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Lu Y, Lu X, Zhang C, Marchand PJ, Lesage F. Longitudinal optical coherence tomography imaging of tissue repair and microvasculature regeneration and function after targeted cerebral ischemia. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-15. [PMID: 32285652 PMCID: PMC7152803 DOI: 10.1117/1.jbo.25.4.046002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 03/09/2020] [Indexed: 06/11/2023]
Abstract
SIGNIFICANCE Understanding how the brain recovers from cerebral tissue and vascular damage after an ischemic event can help develop new therapeutic strategies for the treatment of stroke. AIM We investigated cerebral tissue repair and microvasculature regeneration and function after a targeted ischemic stroke. APPROACH Following photothrombosis occlusion of microvasculature, chronic optical coherence tomography (OCT)-based angiography was used to track ischemic tissue repair and microvasculature regeneration at three different cortical depths and up to 28 days in awake animals. Capillary network orientation analysis was performed to study the structural pattern of newly formed microvasculature. Based on the time-resolved OCT-angiography, we also investigated capillary stalling, which is likely related to ischemic stroke-induced inflammation. RESULTS Deeper cerebral tissue was found to have a larger ischemic area than shallower regions at any time point during the course of poststroke recovery, which suggests that cerebral tissue located deep in the cortex is more vulnerable. Regenerated microvasculature had a highly organized pattern at all cortical depths with a higher degree of structural reorganization in deeper regions. Additionally, capillary stalling event analysis revealed that cerebral ischemia augmented stalling events considerably. CONCLUSION Longitudinal OCT angiography reveals that regenerated capillary network has a highly directional pattern and an increased density and incidence of capillary stalling event.
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Affiliation(s)
- Yuankang Lu
- Laboratoire d’Imagerie Optique et Moléculaire, École Polytechnique de Montréal, Montréal, Québec, Canada
| | - Xuecong Lu
- Laboratoire d’Imagerie Optique et Moléculaire, École Polytechnique de Montréal, Montréal, Québec, Canada
| | - Cong Zhang
- Laboratoire d’Imagerie Optique et Moléculaire, École Polytechnique de Montréal, Montréal, Québec, Canada
- Université de Montreal, Montréal, Québec, Canada
| | - Paul J. Marchand
- Laboratoire d’Imagerie Optique et Moléculaire, École Polytechnique de Montréal, Montréal, Québec, Canada
| | - Frédéric Lesage
- Laboratoire d’Imagerie Optique et Moléculaire, École Polytechnique de Montréal, Montréal, Québec, Canada
- Institut de Cardiologie de Montréal, Montréal, Québec, Canada
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102
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Czakó C, István L, Benyó F, Élő Á, Erdei G, Horváth H, Nagy ZZ, Kovács I. The Impact of Deterministic Signal Loss on OCT Angiography Measurements. Transl Vis Sci Technol 2020; 9:10. [PMID: 32821482 PMCID: PMC7401964 DOI: 10.1167/tvst.9.5.10] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 02/19/2020] [Indexed: 01/09/2023] Open
Abstract
Purpose In this study, we aimed at investigating the impact of deterministic signal loss on image quality and, thus, on optical coherence tomography angiography (OCTA) measurements performed by the RTVue-XR Avanti System. Methods Absorptive filters with different optical densities (ODs) were used to simulate signal loss in a controlled way in 30 eyes from 15 healthy subjects. Scan Quality (SQ), provided by the AngioVue software, was applied as a measure of image quality. Results Assessing the effect of decreased light transmittance on SQ values as well as that of attenuated image quality on OCTA parameters revealed a strong systematic dependence between these quantities. Attenuated image quality was associated with significantly decreased macular and peripapillary vessel density (VD) values, and we calculated a correction factor of 2.27% to 3.97% for a one-unit change in SQ for the different VD parameters. Conclusions Our findings suggest that the influence of systematic changes in image quality on OCTA parameters needs to be considered during patient follow-up in order to make valid assessment of progression. Translational Relevance For accurate evaluation of longitudinal changes in OCTA parameters, equal scan quality or using a correction factor is suggested.
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Affiliation(s)
- Cecilia Czakó
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Lilla István
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Fruzsina Benyó
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Ágnes Élő
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Gábor Erdei
- Department of Atomic Physics, Budapest University of Technology and Economics, Budapest, Hungary
| | - Hajnalka Horváth
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Zoltán Zsolt Nagy
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Illés Kovács
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
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Chen PH, Chen YJ, Chen YF, Yeh YC, Chang KW, Hou MC, Kuo WC. Quantification of structural and microvascular changes for diagnosing early-stage oral cancer. BIOMEDICAL OPTICS EXPRESS 2020; 11:1244-1256. [PMID: 32206406 PMCID: PMC7075615 DOI: 10.1364/boe.384608] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/16/2020] [Accepted: 01/22/2020] [Indexed: 05/15/2023]
Abstract
Changes in mucosal microvascular networks, called intraepithelial papillary capillary loops (IPCL), are an important key factor for diagnosing early-stage oral cancer in vivo. Nevertheless, there are a lack of tools to quantify these changes objectively. This is the first study to quantify the IPCL changes in vivo to differentiate benign or malignant oral lesions by the optical coherence tomography (OCT) technique. K14-EGFP-miR-211-GFP transgenic mice were inducted by 4-Nitroquinoline-1-oxide to produce oral carcinogenesis in different stages, including normal, premalignancy and cancer. The results showed significant differentiation between benign or malignant lesions by OCT quantitative parameters, including epithelial thickness, IPCL density, radius and tortuosity.
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Affiliation(s)
- Ping-Hsien Chen
- Endoscopy Center for Diagnosis and Treatment, Taipei Veterans General Hospital, Taipei 112, Taiwan
- Department of Medicine, National Yang-Ming University, Taipei 112, Taiwan
- Institute of Biophotonics, National Yang-Ming University, Taipei 112, Taiwan
- These authors contributed equally to this work
| | - Yu-Ju Chen
- Institute of Biophotonics, National Yang-Ming University, Taipei 112, Taiwan
- These authors contributed equally to this work
| | - Yi-Fen Chen
- Institute of Oral Biology, National Yang-Ming University, Taipei 112, Taiwan
| | - Yi-Chen Yeh
- Department of Medicine, National Yang-Ming University, Taipei 112, Taiwan
- Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan
| | - Kuo-Wei Chang
- Institute of Oral Biology, National Yang-Ming University, Taipei 112, Taiwan
- Department of Dentistry, National Yang-Ming University, Taipei 112, Taiwan
- Department of Stomatology, Taipei Veterans General Hospital, Taipei 112, Taiwan
| | - Ming-Chih Hou
- Department of Medicine, National Yang-Ming University, Taipei 112, Taiwan
- Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan
| | - Wen-Chuan Kuo
- Institute of Biophotonics, National Yang-Ming University, Taipei 112, Taiwan
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104
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Xie Z, Wang G, Cheng Y, Zhang Q, Le MN, Wang RK. Optical coherence tomography angiography measures blood pulsatile waveforms at variable tissue depths. Quant Imaging Med Surg 2020; 11:907-917. [PMID: 33654664 DOI: 10.21037/qims-20-778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background Photoplethysmography (PPG) is routinely used to detect the blood pulse signal from skin tissue beds in clinics. However, the origin of the PPG signal remains controversial. The purpose of this study is to explore optical coherence tomography angiography (OCTA) to indicate pulsatile waveforms in the papillary plexus and dermal plexus separately under different hand elevations. Method Optical microangiography (OMAG) algorithm was used to obtain a 3D OCTA signals, from which the depth-resolved pulsatile blood flow signals were extracted from different skin vascular plexus. The systolic amplitude, crest time, and delta T were measured from the OCTA pulsatile signals when the hand was placed at the positions of 50 cm below, 0 cm, and 50 cm above the heart level. Results The pulse signal integrated from all the depths has a similar waveform to that of the PPG and showed the same morphological change at different hand elevations. The pulsatile patterns from the papillary plexus and dermal plexus showed distinct morphological changes at different local blood pressure. Less amplitude difference was found from papillary plexus comparing to that of the dermal plexus. Crest time was found in an increasing trend in the OCTA pulsatile waveform from both plexuses when the arm was raised from the position below to above the heart level. In contrast, a decreasing trend of Delta T was detected in the dermal pulsatile but was not observed from that of the papillary plexus, indicating that vascular resistance associated with the arm elevations does not necessarily have the same effect on the two plexuses. Conclusions OCTA can provide depth-resolved pulsatile waveforms within different microvascular plexus within tissue skin beds. This technique could open doors to understanding the mechanisms of how blood flow changes at different skin circulatory plexus.
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Affiliation(s)
- Zhiying Xie
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Geng Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Yuxuan Cheng
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Qinqin Zhang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Minh Nhan Le
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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105
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Vaghefi E, Hill S, Kersten HM, Squirrell D. Quantification of Optical Coherence Tomography Angiography in Age and Age-Related Macular Degeneration Using Vessel Density Analysis. Asia Pac J Ophthalmol (Phila) 2020; 9:137-143. [PMID: 32205475 DOI: 10.1097/apo.0000000000000278] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The aim of this study was to determine whether vessel density (VD) as measured by optical coherence tomography (OCT) angiography provided insights into retinal and choriocapillaris vascular changes with aging and intermediate dry age-related macular degeneration (AMD). DESIGN Non-randomized observational study. METHODS Seventy-five participants were recruited into 3 cohorts: young healthy group, old healthy, and those at high-risk for exudative AMD. Raw OCT and OCT angiography data from TOPCON DRI OCT Triton were exported using Topcon IMAGENET 6.0 software, and 3D datasets were analysed to determine retinal thickness and VD. RESULTS Central macular thickness measurements revealed a trend of overall retinal thinning with increasing age. VD through the full thickness of the retina was highest in Early Treatment Diabetic Retinopathy Study (ETDRS) sector 4 (the inferior macula) in all the cohorts. Mean VD was significantly higher in the deep capillary plexus than the superficial capillary plexus in all ETDRS sectors in all cohorts, but there was no significant difference noted between groups. Choriocapillaris VD was significantly lower in all ETDRS sectors in the AMD group compared with the young healthy and the old healthy groups. CONCLUSIONS Retinal VD maps, derived from the retinal plexi, are not reliable biomarkers for assessing the aging macular. Our nonproprietary analysis of the vascular density of the choriocapillaris revealed a significant drop off of VD with age and disease, but further work is required to corroborate this finding. If repeatable, choriocapillaris VD may provide a noninvasive biomarker of healthy aging and disease.
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Affiliation(s)
- Ehsan Vaghefi
- School of Optometry and Vision Science, University of Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, New Zealand
| | - Sophie Hill
- Department of Ophthalmology, University of Auckland, New Zealand
| | - Hannah M Kersten
- School of Optometry and Vision Science, University of Auckland, New Zealand
| | - David Squirrell
- Department of Ophthalmology, University of Auckland, New Zealand
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106
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Si P, Honkala A, de la Zerda A, Smith BR. Optical Microscopy and Coherence Tomography of Cancer in Living Subjects. Trends Cancer 2020; 6:205-222. [PMID: 32101724 DOI: 10.1016/j.trecan.2020.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 01/05/2020] [Accepted: 01/07/2020] [Indexed: 12/16/2022]
Abstract
Intravital microscopy (IVM) and optical coherency tomography (OCT) are two powerful optical imaging tools that allow visualization of dynamic biological activities in living subjects with subcellular resolutions. Recent advances in labeling and label-free techniques empower IVM and OCT for a wide range of preclinical and clinical cancer imaging, providing profound insights into the complex physiological, cellular, and molecular behaviors of tumors. Preclinical IVM and OCT have elucidated many otherwise inscrutable aspects of cancer biology, while clinical applications of IVM and OCT are revolutionizing cancer diagnosis and therapies. We review important progress in the fields of IVM and OCT for cancer imaging in living subjects, highlighting key technological developments and their emerging applications in fundamental cancer biology research and clinical oncology investigation.
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Affiliation(s)
- Peng Si
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA
| | - Alexander Honkala
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Adam de la Zerda
- Department of Structural Biology, Stanford University, Stanford, CA 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA; Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA; The Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
| | - Bryan Ronain Smith
- Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA; Department of Biomedical Engineering and Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824, USA.
