Minimizing projection artifacts for accurate presentation of choroidal neovascularization in OCT micro-angiography (original) (raw)
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Ophthalmology retina
To visualize and quantify the size and vessel density of macular neovascularization (MNV) using optical coherence tomography angiography (OCTA) with a projection artifact removal algorithm. Multicenter, observational study. Subjects with MNV in at least one eye. Patients were imaged using either a swept-source OCT angiography (SS-OCTA) prototype system or a spectral-domain OCT angiography (SD-OCTA) prototype system. The optical microangiography (OMAG) algorithm was used to generate the OCTA images. Projection artifacts from the overlying retinal circulation were removed from the OMAG OCTA images using a novel algorithm. Following removal of the projection artifacts from the OCTA images, we assessed the size and vascularity of the MNV. Concurrent fluorescein angiography (FA) and indocyanine green angiography (ICGA) images were used to validate the artifact-free OMAG images whenever available. Size and vascularity of MNV imaged with OCTA before and after the use of a projection-artifa...
European Journal of Ophthalmology, 2019
To analyze the ability of optical coherence tomography angiography to identify choroidal neovascularization in multifocal choroiditis and to describe active and inactive choroidal neovascularization findings. Methods: Retrospective study of consecutive patients with multifocal choroiditis and choroidal neovascularization examined between January and November 2016. In addition to usual exams, optical coherence tomography angiography (AngioPlex™ CIRRUS™ HD-OCT model 5000; Carl Zeiss Meditec, Inc., Dublin, CA, USA) images were assessed for morphological analysis: choroidal neovascularization size, choroidal neovascularization margin (well or poorly circumscribed), choroidal neovascularization shape (tangled or interlacing), choroidal neovascularization core (feeder vessel) and dark ring around the choroidal neovascularization. Results: A total of 10 eyes were included. Optical coherence tomography angiography identified all choroidal neovascularization. Active choroidal neovascularization had well-circumscribed margins (67%), interlacing shape (83%), and a surrounding dark ring (83%). Inactive choroidal neovascularization had rather poorly circumscribed margins (75%), tangled shape, and "dead tree" appearance (50%) with less frequently a surrounding dark ring (50%). Conclusion: Optical coherence tomography angiography is adapted to confirm the diagnosis of choroidal neovascularization complicating multifocal choroiditis, but it is still insufficient to differentiate active and inactive lesions.
Retina (Philadelphia, Pa.), 2018
To compare the sensitivity of detection and the measured size of choroidal neovascularization (CNV) on two commercially available spectral domain optical coherence tomography angiography (OCTA) devices, the Optovue RTVue XR Avanti with AngioVue and the Zeiss Cirrus HD-OCT with AngioPlex. Patients with CNV lesions were imaged consecutively on both OCTA devices on the same day of their visit. 3 × 3 mm and 6 × 6 mm scans centered at the fovea were obtained. Two independent masked readers evaluated the OCTA images for CNV identification and its area measurements. No significant differences were observed between the 2 OCTA devices in CNV area measurements on their 3 × 3 mm and 6 × 6 mm scans. However, there was suboptimal performance of their automated segmentation algorithms as compared to manually adjusted segmentation for visualizing CNV lesions. There was no significant difference in the size of the CNV lesion as measured on either commercially available spectral domain OCTA device. ...
Investigative ophthalmology & visual science, 2017
To compare the lesion sizes of choroidal neovascularization (CNV) imaged with spectral-domain (SD) and swept-source (SS) optical coherence tomography angiography (OCTA) and measured using an automated detection algorithm. Patients diagnosed with CNV were imaged by SD-OCTA and SS-OCTA systems using 3 × 3-mm and 6 × 6-mm scans. The complex optical microangiography (OMAGC) algorithm was used to generate the OCTA images. Optical coherence tomography A datasets for imaging CNV were derived by segmenting from the outer retina to 8 μm below Bruch's membrane. An artifact removal algorithm was used to generate angiograms free of retinal vessel projection artifacts. An automated detection algorithm was developed to quantify the size of the CNV. Automated measurements were compared with manual measurements. Measurements from SD-OCTA and SS-OCTA instruments were compared as well. Twenty-seven eyes from 23 subjects diagnosed with CNV were analyzed. No significant differences were detected be...
