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Intra‐session repeatability of quantitative metrics using widefield optical coherence tomography angiography ( OCTA ) in elderly subjects
Author(s) -
Hong Jimmy,
Tan Bingyao,
Quang Nguyen Duc,
Gupta Preeti,
Lin Emily,
Wong Damon,
Ang Marcus,
Lamoureux Ecosse,
Schmetterer Leopold,
Chua Jacqueline
Publication year - 2020
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/aos.14327
Subject(s) - repeatability , optical coherence tomography angiography , intraclass correlation , optical coherence tomography , nuclear medicine , gabor filter , filter (signal processing) , gaussian filter , medicine , mathematics , ophthalmology , artificial intelligence , reproducibility , computer science , computer vision , statistics , image (mathematics)
Purpose To assess the repeatability of retinal vascular metrics using different postprocessing methods as obtained from the swept‐source optical coherence tomography angiography ( SS ‐ OCTA ). Methods Thirty‐two participants (63% males; mean [ SD ] age, 70 [7] years) underwent SS ‐ OCTA imaging ( PLEX ® Elite 9000, Carl Zeiss Meditec, Inc., Dublin, USA ). Each participant underwent 2 repeated scans of 2 scan protocols: a macular‐centred 3 × 3‐mm 2 and a widefield 12 × 12‐mm 2 for a total of 4 acquisitions. Images of superficial vascular plexuses ( SVP ) and deep vascular plexuses ( DVP ) were processed using different filters to generate the perfusion density ( PD ) and vessel density ( VD ). Vessel enhancement filters ranged from vessel targeted (Hessian and Gabor filters), classical denoising (Gaussian filter), to a scale‐selective adaption (modified Bayesian residual transform [ MBRT ]). Intra‐session repeatability of the different filters and their correlation with the original data set were calculated with the intraclass correlation coefficient ( ICC ) and Pearson's r . Results Of the 32 eyes, 17 and 15 were right and left eyes, respectively. For 3 × 3‐mm 2 scans, both MBRT and Gabor filters yielded very good repeatable PD and VD (both ICC s > 0.87) values. Gabor filter was the most correlated with the original data set for the OCTA metrics ( r = 0.95–0.97). For 12 × 12‐mm 2 scans, MBRT filter produced good‐to‐moderate ICC values for SVP ( ICC >0.89) and DVP ( ICC >0.73) metrics. Both the MBRT and Gabor filters were highly correlated with the original 12 × 12‐mm 2 scan data set ( r = 0.96–0.98). The ICC s for the agreement between 3 × 3‐mm 2 and cropped 12 × 12‐mm 2 were high only for the PD values at the SVP layer and were poor for the VD at SVP and DVP measurements ( ICC < 0.50). Conclusion Our findings show that with the proper choice of postimaging processing methods, SS ‐ OCTA metrics can be obtained with high repeatability, which supports its use in various clinical settings.