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107
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Yao X, Alam MN, Le D, Toslak D. Quantitative optical coherence tomography angiography: A review. Exp Biol Med (Maywood) 2020; 245:301-312. [PMID: 31958986 PMCID: PMC7370602 DOI: 10.1177/1535370219899893] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
As a new optical coherence tomography (OCT) modality, OCT angiography (OCTA) provides a noninvasive method to detect microvascular distortions correlated with eye conditions. By providing unparalleled capability to differentiate individual plexus layers in the retina, OCTA has demonstrated its excellence in clinical management of diabetic retinopathy, glaucoma, sickle cell retinopathy, diabetic macular edema, and other eye diseases. Quantitative OCTA analysis of retinal and choroidal vasculatures is essential to standardize objective interpretations of clinical outcome. Quantitative features, including blood vessel tortuosity, blood vessel caliber, blood vessel density, vessel perimeter index, fovea avascular zone area, fovea avascular zone contour irregularity, vessel branching coefficient, vessel branching angle, branching width ratio, and choroidal vascular analysis have been established for objective OCTA assessment. Moreover, differential artery–vein analysis has been recently demonstrated to improve OCTA performance for objective detection and classification of eye diseases. In this review, technical rationales and clinical applications of these quantitative OCTA features are summarized, and future prospects for using these quantitative OCTA features for artificial intelligence classification of eye conditions are discussed.
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Affiliation(s)
- Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Minhaj N Alam
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - David Le
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Devrim Toslak
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology, Antalya Training and Research Hospital, Antalya 07030, Turkey
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108
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Ogasawara Y, Iwase T, Yamamoto K, Ra E, Terasaki H. RELATIONSHIP BETWEEN ABNORMALITIES OF PHOTORECEPTOR MICROSTRUCTURES AND MICROVASCULAR STRUCTURES DETERMINED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IN EYES WITH BRANCH RETINAL VEIN OCCLUSION. Retina 2020; 40:350-358. [PMID: 31972806 DOI: 10.1097/iae.0000000000002379] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine whether the size of the foveal avascular zone (FAZ) is significantly correlated with the best-corrected visual acuity (BCVA) and to examine the relationship between the size and microstructural changes of the photoreceptors in eyes with a branch retinal vein occlusion. METHODS The medical records of 69 eyes of patients (mean age, 64.6 ± 11.7 years) with a branch retinal vein occlusion were reviewed after the resolution of macular edema. All the patients underwent optical coherence tomography angiography for measurement of the FAZ area and spectral domain optical coherence tomography for determination of microstructural changes of the photoreceptors at the fovea. RESULTS The superficial and deep FAZ areas in eyes with a branch retinal vein occlusion were 0.39 ± 0.36 mm and 0.63 ± 0.18 mm, respectively, and both were significantly larger than those observed in the fellow eyes (both, P < 0.001). The superficial FAZ area correlated with the posttreatment BCVA (r = 0.285, P = 0.027) but not with any parameters regarding the microstructures of the photoreceptors. Multivariate linear regression analysis showed that the pretreatment BCVA (β = 0.519, P < 0.001) and integrity of the external limiting membrane (β = -0.373, P = 0.001) were independent factors that significantly correlated with the posttreatment BCVA. CONCLUSION There was no significant correlation between the FAZ area and microstructural parameters. However, the integrity of the external limiting membrane was significantly correlated with the posttreatment BCVA in eyes with a branch retinal vein occlusion.
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Affiliation(s)
- Yasunobu Ogasawara
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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109
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Arnould L, Guenancia C, Gabrielle PH, Pitois S, Baudin F, Pommier T, Zeller M, Bron AM, Creuzot-Garcher C, Cottin Y. Influence of cardiac hemodynamic variables on retinal vessel density measurement on optical coherence tomography angiography in patients with myocardial infarction. J Fr Ophtalmol 2020; 43:216-221. [PMID: 31973975 DOI: 10.1016/j.jfo.2019.07.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 07/30/2019] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Quantitative measurements of retinal microvasculature by optical coherence tomography angiography (OCT-A) have been used to assess cardiovascular risk profile. However, to date, there are no studies focusing on OCT-A imaging in the setting of the altered hemodynamic status found in high-risk cardiovascular patients. METHODS To determine the potential association between retinal vascular density on OCT-A and a comprehensive battery of hemodynamic variables in patients with myocardial infarction (MI) using data from the acute phase and at 3 months follow-up after cardiac rehabilitation. This prospective longitudinal study included patients who presented with MI in the cardiology intensive care unit at Dijon University Hospital. Main outcomes and measurements were retinal vessel density on OCT-A, hemodynamic status based on left ventricular ejection fraction (LVEF), and indexed cardiac output during the acute phase of myocardial infarction and at 3 months follow-up. RESULTS Overall, 30 patients were included in this pilot study. The median (IQR) age was 64 years (55-71) with 87% men. At admission, the mean (SD) LVEF was 53% (11), and the mean indexed cardiac output was 2.70 (0.83) L/min/m2. On OCT-A, the mean inner retinal vascular density was 19.09 (2.80) mm-1. No significant association was found between retinal vascular density and hemodynamic variables. CONCLUSION We found no significant association between retinal vascular density on OCT-A and hemodynamic variables in the acute phase of a myocardial infarction or after 3 months of cardiac rehabilitation. Therefore, OCT-A findings do not seem to be influenced by the hemodynamic changes associated with myocardial infarction.
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Affiliation(s)
- L Arnould
- Ophthalmology Department, University Hospital, 14, rue Paul-Gaffarel, 21079 Dijon, France; INSERM, CIC1432, clinical epidemiology unit, Dijon, France; Dijon University Hospital, Clinical investigation Centre, Clinical epidemiology/clinical trials unit, Dijon, France; Centre des sciences du goût et de l'alimentation, Agrosup Dijon, CNRS, INRAE, université Bourgogne Franche-Comté, 21000 Dijon, France
| | - C Guenancia
- Cardiology Department, University Hospital, Dijon, France; PEC 2, University Hospital, Dijon, France
| | - P-H Gabrielle
- Ophthalmology Department, University Hospital, 14, rue Paul-Gaffarel, 21079 Dijon, France; Centre des sciences du goût et de l'alimentation, Agrosup Dijon, CNRS, INRAE, université Bourgogne Franche-Comté, 21000 Dijon, France
| | - S Pitois
- Cardiology Department, University Hospital, Dijon, France
| | - F Baudin
- Ophthalmology Department, University Hospital, 14, rue Paul-Gaffarel, 21079 Dijon, France
| | - T Pommier
- Cardiology Department, University Hospital, Dijon, France
| | - M Zeller
- Cardiology Department, University Hospital, Dijon, France
| | - A M Bron
- Ophthalmology Department, University Hospital, 14, rue Paul-Gaffarel, 21079 Dijon, France; Centre des sciences du goût et de l'alimentation, Agrosup Dijon, CNRS, INRAE, université Bourgogne Franche-Comté, 21000 Dijon, France
| | - C Creuzot-Garcher
- Ophthalmology Department, University Hospital, 14, rue Paul-Gaffarel, 21079 Dijon, France; Centre des sciences du goût et de l'alimentation, Agrosup Dijon, CNRS, INRAE, université Bourgogne Franche-Comté, 21000 Dijon, France.
| | - Y Cottin
- Cardiology Department, University Hospital, Dijon, France; PEC 2, University Hospital, Dijon, France
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Dadkhah A, Jiao S. Integrating photoacoustic microscopy, optical coherence tomography, OCT angiography, and fluorescence microscopy for multimodal imaging. Exp Biol Med (Maywood) 2020; 245:342-347. [PMID: 31914810 DOI: 10.1177/1535370219897584] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We have developed a multimodal imaging system, which integrated optical resolution photoacoustic microscopy, optical coherence tomography, optical coherence tomography angiography, and confocal fluorescence microscopy in one platform. The system is able to image complementary features of a biological sample by combining different contrast mechanisms. We achieved fast imaging and large field of view by combining optical scanning with mechanical scanning, similar to our previous publication. We have demonstrated the capability of the multimodal imaging system by imaging a mouse ear in vivo. Impact statement Photoacoustic microscopy-based multimodal imaging technology can provide high-resolution complementary information for biological tissues in vivo. It will potentially bring significant impact on the research and diagnosis of diseases by providing combined structural and functional information.
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Affiliation(s)
- Arash Dadkhah
- Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA
| | - Shuliang Jiao
- Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA
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111
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Shi Y, Zhang Q, Zheng F, Russell JF, Motulsky EH, Banta JT, Chu Z, Zhou H, Patel NA, de Sisternes L, Durbin MK, Feuer W, Gregori G, Wang RK, Rosenfeld PJ. Correlations Between Different Choriocapillaris Flow Deficit Parameters in Normal Eyes Using Swept Source OCT Angiography. Am J Ophthalmol 2020; 209:18-26. [PMID: 31562858 PMCID: PMC7017580 DOI: 10.1016/j.ajo.2019.09.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 09/16/2019] [Accepted: 09/17/2019] [Indexed: 11/24/2022]
Abstract
PURPOSE Choriocapillaris (CC) imaging of normal eyes with swept-source optical coherence tomographic angiography (SS-OCTA) was performed, and the percentage of CC flow deficits (FD%) and the average area of CC flow deficits (FDa) were compared within the given macular regions. DESIGN A prospective, cross-sectional study. METHODS Subjects with normal eyes ranging in age from their 20s through their 80s were imaged with SS-OCTA (PLEX Elite 9000; Carl Zeiss Meditec, Dublin, California, USA) using both 3×3-mm and 6×6-mm macular scan patterns. The CC images were generated using a previously published and validated algorithm. In both 3×3-mm and 6×6-mm scans, the CC FD% and FDa were measured in circular regions centered on the fovea with diameters as 1 mm and 2.5 mm (C1 and C2.5). In 6×6-mm scans, the FD% and FDa were measured within an additional circular region with diameter as 5 mm (C5). The correlations between FD% and FDa from each region were analyzed with Pearson correlation coefficients. RESULTS A total of 164 eyes were analyzed. There was excellent correlation between CC FDa and FD% measurements from each region. In the 3×3-mm scans, the correlations in the C1 and C2.5 regions were 0.83 and 0.90, respectively. In the 6×6-mm scans, the correlations in C1, C2.5, and C5 regions were 0.90, 0.89, and 0.89, respectively. CONCLUSIONS When measuring CC FDs, we found excellent correlations between FDa and FD% in regions from 3×3-mm and 6×6-mm scans. Further studies are needed to determine if one parameter is more useful when studying diseased eyes.
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Affiliation(s)
- Yingying Shi
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Qinqin Zhang
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Fang Zheng
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Jonathan F Russell
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Elie H Motulsky
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - James T Banta
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Zhongdi Chu
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Hao Zhou
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Nimesh A Patel
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Luis de Sisternes
- Research and Development, Carl Zeiss Meditec, Inc, Dublin, California, USA
| | - Mary K Durbin
- Research and Development, Carl Zeiss Meditec, Inc, Dublin, California, USA
| | - William Feuer
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Giovanni Gregori
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Philip J Rosenfeld
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA.
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Park JH, Yoo C, Kim YY. Peripapillary Vessel Density in Young Patients with Open-Angle Glaucoma: Comparison between High-Tension and Normal-Tension Glaucoma. Sci Rep 2019; 9:19160. [PMID: 31844171 PMCID: PMC6914787 DOI: 10.1038/s41598-019-55707-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 11/27/2019] [Indexed: 12/31/2022] Open
Abstract
Although primary open-angle glaucoma (OAG) generally occurs in older individuals and manifests in eyes with elevated intraocular pressure (IOP), it may also occur in young patients or in eyes with an IOP that always measures within the statistically normal range. Recent advances in optical coherence tomography angiography have enabled noninvasive visualization of the vasculature around the optic disc. In this study, we investigated the clinical features of young Korean patients with OAG and compared the peripapillary vessel density of patients with normal-tension glaucoma (NTG) to those with high-tension glaucoma (HTG). The peripapillary vessel density was reduced in eyes with HTG compared with that in normal subjects (HTG: 23.18 ± 2.06% vs. normal subjects: 24.74 ± 1.88%, P value = 0.013). In contrast, the peripapillary vessel density of eyes with NTG was comparable with that of normal eyes (NTG: 23.98 ± 2.30% vs. normal subjects: 24.74 ± 1.88%, P value = 0.505). These findings suggest that young patients with HTG show greater peripapillary microvascular attenuation than healthy subjects or young patients with NTG, indicating that different levels of the initial untreated IOP may have different effects on the peripapillary vessel density in young patients with OAG.
