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Harmon JN, Hyde JE, Jensen DE, D'cessare EC, Odarenko AA, Bruce MF, Khaing ZZ. Quantifying injury expansion in the cervical spinal cord with intravital ultrafast contrast-enhanced ultrasound imaging. Exp Neurol 2024; 374:114681. [PMID: 38199511 PMCID: PMC10922898 DOI: 10.1016/j.expneurol.2024.114681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/08/2023] [Accepted: 01/02/2024] [Indexed: 01/12/2024]
Abstract
Spinal cord injury is characterized by hemodynamic disruption at the injury epicenter and hypoperfusion in the penumbra, resulting in progressive ischemia and cell death. This degenerative secondary injury process has been well-described, though mostly using ex vivo or depth-limited optical imaging techniques. Intravital contrast-enhanced ultrasound enables longitudinal, quantitative evaluation of anatomical and hemodynamic changes in vivo through the entire spinal parenchyma. Here, we used ultrasound imaging to visualize and quantify subacute injury expansion (through 72 h post-injury) in a rodent cervical contusion model. Significant intraparenchymal hematoma expansion was observed through 72 h post-injury (1.86 ± 0.17-fold change from acute, p < 0.05), while the volume of the ischemic deficit largely increased within 24 h post-injury (2.24 ± 0.27-fold, p < 0.05). Histology corroborated these findings; increased apoptosis, tissue and vessel loss, and sustained tissue hypoxia were observed at 72 h post-injury. Vascular resistance was significantly elevated in the remaining perfused tissue, likely due in part to deformation of the central sulcal artery nearest to the lesion site. In conjunction, substantial hyperemia was observed in all perilesional areas examined except the ipsilesional gray matter. This study demonstrates the utility of longitudinal ultrasound imaging as a quantitative tool for tracking injury progression in vivo.
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Affiliation(s)
- Jennifer N Harmon
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA.
| | - Jeffrey E Hyde
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA.
| | - Dylan E Jensen
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA.
| | - Emma C D'cessare
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA.
| | - Anton A Odarenko
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA.
| | - Matthew F Bruce
- Applied Physics Laboratory, University of Washington, Seattle, WA, USA.
| | - Zin Z Khaing
- Department of Neurological Surgery, University of Washington, 1959 NE Pacific St., Seattle, WA, USA.
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2
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Yan F, Alhajeri ZA, Nyul-Toth A, Wang C, Zhang Q, Mercyshalinie ERS, Delfavero J, Ahire C, Mutembei BM, Tarantini S, Csiszar A, Tang Q. Dimension-based quantification of aging-associated cerebral microvasculature determined by optical coherence tomography and two-photon microscopy. JOURNAL OF BIOPHOTONICS 2024; 17:e202300409. [PMID: 38176434 PMCID: PMC10961197 DOI: 10.1002/jbio.202300409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 11/18/2023] [Accepted: 12/09/2023] [Indexed: 01/06/2024]
Abstract
Cerebral microvascular health is a key biomarker for the study of natural aging and associated neurological diseases. Our aim is to quantify aging-associated change of microvasculature at diverse dimensions in mice brain. We used optical coherence tomography (OCT) and two-photon microscopy (TPM) to obtain nonaged and aged C57BL/6J mice cerebral microvascular images in vivo. Our results indicated that artery & vein, arteriole & venule, and capillary from nonaged and aged mice showed significant differences in density, diameter, complexity, perimeter, and tortuosity. OCT angiography and TPM provided the comprehensive quantification for arteriole and venule via compensating the limitation of each modality alone. We further demonstrated that arteriole and venule at specific dimensions exhibited negative correlations in most quantification analyses between nonaged and aged mice, which indicated that TPM and OCT were able to offer complementary vascular information to study the change of cerebral blood vessels in aging.
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Affiliation(s)
- Feng Yan
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019
| | - Zaid A. Alhajeri
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019
| | - Adam Nyul-Toth
- Vascular Cognitive Impairment, Neurodegeneration, and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network, Szeged, Hungary
| | - Chen Wang
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019
| | - Qinghao Zhang
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019
| | | | - Jordan Delfavero
- Vascular Cognitive Impairment, Neurodegeneration, and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Chetan Ahire
- Vascular Cognitive Impairment, Neurodegeneration, and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Bornface M. Mutembei
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019
| | - Stefano Tarantini
- Vascular Cognitive Impairment, Neurodegeneration, and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Stephenson Cancer Center, University of Oklahoma, Oklahoma City, OK, USA
| | - Anna Csiszar
- Vascular Cognitive Impairment, Neurodegeneration, and Healthy Brain Aging Program, Department of Neurosurgery, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Oklahoma Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Stephenson Cancer Center, University of Oklahoma, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Qinggong Tang
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, OK 73019
- Institute for Biomedical Engineering, Science, and Technology (IBEST), University of Oklahoma, Norman, OK 73019, USA
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3
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Amirmoezzi Y, Ghofrani-Jahromi M, Parsaei H, Afarid M, Mohsenipoor N. An Open-source Image Analysis Toolbox for Quantitative Retinal Optical Coherence Tomography Angiography. J Biomed Phys Eng 2024; 14:31-42. [PMID: 38357600 PMCID: PMC10862112 DOI: 10.31661/jbpe.v0i0.2106-1349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/07/2021] [Indexed: 02/16/2024]
Abstract
Background Qualitative and quantitative assessment of retinal perfusion using optical coherence tomography angiography (OCTA) has shown to be effective in the treatment and management of various retinal and optic nerve diseases. However, manual analyses of OCTA images to calculate metrics related to Foveal Avascular Zone (FAZ) morphology, and retinal vascular density and morphology are costly, time-consuming, subject to human error, and are exposed to both inter and intra operator variability. Objective This study aimed to develop an open-source software framework for quantitative OCTA (QOCTA). Particularly, for analyzing OCTA images and measuring several indices describing microvascular morphology, vessel morphology, and FAZ morphology. Material and Methods In this analytical study, we developed a toolbox or QOCTA using image processing algorithms provided in MATLAB. The software automatically determines FAZ and measures several parameters related to both size and shape of FAZ including area, perimeter, Feret's diameter circularity, axial ratio, roundness, and solidity. The microvascular structure is derived from the processed image to estimate the vessel density (VD). To assess the reliability of the software, three independent operators measured the mentioned parameters for the eyes of 21 subjects. The consistency of the values was assessed using the intraclass correlation coefficient (ICC) index. Results Excellent consistency was observed between the measurements completed for the superficial layer, ICC >0.9. For the deep layer, good reliability in the measurements was achieved, ICC >0.7. Conclusion The developed software is reliable; hence, it can facilitate quantitative OCTA, further statistical comparison in cohort OCTA studies, and can assist with obtaining deeper insights into retinal variations in various populations.
