional Innovation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Tetsuro Oshika
- Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Hideaki Kano
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
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10
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Huang Y, Jerwick J, Liu G, Zhou C. Full-range space-division multiplexing optical coherence tomography angiography. BIOMEDICAL OPTICS EXPRESS 2020; 11:4817-4834. [PMID: 32923080 PMCID: PMC7449723 DOI: 10.1364/boe.400162] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/20/2020] [Accepted: 07/26/2020] [Indexed: 06/11/2023]
Abstract
In this study, we demonstrated a full-range space-division multiplexing optical coherence tomography (FR-SDM-OCT) system. Utilizing the galvanometer-based phase modulation full-range technique, the total imaging range of FR-SDM-OCT can be extended to >20 mm in tissue, with a digitizer sampling rate of 500 MS/s and a laser sweeping rate of 100 kHz. Complex conjugate terms were suppressed in FR-SDM-OCT images with a measured rejection ratio of up to ∼46 dB at ∼1.4 mm depth and ∼30 dB at ∼19.4 mm depth. The feasibility of FR-SDM-OCT was validated by imaging Scotch tapes and human fingernails. Furthermore, we demonstrated the feasibility of FR-SDM-OCT angiography (FR-SDM-OCTA) to perform simultaneous acquisition of human fingernail angiograms from four positions, with a total field-of-view of ∼1.7 mm × ∼7.5 mm. Employing the full-range technique in SDM-OCT can effectively alleviate hardware requirements to achieve the long depth measurement range, which is required by SDM-OCT to separate multiple images at different sample locations. FR-SDM-OCTA creates new opportunities to apply SDM-OCT to obtain wide-field angiography of in vivo tissue samples free of labeling.
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Affiliation(s)
- Yongyang Huang
- Department of Electrical and Computer Engineering, Lehigh University, 19 Memorial Drive West, Bethlehem, PA 18015, USA
| | - Jason Jerwick
- Department of Electrical and Computer Engineering, Lehigh University, 19 Memorial Drive West, Bethlehem, PA 18015, USA
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO 63130, USA
| | - Guoyan Liu
- Department of Electrical and Computer Engineering, Lehigh University, 19 Memorial Drive West, Bethlehem, PA 18015, USA
- Department of Dermatology, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China
| | - Chao Zhou
- Department of Electrical and Computer Engineering, Lehigh University, 19 Memorial Drive West, Bethlehem, PA 18015, USA
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO 63130, USA
- Department of Bioengineering, Lehigh University, Bethlehem, PA 18015, USA
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11
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Kurokawa K, Crowell JA, Zhang F, Miller DT. Suite of methods for assessing inner retinal temporal dynamics across spatial and temporal scales in the living human eye. NEUROPHOTONICS 2020; 7:015013. [PMID: 32206680 PMCID: PMC7070771 DOI: 10.1117/1.nph.7.1.015013] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 02/17/2020] [Indexed: 05/08/2023]
Abstract
Significance: There are no label-free imaging descriptors related to physiological activity of inner retinal cells in the living human eye. A major reason is that inner retinal neurons are highly transparent and reflect little light, making them extremely difficult to visualize and quantify. Aim: To measure physiologically-induced optical changes of inner retinal cells despite their challenging optical properties. Approach: We developed an imaging method based on adaptive optics and optical coherence tomography (AO-OCT) and a suite of postprocessing algorithms, most notably a new temporal correlation method. Results: We captured the temporal dynamics of entire inner retinal layers, of specific tissue types, and of individual cells across three different timescales from fast (seconds) to extremely slow (one year). Time correlation analysis revealed significant differences in time constant (up to 0.4 s) between the principal layers of the inner retina with the ganglion cell layer (GCL) being the most dynamic. At the cellular level, significant differences were found between individual GCL somas. The mean time constant of the GCL somas ( 0.69 ± 0.17 s ) was ∼ 30 % smaller than that of nerve fiber bundles and inner plexiform layer synapses and processes. Across longer durations, temporal speckle contrast and time-lapse imaging revealed motion of macrophage-like cells (over minutes) and GCL neuron loss and remodeling (over one year). Conclusions: Physiological activity of inner retinal cells is now measurable in the living human eye.