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Affiliation(s)
- Ji-Hye Park
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
| | - Chungkwon Yoo
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea.
| | - Yong Yeon Kim
- Department of Ophthalmology, Korea University College of Medicine, Seoul, Korea
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113
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Mangouritsas G, Koutropoulou N, Ragkousis A, Boutouri E, Diagourtas A. Peripapillary Vessel Density In Unilateral Preperimetric Glaucoma. Clin Ophthalmol 2019; 13:2511-2519. [PMID: 31997876 PMCID: PMC6917599 DOI: 10.2147/opth.s224757] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/18/2019] [Indexed: 01/08/2023] Open
Abstract
Purpose To investigate vessel density (VD) of radial peripapillary capillaries (RPC) and structural alterations in patients with unilateral preperimetric glaucoma (PPG) using optical coherence tomography angiography (OCTA). Methods This cross-sectional observational study included 13 untreated patients with unilateral PPG. PPG eyes had larger excavation and abnormal thinning of retinal nerve fiber layer (RNFL) and/or ganglion cell complex (GCC) compared with fellow eyes (F). Both RNFL and GCC thickness in F were statistically within normal limits and/or borderline. The RPC VD on optic disc (idVD), of peripapillary (ppVD) and whole image (wiVD) scan area was measured. Twenty healthy eyes (H) served as controls. Structural and vascular parameters obtained by spectral-domain OCT/OCTA (Optovue; Fremont, CA) were compared between PPG, F and H. Results Mean RNFL and GCC average thickness in microns differed significantly (p<0.001) between PPG (82.4±7.1, 81.4±5.9), F (91.0±7.1, 88.5±3.8) and H (103.5±6.0, 99.3±5.7). PPG compared with F showed significantly (p<0.001) lower mean ppVD (43.8%±3.0% versus 47.8%±3.2%) and wiVD (45.9%±3.5% versus 50.1%±3.9%). Mean ppVD (49.7%±2.4%) and wiVD (52.6%±3.0%) in H were not significantly higher than in F. Mean idVD showed no significant differences among the 3 groups. Areas under the receiver operating characteristic curves (AUROCs) for RNFL, GCC, ppVD and wiVD between PPG and H were excellent (>0.9). AUROCs between F and H demonstrated an excellent diagnostic ability for structural parameters and a poor one (<0.7) for vascular parameters. Conclusion Affected eyes of patients with unilateral PPG demonstrated significant RPC dropout. Clinically unaffected eyes showed thinner structural parameters but no significant microvasculature differences compared with non-glaucomatous eyes. Diagnostic ability of peripapillary vascular parameters was not superior to structural measurements. Microvascular dysfunction seems to be an early but not a primary event in glaucoma continuum at the stage of undetectable visual field loss. OCTA can be useful in early glaucoma diagnosis.
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Affiliation(s)
- G Mangouritsas
- Eye Clinic, General Hospital ''Red Cross'', Athens, Greece
| | - N Koutropoulou
- Eye Clinic, General Hospital ''Red Cross'', Athens, Greece
| | - A Ragkousis
- Eye Clinic, General Hospital ''Red Cross'', Athens, Greece
| | - E Boutouri
- Eye Clinic, General Hospital ''Red Cross'', Athens, Greece
| | - A Diagourtas
- 1st University Eye Clinic, General Hospital "G. Gennimatas", Athens, Greece
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114
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Casper MJ, Glahn J, Evers M, Schulz-Hildebrandt H, Kositratna G, Birngruber R, Hüttmann G, Manstein D. Capillary Refill-The Key to Assessing Dermal Capillary Capacity and Pathology in Optical Coherence Tomography Angiography. Lasers Surg Med 2019; 52:653-658. [PMID: 31755127 PMCID: PMC7496142 DOI: 10.1002/lsm.23188] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2019] [Indexed: 12/12/2022]
Abstract
Background/Objectives Standard optical coherence tomography angiography (OCTA) has been limited to imaging blood vessels actively undergoing perfusion, providing a temporary picture of surface microvasculature. Capillary perfusion in the skin is dynamic and changes in response to the surrounding tissue's respiratory, nutritional, and thermoregulatory needs. Hence, OCTA often represents a given perfusion state without depicting the actual extent of the vascular network. Here we present a method for obtaining a more accurate anatomic representation of the surface capillary network in human skin using OCTA, along with proposing a new parameter, the Relative Capillary Capacity (RCC), a quantifiable proxy for assessing capillary dilation potential and permeability. Methods OCTA images were captured at baseline and after compression of the skin. Baseline images display ambient capillary perfusion, while images taken upon capillary refill display the network of existing capillaries at full capacity. An optimization‐based automated vessel segmentation method was used to automatically analyze and compare OCTA image sequences obtained from two volunteers. RCC was then compared with visual impressions of capillary viability. Results Our OCTA imaging sequence provides a method for mapping cutaneous capillary networks independent of ambient perfusion. Differences between baseline and refill images clearly demonstrate the shortcomings of standard OCTA imaging and produce the RCC biometric as a quantifiable proxy for assessing capillary dilation potential and permeability. Conclusion Future dermatological OCTA diagnostic studies should implement the Capillary Refill Methods over standard imaging techniques and further explore the relevance of RCC to differential diagnosis and dermatopathology. Lasers Surg. Med. © The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.
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Affiliation(s)
- M J Casper
- Harvard Medical School, Cutaneous Biology Research Center, Massachusetts General Hospital, 149 13th Street, Boston, Massachusetts, 02129.,Institute of Biomedical Optics, Universität zu Lübeck, Peter-Monnik-Weg 4, Lübeck, 23562, Germany
| | - J Glahn
- Harvard Medical School, Cutaneous Biology Research Center, Massachusetts General Hospital, 149 13th Street, Boston, Massachusetts, 02129
| | - M Evers
- Harvard Medical School, Cutaneous Biology Research Center, Massachusetts General Hospital, 149 13th Street, Boston, Massachusetts, 02129.,Institute of Biomedical Optics, Universität zu Lübeck, Peter-Monnik-Weg 4, Lübeck, 23562, Germany
| | - H Schulz-Hildebrandt
- Institute of Biomedical Optics, Universität zu Lübeck, Peter-Monnik-Weg 4, Lübeck, 23562, Germany.,Medical Laser Center Lübeck, Peter-Monnik-Weg 4, Lübeck, 23562, Germany
| | - G Kositratna
- Harvard Medical School, Cutaneous Biology Research Center, Massachusetts General Hospital, 149 13th Street, Boston, Massachusetts, 02129
| | - R Birngruber
- Institute of Biomedical Optics, Universität zu Lübeck, Peter-Monnik-Weg 4, Lübeck, 23562, Germany.,Medical Laser Center Lübeck, Peter-Monnik-Weg 4, Lübeck, 23562, Germany.,Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, 02114
| | - G Hüttmann
- Institute of Biomedical Optics, Universität zu Lübeck, Peter-Monnik-Weg 4, Lübeck, 23562, Germany.,Medical Laser Center Lübeck, Peter-Monnik-Weg 4, Lübeck, 23562, Germany.,Airway Research Center North (ARCN), Member of the German Center of Lung Research (DZL), Gießen, Germany
| | - D Manstein
- Harvard Medical School, Cutaneous Biology Research Center, Massachusetts General Hospital, 149 13th Street, Boston, Massachusetts, 02129
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115
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Lim HB, Kim YW, Nam KY, Ryu CK, Jo YJ, Kim JY. Signal Strength as an Important Factor in the Analysis of Peripapillary Microvascular Density Using Optical Coherence Tomography Angiography. Sci Rep 2019; 9:16299. [PMID: 31705032 PMCID: PMC6841660 DOI: 10.1038/s41598-019-52818-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 10/22/2019] [Indexed: 12/22/2022] Open
Abstract
The quality of the scan image is important in peripapillary circulation analysis using optical coherence tomography angiography (OCTA). We aimed to investigate the effects of signal strength (SS) on the peripapillary microvascular density acquired from OCTA. A total of 259 eyes from 259 young healthy subjects were included. Peripapillary OCTA images using 3 × 3 mm angiography scan were acquired from all participants. Subjects were divided into four groups according to the SS: SS 7, SS 8, SS 9, and SS 10. Vessel density (VD) and perfusion density (PD) of the superficial capillary plexus were calculated. VD and PD were compared among the four groups, and linear regression analyses were performed to identify and evaluate the clinical factors associated with average VD. As the SS increased from 7 to 10, the average VD and PD increased; these increases were statistically significant (all, p < 0.001). Regression analyses showed that four factors were significantly correlated with average VD: age (partial r = 0.133), average retinal nerve fiber layer thickness (partial r = 0.169), cup/disc ratio (partial r =-0.481), and SS (partial r = 0.413). SS is a significant factor affecting peripapillary microvascular density, and its influence is similar to well-known structural parameters associated with glaucoma.
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Affiliation(s)
- Hyung Bin Lim
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Republic of Korea.,Department of Ophthalmology, Armed Forces Capital Hospital, Seongnam, Republic of Korea
| | - Yong Woo Kim
- Department of Ophthalmology, Armed Forces Capital Hospital, Seongnam, Republic of Korea.,Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Ki Yup Nam
- Department of Ophthalmology, Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - Cheon Kuk Ryu
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Republic of Korea
| | - Young Joon Jo
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Republic of Korea
| | - Jung Yeul Kim
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Republic of Korea.
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116
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Lee TH, Lim HB, Nam KY, Kim K, Kim JY. Factors Affecting Repeatability of Assessment of the Retinal Microvasculature Using Optical Coherence Tomography Angiography in Healthy Subjects. Sci Rep 2019; 9:16291. [PMID: 31704998 PMCID: PMC6841961 DOI: 10.1038/s41598-019-52782-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 10/16/2019] [Indexed: 01/02/2023] Open
Abstract
Various factors can affect repeatability of optical coherence tomography angiography (OCTA) measurements, and they have not been studied sufficiently. We aimed to investigate the factors associated with the repeatability of automated superficial retinal vessel density (VD) and foveal avascular zone (FAZ) metrics acquired from OCTA. A total of 141 normal eyes from 141 healthy subjects were included, and two consecutive macular 6 × 6-mm angiography scans were performed. VD, perfusion density (PD), and FAZ of the superficial capillary plexus were calculated automatically. Reproducibility was assessed based on intraclass correlations (ICCs) and coefficients of variation (CVs). VD (ICC: 0.824, CV: 3.898) and PD (ICC: 0.845, CV: 4.042) over the entire 6-mm scan area showed better repeatability than VD (ICC: 0.752, CV: 17.470) and PD (ICC: 0.752, CV: 18.552) in the 1-mm scan, and with respect to the obtained FAZ metrics (ICC < 0.75, CV > 10.0%). Regression analyses showed that two factors, signal strength (p = 0.004) and average VD over the total 6-mm scan area (p < 0.001), were significantly correlated with the CV of the VD. Signal strength was associated with the repeatability of OCTA measurements and should be considered in the analysis of retinal VD and FAZ.
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Affiliation(s)
- Taek Hoon Lee
- Rhee's Eye Hospital, Daejeon, Republic of Korea.,Graduate School of Medicine, Chungnam National University College of Medicine, Daejeon, Republic of Korea
| | - Hyung Bin Lim
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Republic of Korea
| | - Ki Yup Nam
- Department of Ophthalmology, Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - Kyeungmin Kim
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Republic of Korea
| | - Jung Yeul Kim
- Graduate School of Medicine, Chungnam National University College of Medicine, Daejeon, Republic of Korea. .,Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, Republic of Korea.
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117
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Czakó C, István L, Ecsedy M, Récsán Z, Sándor G, Benyó F, Horváth H, Papp A, Resch M, Borbándy Á, Nagy ZZ, Kovács I. The effect of image quality on the reliability of OCT angiography measurements in patients with diabetes. Int J Retina Vitreous 2019; 5:46. [PMID: 31709114 PMCID: PMC6829984 DOI: 10.1186/s40942-019-0197-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/28/2019] [Indexed: 01/21/2023] Open
Abstract
Background This study aimed to determine the relationship between image quality and measurement repeatability of optical coherence tomography angiography (OCTA) parameters in patients with non-proliferative diabetic retinopathy. Methods A total of 100 eyes of 50 patients were included in the study. Three OCTA images were obtained consecutively during one session of imaging in all patients using the RTVue AngioVue OCTA device. We applied the signal strength index (SSI) provided by the RTVue system to define scan quality. Superficial vessel density (VD) in the central 3 × 3 mm macular and in the perifoveal region, as well as foveal avascular zone (FAZ) area were evaluated by the AngioAnalytics software for each scan from three consecutive measurements, whereby measurement repeatability of the OCTA parameters were calculated. The effect of SSI value on OCTA parameters, as well as on measurement errors was assessed. Results Values of SSI ranged from 30 to 85 with an overall mean of 61.79 ± 10.38. Mean SSI values showed significant positive correlation with the mean retinal capillary vessel density values, but not with non-flow area. Repeatability of OCTA parameters was generally improved with higher SSI values. We calculated a mean correction factor of 0.22% (95% CI 0.20–0.24 µm; p < 0.001) for VD at the 3 × 3 mm macular scan, 0.23% (95% CI 0.21–0.26%; p < 0.001) for perifoveal VD and − 0.001 mm2 (95% CI − 0.001 to 0.002; p = 0.001) for the non-flow area for each unit increase in SSI for the comparison of images with different SSI values. Conclusions The influence of image quality on OCTA metrics should be considered for image comparisons during follow-up to avoid misinterpretation of small changes in OCTA parameters in patients with diabetes.