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Affiliation(s)
- Yalda Amirmoezzi
- Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- Shiraz Neuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Hossein Parsaei
- Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- Shiraz Neuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mehrdad Afarid
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Negar Mohsenipoor
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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Hangartner K, Bajka A, Wiest MRJ, Sidhu S, Toro MD, Maloca PM, Zweifel SA. Assessment of Retinal Vessel Tortuosity Index in Patients with Fabry Disease Using Optical Coherence Tomography Angiography (OCTA). Diagnostics (Basel) 2023; 13:2496. [PMID: 37568859 PMCID: PMC10417007 DOI: 10.3390/diagnostics13152496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 07/16/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
Vessel tortuosity (VT) is a parameter used to assess retinal involvement in patients affected by systemic diseases such as Fabry disease (FD). In this study, we assessed a retinal VT index (VTI) using optical coherence tomography angiography (OCTA) in a group of patients with FD (FD cohort) compared to a healthy control group (HC cohort). This is a single-center, retrospective study analysis of all consecutive patients with genetically tested and confirmed FD who underwent regular ophthalmological visits from December 2017 to January 2020 at the Department of Ophthalmology at the University Hospital of Zurich, Switzerland. VTI was calculated for each OCTA image and the results were compared between FD and HC cohort. A total of 56 participants, 32 (male:female ratio 12:20) in the FD cohort and 24 (male:female ratio 13:11) in the HC cohort. Classic onset was determined in 18 patients. Overall, mean VTI (±SD) was 0.21 (±0.07). Male patients with classic-onset FD had a significantly higher mean VTI (0.33, SD ± 0.35) compared to all other subgroups (p-value < 0.05). Further investigations of retinal VTI in patients with FD could be helpful to use OCTA as a noninvasive screening and follow-up modality to assess disease progression in affected patients.
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Affiliation(s)
- Kevin Hangartner
- Faculty of Human Medicine, University of Zurich, 8032 Zurich, Switzerland
| | - Anahita Bajka
- Faculty of Human Medicine, University of Zurich, 8032 Zurich, Switzerland
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland
| | - Maximilian R. J. Wiest
- Faculty of Human Medicine, University of Zurich, 8032 Zurich, Switzerland
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland
| | - Sophia Sidhu
- Faculty of Medicine, University of California San Diego, 5998 Alcala Park, San Diego, CA 92110, USA
| | - Mario D. Toro
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland
- Chair and Department of General and Pediatric Ophthalmology, Medical University of Lublin, 20079 Lublin, Poland
- Eye Clinic, Department of Public Health, University Federico II, 80131 Naples, Italy
| | - Peter M. Maloca
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031 Basel, Switzerland
- Department of Ophthalmology, University Hospital Basel, 4031 Basel, Switzerland
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Sandrine A. Zweifel
- Faculty of Human Medicine, University of Zurich, 8032 Zurich, Switzerland
- Department of Ophthalmology, University Hospital of Zurich, University of Zurich, 8091 Zurich, Switzerland
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Guo T, Xiong K, Yuan B, Zhang Z, Wang L, Zhang Y, Liang C, Liu Z. Homogeneous-resolution photoacoustic microscopy for ultrawide field-of-view neurovascular imaging in Alzheimer's disease. PHOTOACOUSTICS 2023; 31:100516. [PMID: 37313359 PMCID: PMC10258506 DOI: 10.1016/j.pacs.2023.100516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/25/2023] [Accepted: 05/25/2023] [Indexed: 06/15/2023]
Abstract
Neurovascular imaging is essential for investigating neurodegenerative diseases. However, the existing neurovascular imaging technology suffers from a trade-off between a field of view (FOV) and resolution in the whole brain, resulting in an inhomogeneous resolution and lack of information. Here, homogeneous-resolution arched-scanning photoacoustic microscopy (AS-PAM), which has an ultrawide FOV to cover the entire mouse cerebral cortex, was developed. Imaging of the neurovasculature was performed with a homogenous resolution of 6.9 µm from the superior sagittal sinus to the middle cerebral artery and caudal rhinal vein in an FOV of 12 × 12 mm2. Moreover, using AS-PAM, vascular features of the meninges and cortex were quantified in early Alzheimer's disease (AD) and wild-type (WT) mice. The results demonstrated high sensitivity to the pathological progression of AD on tortuosity and branch index. The high-fidelity imaging capability in large FOV enables AS-PAM to be a promising tool for precise brain neurovascular visualization and quantification.
