Cyst Detection and Motion Artifact Elimination in Enface Optical Coherence Tomography Angiograms

The correct detection of cysts in Optical Coherence Tomography Angiography images is of crucial importance for allowing reliable quantitative evaluation in patients with macular edema. However, this is a challenging task, since the commercially available software only allows manual cysts delineation. Moreover, even small eye movements can cause motion artifacts that are not always compensated by the commercial software. In this paper, we propose a novel algorithm based on the use of filters and morphological operators, to eliminate the motion artifacts and delineate the cysts contours/borders. The method has been validated on a dataset including 194 images from 30 patients, comparing the algorithm results with the ground truth produced by the medical doctors. The Jaccard index between the algorithmic and the manual detection is 98.97%, with an overall accuracy of 99.62%.

Download Full-text

Applicability of optical coherence tomography angiography (OCTA) imaging in Parkinson’s disease

Scientific Reports ◽

10.1038/s41598-021-84862-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jost L. Lauermann ◽

Jan A. M. Sochurek ◽

Pauline Plöttner ◽

Florian Alten ◽

Meike Kasten ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Motion Artifact ◽

Cross Sectional Study ◽

Motion Artifacts ◽

Healthy Controls ◽

Optical Coherence ◽

Cross Sectional

AbstractTo evaluate the significance of motion artifacts in optical coherence tomography angiography (OCTA) images of patients with Parkinson’s disease (PD) and healthy controls. In this prospective, cross-sectional study subjects with medicated PD (ON) and healthy, age- and gender-matched volunteers were recruited. Participants underwent specific ophthalmological examinations, including OCTA. Angiograms of the superficial retinal capillary plexus were evaluated for the type and frequency of artifacts using a validated motion artifact score (MAS). A total of 30 PD patients (60 eyes), average disease duration of 9.61 ± 5.55 years, and 30 matched, healthy controls (60 eyes) were recruited. Twenty percent of all eyes had an eye disease, unknown to the participant, with a significant impact on OCTA results. After cleansing the dataset by excluding subjects with confounding ocular comorbidities 42 eyes of 28 PD patients and 53 eyes of 29 healthy controls were further evaluated. Overall MAS and all five subtypes of motion artifacts were comparable without significant differences between groups. OCTA can be used in treated PD patients (ON) without a significant increase in motion artifacts. Nevertheless, special attention should be paid to image quality during the acquisition of OCTA data, for which an experienced OCTA operator is useful.

Download Full-text

The impact of motion artifacts on quantitative optical coherence tomography angiography analysis in Parkinson's disease

Parkinsonism & Related Disorders ◽

10.1016/j.parkreldis.2022.01.006 ◽

2022 ◽

Author(s):

Mahdy Ranjbar ◽

Pauline Plöttner ◽

Jan A.M. Sochurek ◽

Jost L. Lauermann ◽

Florian Alten ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Motion Artifacts ◽

Optical Coherence ◽

The Impact

Download Full-text

Optical coherence tomography angiography in diabetes: A review

European Journal of Ophthalmology ◽

10.1177/1120672119899901 ◽

2020 ◽

Vol 30 (3) ◽

pp. 411-416 ◽

Cited By ~ 5

Author(s):

Marco Battista ◽

Enrico Borrelli ◽

Riccardo Sacconi ◽

Francesco Bandello ◽

Giuseppe Querques

Keyword(s):

Optical Coherence Tomography ◽

Diabetic Retinopathy ◽

Optical Coherence Tomography Angiography ◽

Research Field ◽

Motion Artifacts ◽

Foveal Avascular Zone ◽

Imaging Method ◽

Optical Coherence ◽

Avascular Zone ◽

Heavy Burden

Diabetic retinopathy is a common diabetes complication representing a heavy burden in terms of visual impairment and heath expenditure. Optical coherence tomography angiography is a relatively new imaging method and has proven to be a powerful tool in the analysis of diabetic retinopathy common features, including microaneurysms, intraretinal microvascular abnormalities, or neovascularization, as well as in research field, challenging the gold standard of fluorescein angiography. Many studies underlined the vascular impairment observed through optical coherence tomography angiography and its typical parameters such as vessel length density, foveal avascular zone, and fractal dimension. Choriocapillaris involvement in the pathogenesis of diabetic retinopathy is an interesting point, derived from the analysis of this plexus using optical coherence tomography angiography. In conclusion, optical coherence tomography angiography, which is not free of limitations, such as motion artifacts or segmentation errors, has become an indispensable technique in adding more information to our understanding of diabetic retinopathy.