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Affiliation(s)
- Cecília Czakó
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - Lilla István
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - Mónika Ecsedy
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - Zsuzsa Récsán
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - Gábor Sándor
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - Fruzsina Benyó
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - Hajnalka Horváth
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - András Papp
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - Miklós Resch
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - Ágnes Borbándy
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - Zoltán Zsolt Nagy
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
| | - Illés Kovács
- Department of Ophthalmology, Semmelweis University, 26 Üllői Street, Budapest, 1085 Hungary
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118
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Lee HJ, Samiudin NM, Lee TG, Doh I, Lee SW. Retina phantom for the evaluation of optical coherence tomography angiography based on microfluidic channels. BIOMEDICAL OPTICS EXPRESS 2019; 10:5535-5548. [PMID: 31799029 PMCID: PMC6865089 DOI: 10.1364/boe.10.005535] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/28/2019] [Accepted: 09/28/2019] [Indexed: 05/22/2023]
Abstract
Optical coherence tomography (OCT) angiography (OCTA) has been actively studied as a noninvasive imaging technology to generate retinal blood vessel network maps for the diagnoses of retinal diseases. Given that the uses of OCT and OCTA have increased in the field of ophthalmology, it is necessary to develop retinal phantoms for clinical OCT for product development, performance evaluation, calibration, certification, medical device licensing, and production processes. We developed a retinal layer-mimicking phantom with microfluidic channels based on microfluidic fabrication technology using polydimethylsiloxane (PDMS) and titanium dioxide (TiO2) powder. We implemented superficial and deep retinal vessels using microfluidic channels. In addition, multilayered thin films were synthesized with multiple spin-coating processes that comprised layers that corresponded to the retinal layers, including the ganglion cell layer (GCL), inner plexiform layer (IPL), and inner nuclear layer (INL). The phantom was formed by merging the multilayered thin film, and microfluidic channels were assembled with an optical lens, water chamber, and an aluminum tube case. Finally, we obtained cross-sectional OCT images and en-face OCTA images of the retinal phantom using lab-made ophthalmic OCT. From the cross-sectional OCT image, we could compare each of the layer thicknesses of the phantom with the corresponding layer thicknesses of the human retina. In addition, we obtained en-face OCTA images with injections of intralipid solutions. It is shown that this phantom will be able to be potentially used as a convenient tool to evaluate and standardize the quality and accuracy of OCT and OCTA images.
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Affiliation(s)
- Hyun-Ji Lee
- Center for Nano-Bio Measurement, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
- Department of Medical Physics, Korea University of Science and Technology, 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - Nafra M Samiudin
- Center for Medical Convergence Metrology, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
- Department of Medical Physics, Korea University of Science and Technology, 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - Tae Geol Lee
- Center for Nano-Bio Measurement, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
- Department of Nano Science, Korea University of Science and Technology, 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - Il Doh
- Center for Medical Convergence Metrology, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
- Department of Medical Physics, Korea University of Science and Technology, 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - Sang-Won Lee
- Center for Nano-Bio Measurement, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
- Department of Medical Physics, Korea University of Science and Technology, 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
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119
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OCT angiography features associated with macular edema recurrence after intravitreal bevacizumab treatment in branch retinal vein occlusion. Sci Rep 2019; 9:14153. [PMID: 31578437 PMCID: PMC6775095 DOI: 10.1038/s41598-019-50637-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 09/17/2019] [Indexed: 11/24/2022] Open
Abstract
We aimed to evaluate the relationship between the capillary abnormalities including nonperfusion area (NPA) in optical coherence tomography angiography (OCTA) images and the recurrence of macular edema (ME) secondary to branch retinal vein occlusion (BRVO) after intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF; bevacizumab). The records of 40 patients who underwent intravitreal bevacizumab injection for ME secondary to BRVO and had at least six months of follow-up were reviewed. Central retinal thickness (CRT; μm) and macular edema type were evaluated prior to treatment. After ME resolution, nonperfusion areas in the 1 mm (NPA1) and 1–3 mm (NPA3) zones on the Early Treatment Diabetic Retinopathy Study (ETDRS) circle within the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were measured using OCTA images. Furthermore, other microvascular abnormalities in the both SCP and DCP were compared between groups. ME recurred in 25 of 40 (62.5%) eyes. The NPA1 of the SCP and DCP (p = 0.002, 0.004, respectively), NPA3 of the SCP and DCP (p = 0.002, 0.008, respectively), and initial CRT (p = 0.022) differed significantly between eyes with and without ME recurrence. In multivariate logistic regression analyses, the NPA1 of the DCP (OR: 344.718; p = 0.029) and NPA3 of the SCP (OR: 4.072; p = 0.018) were significantly associated with ME recurrence. Other microvascular abnormalities were not significantly different between two groups. The central NPA and parafoveal NPA of the SCP in OCTA images correlated strongly with ME recurrence in BRVO patients after intravitreal anti-VEGF injection.
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120
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Malone JD, El-Haddad MT, Yerramreddy SS, Oguz I, Tao YK. Handheld spectrally encoded coherence tomography and reflectometry for motion-corrected ophthalmic optical coherence tomography and optical coherence tomography angiography. NEUROPHOTONICS 2019; 6:041102. [PMID: 32042852 PMCID: PMC6991137 DOI: 10.1117/1.nph.6.4.041102] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/12/2019] [Indexed: 05/05/2023]
Abstract
Optical coherence tomography (OCT) is the gold standard for quantitative ophthalmic imaging. The majority of commercial and research systems require patients to fixate and be imaged in a seated upright position, which limits the ability to perform ophthalmic imaging in bedridden or pediatric patients. Handheld OCT devices overcome this limitation, but image quality often suffers due to a lack of real-time aiming and patient eye and photographer motion. We describe a handheld spectrally encoded coherence tomography and reflectometry (SECTR) system that enables simultaneous en face reflectance and cross-sectional OCT imaging. The handheld probe utilizes a custom double-pass scan lens for fully telecentric OCT scanning with a compact optomechanical design and a rapid-prototyped enclosure to reduce the overall system size and weight. We also introduce a variable velocity scan waveform that allows for simultaneous acquisition of densely sampled OCT angiography (OCTA) volumes and widefield reflectance images, which enables high-resolution vascular imaging with precision motion-tracking for volumetric motion correction and multivolumetric mosaicking. Finally, we demonstrate in vivo human retinal OCT and OCT angiography (OCTA) imaging using handheld SECTR on a healthy volunteer. Clinical translation of handheld SECTR will allow for high-speed, motion-corrected widefield OCT and OCTA imaging in bedridden and pediatric patients who may benefit ophthalmic disease diagnosis and monitoring.
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Affiliation(s)
- Joseph D. Malone
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Mohamed T. El-Haddad
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
| | - Suhaas S. Yerramreddy
- Vanderbilt University, Department of Electrical Engineering and Computer Science, Nashville, Tennessee, United States
| | - Ipek Oguz
- Vanderbilt University, Department of Electrical Engineering and Computer Science, Nashville, Tennessee, United States
| | - Yuankai K. Tao
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee, United States
- Address all correspondence to Yuankai K. Tao, E-mail:
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121
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Wei W, Tang P, Xie Z, Li Y, Wang RK. Dynamic imaging and quantification of subcellular motion with eigen-decomposition optical coherence tomography-based variance analysis. JOURNAL OF BIOPHOTONICS 2019; 12:e201900076. [PMID: 31033200 PMCID: PMC6774886 DOI: 10.1002/jbio.201900076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 04/21/2019] [Accepted: 04/26/2019] [Indexed: 06/01/2023]
Abstract
The dynamic properties of subcellular organism are important biomarkers of the health. Imaging subcellular level dynamics provides effective solutions for evaluating cell metabolism and testing the responses of cells to pathogens and drugs in pharmaceutical engineering. In this paper, we demonstrate an innovative approach to contrast the subcellular motion by using eigen decomposition (ED)-based variance analysis of time-dependent complex optical coherence tomography signals. This method reveals a superior advantage of contrast to noise ratio when compared with the approach that employs intensity decorrelation. Furthermore, the eigen values derived from ED processing are calculated and applied to assess the power ratios of complex signal invariance that decreases exponentially along time dimension. The validation experiments are performed on the patterned samples of yeast powder mixed with gelatin/TiO2 water solution. Additionally, the proposed method is used to image mouse cerebral cortex in normal and pathological conditions, suggesting the practicality of variance power mapping in analyzing cortical neural activities. The technique promises efficient measurement of subcellular motions with high sensitivity and high throughput for in vivo and in situ applications.
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Affiliation(s)
- Wei Wei
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Peijun Tang
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Zhiying Xie
- Department of Biology, University of Washington, Seattle, Washington
| | - Yuandong Li
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, Washington
- Department of Ophthalmology, University of Washington, Seattle, Washington
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122
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Moshiri Y, Legocki AT, Zhou K, Cabrera MT, Rezaei KA, Tarczy-Hornoch K, Wang RK. Handheld swept-source optical coherence tomography with angiography in awake premature neonates. Quant Imaging Med Surg 2019; 9:1495-1502. [PMID: 31667136 DOI: 10.21037/qims.2019.09.01] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background Retinopathy of prematurity (ROP) can lead to retinal detachment and severe vision loss and is a common cause of childhood blindness. Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality that can be used to detect potential abnormalities in the microvasculature in this population. The objective of this study is to assess the feasibility of a newly developed handheld swept source OCT (SS-OCT) device to successfully acquire structural vitreoretinal and retinal microvascular images in awake premature infants. Methods OCT and OCTA images were acquired at the time of routine ROP examinations from awake, unsedated preterm infants in the Neonatal Intensive Care Unit using a clinical research prototype handheld probe integrated with an SS-OCT system working at 1,060 nm wavelength and an imaging speed of 200,000 A-scans per second (200 kHz), enabling volume OCT and OCTA scans. Each volume was acquired with approximately 36˚ field of view (~6.3×6.3 mm in infants) in 4.8 s. Quality of acquired OCT and OCTA volume images, microvascular information, and vitreoretinal features were determined by 3-masked grader consensus. Results Twelve infants (5 females, mean gestational age 28.3 weeks, median birth weight 901 g, stages 0 to 3 ROP) underwent a total of 73 individual eye imaging sessions. High-quality OCT images of the fovea and the optic nerve were present in 69/73 (94.5%) and 56/73 (76.7%) scans, respectively. Vitreous bands were observed in 10/73 (13.7%); punctate hyperreflective vitreous opacities in 47/73 (64.4%); epiretinal membrane (ERM) in 6/73 (8.2%); and cystoid macular edema (CME) in 12/73 (16.4%) scans. Mild vessel elevation was noted in 3/73 (4.1%) images, and severe vessel elevation in 4/73 (5.5%) scans. OCTA images obtained in 8 awake infants revealed good quality images of the foveal microvasculature in 11/19 (58%) eye imaging sessions for 6/8 (75%) infants; and peripapillary microvasculature in 14/19 (74%) eye imaging sessions for 5/8 (63%) infants. Conclusions The SS-OCTA handheld device can capture important vitreoretinal characteristics such as peripapillary and foveal microvasculature, as well as hyperreflective punctate vitreous opacities and tractional vitreous bands, which may predict ROP severity. These images were captured in awake, premature infants without the use of direct ocular contact, an eyelid speculum, or sedation.
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Affiliation(s)
- Yasman Moshiri
- Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA
| | - Alex T Legocki
- Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA
| | - Kanheng Zhou
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Michelle T Cabrera
- Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA.,Department of Ophthalmology, Seattle Children's Hospital, Seattle, WA 98105, USA
| | - Kasra A Rezaei
- Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA
| | | | - Ruikang K Wang
- Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA.,Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
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123
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Kirby MA, Zhou K, Pitre JJ, Gao L, Li D, Pelivanov I, Song S, Li C, Huang Z, Shen T, Wang R, O’Donnell M. Spatial resolution in dynamic optical coherence elastography. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-16. [PMID: 31535538 PMCID: PMC6749618 DOI: 10.1117/1.jbo.24.9.096006] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 08/26/2019] [Indexed: 05/03/2023]
Abstract
Dynamic optical coherence elastography (OCE) tracks elastic wave propagation speed within tissue, enabling quantitative three-dimensional imaging of the elastic modulus. We show that propagating mechanical waves are mode converted at interfaces, creating a finite region on the order of an acoustic wavelength where there is not a simple one-to-one correspondence between wave speed and elastic modulus. Depending on the details of a boundary’s geometry and elasticity contrast, highly complex propagating fields produced near the boundary can substantially affect both the spatial resolution and contrast of the elasticity image. We demonstrate boundary effects on Rayleigh waves incident on a vertical boundary between media of different shear moduli. Lateral resolution is defined by the width of the transition zone between two media and is the limit at which a physical inclusion can be detected with full contrast. We experimentally demonstrate results using a spectral-domain OCT system on tissue-mimicking phantoms, which are replicated using numerical simulations. It is shown that the spatial resolution in dynamic OCE is determined by the temporal and spatial characteristics (i.e., bandwidth and spatial pulse width) of the propagating mechanical wave. Thus, mechanical resolution in dynamic OCE inherently differs from the optical resolution of the OCT imaging system.