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Affiliation(s)
- Ting Guo
- School of Medicine South China University of Technology, Guangzhou 510006, China
- Department of Radiology, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510080, China
- Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Guangzhou 510080, China
| | - Kedi Xiong
- MOE Key Laboratory of Laser Life Science Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China
- Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Bo Yuan
- MOE Key Laboratory of Laser Life Science Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China
- Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Zhenhui Zhang
- MOE Key Laboratory of Laser Life Science Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China
- Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Lijuan Wang
- Department of Radiology, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510080, China
- Guangzhou Key Laboratory of Diagnosis and Treatment for Neurodegenerative Diseases, Guangzhou 510080, China
| | - Yuhu Zhang
- Department of Radiology, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510080, China
- Guangzhou Key Laboratory of Diagnosis and Treatment for Neurodegenerative Diseases, Guangzhou 510080, China
| | - Changhong Liang
- Department of Radiology, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510080, China
- Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Guangzhou 510080, China
| | - Zaiyi Liu
- Department of Radiology, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 510080, China
- Guangdong Provincial Key Laboratory of Artificial Intelligence in Medical Image Analysis and Application, Guangzhou 510080, China
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Deshpande A, Raman S, Dubey A, Susvar P, Raman R. An ImageJ macro tool for OCTA-based quantitative analysis of Myopic Choroidal neovascularization. PLoS One 2023; 18:e0283929. [PMID: 37083836 PMCID: PMC10120933 DOI: 10.1371/journal.pone.0283929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 03/20/2023] [Indexed: 04/22/2023] Open
Abstract
Myopic Choroidal neovascularization (mCNV) is one of the most common vision-threatening com- plications of pathological myopia among many retinal diseases. Optical Coherence Tomography Angiography (OCTA) is an emerging newer non-invasive imaging technique and is recently being included in the investigation and treatment of mCNV. However, there exists no standard tool for time-efficient and dependable analysis of OCTA images of mCNV. In this study, we propose a customizable ImageJ macro that automates the OCTA image processing and lets users measure nine mCNV biomarkers. We developed a three-stage image processing pipeline to process the OCTA images using the macro. The images were first manually delineated, and then denoised using a Gaussian Filter. This was followed by the application of the Frangi filter and Local Adaptive thresholding. Finally, skeletonized images were obtained using the Mexican Hat filter. Nine vascular biomarkers including Junction Density, Vessel Diameter, and Fractal Dimension were then computed from the skeletonized images. The macro was tested on a 26 OCTA image dataset for all biomarkers. Two trends emerged in the computed biomarker values. First, the lesion-size dependent parameters (mCNV Area (mm2) Mean = 0.65, SD = 0.46) showed high variation, whereas normalized parameters (Junction Density(n/mm): Mean = 10.24, SD = 0.63) were uniform throughout the dataset. The computed values were consistent with manual measurements within existing literature. The results illustrate our ImageJ macro to be a convenient alternative for manual OCTA image processing, including provisions for batch processing and parameter customization, providing a systematic, reliable analysis of mCNV.
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Affiliation(s)
- Aadit Deshpande
- Department of Computer Science, Birla Institute of Technology and Science Pilani, Pilani, India
| | - Sundaresan Raman
- Department of Computer Science, Birla Institute of Technology and Science Pilani, Pilani, India
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Four Severity Levels for Grading the Tortuosity of a Retinal Fundus Image. J Imaging 2022; 8:jimaging8100258. [PMID: 36286352 PMCID: PMC9605460 DOI: 10.3390/jimaging8100258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/11/2022] [Accepted: 09/15/2022] [Indexed: 12/02/2022] Open
Abstract
Hypertensive retinopathy severity classification is proportionally related to tortuosity severity grading. No tortuosity severity scale enables a computer-aided system to classify the tortuosity severity of a retinal image. This work aimed to introduce a machine learning model that can identify the severity of a retinal image automatically and hence contribute to developing a hypertensive retinopathy or diabetic retinopathy automated grading system. First, the tortuosity is quantified using fourteen tortuosity measurement formulas for the retinal images of the AV-Classification dataset to create the tortuosity feature set. Secondly, a manual labeling is performed and reviewed by two ophthalmologists to construct a tortuosity severity ground truth grading for each image in the AV classification dataset. Finally, the feature set is used to train and validate the machine learning models (J48 decision tree, ensemble rotation forest, and distributed random forest). The best performance learned model is used as the tortuosity severity classifier to identify the tortuosity severity (normal, mild, moderate, and severe) for any given retinal image. The distributed random forest model has reported the highest accuracy (99.4%) compared to the J48 Decision tree model and the rotation forest model with minimal least root mean square error (0.0000192) and the least mean average error (0.0000182). The proposed tortuosity severity grading matched the ophthalmologist’s judgment. Moreover, detecting the tortuosity severity of the retinal vessels’, optimizing vessel segmentation, the vessel segment extraction, and the created feature set have increased the accuracy of the automatic tortuosity severity detection model.
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Lyu X, Cheng L, Zhang S. The RETA Benchmark for Retinal Vascular Tree Analysis. Sci Data 2022; 9:397. [PMID: 35817778 PMCID: PMC9273761 DOI: 10.1038/s41597-022-01507-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 06/28/2022] [Indexed: 12/23/2022] Open
Abstract
Topological and geometrical analysis of retinal blood vessels could be a cost-effective way to detect various common diseases. Automated vessel segmentation and vascular tree analysis models require powerful generalization capability in clinical applications. In this work, we constructed a novel benchmark RETA with 81 labelled vessel masks aiming to facilitate retinal vessel analysis. A semi-automated coarse-to-fine workflow was proposed for vessel annotation task. During database construction, we strived to control inter-annotator and intra-annotator variability by means of multi-stage annotation and label disambiguation on self-developed dedicated software. In addition to binary vessel masks, we obtained other types of annotations including artery/vein masks, vascular skeletons, bifurcations, trees and abnormalities. Subjective and objective quality validations of the annotated vessel masks demonstrated significantly improved quality over the existing open datasets. Our annotation software is also made publicly available serving the purpose of pixel-level vessel visualization. Researchers could develop vessel segmentation algorithms and evaluate segmentation performance using RETA. Moreover, it might promote the study of cross-modality tubular structure segmentation and analysis.
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Affiliation(s)
- Xingzheng Lyu
- College of Computer Science and Technology, Zhejiang University, Hangzhou, 310027, China.
| | - Li Cheng
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, T6G 1H9, Canada
| | - Sanyuan Zhang
- College of Computer Science and Technology, Zhejiang University, Hangzhou, 310027, China.