Download Full-text

Changes in Chorioretinal Flow Index after Cataract Surgery: An Optical Coherence Tomography Angiography Study

10.21203/rs.3.rs-1048031/v1 ◽

2021 ◽

Author(s):

Achia Nemet ◽

Michael Mimouni ◽

Fadi Haddad ◽

Shadi Safuri ◽

Asaf Achiron ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Cataract Surgery ◽

Optical Coherence Tomography Angiography ◽

Outcome Measure ◽

Cataract Extraction ◽

Motion Artifacts ◽

Flow Index ◽

Optical Coherence ◽

Strength Index ◽

Exclusion Criteria

Abstract PURPOSE: Pseudophakic cystoid macular edema (CME) occurs in up to 2% of uneventful cataract surgeries. This study evaluates changes in macular blood flow succeeding uneventful phacoemulsification cataract extraction among otherwise visually healthy subjects.METHODS: This prospective study included 18 eyes of 18 patients undergoing routine phacoemulsification. Optical coherence tomography angiography (OCT-A) was performed using the Angio-Retina 6x6mm protocol with the XR Avanti Angio-Vue system (Optovue Inc., Fremont, California) prior to the surgery and 4-8 weeks thereafter. Exclusion criteria included motion artifacts, segmentation errors and signal strength index (SSI) ˂40. The main outcome measure was change in flow index (FI) measured in all 4 retinal segmentation layers within an area of 1mm diameter around the foveal center.RESULTS: Following surgery, a significant increase in SSI (46.65±8.62 versus 53.12±8.07, p=0.01), superficial plexus FI (0.98±0.23 versus 1.16±0.16, p=0.02) and deep plexus FI (0.54±0.46 versus 0.93±0.39, p=0.01) was found. No significant changes were noted in the outer retina or the choriocapillaris. CONCLUSION: The study demonstrates a significant increase in FI in the superficial and deep retinal plexus following uneventful cataract surgery, with the greatest changes occurring in the latter. These findings corroborate evidence from structural imaging and support the vascular etiology of pseudophakic CME.

Download Full-text

Motion artifact removal of optical coherence tomography angiography based on tensor voting

Optical Coherence Tomography and Coherence Domain Optical Methods in Biomedicine XXIII ◽

10.1117/12.2510559 ◽

2019 ◽

Author(s):

Ang Li ◽

Congwu Du ◽

Yingtian Pan

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Motion Artifact ◽

Optical Coherence ◽

Tensor Voting ◽

Artifact Removal

Download Full-text

Widefield Optical Coherence Tomography Angiography in Diabetic Retinopathy

Journal of Diabetes Research ◽

10.1155/2020/8855709 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Alessia Amato ◽

Francesco Nadin ◽

Federico Borghesan ◽

Maria Vittoria Cicinelli ◽

Irini Chatziralli ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Diabetic Retinopathy ◽

Optical Coherence Tomography Angiography ◽

Clinical Findings ◽

Motion Artifacts ◽

Optical Coherence ◽

Quantitative Estimates ◽

Acquisition Strategies ◽

Objective Metrics

Purpose. To summarize the role of widefield optical coherence tomography angiography (WF-OCTA) in diabetic retinopathy (DR), extending from the acquisition strategies to the main clinical findings. Methods. A PubMed-based search was carried out using the terms “Diabetic retinopathy”, “optical coherence tomography angiography”, “widefield imaging”, and “ultra-widefield imaging”. All studies published in English up to August 2020 were reviewed. Results. WF-OCTA can be obtained with different approaches, offering advantages over traditional imaging in the study of nonperfusion areas (NPAs) and neovascularization (NV). Quantitative estimates and topographic distribution of NPA and NV are useful for treatment monitoring and artificial intelligence-based approaches. Curvature, segmentation, and motion artifacts should be assessed when using WF-OCTA. Conclusions. WF-OCTA harbors interesting potential in DR because of its noninvasiveness and capability of objective metrics of retinal vasculature. Further studies will facilitate the migration from traditional imaging to WF-OCTA in both the research and clinical practice fields.

Download Full-text