TY - JOUR
T1 - Automated quantification of choriocapillaris anatomical features in ultrahigh-speed optical coherence tomography angiograms
AU - Marsh-Armstrong, Brennan
AU - Migacz, Justin
AU - Jonnal, Ravi
AU - Werner, John S.
PY - 2019/10/1
Y1 - 2019/10/1
N2 - In vivo visualization and quantification of choriocapillaris vascular anatomy is a fundamental step in understanding the relation between choriocapillaris degradation and atrophic retinopathies, including geographic atrophy. We describe a process utilizing ultrahigh-speed swept-source optical coherence tomography and a custom-designed “local min-max normalized masking” algorithm to extract in vivo anatomical metrics of the choriocapillaris. We used a swept-source optical coherence tomography system with a 1.6 MHz A-scan rate to image healthy retinas. With the postprocessing algorithm, we reduced noise, optimized visibility of vasculature, and skeletonized the vasculature within the images. These skeletonizations were in 89% agreement with those made by skilled technicians and were, on average, completed in 18.6 s as compared to the 5.6 h technicians required. Anatomy within the processed images and skeletonizations was analyzed to identify average values (mean±SD) of flow void radius (9.8 ± 0.7 µm), flow void area (749 ± 110 µm2), vessel radius (5.0 ± 0.3 µm), branch-point to branch-point vessel length (26.8 ± 1.1 µm), and branches per branch-point (3.1 ± 0.1). To exemplify the uses of this tool a retina with geographic atrophy was imaged and processed to reveal statistically significant (p<0.05) increases in flow void radii and decreases in vessel radii under atrophic lesions as compared to atrophy-free regions on the same retina. Our results demonstrate a new avenue for quantifying choriocapillaris anatomy and studying vasculature changes in atrophic retinopathies.
AB - In vivo visualization and quantification of choriocapillaris vascular anatomy is a fundamental step in understanding the relation between choriocapillaris degradation and atrophic retinopathies, including geographic atrophy. We describe a process utilizing ultrahigh-speed swept-source optical coherence tomography and a custom-designed “local min-max normalized masking” algorithm to extract in vivo anatomical metrics of the choriocapillaris. We used a swept-source optical coherence tomography system with a 1.6 MHz A-scan rate to image healthy retinas. With the postprocessing algorithm, we reduced noise, optimized visibility of vasculature, and skeletonized the vasculature within the images. These skeletonizations were in 89% agreement with those made by skilled technicians and were, on average, completed in 18.6 s as compared to the 5.6 h technicians required. Anatomy within the processed images and skeletonizations was analyzed to identify average values (mean±SD) of flow void radius (9.8 ± 0.7 µm), flow void area (749 ± 110 µm2), vessel radius (5.0 ± 0.3 µm), branch-point to branch-point vessel length (26.8 ± 1.1 µm), and branches per branch-point (3.1 ± 0.1). To exemplify the uses of this tool a retina with geographic atrophy was imaged and processed to reveal statistically significant (p<0.05) increases in flow void radii and decreases in vessel radii under atrophic lesions as compared to atrophy-free regions on the same retina. Our results demonstrate a new avenue for quantifying choriocapillaris anatomy and studying vasculature changes in atrophic retinopathies.
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U2 - 10.1364/BOE.10.005337
DO - 10.1364/BOE.10.005337
M3 - Article
AN - SCOPUS:85078699118
VL - 10
SP - 5337
EP - 5350
JO - Biomedical Optics Express
JF - Biomedical Optics Express
SN - 2156-7085
IS - 10
ER -