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Affiliation(s)
- Kazuhiro Kurokawa
- Indiana University, School of Optometry, Bloomington, Indiana, United States
| | - James A. Crowell
- Indiana University, School of Optometry, Bloomington, Indiana, United States
| | - Furu Zhang
- Indiana University, School of Optometry, Bloomington, Indiana, United States
| | - Donald T. Miller
- Indiana University, School of Optometry, Bloomington, Indiana, United States
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12
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Camino A, Jia Y, Yu J, Wang J, Liu L, Huang D. Automated detection of shadow artifacts in optical coherence tomography angiography. BIOMEDICAL OPTICS EXPRESS 2019; 10:1514-1531. [PMID: 30891364 PMCID: PMC6420267 DOI: 10.1364/boe.10.001514] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 02/19/2019] [Accepted: 02/19/2019] [Indexed: 05/06/2023]
Abstract
Frequently, when imaging retinal vasculature with optical coherence tomography angiography (OCTA) in diseased eyes, there are unavoidable obstacles to the propagation of light such as vitreous floaters or the pupil boundary. These obstacles can block the optical coherence tomography (OCT) beam and impede the visualization of the underlying retinal microcirculation. Detecting these shadow artifacts is especially important in the quantification of metrics that assess retinal disease progression because they might masquerade as regional perfusion loss. In this work, we present an algorithm to identify shadowed areas in OCTA of healthy subjects as well as patients with diabetic retinopathy, uveitis and age-related macular degeneration. The aim is to exclude these areas from analysis so that the overall OCTA parameters are minimally affected by shadow artifacts.
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Affiliation(s)
- Acner Camino
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | - Jeffrey Yu
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Jie Wang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | - Liang Liu
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
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13
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Wang Q, Gong P, Cense B, Sampson DD. Short-time series optical coherence tomography angiography and its application to cutaneous microvasculature. BIOMEDICAL OPTICS EXPRESS 2019; 10:293-307. [PMID: 30775101 PMCID: PMC6363186 DOI: 10.1364/boe.10.000293] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 11/14/2018] [Accepted: 11/28/2018] [Indexed: 05/25/2023]
Abstract
We present a new optical coherence tomography (OCT) angiography method for imaging tissue microvasculature in vivo based on the characteristic frequency-domain flow signature in a short time series of a single voxel. The angiography signal is generated by Fourier transforming the OCT signal time series from a given voxel in multiple acquisitions and computing the average magnitude of non-zero (high-pass) frequency components. Larger temporal variations of the OCT signal caused by blood flow result in higher values of the average magnitude in the frequency domain compared to those from static tissue. Weighting of the signal by the inverse of the zero-frequency component (i.e., the sum of the OCT signal time series) improves vessel contrast in flow regions of low OCT signal. The method is demonstrated on a fabricated flow phantom and on human skin in vivo and, at only 5 time points per voxel, shows enhanced vessel contrast in comparison to conventional correlation mapping/speckle decorrelation and speckle variance methods.
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Affiliation(s)
- Qiang Wang
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Perth WA 6009, Australia
| | - Peijun Gong
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Perth WA 6009, Australia
| | - Barry Cense
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Perth WA 6009, Australia
| | - David D. Sampson
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Highway, Perth WA 6009, Australia
- University of Surrey, Guildford, Surrey, GU2 7XH, UK
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14
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Applications of Optical Coherence Tomography Angiography in Diabetic Eye Disease. Clin Ophthalmol 2018; 59:209-219. [PMID: 30585927 DOI: 10.1097/iio.0000000000000254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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15
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McClintic SM, Gao S, Wang J, Hagag A, Lauer AK, Flaxel CJ, Bhavsar K, Hwang TS, Huang D, Jia Y, Bailey ST. Quantitative Evaluation of Choroidal Neovascularization under Pro Re Nata Anti-Vascular Endothelial Growth Factor Therapy with OCT Angiography. Ophthalmol Retina 2018; 2:931-941. [PMID: 30238069 PMCID: PMC6139650 DOI: 10.1016/j.oret.2018.01.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PURPOSE To use optical coherence tomography angiography (OCTA) derived quantitative metrics to assess the response of choroidal neovascularization to pro-re-nata (PRN) anti-endothelial growth factor (anti-VEGF) treatment in neovascular age-related macular degeneration (AMD). DESIGN Prospective longitudinal cohort study. PARTICIPANTS Fourteen eyes from 14 study participants with treatment-naïve neovascular AMD were enrolled. METHODS Subjects were evaluated monthly and treated with intravitreal anti-VEGF agents under a PRN protocol for one year. At each visit, two 3×3 mm2 OCTA scans were obtained. Custom image processing was applied to segment the outer retinal slab, suppress projection artifact, and automatically detect CNV. CNV membrane area (mm2) and CNV vessel area (mm2) was calculated. MAIN OUTCOMES Individual and mean CNV membrane area and CNV vessel area at each visit; within-visit repeatability determined by coefficient of variation. RESULTS Eight eyes had entire CNV within 3×3 mm2 scanning area and had adequate image quality for CNV quantification. One case (case #2) was excluded from analysis due to the presence of a large subretinal hemorrhage overlying the CNV membrane. In the remaining cases, CNV vessel area was reduced by 39%, 50%, 43%, and 41% at months 1, 3, 6, and 12 respectively. CNV membrane area was reduced by 39%, 51%, 54%, and 45% at months 1, 3, 6, and 12. At month 6, mean change from baseline was not statistically significant for CNV vessel area, while it was statistically significant for CNV membrane area. Neither metric was significantly different compared to baseline at month 12. Individual analyses revealed each CNV had a unique response under PRN treatment. Within-visit repeatability was was 7.96% (coefficient of variation) for CNV vessel area and 7.37% for CNV membrane area. CONCLUSIONS In this small exploratory study of CNV response to PRN anti-VEGF treatment, both CNV vessel area and membrane area were reduced compared to baseline after three months. After one year of follow-up, these reductions were no longer statistically significant. When anti-VEGF treatment was held, increasing CNV vessel area over time often resulted in exudation, but it was not possible to exactly when exudation occurs.