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Affiliation(s)
- Mitchell A. Kirby
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
| | - Kanheng Zhou
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
- University of Dundee, School of Science and Engineering, Dundee, United Kingdom
| | - John J. Pitre
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
| | - Liang Gao
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
| | - David Li
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
- University of Washington, Department of Chemical Engineering, Seattle, Washington, United States
| | - Ivan Pelivanov
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
- Address all correspondence to Ivan Pelivanov, E-mail:
| | - Shaozhen Song
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
| | - Chunhui Li
- University of Dundee, School of Science and Engineering, Dundee, United Kingdom
| | - Zhihong Huang
- University of Dundee, School of Science and Engineering, Dundee, United Kingdom
| | - Tueng Shen
- University of Washington, Department of Ophthalmology, Seattle, Washington, United States
| | - Ruikang Wang
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
- University of Washington, Department of Ophthalmology, Seattle, Washington, United States
| | - Matthew O’Donnell
- University of Washington, Department of Bioengineering, Seattle, Washington, United States
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124
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Meiburger KM, Chen Z, Sinz C, Hoover E, Minneman M, Ensher J, Kittler H, Leitgeb RA, Drexler W, Liu M. Automatic skin lesion area determination of basal cell carcinoma using optical coherence tomography angiography and a skeletonization approach: Preliminary results. JOURNAL OF BIOPHOTONICS 2019; 12:e201900131. [PMID: 31100191 PMCID: PMC7065618 DOI: 10.1002/jbio.201900131] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 05/05/2023]
Abstract
Cutaneous blood flow plays a key role in numerous physiological and pathological processes and has significant potential to be used as a biomarker to diagnose skin diseases such as basal cell carcinoma (BCC). The determination of the lesion area and vascular parameters within it, such as vessel density, is essential for diagnosis, surgical treatment and follow-up procedures. Here, an automatic skin lesion area determination algorithm based on optical coherence tomography angiography (OCTA) images is presented for the first time. The blood vessels are segmented within the OCTA images and then skeletonized. Subsequently, the skeleton is searched over the volume and numerous quantitative vascular parameters are calculated. The vascular density is then used to segment the lesion area. The algorithm is tested on both nodular and superficial BCC, and comparing with dermatological and histological results, the proposed method provides an accurate, non-invasive, quantitative and automatic tool for BCC lesion area determination.
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Affiliation(s)
- Kristen M. Meiburger
- Biolab, Department of Electronics and TelecommunicationsPolitecnico di TorinoTorinoItaly
| | - Zhe Chen
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Christoph Sinz
- Department of DermatologyMedical University of ViennaViennaAustria
| | | | | | | | - Harald Kittler
- Department of DermatologyMedical University of ViennaViennaAustria
| | - Rainer A. Leitgeb
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Wolfgang Drexler
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Mengyang Liu
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
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125
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An amplitude variation Field subtraction technique for visualization of vasculature of the human eye. Biomed Signal Process Control 2019. [DOI: 10.1016/j.bspc.2019.101573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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126
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Optical coherence tomography angiography in preclinical neuroimaging. Biomed Eng Lett 2019; 9:311-325. [PMID: 31456891 DOI: 10.1007/s13534-019-00118-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/29/2019] [Accepted: 06/27/2019] [Indexed: 01/22/2023] Open
Abstract
Preclinical neuroimaging allows for the assessment of brain anatomy, connectivity, and function in laboratory animals, such as mice and this imaging field has been a rapidly growing aimed at bridging the translation gap between animal and human research. The progress in the animal research could be accelerated by high-resolution in vivo optical imaging technologies. Optical coherence tomography-based angiography (OCTA) estimates the scattering from moving red blood cells, providing the visualization of functional micro-vessel networks within tissue beds in vivo without a need for exogenous contrast agents. Recent advancement of OCTA methods have expanded its application to neuroimaging of small animal models of brain disorders. In this paper, we overview the recent development of OCTA techniques for blood flow imaging and its preclinical applications in neuroimaging. In specific, a summary of preclinical OCTA studies for traumatic brain injury, cerebral stroke, and aging brain on mice is reviewed.
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127
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Lauermann P, van Oterendorp C, Storch MW, Khattab MH, Feltgen N, Hoerauf H, Bemme S. Distance-Thresholded Intercapillary Area Analysis Versus Vessel-Based Approaches to Quantify Retinal Ischemia in OCTA. Transl Vis Sci Technol 2019; 8:28. [PMID: 31440425 PMCID: PMC6701872 DOI: 10.1167/tvst.8.4.28] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 06/04/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose To develop and compare different analytic approaches for quantifying ischemia in OCT-angiography (OCTA), including vessel-based approaches and intercapillary area analysis. Methods En face OCTA (6 × 6) images of the superficial plexus of 20 healthy eyes and 20 eyes with different ischemic retinal diseases were analyzed retrospectively. Included retinal diseases were diabetic retinopathy (n = 9), central (n = 5) and branch retinal vein occlusion (n = 4), hypertensive retinopathy (n = 1), and occlusive retinal vasculitis in sarcoidosis (n = 1). Vessel-based approaches consisted of the mean gray scale, perfusion density, and vessel density. Intercapillary areas (ICAs) were analyzed measuring the distance of each intercapillary pixel from the surrounding vessels. In particular, we applied a vector method to measure the shortest, the mean, and the longest distance in eight predefined directions. Size of ICAs was determined applying different global or local distance thresholds. Results All approaches revealed significant differences between ischemic and healthy retinae (P < 0.001, with Bonferroni-Holm correction P = 0.001–0.025; Wilcoxon-Mann-Whitney test). Discrimination between the healthy and ischemic retinae based on ROC curves was best in the ICA analysis using a locally set threshold of the shortest distance. Conclusions In the present study, ICA analysis was superior to vessel-based approaches in the quantification of retinal ischemia when defining a local or global distance threshold. Translational Relevance In order to establish OCTA imaging in everyday clinical and scientific practice, standardized, device-independent image analysis methods are necessary.
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Affiliation(s)
- Peer Lauermann
- Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
| | | | - Marcus W Storch
- Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
| | - Mohammed H Khattab
- Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
| | - Nicolas Feltgen
- Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
| | - Hans Hoerauf
- Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
| | - Sebastian Bemme
- Department of Ophthalmology, University Medical Center Göttingen, Göttingen, Germany
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128
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Motulsky EH, Liu G, Shi Y, Zheng F, Flynn HW, Gregori G, Rosenfeld PJ. Widefield Swept-Source Optical Coherence Tomography Angiography of Proliferative Diabetic Retinopathy. Ophthalmic Surg Lasers Imaging Retina 2019; 50:474-484. [DOI: 10.3928/23258160-20190806-01] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 01/17/2019] [Indexed: 12/27/2022]
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129
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Advances in the simulation of light-tissue interactions in biomedical engineering. Biomed Eng Lett 2019; 9:327-337. [PMID: 31456892 DOI: 10.1007/s13534-019-00123-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 07/15/2019] [Accepted: 07/18/2019] [Indexed: 12/15/2022] Open
Abstract
Monte Carlo (MC) simulation for light propagation in scattering and absorbing media is the gold standard for studying the interaction of light with biological tissue and has been used for years in a wide variety of cases. The interaction of photons with the medium is simulated based on its optical properties and the original approximation of the scattering phase function. Over the past decade, with the new measurement geometries and recording techniques invented also the corresponding sophisticated methods for the description of the underlying light-tissue interaction taking into account realistic parameters and settings were developed. Applications, such as multiple scattering, optogenetics, optical coherence tomography, Raman spectroscopy, polarimetry and Mueller matrix measurement have emerged and are still constantly improved. Here, we review the advances and recent applications of MC simulation for the active field of the life sciences and the medicine pointing out the new insights enabled by the theoretical concepts.
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130
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Gottschalk HM, Wecker T, Khattab MH, Fischer CV, Callizo J, Rehfeldt F, Lubjuhn R, Russmann C, Hoerauf H, van Oterendorp C. Lipid Emulsion-Based OCT Angiography for Ex Vivo Imaging of the Aqueous Outflow Tract. Invest Ophthalmol Vis Sci 2019; 60:397-406. [PMID: 30682210 DOI: 10.1167/iovs.18-25223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Contrast agents applicable for optical coherence tomography (OCT) imaging are rare. The intrascleral aqueous drainage system would be a potential application for a contrast agent, because the aqueous veins are of small diameter and located deep inside the highly scattering sclera. We tested lipid emulsions (LEs) as candidate OCT contrast agents in vitro and ex vivo, including milk and the anesthetic substance Propofol. Methods Commercial OCT and OCT angiography (OCTA) devices were used. Maximum reflectivity and signal transmission of LE were determined in tube phantoms. Absorption spectra and light scattering was analyzed. The anterior chamber of enucleated porcine eyes was perfused with LEs, and OCTA imaging of the LEs drained via the aqueous outflow tract was performed. Results All LEs showed a significantly higher reflectivity than water (P < 0.001). Higher milk lipid content was positively correlated with maximum reflectivity and negatively with signal transmission. Propofol exhibited the best overall performance. Due to a high degree of signal fluctuation, OCTA could be applied for detection of LE. Compared with blood, the OCTA signal of Propofol was significantly stronger (P = 0.001). As a proof of concept, time-resolved aqueous angiography of porcine eyes was performed. The three-dimensional (3D) structure and dynamics of the aqueous outflow were significantly different from humans. Conclusions LEs induced a strong signal in OCT and OCTA. LE-based OCTA allowed the ability to obtain time-resolved 3D datasets of aqueous outflow. Possible interactions of LE with inner eye's structures need to be further investigated before in vivo application.
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Affiliation(s)
- Hanna M Gottschalk
- Department of Ophthalmology, University Medical Center, Göttingen, Germany
| | | | - Mohammed H Khattab
- Department of Ophthalmology, University Medical Center, Göttingen, Germany
| | | | - Josep Callizo
- Department of Ophthalmology, University Medical Center, Göttingen, Germany
| | - Florian Rehfeldt
- Third Institute of Physics, Biophysics, Georg-August-University, Göttingen, Germany
| | - Roswitha Lubjuhn
- Department of Anaesthesiology, University Medical Center, Göttingen, Germany
| | - Christoph Russmann
- Faculty of Natural Science and Technology, University of Applied Sciences and Arts, Göttingen, Germany.,Molecular Biomarkers Nano-Imaging Laboratory, Brigham and Women's Hospital, and Department of Radiology, Harvard Medical School, Boston, Massachusetts, United States
| | - Hans Hoerauf
- Department of Ophthalmology, University Medical Center, Göttingen, Germany
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131
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Zhou K, Song S, Zhang Q, Chu Z, Huang Z, Wang RK. Visualizing choriocapillaris using swept-source optical coherence tomography angiography with various probe beam sizes. BIOMEDICAL OPTICS EXPRESS 2019; 10:2847-2860. [PMID: 31259055 PMCID: PMC6583358 DOI: 10.1364/boe.10.002847] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/02/2019] [Accepted: 05/09/2019] [Indexed: 05/29/2023]
Abstract
Imaging choriocapillaris (CC) is a long-term challenge for commercial OCT angiography (OCTA) systems due to limited transverse resolution. Effects of transverse resolution on the visualization of a CC microvascular network are explored and demonstrated in this paper. We use three probe beams with sizes of ~1.12 mm, ~2.51 mm and ~3.50 mm at the pupil plane, which deliver an estimated transverse resolution at the retina of 17.5 µm, 8.8 µm and 7.0 µm, respectively, to investigate the ability of OCTA to resolve the CC capillary vessels. The complex optical microangiography algorithm is applied to extract blood flow in the CC slab. Mean retinal pigment epithelium (RPE) to CC (RPE-CC) distance, mean CC inter-vascular spacing and the magnitude in the radially-averaged power spectrum are quantified. We demonstrate that a clearer CC lobular capillary network is resolved in the angiograms provided by a larger beam size. The image contrast of the CC angiogram with a large beam size of 3.50 mm is 114% higher than that with a small beam size of 1.12 mm. While the measurements of the mean RPE-CC distance and CC inter-vascular spacing are almost consistent regardless of the beam sizes, they are more reliable and stable with the larger beam size of 3.50 mm. We conclude that the beam size is a key parameter for CC angiography if the purpose of the investigation is to visualize the individual CC capillaries.