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Moss HE, Cao J, Wasi M, Feldon SE, Shahidi M. Variability of Retinal Vessel Tortuosity Measurements Using a Semiautomated Method Applied to Fundus Images in Subjects With Papilledema. Transl Vis Sci Technol 2021; 10:32. [PMID: 34967836 PMCID: PMC8727308 DOI: 10.1167/tvst.10.14.32] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Purpose To develop methods to quantitatively measure retinal vessel tortuosity from fundus images acquired in subjects with papilledema and assess sources of variability in these measurements. Methods Digital fundus images from 30 eyes of subjects with untreated idiopathic intracranial hypertension and papilledema were analyzed. Retinal vein and artery tortuosities for three to four vessels of each type were measured in a region of interest 1.8 to 2.7 mm from the center of the optic nerve head. Measurements were averaged to generate a venous tortuosity index (VTI) and arterial tortuosity index (ATI) for each eye. One image of each eye was analyzed two times by the same rater. Two images of each eye, differing by focal depth, were analyzed by the same rater. Correlations between VTI and ATI for the same image and different images were calculated. Results Intrarater Pearson correlations (r) were 0.8 (95% confidence interval [CI], 0.59–0.9) and 0.90 (95% CI, 0.73–0.96) for VTI and ATI, respectively, with one outlier removed. Interimage r values were 0.72 (95% CI, 0.48–0.87) and 0.96 (95% CI, 0.89–0.99) for VTI and ATI, respectively, with one outlier removed. The intraclass correlation coefficients for agreement and consistency were similar, suggesting that the discrepancy between measurements was due to residual random error. Conclusions The finding of similar intrarater and interimage variability suggests that intrarater variability may be a more dominant source than physiology and image acquisition. Translational Relevance Standardizing rater procedures and averaging multiple measuring sessions are strategies to reduce variability and improve reliability of detecting retinal vessel tortuosity changes in images of eyes with papilledema.
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Affiliation(s)
- Heather E Moss
- Department of Ophthalmology, Stanford University, Palo Alto, CA, USA.,Department of Neurology & Neurological Sciences, Stanford University, Palo Alto, CA, USA
| | - Jing Cao
- Department of Statistical Science, Southern Methodist University, Dallas, TX, USA
| | - Munam Wasi
- Department of Ophthalmology, Stanford University, Palo Alto, CA, USA
| | - Steven E Feldon
- Department of Ophthalmology, University of Rochester, Rochester, NY, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA.,Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA
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Kalra G, Zarranz-Ventura J, Chahal R, Bernal-Morales C, Lupidi M, Chhablani J. Optical coherence tomography (OCT) angiolytics: a review of OCT angiography quantitative biomarkers. Surv Ophthalmol 2021; 67:1118-1134. [PMID: 34748794 DOI: 10.1016/j.survophthal.2021.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 10/29/2021] [Accepted: 11/01/2021] [Indexed: 02/08/2023]
Abstract
Optical coherence tomography angiography (OCTA) provides a non-invasive method to obtain angiography of the chorioretinal vasculature leading to its recent widespread adoption. With a growing number of studies exploring the use of OCTA, various biomarkers quantifying the vascular characteristics have come to light. In the current report, we summarize the biomarkers currently described for retinal and choroidal vasculature using OCTA systems and the methods used to obtain them. Further, we present a critical review of these methods and key findings in common retinal diseases and appraise future directions, including applications of artificial intelligence in OCTA .
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Affiliation(s)
- Gagan Kalra
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA; Government Medical College and Hospital, Chandigarh, India
| | - Javier Zarranz-Ventura
- Institut Clinic d'Oftalmologia (ICOF) Hospital Clinic, Barcelona, Spain; Institut de Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Rutvi Chahal
- Government Medical College and Hospital, Chandigarh, India
| | - Carolina Bernal-Morales
- Institut Clinic d'Oftalmologia (ICOF) Hospital Clinic, Barcelona, Spain; Institut de Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Marco Lupidi
- Department of Surgical and Biomedical Sciences, University of Perugia, S.Maria della Misericordia Hospital, Perugia, Italy
| | - Jay Chhablani
- University of Pittsburgh Medical Center Eye Center, University of Pittsburgh, Pittsburgh, PA, USA.
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Dumitrascu OM, Rosenberry R, Sherman DS, Khansari MM, Sheyn J, Torbati T, Sherzai A, Sherzai D, Johnson KO, Czeszynski AD, Verdooner S, Black KL, Frautschy S, Lyden PD, Shi Y, Cheng S, Koronyo Y, Koronyo-Hamaoui M. Retinal Venular Tortuosity Jointly with Retinal Amyloid Burden Correlates with Verbal Memory Loss: A Pilot Study. Cells 2021; 10:cells10112926. [PMID: 34831149 PMCID: PMC8616417 DOI: 10.3390/cells10112926] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/21/2021] [Accepted: 10/25/2021] [Indexed: 12/11/2022] Open
Abstract
Introduction: Retinal imaging is a non-invasive tool to study both retinal vasculature and neurodegeneration. In this exploratory retinal curcumin-fluorescence imaging (RFI) study, we sought to determine whether retinal vascular features combined with retinal amyloid burden correlate with the neurocognitive status. Methods: We used quantitative RFI in a cohort of patients with cognitive impairment to automatically compute retinal amyloid burden. Retinal blood vessels were segmented, and the vessel tortuosity index (VTI), inflection index, and branching angle were quantified. We assessed the correlations between retinal vascular and amyloid parameters, and cognitive domain Z-scores using linear regression models. Results: Thirty-four subjects were enrolled and twenty-nine (55% female, mean age 64 ± 6 years) were included in the combined retinal amyloid and vascular analysis. Eleven subjects had normal cognition and 18 had impaired cognition. Retinal VTI was discriminated among cognitive scores. The combined proximal mid-periphery amyloid count and venous VTI index exhibited significant differences between cognitively impaired and cognitively normal subjects (0.49 ± 1.1 vs. 0.91 ± 1.4, p = 0.006), and correlated with both the Wechsler Memory Scale-IV and SF-36 mental component score Z-scores (p < 0.05). Conclusion: This pilot study showed that retinal venular VTI combined with the proximal mid-periphery amyloid count could predict verbal memory loss. Future research is needed to finesse the clinical application of this retinal imaging-based technology.