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Affiliation(s)
- Scott M McClintic
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Simon Gao
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Jie Wang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ahmed Hagag
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Andreas K Lauer
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Christina J Flaxel
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Kavita Bhavsar
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Thomas S Hwang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Steven T Bailey
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
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16
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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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17
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Spaide RF, Fujimoto JG, Waheed NK, Sadda SR, Staurenghi G. Optical coherence tomography angiography. Prog Retin Eye Res 2018; 64:1-55. [PMID: 29229445 PMCID: PMC6404988 DOI: 10.1016/j.preteyeres.2017.11.003] [Citation(s) in RCA: 1113] [Impact Index Per Article: 159.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 11/20/2017] [Accepted: 11/22/2017] [Indexed: 02/07/2023]
Abstract
Optical coherence tomography (OCT) was one of the biggest advances in ophthalmic imaging. Building on that platform, OCT angiography (OCTA) provides depth resolved images of blood flow in the retina and choroid with levels of detail far exceeding that obtained with older forms of imaging. This new modality is challenging because of the need for new equipment and processing techniques, current limitations of imaging capability, and rapid advancements in both imaging and in our understanding of the imaging and applicable pathophysiology of the retina and choroid. These factors lead to a steep learning curve, even for those with a working understanding dye-based ocular angiography. All for a method of imaging that is a little more than 10 years old. This review begins with a historical account of the development of OCTA, and the methods used in OCTA, including signal processing, image generation, and display techniques. This forms the basis to understand what OCTA images show as well as how image artifacts arise. The anatomy and imaging of specific vascular layers of the eye are reviewed. The integration of OCTA in multimodal imaging in the evaluation of retinal vascular occlusive diseases, diabetic retinopathy, uveitis, inherited diseases, age-related macular degeneration, and disorders of the optic nerve is presented. OCTA is an exciting, disruptive technology. Its use is rapidly expanding in clinical practice as well as for research into the pathophysiology of diseases of the posterior pole.
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Affiliation(s)
- Richard F Spaide
- Vitreous, Retina, Macula Consultants of New York, New York, NY, United States.
| | - James G Fujimoto
- Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA, United States
| | - Nadia K Waheed
- The Department of Ophthalmology, Tufts University School of Medicine, Boston MA, United States
| | - Srinivas R Sadda
- Doheny Eye Institute, University of California - Los Angeles, Los Angeles, CA, United States
| | - Giovanni Staurenghi
- Eye Clinic, Department of Biomedical and Clinical Sciences "Luigi Sacco", Luigi Sacco Hospital, University of Milan, Milan, Italy
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18
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The application of optical coherence tomography angiography in retinal diseases. Surv Ophthalmol 2017; 62:838-866. [DOI: 10.1016/j.survophthal.2017.05.006] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 05/18/2017] [Accepted: 05/19/2017] [Indexed: 01/30/2023]
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19
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Mo S, Krawitz B, Efstathiadis E, Geyman L, Weitz R, Chui TYP, Carroll J, Dubra A, Rosen RB. Imaging Foveal Microvasculature: Optical Coherence Tomography Angiography Versus Adaptive Optics Scanning Light Ophthalmoscope Fluorescein Angiography. Invest Ophthalmol Vis Sci 2017; 57:OCT130-40. [PMID: 27409463 PMCID: PMC4968918 DOI: 10.1167/iovs.15-18932] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE To compare the use of optical coherence tomography angiography (OCTA) and adaptive optics scanning light ophthalmoscope fluorescein angiography (AOSLO FA) for characterizing the foveal microvasculature in healthy and vasculopathic eyes. METHODS Four healthy controls and 11 vasculopathic patients (4 diabetic retinopathy, 4 retinal vein occlusion, and 3 sickle cell retinopathy) were imaged with OCTA and AOSLO FA. Foveal perfusion maps were semiautomatically skeletonized for quantitative analysis, which included foveal avascular zone (FAZ) metrics (area, perimeter, acircularity index) and vessel density in three concentric annular regions of interest. On each set of OCTA and AOSLO FA images, matching vessel segments were used for lumen diameter measurement. Qualitative image comparisons were performed by visual identification of microaneurysms, vessel loops, leakage, and vessel segments. RESULTS Adaptive optics scanning light ophthalmoscope FA and OCTA showed no statistically significant differences in FAZ perimeter, acircularity index, and vessel densities. Foveal avascular zone area, however, showed a small but statistically significant difference of 1.8% (P = 0.004). Lumen diameter was significantly larger on OCTA (mean difference 5.7 μm, P < 0.001). Microaneurysms, fine structure of vessel loops, leakage, and some vessel segments were visible on AOSLO FA but not OCTA, while blood vessels obscured by leakage were visible only on OCTA. CONCLUSIONS Optical coherence tomography angiography is comparable to AOSLO FA at imaging the foveal microvasculature except for differences in FAZ area, lumen diameter, and some qualitative features. These results, together with its ease of use, short acquisition time, and avoidance of potentially phototoxic blue light, support OCTA as a tool for monitoring ocular pathology and detecting early disease.