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Affiliation(s)
- Kanheng Zhou
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, UK
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Shaozhen Song
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Qinqin Zhang
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Zhongdi Chu
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Zhihong Huang
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, UK
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
- Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA
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Thulliez M, Zhang Q, Shi Y, Zhou H, Chu Z, de Sisternes L, Durbin MK, Feuer W, Gregori G, Wang RK, Rosenfeld PJ. Correlations between Choriocapillaris Flow Deficits around Geographic Atrophy and Enlargement Rates Based on Swept-Source OCT Imaging. Ophthalmol Retina 2019; 3:478-488. [PMID: 31174669 PMCID: PMC11402513 DOI: 10.1016/j.oret.2019.01.024] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/08/2018] [Accepted: 01/30/2019] [Indexed: 01/12/2023]
Abstract
PURPOSE To determine the possible correlation between the annual enlargement rates (ERs) of geographic atrophy (GA) with the percentage and size of the choriocapillaris (CC) flow deficits (FDs) surrounding GA, measured with swept-source OCT angiography (SS-OCTA) images. DESIGN Prospective, observational case series. PARTICIPANTS Patients with GA secondary to nonexudative AMD. METHODS Patients were imaged with a 100-kHz SS-OCTA instrument (PLEX Elite 9000, Carl Zeiss Meditec, Dublin, CA) using a 6×6-mm field of view scan pattern. The GA area measurements were obtained from en face SS-OCT sub-retinal pigment epithelium (RPE) slab images. Visualization of the CC and quantification of FDs were performed using a previously published validated algorithm based on a 20-μm thickness slab with the inner boundary located beneath Bruch's membrane. The percentage of CC FDs (FD%) and the average FD area measurements were calculated in different regions around the GA. MAIN OUTCOME MEASURES The correlation between the CC FDs and the ERs of GA. RESULTS Twenty-two eyes from 15 patients were eligible for the analysis. The annual square root ERs for GA ranged from 0.07 to 0.75 mm/year. The CC FD% and average FD area measurements were highly correlated with each other (P < 0.001), with the highest FD values found in the region closest to the margin of GA. The ERs correlated best with the average CC FD area measurements in the total scan area minus the area of GA (Pearson r = 0.747; P < 0.001) than those in the regions immediately surrounding the GA (r = 0.544; P = 0.009). CONCLUSIONS Contrary to expectations, the global CC FD measurements had a better correlation with the ERs of GA than those in the regions immediately around the GA. The most likely explanation for this outcome is that normal age-related increases in FDs within the central macula confound the correlations between the ERs of GA and FDs, whereas the regions furthest away from the margins of GA are less affected by normal age-related changes and reflect FD alterations related to AMD severity.
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Affiliation(s)
- Marie Thulliez
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Qinqin Zhang
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Yingying Shi
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Hao Zhou
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Zhongdi Chu
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Luis de Sisternes
- Research and Development, Carl Zeiss Meditec, Inc, Dublin, California
| | - Mary K Durbin
- Research and Development, Carl Zeiss Meditec, Inc, Dublin, California
| | - William Feuer
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Giovanni Gregori
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Philip J Rosenfeld
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.
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Enders C, Baeuerle F, Lang GE, Dreyhaupt J, Lang GK, Loidl M, Werner JU. Comparison between Findings in Optical Coherence Tomography Angiography and in Fluorescein Angiography in Patients with Diabetic Retinopathy. Ophthalmologica 2019; 243:21-26. [PMID: 31137028 DOI: 10.1159/000499114] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 02/25/2019] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To compare typical findings of diabetic retinopathy in optical coherence tomography angiography (OCTA) and fluorescein angiography (FA). SUBJECTS/METHODS 42 patients were enrolled in this study. We performed FA and obtained en face 3 × 3 mm OCTA images of the macular region. The count of microaneurysms (MAs) and the size of the foveal avascular zone (FAZ) were compared. The assessability of the imaging modalities was graded in each eye. RESULTS 53 eyes of 42 patients with a mean age of 61 years were included. 36/53 eyes revealed nonproliferative diabetic retinopathy, 17/53 eyes had proliferative diabetic retinopathy. The mean size of the FAZ was 0.39 mm2 in FA and 0.42 mm2 in OCTA. The mean MA count was 14 in FA and 13 in OCTA. The assessability was favorable to OCTA in 38-41/53 eyes regarding the FAZ and favorable to FA in 45-49/53 eyes regarding MAs. CONCLUSION We found a good agreement for the size of the FAZ and a weak agreement regarding the count of MAs in both imaging modalities. The readers favored OCTA for the assessment of the FAZ and FA for the assessment of MAs. Complementary use of FA and OCTA ensures the best diagnostic approach in patients with diabetic retinopathy.
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Affiliation(s)
| | | | | | - Jens Dreyhaupt
- Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany
| | - Gerhard K Lang
- Department of Ophthalmology, Ulm University, Ulm, Germany
| | - Max Loidl
- Department of Ophthalmology, Ulm University, Ulm, Germany
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Dingerkus VLS, Munk MR, Brinkmann MP, Freiberg FJ, Heussen FMA, Kinzl S, Lortz S, Orgül S, Becker M. Optical coherence tomography angiography (OCTA) as a new diagnostic tool in uveitis. J Ophthalmic Inflamm Infect 2019; 9:10. [PMID: 31139955 PMCID: PMC6538703 DOI: 10.1186/s12348-019-0176-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 05/06/2019] [Indexed: 01/05/2023] Open
Abstract
Background The broad spectrum of uveitis disorders requires a multimodal imaging approach in the daily practice of an ophthalmologist. As inflammatory conditions, they have in common an alteration in leukocyte migration. In this context, optical coherence tomography angiography (OCTA) might be of great value for diagnosing or following up patients with these disorders. To date, OCTA has rather been used as an additional tool besides the well-established diagnostic imaging tools, but its complementary diagnostic features become increasingly relevant, to follow disease activity and treatment response and for the understanding of pathomechanisms of various uveitis types. This review summarizes the possible applications of OCTA and its advantages and disadvantages as opposed to dye-based angiographies in uveitic diseases. Main body Hitherto gold standards in the diagnostic workup of posterior or intermediate uveitis have been angiography on a dye-based method, which is fluorescein or indocyanine green. It gives information about the status of the blood-retinal barrier and the retinal and choroidal vasculature by visualizing diffuse leakage as a state of inflammation or complications as an ischemia or choroidal neovascularization. As noninvasive methods, fundus autofluorescence depicts the status of metabolic activity of the retinal pigment epithelium and OCT or enhanced depth imaging OCT, respectively, as a depth-resolving imaging method can supply additional information. OCTA as a non-invasive, depth-resolution imaging tool of retinal and choroidal vessels adds detailed qualitative and quantitative information of the status of retinal and choroidal vessels and bridges the gap between the mentioned conventional diagnostic tools used in uveitis. It is important, though, to be aware of its limitations, such as its susceptibility to motion artifacts, limited comparability among different devices, and restricted contribution of information regarding the grade of disease activity. Conclusion OCTA as a non-invasive, depth-resolution imaging tool can give qualitative and quantitative information about the status of retinal and choroidal vessels, but also has certain limitations. Employing OCTA as a complementary rather than exclusive tool, it can give important additional information about the macro- and microvasculature under inflammatory circumstances. Thereby, it also contributes to the understanding of the pathophysiology of various uveitis entities.
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Affiliation(s)
- Vita L S Dingerkus
- Department of Ophthalmology, City Hospital Triemli, Birmensdorferstrasse 497, CH-8063, Zürich, Switzerland.
| | - Marion R Munk
- Department of Ophthalmology, University Clinic Bern, Bern, Switzerland
| | - Max P Brinkmann
- Department of Ophthalmology, City Hospital Triemli, Birmensdorferstrasse 497, CH-8063, Zürich, Switzerland
| | - Florentina J Freiberg
- Department of Ophthalmology, City Hospital Triemli, Birmensdorferstrasse 497, CH-8063, Zürich, Switzerland
| | - Florian M A Heussen
- Department of Ophthalmology, City Hospital Triemli, Birmensdorferstrasse 497, CH-8063, Zürich, Switzerland
| | - Stephan Kinzl
- Department of Ophthalmology, City Hospital Triemli, Birmensdorferstrasse 497, CH-8063, Zürich, Switzerland
| | - Sandra Lortz
- Department of Ophthalmology, City Hospital Triemli, Birmensdorferstrasse 497, CH-8063, Zürich, Switzerland
| | - Selim Orgül
- Department of Ophthalmology, City Hospital Triemli, Birmensdorferstrasse 497, CH-8063, Zürich, Switzerland
| | - Matthias Becker
- Department of Ophthalmology, City Hospital Triemli, Birmensdorferstrasse 497, CH-8063, Zürich, Switzerland.,Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany
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135
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Burwood GWS, Fridberger A, Wang RK, Nuttall AL. Revealing the morphology and function of the cochlea and middle ear with optical coherence tomography. Quant Imaging Med Surg 2019; 9:858-881. [PMID: 31281781 PMCID: PMC6571188 DOI: 10.21037/qims.2019.05.10] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 05/09/2019] [Indexed: 01/17/2023]
Abstract
Optical coherence tomography (OCT) has revolutionized physiological studies of the hearing organ, the vibration and morphology of which can now be measured without opening the surrounding bone. In this review, we provide an overview of OCT as used in the otological research, describing advances and different techniques in vibrometry, angiography, and structural imaging.
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Affiliation(s)
- George W. S. Burwood
- Department of Otolaryngology, Oregon Hearing Research Center/HNS, Oregon Health & Science University, Portland, OR, USA
| | - Anders Fridberger
- Department of Otolaryngology, Oregon Hearing Research Center/HNS, Oregon Health & Science University, Portland, OR, USA
- Department of Clinical and Experimental Medicine, Section for Neurobiology, Linköping University, Linköping, Sweden
| | - Ruikang K. Wang
- Department of Bioengineering and Department of Ophthalmology, University of Washington, Seattle, WA, USA
| | - Alfred L. Nuttall
- Department of Otolaryngology, Oregon Hearing Research Center/HNS, Oregon Health & Science University, Portland, OR, USA
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136
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Deegan AJ, Mandell SP, Wang RK. Optical coherence tomography correlates multiple measures of tissue damage following acute burn injury. Quant Imaging Med Surg 2019; 9:731-741. [PMID: 31281770 DOI: 10.21037/qims.2019.04.19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Background The visual assessment of burned skin is inherently subjective, and whilst a number of imaging modalities have identified quantifiable parameters to characterize vascular and structural changes following burn damage, none have become common place in the assessment protocol. Here, we use optical coherence tomography (OCT)-based angiography (OCTA) to introduce novel correlations between vessel depth, i.e., the depth of functional blood vessels beneath the tissue surface, edema depth, i.e., the depth of interstitial fluid buildup beneath the tissue surface, and tissue injury depth, i.e., the depth of collagen denaturation beneath the tissue surface, following burn injury. Methods A clinical prototype OCT system was used to collect OCT images from various sites of burned skin in patients. Optical microangiography (OMAG) algorithm was used to derive OCTA information from the acquired OCT images, from which the presence of blood vessels and edema were detected. The optical attenuation mapping of structural OCT information was used to detect tissue injury depth. The depths of vessel, edema and tissue injury were measured using a semi-automatic segmentation algorithm. Correlation analysis was performed using a Pearson correlation coefficient using one-tailed analysis with significance being established by a P value ≤0.05. Results Four burn patients were recruited and scanned at multiple sites using the prototype system within 3-6 days of injury. Approximate measurements include a vessel depth range of 320-1,360 µm, an edema depth range of 0-400 µm, and a tissue injury depth range of 130-420 µm. Correlations were subsequently observed between vessel depth and edema depth (r=0.8521, P=0.0001), and vessel depth and tissue injury depth (r=0.6296, P=0.0106). Conclusions OCT is feasible to provide the critical information of vessel depth, edema depth, and tissue injury depth of skin burns, which may represent viable assessment criteria for the characterization of cutaneous burns in future.
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Affiliation(s)
- Anthony J Deegan
- Department of Bioengineering, University of Washington, Seattle, WA 98104, USA
| | - Samuel P Mandell
- Division of Trauma, Critical Care, and Burn, Harborview Medical Center, University of Washington, Seattle, WA 98104, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, WA 98104, USA.,Department of Ophthalmology, University of Washington, Seattle, WA 98104, USA
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137
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Ju MJ, Hsu D, Kwon JH, Wahl DJ, Bonora S, Jian Y, Makita S, Yasuno Y, Sarunic MV. Multi-scale and -contrast sensorless adaptive optics optical coherence tomography. Quant Imaging Med Surg 2019; 9:757-768. [PMID: 31281772 DOI: 10.21037/qims.2019.05.17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Background The roles of the retinal microvasculature and the retinal pigment epithelium (RPE) in maintaining the health and metabolic activity of the retina lend great clinical value to their high-resolution visualization. Methods By integrating polarization diversity detection (PDD) into multi-scale and -contrast sensorless adaptive optics optical coherence tomography (MSC-SAO-OCT), we have developed a novel multi-contrast SAO OCT system for imaging pigment in the RPE as well as flow in the retinal capillaries using OCT angiography (OCTA). Aberration correction was performed based on the image quality using transmissive deformable optical elements. Results MSC-SAO-OCTA imaging was performed at multiple fields-of-view (FOVs) with adjustable numerical aperture (NA). Retinal flow and RPE structural images for in vivo healthy and pathological human posterior eyes were demonstrated to show clinical feasibility of the system. Conclusions High-resolution imaging of retinal vasculature at both large and small FOVs, as well as characterization of RPE topology and deformation, enables more sophisticated and concise investigation of retinal pathologies for in vivo human imaging. MSC imaging may permit detection and analysis of even subtle deformations in the RPE layer using a single instrument.