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Affiliation(s)
- Oana M. Dumitrascu
- Department of Neurology, Mayo Clinic, Scottsdale, AZ 85251, USA
- Correspondence: (O.M.D.); (M.K.-H.); Tel.: +480-301-8100 (O.M.D.); Fax: +480-301-9494 (O.M.D.)
| | - Ryan Rosenberry
- Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.R.); (S.C.)
| | - Dale S. Sherman
- Department of Neuropsychology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA;
| | - Maziyar M. Khansari
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90007, USA; (M.M.K.); (Y.S.)
| | - Julia Sheyn
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Tania Torbati
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Ayesha Sherzai
- Department of Neurology, Loma Linda University, Loma Linda, CA 92350, USA; (A.S.); (D.S.)
| | - Dean Sherzai
- Department of Neurology, Loma Linda University, Loma Linda, CA 92350, USA; (A.S.); (D.S.)
| | - Kenneth O. Johnson
- NeuroVision Imaging Inc., Sacramento, CA 95833, USA; (K.O.J.); (A.D.C.); (S.V.)
| | - Alan D. Czeszynski
- NeuroVision Imaging Inc., Sacramento, CA 95833, USA; (K.O.J.); (A.D.C.); (S.V.)
| | - Steven Verdooner
- NeuroVision Imaging Inc., Sacramento, CA 95833, USA; (K.O.J.); (A.D.C.); (S.V.)
| | - Keith L. Black
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Sally Frautschy
- Department of Neurology, University of California Los Angeles, Los Angeles, CA 90095, USA;
| | - Patrick D. Lyden
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA;
| | - Yonggang Shi
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA 90007, USA; (M.M.K.); (Y.S.)
| | - Susan Cheng
- Department of Cardiology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (R.R.); (S.C.)
| | - Yosef Koronyo
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; (J.S.); (T.T.); (K.L.B.); (Y.K.)
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
- Correspondence: (O.M.D.); (M.K.-H.); Tel.: +480-301-8100 (O.M.D.); Fax: +480-301-9494 (O.M.D.)
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12
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Wang G, Li M, Yun Z, Duan Z, Ma K, Luo Z, Xiao P, Yuan J. A novel multiple subdivision-based algorithm for quantitative assessment of retinal vascular tortuosity. Exp Biol Med (Maywood) 2021; 246:2222-2229. [PMID: 34308658 DOI: 10.1177/15353702211032898] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Vascular tortuosity as an indicator of retinal vascular morphological changes can be quantitatively analyzed and used as a biomarker for the early diagnosis of relevant disease such as diabetes. While various methods have been proposed to evaluate retinal vascular tortuosity, the main obstacle limiting their clinical application is the poor consistency compared with the experts' evaluation. In this research, we proposed to apply a multiple subdivision-based algorithm for the vessel segment vascular tortuosity analysis combining with a learning curve function of vessel curvature inflection point number, emphasizing the human assessment nature focusing not only global but also on local vascular features. Our algorithm achieved high correlation coefficients of 0.931 for arteries and 0.925 for veins compared with clinical grading of extracted retinal vessels. For the prognostic performance against experts' prediction in retinal fundus images from diabetic patients, the area under the receiver operating characteristic curve reached 0.968, indicating a good consistency with experts' predication in full retinal vascular network evaluation.
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Affiliation(s)
- Gengyuan Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Meng Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Zhaoqiang Yun
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
| | - Zhengyu Duan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Ke Ma
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Zhongzhou Luo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Peng Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Jin Yuan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
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13
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Auvazian SL, Cano J, Leahy S, Karamian P, Kashani A, Moshfeghi A, Ameri H, Blair NP, Shahidi M. Relating Retinal Vascular Oxygen Saturation and Microvasculature Morphology at Progressive Stages of Diabetic Retinopathy. Transl Vis Sci Technol 2021; 10:4. [PMID: 34111249 PMCID: PMC8107511 DOI: 10.1167/tvst.10.6.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Purpose Diabetic retinopathy (DR) is a common cause of vision loss in working age adults and presents changes in retinal vessel oxygenation and morphology. The purpose of this study was to test the hypothesis that there is an association of retinal vessel oxygen saturation with vessel density (VD) and tortuosity in DR. Methods Ninety-five subjects were classified in the following groups: nondiabetic control (N = 25), no DR (N = 28), mild nonproliferative DR (NPDR; N = 21), moderate to severe NPDR (N = 14), or treated proliferative DR (PDR; N = 7). Retinal oximetry was performed to measure arterial and venous oxygen saturation (SO2A and SO2V) and calculate oxygen extraction fraction (OEF). Optical coherence tomography angiography (OCTA) was performed for measurements of VD and vessel tortuosity index (VTI). Results There were statistically significant differences in SO2A and SO2V among groups (P< 0.004). SO2A and SO2V were higher in the PDR group compared to the control group and SO2V was also higher in the moderate to severe NPDR group. VD differed significantly among groups (P = 0.003), whereas VTI was not significantly different (P = 0.22). Compared to the control group, VD was lower in moderate to severe NPDR and PDR groups. VD was also lower in the PDR group than that in the no DR group (P = 0.03). There was a significant correlation of VTI with SO2V (r = 0.32, P = 0.002) and OEF (r = −0.35, P = 0.001). Conclusions Retinal vessel morphology, oxygenation, and tissue oxygen extraction were associated with each other in a cohort of subjects with and without DR. Translational Relevance The findings of this study have the potential to improve clinical management of DR by providing better understanding of human disease pathophysiology and propelling future studies to identify multiple image-based biomarkers for improved disease diagnosis and monitoring.