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Affiliation(s)
- Shelley Mo
- Icahn School of Medicine at Mount Sinai, New York, New York, United States 2Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York, United States
| | - Brian Krawitz
- Icahn School of Medicine at Mount Sinai, New York, New York, United States 2Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York, United States
| | - Eleni Efstathiadis
- Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York, United States 3William E. Macaulay Honors College, New York, New York, United States
| | - Lawrence Geyman
- Icahn School of Medicine at Mount Sinai, New York, New York, United States 2Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York, United States
| | - Rishard Weitz
- Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York, United States
| | - Toco Y P Chui
- Icahn School of Medicine at Mount Sinai, New York, New York, United States 2Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York, United States
| | - Joseph Carroll
- Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States 5Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States 6Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, Unit
| | - Alfredo Dubra
- Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States 5Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States 6Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, Unit
| | - Richard B Rosen
- Icahn School of Medicine at Mount Sinai, New York, New York, United States 2Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York, United States
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20
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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: 253] [Impact Index Per Article: 31.6] [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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21
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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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22
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Kurokawa K, Liu Z, Miller DT. Adaptive optics optical coherence tomography angiography for morphometric analysis of choriocapillaris [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1803-1822. [PMID: 28663867 PMCID: PMC5480582 DOI: 10.1364/boe.8.001803] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 02/14/2017] [Accepted: 02/14/2017] [Indexed: 05/18/2023]
Abstract
Histological studies have shown that morphometric changes at the microscopic level of choriocapillaris (CC) occur with aging and disease onset, and therefore may be sensitive biomarkers of outer retinal health. However, visualizing CC at this level in the living human eye is challenging because its microvascular is tightly interconnected and weakly reflecting. In this study, we address these challenges by developing and validating a method based on adaptive optics optical coherence tomography with angiography (AO-OCTA) that provides the necessary 3D resolution and image contrast to visualize and quantify these microscopic details. The complex network of anastomotic CC capillaries was successfully imaged in nine healthy subjects (26 to 68 years of age) and at seven retinal eccentricities across the macula. Using these images, four fundamental morphometric parameters of CC were characterized: retinal pigment epithelium-to-CC depth separation (17.5 ± 2.1 µm), capillary diameter (17.4 ± 2.3 µm), normalized capillary density (0.53 ± 0.08), and capillary length per unit area (50.4 ± 9.5 mm-1). AO-OCTA results were consistent with histologic studies and, unlike OCTA, showed clear delineation of CC capillaries, a requirement for measuring three of the four morphometric parameters. Success in younger and older eyes establishes a path for testing aging and disease effects in larger populations. To the best of our knowledge, this is the first quantitative morphometry of choriocapillaris at the level of individual capillaries in the living human retina.
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23
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Chen CL, Wang RK. Optical coherence tomography based angiography [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1056-1082. [PMID: 28271003 PMCID: PMC5330554 DOI: 10.1364/boe.8.001056] [Citation(s) in RCA: 286] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/16/2017] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT)-based angiography (OCTA) provides in vivo, three-dimensional vascular information by the use of flowing red blood cells as intrinsic contrast agents, enabling the visualization of functional vessel networks within microcirculatory tissue beds non-invasively, without a need of dye injection. Because of these attributes, OCTA has been rapidly translated to clinical ophthalmology within a short period of time in the development. Various OCTA algorithms have been developed to detect the functional micro-vasculatures in vivo by utilizing different components of OCT signals, including phase-signal-based OCTA, intensity-signal-based OCTA and complex-signal-based OCTA. All these algorithms have shown, in one way or another, their clinical values in revealing micro-vasculatures in biological tissues in vivo, identifying abnormal vascular networks or vessel impairment zones in retinal and skin pathologies, detecting vessel patterns and angiogenesis in eyes with age-related macular degeneration and in skin and brain with tumors, and monitoring responses to hypoxia in the brain tissue. The purpose of this paper is to provide a technical oriented overview of the OCTA developments and their potential pre-clinical and clinical applications, and to shed some lights on its future perspectives. Because of its clinical translation to ophthalmology, this review intentionally places a slightly more weight on ophthalmic OCT angiography.