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Affiliation(s)
- Myeong Jin Ju
- Department of Engineering Science, Simon Fraser University, Burnaby, Canada.,Beckman Laser Institute-Korea, College of Medicine, Dankook University, Cheonan, South Korea
| | - Destiny Hsu
- Department of Engineering Science, Simon Fraser University, Burnaby, Canada
| | - Ji Hoon Kwon
- Department of Engineering Science, Simon Fraser University, Burnaby, Canada
| | - Daniel J Wahl
- Department of Engineering Science, Simon Fraser University, Burnaby, Canada
| | - Stefano Bonora
- CNR-Institute for Photonics and Nanotechnology, Padova, Italy
| | - Yifan Jian
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Shuichi Makita
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Marinko V Sarunic
- Department of Engineering Science, Simon Fraser University, Burnaby, Canada
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138
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Viehland C, Chen X, Tran-Viet D, Jackson-Atogi M, Ortiz P, Waterman G, Vajzovic L, Toth CA, Izatt JA. Ergonomic handheld OCT angiography probe optimized for pediatric and supine imaging. BIOMEDICAL OPTICS EXPRESS 2019; 10:2623-2638. [PMID: 31143506 PMCID: PMC6524583 DOI: 10.1364/boe.10.002623] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/20/2019] [Accepted: 04/20/2019] [Indexed: 05/09/2023]
Abstract
OCT angiography is a functional extension of OCT that allows for non-invasive imaging of retinal microvasculature. However, most current OCT angiography systems are tabletop systems that are typically used for imaging compliant, seated subjects. These systems cannot be readily applied for imaging important patient populations such as bedridden patients, patients undergoing surgery in the operating room, young children in the clinic, and infants in the intensive care nursery. In this manuscript, we describe the design and development of a non-contact, handheld probe optimized for OCT angiography that features a novel diverging light on the scanner optical design that provides improved optical performance over traditional OCT scanner designs. Unlike most handheld OCT probes, which are designed to be held by the side of the case or by a handle, the new probe was optimized for ergonomics of supine imaging where imagers prefer to hold the probe by the lens tube. The probe's design also includes an adjustable brace that gives the operator a point of contact closer to the center of mass of the probe, reducing the moment of inertia around the operator's fingers, facilitating stabilization, and reducing operator fatigue. The probe supports high-speed imaging using a 200 kHz swept source OCT engine, has a motorized stage that provides + 10 to -10 D refractive error correction and weighs 700g. We present initial handheld OCT angiography images from healthy adult volunteers, young children during exams under anesthesia, and non-sedated infants in the intensive care nursery. To the best of our knowledge, this represents the first reported use of handheld OCT angiography in non-sedated infants, and the first handheld OCT angiography images which show the clear delineation of key features of the retinal capillary complex including the foveal avascular zone, peripapillary vasculature, the superficial vascular complex, and the deep vascular complex.
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Affiliation(s)
- Christian Viehland
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Xi Chen
- Department of Ophthalmology, Duke University, Durham, NC, 27708, USA
| | - Du Tran-Viet
- Department of Ophthalmology, Duke University, Durham, NC, 27708, USA
| | | | - Pablo Ortiz
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Gar Waterman
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Lejla Vajzovic
- Department of Ophthalmology, Duke University, Durham, NC, 27708, USA
| | - Cynthia A. Toth
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Department of Ophthalmology, Duke University, Durham, NC, 27708, USA
| | - Joseph A. Izatt
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Department of Ophthalmology, Duke University, Durham, NC, 27708, USA
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139
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Erdener ŞE, Tang J, Sajjadi A, Kılıç K, Kura S, Schaffer CB, Boas DA. Spatio-temporal dynamics of cerebral capillary segments with stalling red blood cells. J Cereb Blood Flow Metab 2019; 39:886-900. [PMID: 29168661 PMCID: PMC6501506 DOI: 10.1177/0271678x17743877] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Optical coherence tomography (OCT) allows label-free imaging of red blood cell (RBC) flux within capillaries with high spatio-temporal resolution. In this study, we utilized time-series OCT-angiography to demonstrate interruptions in capillary RBC flux in mouse brain in vivo. We noticed ∼7.5% of ∼200 capillaries had at least one stall in awake mice with chronic windows during a 9-min recording. At any instant, ∼0.45% of capillaries were stalled. Average stall duration was ∼15 s but could last over 1 min. Stalls were more frequent and longer lasting in acute window preparations. Further, isoflurane anesthesia in chronic preparations caused an increase in the number of stalls. In repeated imaging, the same segments had a tendency to stall again over a period of one month. In awake animals, functional stimulation decreased the observance of stalling events. Stalling segments were located distally, away from the first couple of arteriolar-side capillary branches and their average RBC and plasma velocities were lower than nonstalling capillaries within the same region. This first systematic analysis of capillary RBC stalls in the brain, enabled by rapid and continuous volumetric imaging of capillaries with OCT-angiography, will lead to future investigations of the potential role of stalling events in cerebral pathologies.
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Affiliation(s)
- Şefik Evren Erdener
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Jianbo Tang
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Amir Sajjadi
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Kıvılcım Kılıç
- 2 Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sreekanth Kura
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Chris B Schaffer
- 3 Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - David A Boas
- 1 Optics Division, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.,2 Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
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140
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Sirotkina MA, Moiseev AA, Matveev LA, Zaitsev VY, Elagin VV, Kuznetsov SS, Gelikonov GV, Ksenofontov SY, Zagaynova EV, Feldchtein FI, Gladkova ND, Vitkin A. Accurate early prediction of tumour response to PDT using optical coherence angiography. Sci Rep 2019; 9:6492. [PMID: 31019242 PMCID: PMC6482310 DOI: 10.1038/s41598-019-43084-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 04/16/2019] [Indexed: 12/12/2022] Open
Abstract
Prediction of tumour treatment response may play a crucial role in therapy selection and optimization of its delivery parameters. Here we use optical coherence angiography (OCA) as a minimally-invasive, label-free, real-time bioimaging method to visualize normal and pathological perfused vessels and monitor treatment response following vascular-targeted photodynamic therapy (PDT). Preclinical results are reported in a convenient experimental model (CT-26 colon tumour inoculated in murine ear), enabling controlled PDT and post-treatment OCA monitoring. To accurately predict long-term treatment outcome, a robust and simple microvascular metric is proposed. It is based on perfused vessels density (PVD) at t = 24 hours post PDT, calculated for both tumour and peri-tumour regions. Histological validation in the examined experimental cohort (n = 31 animals) enabled further insight into the excellent predictive power of the derived early-response OCA microvascular metric. The results underscore the key role of peri-tumour microvasculature in determining the long-term PDT response.
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Affiliation(s)
- M A Sirotkina
- Privolzhsky Research Medical University, Minin Square 10/1, 603950, Nizhny Novgorod, Russia.
| | - A A Moiseev
- Institute of Applied Physics of the Russian Academy of Sciences, Ulyanov Street 46, 603950, Nizhny Novgorod, Russia
| | - L A Matveev
- Institute of Applied Physics of the Russian Academy of Sciences, Ulyanov Street 46, 603950, Nizhny Novgorod, Russia
| | - V Y Zaitsev
- Institute of Applied Physics of the Russian Academy of Sciences, Ulyanov Street 46, 603950, Nizhny Novgorod, Russia
| | - V V Elagin
- Privolzhsky Research Medical University, Minin Square 10/1, 603950, Nizhny Novgorod, Russia
| | - S S Kuznetsov
- Privolzhsky Research Medical University, Minin Square 10/1, 603950, Nizhny Novgorod, Russia
| | - G V Gelikonov
- Institute of Applied Physics of the Russian Academy of Sciences, Ulyanov Street 46, 603950, Nizhny Novgorod, Russia
| | - S Y Ksenofontov
- Institute of Applied Physics of the Russian Academy of Sciences, Ulyanov Street 46, 603950, Nizhny Novgorod, Russia
| | - E V Zagaynova
- Privolzhsky Research Medical University, Minin Square 10/1, 603950, Nizhny Novgorod, Russia
| | - F I Feldchtein
- Privolzhsky Research Medical University, Minin Square 10/1, 603950, Nizhny Novgorod, Russia
| | - N D Gladkova
- Privolzhsky Research Medical University, Minin Square 10/1, 603950, Nizhny Novgorod, Russia
| | - A Vitkin
- Departments of Medical Biophysics and Radiation Oncology, University of Toronto and University Health Network, 610 University Ave., Toronto, Ontario, M5G 2M9, Canada
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141
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Optical coherence tomography angiography for noninvasive evaluation of angiogenesis in a limb ischemia mouse model. Sci Rep 2019; 9:5980. [PMID: 30979948 PMCID: PMC6461622 DOI: 10.1038/s41598-019-42520-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 04/02/2019] [Indexed: 01/15/2023] Open
Abstract
We developed an optical coherence tomography angiography technique by improving the speckle contrast algorithm and the imaging process. This technique, which can achieve angiogenesis imaging in vivo without increasing trauma, was used to evaluate the microvasculature in limb ischemia mice. Sixteen left hindlimb ischemia mice were randomly allocated into CuSO4 and saline groups. Within 7 days after treatment, limb ischemic damage, temperature and histological staining were assessed by traditional methods. In addition, angiogenesis was evaluated using an optical coherence tomography angiography system in vivo. All results were compared. After 7 days of treatment, both the ischemic tissue damage score and temperature ratio of the CuSO4 group were significantly higher than those of the control group (all P < 0.05). The number of CD31-positive endothelial cells in the CuSO4 group (0.1836 ± 0.0153) was significantly greater than that in the saline control group (0.0436 ± 0.0069) (P < 0.001). Optical coherence tomography angiography showed that the vessel area density of mice in the CuSO4 group (0.2566 ± 0.0060) was significantly greater than that of mice in the control group (0.2079 ± 0.0202) (P = 0.027). Optical coherence tomography angiography represents a practical and effective method for observing angiogenesis in the mouse hindlimb in vivo without increasing trauma.
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142
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Song S, Zhou K, Xu JJ, Zhang Q, Lyu S, Wang R. Development of a clinical prototype of a miniature hand-held optical coherence tomography probe for prematurity and pediatric ophthalmic imaging. BIOMEDICAL OPTICS EXPRESS 2019; 10:2383-2398. [PMID: 31143494 DOI: 10.1364/boe.10.002383] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/06/2019] [Accepted: 04/08/2019] [Indexed: 02/05/2023]
Abstract
We report a novel design and operation of a highly integrated miniature handheld OCT probe, with high-speed angiography function that can be used in clinical settings for young children and infants, providing rapid, non-invasive structural and angiographic imaging of the retina and choroid. The imaging system is operated at 200 kHz, with 3D OCT and OCTA scan time of 0.8 and 3.2 seconds, respectively, and the scanning angle on the pupil is ± 36°, covering the full perifoveal region. Operator assisting features of the direct-view iris camera and on-probe display are integrated into the hand-held probe, and the fixation target can display animations to attract the attention of young subjects. Compared to conventional OCT systems, the high-speed hand-held OCT system significantly improves the operator's experience and scanning efficiency, which is important for imaging infants. Imaging results indicate a significant reduction in total time consumption in pediatric ophthalmic imaging sessions, as well as the image quality of OCT angiography.
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Affiliation(s)
- Shaozhen Song
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Kanheng Zhou
- Department of Bioengineering, University of Washington, Seattle, Washington, USA.,School of Science and Engineering, University of Dundee, Dundee, Scotland, United Kingdom
| | - Jing Jiang Xu
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Qinqin Zhang
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Shuyuan Lyu
- Department of Bioengineering, University of Washington, Seattle, Washington, USA.,Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Ruikang Wang
- Department of Bioengineering, University of Washington, Seattle, Washington, USA.,Department of Ophthalmology, University of Washington, Seattle, Washington, USA
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143
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Akil H, Karst S, Heisler M, Etminan M, Navajas E, Maberley D. Application of optical coherence tomography angiography in diabetic retinopathy: a comprehensive review. Can J Ophthalmol 2019; 54:519-528. [PMID: 31564340 DOI: 10.1016/j.jcjo.2019.02.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 12/12/2022]
Abstract
Optical coherence tomography angiography (OCTA) is a noninvasive method that enables visualization of blood flow within retinal vessels down to the size of capillaries by detecting motion contrast from moving blood cells. OCTA provides a fast and safe procedure to assess retinal microvasculature with higher contrast and resolution than conventional fluorescence angiography. The different capillary plexuses are displayed separately and their perfusion density can be quantified. Imaging capabilities such as these have led to an emerging field of clinical application for OCTA in vascular diseases such as diabetic retinopathy (DR). Evaluation of parameters such as parafoveal capillary perfusion density could be a biomarker for disease diagnosis and progression. Typical microvascular changes in DR such as capillary nonperfusion, microaneurysms, intraretinal microvascular abnormalities, and neovascularization can be reliably detected in optical coherence tomography angiograms, characterized in detail and attributed to the different capillary plexuses. Monitoring of these lesions in vivo gives potential novel insight into the pathophysiology in DR. The aim of this article is to summarize the potential applications/utility of OCTA in DR reported in the literature.