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Affiliation(s)
- Selin L Auvazian
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Jennifer Cano
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Sophie Leahy
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Preny Karamian
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Amir Kashani
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Andrew Moshfeghi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Hossein Ameri
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
| | - Norman P Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
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14
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Xu X, Wu X, Zhu C, Zhang R, Jiaerken Y, Wang S, Hong H, Yu W, Li K, Zeng Q, Luo X, Yu X, Sun J, Zhang M, Huang P. Characterization of Lenticulostriate Arteries and Its Associations With Vascular Risk Factors in Community-Dwelling Elderly. Front Aging Neurosci 2021; 13:685571. [PMID: 34239436 PMCID: PMC8258402 DOI: 10.3389/fnagi.2021.685571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/17/2021] [Indexed: 11/18/2022] Open
Abstract
Lenticulostriate arteries (LSAs) supply blood to important subcortical areas and are, therefore, essential for maintaining the optimal functioning of the brain’s most metabolically active nuclei. Past studies have demonstrated the potential for quantifying the morphology of LSAs as biomarkers of vascular fragility or underlying arteriopathies. Thus, the current study aims to evaluate the morphological features of LSAs, their potential value in cerebrovascular risk stratification, and their concordance with other vascular risk factors in community-dwelling elderly people. A total of 125 community-dwelling elderly subjects who underwent a brain MRI scan were selected from our prospectively collected imaging database. The morphological measures of LSAs were calculated on the vascular skeletons obtained by manual tracing, and the number of LSAs was counted. Additionally, imaging biomarkers of small vessel disease were evaluated, and the diameters of major cerebral arteries were measured. The effects of vascular risk factors on LSA morphometry, as well as the relationship between LSA measures and other imaging biomarkers, were investigated. We found that smokers had shorter (p = 0.04) and straighter LSAs (p < 0.01) compared to nonsmokers, and the presence of hypertension is associated with less tortuous LSAs (p = 0.03) in community-dwelling elderly. Moreover, the middle cerebral artery diameter was positively correlated with LSA count (r = 0.278, p = 0.025) and vessel tortuosity (r = 0.257, p = 0.04). The posterior cerebral artery diameter was positively correlated with vessel tortuosity and vessel length. Considering the scarcity of noninvasive methods for measuring small artery abnormalities in the brain, the LSA morphological measures may provide valuable information to better understand cerebral small vessel degeneration during aging.
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Affiliation(s)
- Xiaopei Xu
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiao Wu
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chengcheng Zhu
- Department of Radiology, University of Washington, Seattle, WA, United States
| | - Ruiting Zhang
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yeerfan Jiaerken
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Shuyue Wang
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hui Hong
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wenke Yu
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Kaicheng Li
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Qingze Zeng
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiao Luo
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xinfeng Yu
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianzhong Sun
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Minming Zhang
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Peiyu Huang
- Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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15
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Schmidt-Erfurth U, Reiter GS, Riedl S, Seeböck P, Vogl WD, Blodi BA, Domalpally A, Fawzi A, Jia Y, Sarraf D, Bogunović H. AI-based monitoring of retinal fluid in disease activity and under therapy. Prog Retin Eye Res 2021; 86:100972. [PMID: 34166808 DOI: 10.1016/j.preteyeres.2021.100972] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 12/21/2022]
Abstract
Retinal fluid as the major biomarker in exudative macular disease is accurately visualized by high-resolution three-dimensional optical coherence tomography (OCT), which is used world-wide as a diagnostic gold standard largely replacing clinical examination. Artificial intelligence (AI) with its capability to objectively identify, localize and quantify fluid introduces fully automated tools into OCT imaging for personalized disease management. Deep learning performance has already proven superior to human experts, including physicians and certified readers, in terms of accuracy and speed. Reproducible measurement of retinal fluid relies on precise AI-based segmentation methods that assign a label to each OCT voxel denoting its fluid type such as intraretinal fluid (IRF) and subretinal fluid (SRF) or pigment epithelial detachment (PED) and its location within the central 1-, 3- and 6-mm macular area. Such reliable analysis is most relevant to reflect differences in pathophysiological mechanisms and impacts on retinal function, and the dynamics of fluid resolution during therapy with different regimens and substances. Yet, an in-depth understanding of the mode of action of supervised and unsupervised learning, the functionality of a convolutional neural net (CNN) and various network architectures is needed. Greater insight regarding adequate methods for performance, validation assessment, and device- and scanning-pattern-dependent variations is necessary to empower ophthalmologists to become qualified AI users. Fluid/function correlation can lead to a better definition of valid fluid variables relevant for optimal outcomes on an individual and a population level. AI-based fluid analysis opens the way for precision medicine in real-world practice of the leading retinal diseases of modern times.
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Affiliation(s)
- Ursula Schmidt-Erfurth
- Department of Ophthalmology Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
| | - Gregor S Reiter
- Department of Ophthalmology Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
| | - Sophie Riedl
- Department of Ophthalmology Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
| | - Philipp Seeböck
- Department of Ophthalmology Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
| | - Wolf-Dieter Vogl
- Department of Ophthalmology Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
| | - Barbara A Blodi
- Fundus Photograph Reading Center, Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI, USA.
| | - Amitha Domalpally
- Fundus Photograph Reading Center, Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI, USA.
| | - Amani Fawzi
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
| | - Yali Jia
- Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA.
| | - David Sarraf
- Stein Eye Institute, University of California Los Angeles, Los Angeles, CA, USA.
| | - Hrvoje Bogunović
- Department of Ophthalmology Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
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16
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Hormel TT, Jia Y, Jian Y, Hwang TS, Bailey ST, Pennesi ME, Wilson DJ, Morrison JC, Huang D. Plexus-specific retinal vascular anatomy and pathologies as seen by projection-resolved optical coherence tomographic angiography. Prog Retin Eye Res 2021; 80:100878. [PMID: 32712135 PMCID: PMC7855241 DOI: 10.1016/j.preteyeres.2020.100878] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 05/13/2020] [Accepted: 05/18/2020] [Indexed: 12/22/2022]
Abstract
Optical coherence tomographic angiography (OCTA) is a novel technology capable of imaging retinal vasculature three-dimensionally at capillary scale without the need to inject any extrinsic dye contrast. However, projection artifacts cause superficial retinal vascular patterns to be duplicated in deeper layers, thus interfering with the clean visualization of some retinal plexuses and vascular pathologies. Projection-resolved OCTA (PR-OCTA) uses post-processing algorithms to reduce projection artifacts. With PR-OCTA, it is now possible to resolve up to 4 distinct retinal vascular plexuses in the living human eye. The technology also allows us to detect and distinguish between various retinal and optic nerve diseases. For example, optic nerve diseases such as glaucoma primarily reduces the capillary density in the superficial vascular complex, which comprises the nerve fiber layer plexus and the ganglion cell layer plexus. Outer retinal diseases such as retinitis pigmentosa primarily reduce the capillary density in the deep vascular complex, which comprises the intermediate capillary plexus and the deep capillary plexus. Retinal vascular diseases such as diabetic retinopathy and vein occlusion affect all plexuses, but with different patterns of capillary loss and vascular malformations. PR-OCTA is also useful in distinguishing various types of choroidal neovascularization and monitoring their response to anti-angiogenic medications. In retinal angiomatous proliferation and macular telangiectasia type 2, PR-OCTA can trace the pathologic vascular extension into deeper layers as the disease progress through stages. Plexus-specific visualization and measurement of retinal vascular changes are improving our ability to diagnose, stage, monitor, and assess treatment response in a wide variety of optic nerve and retinal diseases. These applications will be further enhanced with the continuing improvement of the speed and resolution of the OCT platforms, as well as the development of software algorithms to reduce artifacts, improve image quality, and make quantitative measurements.