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Affiliation(s)
- Chieh-Li Chen
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
- Department of Ophthalmology, University of Washington, 325 9th Ave, Seattle, WA 98104, USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
- Department of Ophthalmology, University of Washington, 325 9th Ave, Seattle, WA 98104, USA
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24
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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: 0.8] [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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25
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Cheng Y, Guo L, Pan C, Lu T, Hong T, Ding Z, Li P. Statistical analysis of motion contrast in optical coherence tomography angiography. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:116004. [PMID: 26524681 DOI: 10.1117/1.jbo.20.11.116004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 10/02/2015] [Indexed: 05/08/2023]
Abstract
Optical coherence tomography angiography (Angio-OCT), mainly based on the temporal dynamics of OCT scattering signals, has found a range of potential applications in clinical and scientific research. Based on the model of random phasor sums, temporal statistics of the complex-valued OCT signals are mathematically described. Statistical distributions of the amplitude differential and complex differential Angio-OCT signals are derived. The theories are validated through the flow phantom and live animal experiments. Using the model developed, the origin of the motion contrast in Angio-OCT is mathematically explained, and the implications in the improvement of motion contrast are further discussed, including threshold determination and its residual classification error, averaging method, and scanning protocol. The proposed mathematical model of Angio-OCT signals can aid in the optimal design of the system and associated algorithms.
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Affiliation(s)
- Yuxuan Cheng
- Zhejiang University, College of Optical Science and Engineering, State Key Laboratory of Modern Optical Instrumentation and the Collaborative Innovation Center for Brain Science, Hangzhou, Zhejiang 310027, China
| | - Li Guo
- Zhejiang University, College of Optical Science and Engineering, State Key Laboratory of Modern Optical Instrumentation and the Collaborative Innovation Center for Brain Science, Hangzhou, Zhejiang 310027, China
| | - Cong Pan
- Zhejiang University, College of Optical Science and Engineering, State Key Laboratory of Modern Optical Instrumentation and the Collaborative Innovation Center for Brain Science, Hangzhou, Zhejiang 310027, China
| | - Tongtong Lu
- Zhejiang University, College of Optical Science and Engineering, State Key Laboratory of Modern Optical Instrumentation and the Collaborative Innovation Center for Brain Science, Hangzhou, Zhejiang 310027, China
| | - Tianyu Hong
- Zhejiang University, College of Biomedical Engineering and Instrument Science, Hangzhou, Zhejiang 310027, China
| | - Zhihua Ding
- Zhejiang University, College of Optical Science and Engineering, State Key Laboratory of Modern Optical Instrumentation and the Collaborative Innovation Center for Brain Science, Hangzhou, Zhejiang 310027, China
| | - Peng Li
- Zhejiang University, College of Optical Science and Engineering, State Key Laboratory of Modern Optical Instrumentation and the Collaborative Innovation Center for Brain Science, Hangzhou, Zhejiang 310027, China
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26
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Detecting Blood Flow Response to Stimulation of the Human Eye. BIOMED RESEARCH INTERNATIONAL 2015; 2015:121973. [PMID: 26504775 PMCID: PMC4609341 DOI: 10.1155/2015/121973] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/10/2015] [Indexed: 12/14/2022]
Abstract
Retinal blood supply is tightly regulated under a variety of hemodynamic considerations in order to satisfy a high metabolic need and maintain both vessel structure and function. Simulation of the human eye can induce hemodynamics alterations, and attempt to assess the vascular reactivity response has been well documented in the scientific literature. Advancements in noninvasive imaging technologies have led to the characterization of magnitude and time course in retinal blood flow response to stimuli. This allowed for a better understanding of the mechanism in which blood flow is regulated, as well as identifying functional impairments in the diseased eye. Clinically, the ability to detect retinal blood flow reactivity during stimulation of the eye offers potential for the detection, differentiation, and diagnosis of diseases.
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27
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Ruminski D, Sikorski BL, Bukowska D, Szkulmowski M, Krawiec K, Malukiewicz G, Bieganowski L, Wojtkowski M. OCT angiography by absolute intensity difference applied to normal and diseased human retinas. BIOMEDICAL OPTICS EXPRESS 2015; 6:2738-54. [PMID: 26309740 PMCID: PMC4541504 DOI: 10.1364/boe.6.002738] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/30/2015] [Accepted: 06/30/2015] [Indexed: 05/22/2023]
Abstract
We compare four optical coherence tomography techniques for noninvasive visualization of microcapillary network in the human retina and murine cortex. We perform phantom studies to investigate contrast-to-noise ratio for angiographic images obtained with each of the algorithm. We show that the computationally simplest absolute intensity difference angiographic OCT algorithm that bases only on two cross-sectional intensity images may be successfully used in clinical study of healthy eyes and eyes with diabetic maculopathy and branch retinal vein occlusion.