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Affiliation(s)
- Handan Akil
- Department of Ophthalmology, Faculty of Medicine, University of British Columbia, Vancouver, B.C
| | - Sonja Karst
- Department of Ophthalmology, Faculty of Medicine, University of British Columbia, Vancouver, B.C.; Department of Ophthalmology and Optometry, Medical University Vienna, Vienna, Austria
| | - Morgan Heisler
- Faculty of Applied Sciences, Simon Fraser University, Burnaby, B.C
| | - Mahyar Etminan
- Department of Ophthalmology, Faculty of Medicine, University of British Columbia, Vancouver, B.C
| | - Eduardo Navajas
- Department of Ophthalmology, Faculty of Medicine, University of British Columbia, Vancouver, B.C
| | - David Maberley
- Department of Ophthalmology, Faculty of Medicine, University of British Columbia, Vancouver, B.C..
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144
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Generating retinal flow maps from structural optical coherence tomography with artificial intelligence. Sci Rep 2019; 9:5694. [PMID: 30952891 PMCID: PMC6450899 DOI: 10.1038/s41598-019-42042-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 03/14/2019] [Indexed: 11/14/2022] Open
Abstract
Despite advances in artificial intelligence (AI), its application in medical imaging has been burdened and limited by expert-generated labels. We used images from optical coherence tomography angiography (OCTA), a relatively new imaging modality that measures retinal blood flow, to train an AI algorithm to generate flow maps from standard optical coherence tomography (OCT) images, exceeding the ability and bypassing the need for expert labeling. Deep learning was able to infer flow from single structural OCT images with similar fidelity to OCTA and significantly better than expert clinicians (P < 0.00001). Our model allows generating flow maps from large volumes of previously collected OCT data in existing clinical trials and clinical practice. This finding demonstrates a novel application of AI to medical imaging, whereby subtle regularities between different modalities are used to image the same body part and AI is used to generate detailed inferences of tissue function from structure imaging.
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145
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Casper M, Schulz-Hildebrandt H, Evers M, Birngruber R, Manstein D, Hüttmann G. Optimization-based vessel segmentation pipeline for robust quantification of capillary networks in skin with optical coherence tomography angiography. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-11. [PMID: 31041858 PMCID: PMC6990060 DOI: 10.1117/1.jbo.24.4.046005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 04/01/2019] [Indexed: 06/09/2023]
Abstract
Optical coherence tomography angiography (OCTA) provides in-vivo images of microvascular perfusion in high resolution. For its application to basic and clinical research, an automatic and robust quantification of the capillary architecture is mandatory. Only this makes it possible to reliably analyze large amounts of image data, to establish biomarkers, and to monitor disease developments. However, due to its optical properties, OCTA images of skin often suffer from a poor signal-to-noise ratio and contain imaging artifacts. Previous work on automatic vessel segmentation in OCTA mostly focuses on retinal and cerebral vasculature. Its applicability to skin and, furthermore, its robustness against imaging artifacts had not been systematically evaluated. We propose a segmentation method that improves the quality of vascular quantification in OCTA images even if corrupted by imaging artifacts. Both the combination of image processing methods and the choice of their parameters are systematically optimized to match the manual labeling of an expert for OCTA images of skin. The efficacy of this optimization-based vessel segmentation is further demonstrated on sample images as well as by a reduced error of derived quantitative vascular network characteristics.
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Affiliation(s)
- Malte Casper
- Massachusetts General Hospital, Harvard Medical School, Cutaneous Biology Research Center, Department of Dermatology, Charlestown, Massachusetts, United States
- Universität zu Lübeck, Institute of Biomedical Optics, Lübeck, Germany
| | - Hinnerk Schulz-Hildebrandt
- Universität zu Lübeck, Institute of Biomedical Optics, Lübeck, Germany
- LungenClinic Grosshansdorf, Airway Research Center North, Member of the German Center for Lung Research, Grosshansdorf, Germany
| | - Michael Evers
- Massachusetts General Hospital, Harvard Medical School, Cutaneous Biology Research Center, Department of Dermatology, Charlestown, Massachusetts, United States
- Universität zu Lübeck, Institute of Biomedical Optics, Lübeck, Germany
| | - Reginald Birngruber
- Universität zu Lübeck, Institute of Biomedical Optics, Lübeck, Germany
- Medical Laser Center Lübeck, Lübeck, Germany
| | - Dieter Manstein
- Massachusetts General Hospital, Harvard Medical School, Cutaneous Biology Research Center, Department of Dermatology, Charlestown, Massachusetts, United States
| | - Gereon Hüttmann
- Universität zu Lübeck, Institute of Biomedical Optics, Lübeck, Germany
- LungenClinic Grosshansdorf, Airway Research Center North, Member of the German Center for Lung Research, Grosshansdorf, Germany
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146
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Multimodal OCT Reflectivity Analysis of the Cystoid Spaces in Cystoid Macular Edema. BIOMED RESEARCH INTERNATIONAL 2019; 2019:7835372. [PMID: 31016197 PMCID: PMC6446091 DOI: 10.1155/2019/7835372] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 07/12/2018] [Accepted: 12/30/2018] [Indexed: 11/24/2022]
Abstract
Purpose To compare and evaluate images of macular cysts with different degrees of reflectivity (from gray to black signal) as observed in B scan spectral domain OCT (SDOCT) and EnFace OCT with decorrelation signal obtained with OCT-angiography (OCTA) in eyes with cystoid macular edema (CME) secondary to diabetic retinopathy (DR) and retinal vein occlusion (RVO). Methods Images from 3033 patients affected by CME secondary to diabetes or RVO examined OCTA (Optovue XR Avanti, Optovue, USA) at the University Eye Clinic of Créteil, Hôpital Intercommunal, France, and at the University Eye Clinic of Cagliari, “San Giovanni di Dio” Hospital, Italy, were retrospectively examined. The deep capillary plexus OCTA images and the corresponding EnFace OCT images, both acquired with the same automatic segmentation, had been overlapped to compose RGB color images as red and green channels, respectively, using ImageJ software (National Institutes of Health, Bethesda, MD). Afterward, linear regions of interest were traced on the color images to obtain the profiles of OCTA and EnFace gray values. Number of pixels, mean gray value and standard deviation of the area traced in OCT-A, and EnFace image were analyzed and statistically correlated. Data were exported to Excel to create the plots. Results 94 patients with DME and 27 patients with RVO showed intraretinal macular cystoid spaces with similar homogeneous, gray-looking content; 73 patients with DME and 113 patients with RVO showed macular cystoid spaces with homogeneous, black-looking content, as observed at SD-OCT, EnFace and OCTA scans. Interestingly, the limits of macular cystoid spaces were clearly detectable with OCTA. The analysis of red and green profiles demonstrated a clearly visible overlap between average OCTA and EnFace signal observed around cystoid spaces that could be attributed to a relationship between the dynamic vascularization and the structural density of the tissue. Conclusions This is the first investigation that characterizes and correlates OCTA and EnFace signals on images of macular cystoid spaces in DR and RVO. The low intensity OCTA signals observed inside cystoid spaces raise a relevant question about their nature, as to whether they are due to the presence of corpusculated material pouring out from bloodocular-barrier or they should be considered OCTA artifacts.
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Tang J, Erdener SE, Sunil S, Boas DA. Normalized field autocorrelation function-based optical coherence tomography three-dimensional angiography. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-8. [PMID: 30868803 PMCID: PMC6414735 DOI: 10.1117/1.jbo.24.3.036005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 02/06/2019] [Indexed: 05/02/2023]
Abstract
Optical coherence tomography angiography (OCTA) has been widely used for en face visualization of the microvasculature, but is challenged for real three-dimensional (3-D) topologic imaging due to the "tail" artifacts that appear below large vessels. Further, OCTA is generally incapable of differentiating descending arterioles from ascending venules. We introduce a normalized field autocorrelation function-based OCTA (g1-OCTA), which minimizes the tail artifacts and is capable of distinguishing penetrating arterioles from venules in the 3-D image. g1 ( τ ) is calculated from repeated optical coherence tomography (OCT) acquisitions for each spatial location. The decay amplitude of g1 ( τ ) is retrieved to represent the dynamics for each voxel. To account for the small g1 ( τ ) decay in capillaries where red blood cells are flowing slowly and discontinuously, Intralipid is injected to enhance the OCT signal. We demonstrate that the proposed technique realizes 3-D OCTA with negligible tail projections and the penetrating arteries are readily identified. In addition, compared to regular OCTA, the proposed g1-OCTA largely increased the depth-of-field. This technique provides a more accurate rendering of the vascular 3-D anatomy and has the potential for more quantitative characterization of vascular networks.
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Affiliation(s)
- Jianbo Tang
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, United States
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
- Address all correspondence to Jianbo Tang, E-mail:
| | - Sefik Evren Erdener
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, United States
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Smrithi Sunil
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - David A. Boas
- Boston University, Neurophotonics Center, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, United States
- Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
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148
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Lim HB, Lee MW, Park JH, Kim K, Jo YJ, Kim JY. Changes in Ganglion Cell-Inner Plexiform Layer Thickness and Retinal Microvasculature in Hypertension: An Optical Coherence Tomography Angiography Study. Am J Ophthalmol 2019; 199:167-176. [PMID: 30502337 DOI: 10.1016/j.ajo.2018.11.016] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/17/2018] [Accepted: 11/21/2018] [Indexed: 01/24/2023]
Abstract
PURPOSE To investigate retinal blood flow in patients with hypertension using optical coherence tomography angiography (OCTA) and the relationship between blood flow metrics and ganglion cell-inner plexiform layer (GC-IPL) thickness. DESIGN Retrospective, cross-sectional study. METHODS A total of 201 eyes from 117 healthy subjects and 84 hypertensive patients without any ocular abnormalities were included. Hypertensive patients were divided into the 2 groups according to disease periods (<5 years: Hypertension Group 1; ≥5 years: Hypertension Group 2). Macular 3 × 3-mm angiography was acquired using the Zeiss Cirrus 5000 OCT instrument. Vessel density (VD), perfusion density (PD), and foveal avascular zone metrics of the superficial capillary plexus were automatically calculated, and the thicknesses of the central fovea, GC-IPL, and peripapillary retinal nerve fiber layer (RNFL) were measured. All measurements were compared among the 3 groups, and retinal blood flow metrics were correlated with the thickness of each retinal layer. Logistic regression analyses were performed to determine the factors associated with prolonged hypertension. RESULTS The average GC-IPL (P < .001) and peripapillary RNFL (P = .048) thicknesses in Hypertension Group 2 were significantly thinner compared to the control group. The 3 mm total area of the VD and PD was also decreased compared to the control group and Hypertension Group 1 (all P < .05), and was significantly correlated with the GC-IPL (VD: r = 0.450, P = .001; PD: r = 0.467, P < .001) and peripapillary RNFL (VD: r = 0.314, P = .027; PD: r = 0.328, P = .023) thicknesses in Hypertension Group 2. Using multivariate logistic analyses, only the average GC-IPL thickness was a significant factor for prolonged hypertension (odds ratio = 0.911, P = .002). CONCLUSIONS In patients with hypertension lasting more than 5 years, inner retinal layer thinning, particularly GC-IPL thinning, was observed, which was significantly correlated with a decrease in retinal blood flow. Therefore, physicians should consider the effects of hypertension on the GC-IPL.
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Affiliation(s)
- Hyung Bin Lim
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, South Korea; Department of Ophthalmology, Armed Forces Capital Hospital, Seongnam, South Korea
| | - Min Woo Lee
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, South Korea
| | - Jae Hyeong Park
- Division of Cardiology, Department of Internal Medicine, Chungnam National University College of Medicine, Daejeon, South Korea
| | - Kyeungmin Kim
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, South Korea
| | - Young Joon Jo
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, South Korea
| | - Jung Yeul Kim
- Department of Ophthalmology, Chungnam National University College of Medicine, Daejeon, South Korea.
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Shi Y, Motulsky EH, Goldhardt R, Zohar Y, Thulliez M, Feuer W, Gregori G, Rosenfeld PJ. Predictive Value of the OCT Double-Layer Sign for Identifying Subclinical Neovascularization in Age-Related Macular Degeneration. ACTA ACUST UNITED AC 2019; 3:211-219. [DOI: 10.1016/j.oret.2018.10.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/15/2018] [Accepted: 10/19/2018] [Indexed: 11/26/2022]
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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: 4.4] [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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