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Affiliation(s)
- Tristan T Hormel
- 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
| | - Yifan Jian
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA; Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Thomas S Hwang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Steven T Bailey
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Mark E Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - David J Wilson
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - John C Morrison
- 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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17
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Vilela MA, Amaral CE, Ferreira MAT. Retinal vascular tortuosity: Mechanisms and measurements. Eur J Ophthalmol 2020; 31:1497-1506. [PMID: 33307777 DOI: 10.1177/1120672120979907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Retinal vessel tortuosity has been used in the diagnosis and management of different clinical situations. Notwithstanding, basic concepts, standards and tools of measurement, reliable normative data and clinical applications have many gaps or points of divergence. In this review we discuss triggering causes of retinal vessel tortuosity and resources used to assess and quantify it, as well as current limitations.
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Affiliation(s)
- Manuel Ap Vilela
- Federal University of Health Sciences of Porto Alegre, Porto Alegre, Brazil
| | - Carlos Ev Amaral
- Federal University of Health Sciences of Porto Alegre, Porto Alegre, Brazil
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18
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Cano J, O’neill WD, Penn RD, Blair NP, Kashani AH, Ameri H, Kaloostian CL, Shahidi M. Classification of advanced and early stages of diabetic retinopathy from non-diabetic subjects by an ordinary least squares modeling method applied to OCTA images. BIOMEDICAL OPTICS EXPRESS 2020; 11:4666-4678. [PMID: 32923070 PMCID: PMC7449717 DOI: 10.1364/boe.394472] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 07/04/2020] [Accepted: 07/12/2020] [Indexed: 05/02/2023]
Abstract
As the prevalence of diabetic retinopathy (DR) continues to rise, there is a need to develop computer-aided screening methods. The current study reports and validates an ordinary least squares (OLS) method to model optical coherence tomography angiography (OCTA) images and derive OLS parameters for classifying proliferative DR (PDR) and no/mild non-proliferative DR (NPDR) from non-diabetic subjects. OLS parameters were correlated with vessel metrics quantified from OCTA images and were used to determine predicted probabilities of PDR, no/mild NPDR, and non-diabetics. The classification rates of PDR and no/mild NPDR from non-diabetic subjects were 94% and 91%, respectively. The method had excellent predictive ability and was validated. With further development, the method may have potential clinical utility and contribute to image-based computer-aided screening and classification of stages of DR and other ocular and systemic diseases.
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Affiliation(s)
- Jennifer Cano
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90007, USA
| | - William D. O’neill
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Richard D. Penn
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Neurosurgery, Rush University and Hospital, Chicago, IL 60612, USA
| | - Norman P. Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Amir H. Kashani
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90007, USA
| | - Hossein Ameri
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90007, USA
| | - Carolyn L. Kaloostian
- Department of Family Medicine, University of Southern California, Los Angeles, CA 90007, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA 90007, USA
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19
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Garvey SL, Khansari MM, Jiang X, Varma R, Shahidi M. Assessment of retinal vascular oxygenation and morphology at stages of diabetic retinopathy in African Americans. BMC Ophthalmol 2020; 20:295. [PMID: 32682412 PMCID: PMC7368779 DOI: 10.1186/s12886-020-01566-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 07/10/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Diabetic retinopathy (DR) is a microvascular complication of diabetes and a leading cause of blindness in working-age adults. The likelihood of visual impairment associated with DR is two-fold higher in the African-American (AA) compared to non-Hispanic white. Although alterations in retinal vessel oxygenation and morphology have been reported in DR, there is limited knowledge about these vascular changes in AA subjects. The purpose of the current study was to investigate alterations in retinal vascular oxygen saturation (SO2), vessel diameter (D) and tortuosity at severity stages of DR in AA subjects. METHODS A nested case-control study of 56 AA subjects was conducted. Right eyes were grouped as non-diabetic (ND) (N = 26), no clinical DR (NDR) (N = 19), or moderate/severe non-proliferative DR (NPDR) (N = 11). Imaging was performed using a commercially available scanning laser ophthalmoscope. Images were analyzed to determine retinal arterial and venous SO2 (SO2A and SO2V), diameter (DA and DV), and vessel tortuosity index (VTI) (VTIA and VTIV). RESULTS SO2V and DV were higher in NPDR compared to ND and NDR groups (P < 0.05). There were no significant differences in SO2A and DA among ND, NDR, and NPDR groups (P > 0.8). Maximum VTIA was higher in diabetics (NDR and NPDR) compared to non-diabetics (P < 0.03). There was no significant difference in maximum VTIV among the 3 groups (P = 0.5). CONCLUSIONS The findings advance our understanding of DR pathophysiology in the AA population and may propel identification of race-specific retinal vascular biomarkers for improved diagnosis and monitoring of DR.
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Affiliation(s)
- Sarah L Garvey
- College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Maziyar M Khansari
- Department of Ophthalmology, University of Southern California, 1450 San Pablo Street, Los Angeles, California, 90033, USA
- Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA
| | - Xuejuan Jiang
- Department of Ophthalmology, University of Southern California, 1450 San Pablo Street, Los Angeles, California, 90033, USA
| | - Rohit Varma
- Southern California Eye Institute, CHA Hollywood Presbyterian Medical Center, Los Angeles, CA, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, 1450 San Pablo Street, Los Angeles, California, 90033, USA.