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Affiliation(s)
- Daniel Ruminski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
- both authors contributed equally
| | - Bartosz L. Sikorski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
- Department of Ophthalmology, Nicolaus Copernicus University, 9 M. Sklodowskiej-Curie St., 85-094 Bydgoszcz, Poland
- both authors contributed equally
| | - Danuta Bukowska
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
| | - Maciej Szkulmowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
| | - Krzysztof Krawiec
- Laboratory of Intelligent Decision Support Systems, Poznan University of Technology, Piotrowo 2, 60-965 Poznań, Poland
| | - Grazyna Malukiewicz
- Department of Ophthalmology, Nicolaus Copernicus University, 9 M. Sklodowskiej-Curie St., 85-094 Bydgoszcz, Poland
| | - Lech Bieganowski
- Collegium Medicum, Nicolaus Copernicus University in Torun, Jagiellońska 13-15, 85-067 Bydgoszcz, Poland
| | - Maciej Wojtkowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
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Chan G, Balaratnasingam C, Xu J, Mammo Z, Han S, Mackenzie P, Merkur A, Kirker A, Albiani D, Sarunic MV, Yu DY. In vivo optical imaging of human retinal capillary networks using speckle variance optical coherence tomography with quantitative clinico-histological correlation. Microvasc Res 2015; 100:32-9. [DOI: 10.1016/j.mvr.2015.04.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 04/11/2015] [Accepted: 04/19/2015] [Indexed: 10/23/2022]
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29
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Quantitative optical coherence tomography angiography of vascular abnormalities in the living human eye. Proc Natl Acad Sci U S A 2015; 112:E2395-402. [PMID: 25897021 DOI: 10.1073/pnas.1500185112] [Citation(s) in RCA: 499] [Impact Index Per Article: 49.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Retinal vascular diseases are important causes of vision loss. A detailed evaluation of the vascular abnormalities facilitates diagnosis and treatment in these diseases. Optical coherence tomography (OCT) angiography using the highly efficient split-spectrum amplitude decorrelation angiography algorithm offers an alternative to conventional dye-based retinal angiography. OCT angiography has several advantages, including 3D visualization of retinal and choroidal circulations (including the choriocapillaris) and avoidance of dye injection-related complications. Results from six illustrative cases are reported. In diabetic retinopathy, OCT angiography can detect neovascularization and quantify ischemia. In age-related macular degeneration, choroidal neovascularization can be observed without the obscuration of details caused by dye leakage in conventional angiography. Choriocapillaris dysfunction can be detected in the nonneovascular form of the disease, furthering our understanding of pathogenesis. In choroideremia, OCT's ability to show choroidal and retinal vascular dysfunction separately may be valuable in predicting progression and assessing treatment response. OCT angiography shows promise as a noninvasive alternative to dye-based angiography for highly detailed, in vivo, 3D, quantitative evaluation of retinal vascular abnormalities.
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30
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Huang Y, Zhang Q, Wang RK. Efficient method to suppress artifacts caused by tissue hyper-reflections in optical microangiography of retina in vivo. BIOMEDICAL OPTICS EXPRESS 2015; 6:1195-208. [PMID: 25909004 PMCID: PMC4399659 DOI: 10.1364/boe.6.001195] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 01/17/2015] [Accepted: 02/24/2015] [Indexed: 05/20/2023]
Abstract
Optical microangiography (OMAG) is an optical coherence tomography (OCT)-based imaging technique that is capable of achieving the angiographic imaging of biological tissues in vivo with a high imaging resolution and no need for dye injection. OMAG has a potential to become a clinical tool for the diagnosis and treatment monitoring of various retinopathies. In principle, OMAG extracts blood flow information based on a direct differentiation of complex or intensity OCT signals between repeated B-scans acquired at the same cross section, which is sensitive to blood cell movement. In practice, this method is prone to artifacts due to tissue hyper-reflection, commonly seen in retinal diseases such as diabetic retinopathy. In this paper, we propose a novel method to suppress the artifacts induced by hyper-reflection. We propose to scale OMAG flow signals by a weighting factor that is motion-sensitive but hyper-reflection insensitive. We show that this simple weighting approach is effective in suppressing the artifacts due to tissue hyper-reflections while still maintaining the detected capillary networks with high fidelity, especially in deeper retina. The effectiveness of the proposed technique is demonstrated by a phantom study and case studies on patients' eyes with hyper-reflective foci. Finally we discuss potential applications of this technique.