Retina, 2019
Purpose: To compare optical coherence tomography angiography (OCTA) review strategies for optimizing choroidal neovascularization (CNV) detection. Methods: Eyes with CNV in the differential diagnosis were imaged with the Avanti RTVue XR HD (Optovue, Fremont, CA). Three modalities of review for CNV presence were used in each case: a single report generated using automated segmentation within Avanti software; a continuous slab descent video OCTA export; and a manual segmentation approach using cross-sectional OCT with decorrelation signal overlay. Scans were reviewed by two masked expert reviewers; a third reviewer was used for discrepancies. Results: The study included 421 eyes, and 350 eyes had reports deemed sufficient quality for interpretation. Choroidal neovascularization was in the differential diagnosis in 107 of 350 patients. Overall CNV was identified in 55% (59/107) eyes. In those eyes with CNV, the automated segmentation identified CNV in 56% (33/59) of cases, continuous s...
Investigative ophthalmology & visual science, 2017
The purpose of this study was to compare imaging of choroidal neovascularization (CNV) using swept-source (SS) and spectral-domain (SD) optical coherence tomography angiography (OCTA). Optical coherence tomography angiography was performed using a 100-kHz SS-OCT instrument and a 68-kHz SD-OCTA instrument (Carl Zeiss Meditec, Inc.). Both 3 × 3- and 6 × 6-mm2 scans were obtained on both instruments. The 3 × 3-mm2 SS-OCTA scans consisted of 300 A-scans per B-scan at 300 B-scan positions, and the SD-OCTA scans consisted of 245 A-scans at 245 B-scan positions. The 6 × 6-mm2 SS-OCTA scans consisted of 420 A-scans per B-scan at 420 B-scan positions, and the SD-OCTA scans consisted of 350 A-scans and 350 B-scan positions. B-scans were repeated four times at each position in the 3 × 3-mm2 scans and twice in the 6 × 6-mm2 scans. Choroidal neovascularization was excluded if not fully contained within the 3 × 3-mm2 scans. The same algorithm was used to detect CNV on both instruments. Two grader...
2016
Optical coherence tomography (OCT) can be used to detect and monitor fluid exudation and morphologic changes associated with vascular diseases in the posterior segment. However, structural OCT cannot directly detect capillary dropout or neovascularization, the major vascular changes associated with the leading causes of blindness— age-related macular degeneration (AMD) and diabetic retinopathy (DR). The traditional imaging methods used in the study of normal and pathologic retinal vessels, fluorescein angiography (FA) and indocyanine green angiography (ICGA), also do not allow a precise view of neovascularization. They provide blurred images of the vascular network based on dye leakage. These imaging procedures hold a fundamental place in retinal imaging; however, their invasive nature sometimes causes patients to experience mild to serious side effects. OCT angiography (OCTA) is a fast, easy, safe, and inexpensive option for diagnosing and monitoring a variety of retinal disorders....
Proceedings of the National Academy of Sciences of the United States of America, 2015
Retinal vascular diseases are important causes of vision loss. A detailed evaluation of the vascular abnormalities facilitates diagnosis and treatment in these diseases. Optical coherence tomography (OCT) angiography using the highly efficient split-spectrum amplitude decorrelation angiography algorithm offers an alternative to conventional dye-based retinal angiography. OCT angiography has several advantages, including 3D visualization of retinal and choroidal circulations (including the choriocapillaris) and avoidance of dye injection-related complications. Results from six illustrative cases are reported. In diabetic retinopathy, OCT angiography can detect neovascularization and quantify ischemia. In age-related macular degeneration, choroidal neovascularization can be observed without the obscuration of details caused by dye leakage in conventional angiography. Choriocapillaris dysfunction can be detected in the nonneovascular form of the disease, furthering our understanding of...