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20
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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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Khansari MM, Garvey SL, Farzad S, Shi Y, Shahidi M. Relationship between retinal vessel tortuosity and oxygenation in sickle cell retinopathy. Int J Retina Vitreous 2019; 5:47. [PMID: 31832241 PMCID: PMC6859621 DOI: 10.1186/s40942-019-0198-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 10/31/2019] [Indexed: 11/10/2022] Open
Abstract
Background Reduced retinal vascular oxygen (O2) content causes tissue hypoxia and may lead to development of vision-threatening pathologies. Since increased vessel tortuosity is an early sign for some hypoxia-implicated retinopathies, we investigated a relationship between retinal vascular O2 content and vessel tortuosity indices. Methods Dual wavelength retinal oximetry using a commercially available scanning laser ophthalmoscope was performed in both eyes of 12 healthy (NC) and 12 sickle cell retinopathy (SCR) subjects. Images were analyzed to quantify retinal arterial and venous O2 content and determine vessel tortuosity index (VTI) and vessel inflection index (VII) in circumpapillary regions. Linear mixed model analysis was used to determine the effect of disease on vascular O2 content, VTI and VII, and relate vascular O2 content with VTI and VII. Models accounted for vessel type, fellow eyes, age and mean arterial pressure. Results Retinal arterial and venous O2 content were lower in SCR (O2A = 11 ± 4 mLO2/dL, O2V = 7 ± 2 mLO2/dL) compared to NC (O2A = 18 ± 3 mLO2/dL, O2V = 13 ± 3 mLO2/dL) subjects (p < 0.001). As expected, O2 content was higher in arteries (15 ± 5 mLO2/dL) than veins (10 ± 4 mLO2/dL) (p < 0.001), but not different between eyes (OD: 12 ± 5 mLO2/dL; OS:13 ± 5 mLO2/dL) (p = 0.3). VTI was not significantly different between SCR (0.18 ± 0.07) and NC (0.15 ± 0.04) subjects, or between arteries (0.18 ± 0.07) and veins (0.16 ± 0.04), or between eyes (OD: 0.18 ± 0.07, OS:0.17 ± 0.05) (p ≥ 0.06). VII was significantly higher in SCR (10 ± 2) compared to NC subjects (8 ± 1) (p = 0.003). VII was also higher in veins (9 ± 2) compared to arteries (8 ± 5) (p = 0.04), but not different between eyes (OD: 9 ± 2; OS: 9 ± 2) (p = 0.2). There was an inverse linear relationship between vascular O2 (13 ± 5 mLO2/dL) content and VII (9 ± 2) (β = -0.5; p = 0.02). Conclusions The findings augment knowledge of relationship between retinal vascular oxygenation and morphological changes and potentially contribute to identifying biomarkers for assessment of retinal hypoxia due to SCR and other retinopathies.
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Affiliation(s)
- Maziyar M Khansari
- 1Department of Ophthalmology, University of Southern California, 1450 San Pablo Street, Los Angeles, CA 90033-6103 USA.,2Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, Los Angeles, CA USA
| | - Sarah L Garvey
- 3College of Medicine, University of Illinois at Chicago, Chicago, IL USA
| | - Shayan Farzad
- 1Department of Ophthalmology, University of Southern California, 1450 San Pablo Street, Los Angeles, CA 90033-6103 USA
| | - Yonggang Shi
- 2Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, Los Angeles, CA USA
| | - Mahnaz Shahidi
- 1Department of Ophthalmology, University of Southern California, 1450 San Pablo Street, Los Angeles, CA 90033-6103 USA
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Relating retinal blood flow and vessel morphology in sickle cell retinopathy. Eye (Lond) 2019; 34:886-891. [PMID: 31558825 PMCID: PMC7182580 DOI: 10.1038/s41433-019-0604-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 08/14/2019] [Indexed: 01/20/2023] Open
Abstract
Purpose The purpose of the current study was to determine associations between retinal blood flow and vessel morphology metrics in sickle cell retinopathy (SCR) and healthy normal control (NC) subjects. Methods Optical coherence tomography angiography (OCTA) and Doppler OCT imaging were performed in 12 SCR (15 eyes) and 19 NC (26 eyes) subjects. Vessel tortuosity was measured using a dedicated image analysis algorithm applied to OCTA images. Vessel density and spacing between vessels were determined from OCTA images by a fractal dimension analysis method. Retinal blood flow was quantified using a phase-resolved technique applied to en face Doppler OCT images. Results There was a significant association between increased retinal blood flow and increased vessel tortuosity (P = 0.03). Furthermore, increased retinal blood flow was associated with increased vessel density (P = 0.03) and decreased spacing between small vessels (P = 0.01). There was no significant association between retinal blood flow and spacing between large vessels (P = 0.11). Vessel tortuosity and blood flow were increased, whereas spacing between small vessels was decreased in SCR compared to NC group (P ≤ 0.03). There were no significant differences in vessel density or spacing between large vessels between the SCR and NC groups (P ≥ 0.31). Conclusions Associations between retinal hemodynamics and vessel morphology were reported, providing better understanding of retinal pathophysiology and insight into potential quantitative biomarkers to evaluate SCR.
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Leitão Guerra RL, Leitão Guerra CL, Bastos MG, de Oliveira AHP, Salles C. Sickle cell retinopathy: What we now understand using optical coherence tomography angiography. A systematic review. Blood Rev 2019; 35:32-42. [DOI: 10.1016/j.blre.2019.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 02/01/2019] [Accepted: 03/01/2019] [Indexed: 12/20/2022]
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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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Mathew R, Sivaprasad S. Advances in the diagnosis of sickle cell retinopathy. EXPERT REVIEW OF OPHTHALMOLOGY 2018. [DOI: 10.1080/17469899.2018.1523007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
| | - Sobha Sivaprasad
- NIHR Moorfields Biomedical Research Center, London, United Kingdom
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