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31
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Nam AS, Chico-Calero I, Vakoc BJ. Complex differential variance algorithm for optical coherence tomography angiography. BIOMEDICAL OPTICS EXPRESS 2014; 5:3822-32. [PMID: 25426313 PMCID: PMC4242020 DOI: 10.1364/boe.5.003822] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/07/2014] [Accepted: 08/15/2014] [Indexed: 05/17/2023]
Abstract
We describe a complex differential variance (CDV) algorithm for optical coherence tomography based angiography. The algorithm exploits both the intensity and phase changes of optical coherence tomography (OCT) signals from flowing blood to achieve high vascular contrast, and also intrinsically reject undesirable phase signals originating from small displacement axial bulk tissue motion and instrument synchronization errors. We present this algorithm within a broader discussion of the properties of OCT signal dynamics. The performance of the algorithm is compared against two other existing algorithms using both phantom measurements and in vivo data. We show that the algorithm provides better contrast for a given number of measurements and equivalent spatial averaging.
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Affiliation(s)
- Ahhyun S. Nam
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139,
USA
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom Street, Boston, Massachusetts 02114,
USA
| | - Isabel Chico-Calero
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom Street, Boston, Massachusetts 02114,
USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115,
USA
| | - Benjamin J. Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom Street, Boston, Massachusetts 02114,
USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115,
USA
- Department of Health Sciences and Technology, Harvard-MIT, Cambridge, Massachusetts 02139,
USA
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32
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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: 0.6] [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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33
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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: 549] [Impact Index Per Article: 49.9] [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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34
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Schwartz DM, Fingler J, Kim DY, Zawadzki RJ, Morse LS, Park SS, Fraser SE, Werner JS. Phase-variance optical coherence tomography: a technique for noninvasive angiography. Ophthalmology 2013; 121:180-187. [PMID: 24156929 DOI: 10.1016/j.ophtha.2013.09.002] [Citation(s) in RCA: 173] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 08/30/2013] [Accepted: 09/04/2013] [Indexed: 10/26/2022] Open
Abstract
PURPOSE Phase-variance optical coherence tomography (PV-OCT) provides volumetric imaging of the retinal vasculature without the need for intravenous injection of a fluorophore. We compare images from PV-OCT and fluorescein angiography (FA) for normal individuals and patients with age-related macular degeneration (AMD) and diabetic retinopathy. DESIGN This is an evaluation of a diagnostic technology. PARTICIPANTS Four patients underwent comparative retinovascular imaging using FA and PV-OCT. Imaging was performed on 1 normal individual, 1 patient with dry AMD, 1 patient with exudative AMD, and 1 patient with nonproliferative diabetic retinopathy. METHODS Fluorescein angiography imaging was performed using a Topcon Corp (Tokyo, Japan) (TRC-50IX) camera with a resolution of 1280 (H) × 1024 (V) pixels. The PV-OCT images were generated by software data processing of the entire cross-sectional image from consecutively acquired B-scans. Bulk axial motion was calculated and corrected for each transverse location, reducing the phase noise introduced from eye motion. Phase variance was calculated through the variance of the motion-corrected phase changes acquired within multiple B-scans at the same position. Repeating these calculations over the entire volumetric scan produced a 3-dimensional PV-OCT representation of the vasculature. MAIN OUTCOME MEASURES Feasibility of rendering retinal and choroidal microvasculature using PV-OCT was compared qualitatively with FA, the current gold standard for retinovascular imaging. RESULTS Phase-variance OCT noninvasively rendered a 2-dimensional depth color-coded vasculature map of the retinal and choroidal vasculature. The choriocapillaris was imaged with better resolution of microvascular detail using PV-OCT. Areas of geographic atrophy and choroidal neovascularization imaged by FA were depicted by PV-OCT. Regions of capillary nonperfusion from diabetic retinopathy were shown by both imaging techniques; there was not complete correspondence between microaneurysms shown on FA and PV-OCT images. CONCLUSIONS Phase-variance OCT yields high-resolution imaging of the retinal and choroidal microvasculature that compares favorably with FA.
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Affiliation(s)
- Daniel M Schwartz
- Department of Ophthalmology & Vision Science, University of California San Francisco, San Francisco, California.
| | - Jeff Fingler
- Department of Biology, California Institute of Technology, Pasadena, California
| | - Dae Yu Kim
- Department of Biology, California Institute of Technology, Pasadena, California; Department of Ophthalmology & Vision Science, University of California Davis, Davis, California
| | - Robert J Zawadzki
- Department of Ophthalmology & Vision Science, University of California Davis, Davis, California
| | - Lawrence S Morse
- Department of Ophthalmology & Vision Science, University of California Davis, Davis, California
| | - Susanna S Park
- Department of Ophthalmology & Vision Science, University of California Davis, Davis, California
| | - Scott E Fraser
- Department of Biology, California Institute of Technology, Pasadena, California
| | - John S Werner
- Department of Ophthalmology & Vision Science, University of California Davis, Davis, California
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Yousefi S, Qin J, Wang RK. Super-resolution spectral estimation of optical micro-angiography for quantifying blood flow within microcirculatory tissue beds in vivo. BIOMEDICAL OPTICS EXPRESS 2013; 4:1214-28. [PMID: 23847744 PMCID: PMC3704100 DOI: 10.1364/boe.4.001214] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 06/07/2013] [Accepted: 06/08/2013] [Indexed: 05/07/2023]
Abstract
In this paper, we propose a super-resolution spectral estimation technique to quantify microvascular hemodynamics using optical microangiography (OMAG) based on optical coherence tomography (OCT). The proposed OMAG technique uses both amplitude and phase information of the OCT signals which makes it sensitive to the axial and transverse flows. The scanning protocol for the proposed method is identical to three-dimensional ultrahigh sensitive OMAG, and is applicable for in vivo measurements. In contrast to the existing capillary flow quantification methods, the proposed method is less sensitive to tissue motion and does not have aliasing problems due fast flow within large blood vessels. This method is analogous to power Doppler in ultrasonography and estimates the number of red blood cells passing through the beam as opposed to the velocity of the particles. The technique is tested both qualitatively and quantitatively by using OMAG to image microcirculation within mouse ear flap in vivo.
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Liu X, Ramella-Roman JC, Huang Y, Guo Y, Kang JU. Robust spectral-domain optical coherence tomography speckle model and its cross-correlation coefficient analysis. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2013; 30:51-59. [PMID: 23456001 PMCID: PMC3615453 DOI: 10.1364/josaa.30.000051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In this study, we propose a generic speckle simulation for optical coherence tomography (OCT) signal, by convolving the point-spread function (PSF) of the OCT system with the numerically synthesized random sample field. We validate our model and use the simulation method to study the statistical properties of cross-correlation coefficients between A-scans, which have been recently applied in transverse motion analysis by our group. The results of simulation show that oversampling is essential for accurate motion tracking; exponential decay of OCT signal leads to an underestimate of motion that can be corrected; lateral heterogeneity of sample leads to an overestimate of motion for a few pixels corresponding to the structural boundary.
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Affiliation(s)
- Xuan Liu
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA.
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Abstract
We review the principle and some recent applications of Doppler optical coherence tomography (OCT). The advances of the phase-resolved Doppler OCT method are described. Functional OCT algorithms which are based on an extension of the phase-resolved scheme are also introduced. Recent applications of Doppler OCT for quantification of flow, imaging of microvasculature and vocal fold vibration, and optical coherence elastography are briefly discussed.
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Affiliation(s)
- Gangjun Liu
- Beckman Laser Institute, University of California, Irvine, USA
- Department of Biomedical Engineering, University of California, Irvine, USA
| | - Zhongping Chen
- Beckman Laser Institute, University of California, Irvine, USA
- Department of Biomedical Engineering, University of California, Irvine, USA
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Liu G, Lin AJ, Tromberg BJ, Chen Z. A comparison of Doppler optical coherence tomography methods. BIOMEDICAL OPTICS EXPRESS 2012; 3:2669-80. [PMID: 23082305 PMCID: PMC3469988 DOI: 10.1364/boe.3.002669] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 09/11/2012] [Accepted: 09/19/2012] [Indexed: 05/17/2023]
Abstract
We compare, in detail, the phase-resolved color Doppler (PRCD), phase-resolved Doppler variance (PRDV) and intensity-based Doppler variance (IBDV) methods. All the methods are able to quantify flow speed when the flow rate is within a certain range, which is dependent on the adjacent A-line time interval. While PRCD is most sensitive when the flow direction is along the probing beam, PRDV and IBDV can be used to measure the flow when the flow direction is near perpendicular to the probing beam. However, the values of PRDV and IBDV are Doppler angle-dependent when the Doppler angle is above a certain threshold. The sensitivity of all the methods can be improved by increasing the adjacent A-line time interval while still maintaining a high sampling density level. We also demonstrate for the first time, to the best of our knowledge, high resolution inter-frame PRDV method. In applications where mapping vascular network such as angiogram is more important than flow velocity quantification, IBDV and PRDV images show better contrast than PRCD images. The IBDV and PRDV show very similar characteristics and demonstrate comparable results for vasculature mapping. However, the IBDV is less sensitive to bulk motion and with less post-processing steps, which is preferred for fast data processing situations. In vivo imaging of mouse brain with intact skull and human skin with the three methods were demonstrated and the results were compared. The IBDV method was found to be able to obtain high resolution image with a relative simple processing procedure.
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Affiliation(s)
- Gangjun Liu
- Beckman Laser Institute, University of California, Irvine, Irvine, CA 92617, USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92617, USA
| | - Alexander J. Lin
- Beckman Laser Institute, University of California, Irvine, Irvine, CA 92617, USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92617, USA
| | - Bruce J. Tromberg
- Beckman Laser Institute, University of California, Irvine, Irvine, CA 92617, USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92617, USA
| | - Zhongping Chen
- Beckman Laser Institute, University of California, Irvine, Irvine, CA 92617, USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92617, USA
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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: 58] [Impact Index Per Article: 4.5] [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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