Abstract
Purpose: Quantification of optical coherence tomography angiography (OCTA) is confounded by the prevalence of bulk motion. We have previously developed a regression-based bulk motion subtraction (rb-BMS) algorithm that estimates bulk motion velocity and corrects for its effect on flow signal. Here, we aim to investigate its ability to improve the reliability of capillary density (CD) quantification. Methods: Two spectral-domain systems (70-kHz Avanti/AngioVue and 68-kHz Cirrus/ AngioPlex) acquired 6 × 6-mm OCTA scans. The rb-BMS algorithm was applied on each OCTA volume. Regression analysis of angiographic versus reflectance signal of avascular A-lines in B-frames was used to set an optimized reflectance-adjusted threshold for discriminating vascular versus nonvascular voxels. The CD was calculated from en face maximum projections of the superficial vascular complex in macular scans and the nerve fiber layer plexus in disc scans, excluding large vessels. The retinal signal strength (RSS) was calculated by averaging the logarithmic-scale OCT reflectance signal, and its correlation with CD was investigated. Results: Eight healthy eyes were scanned with each instrument on 2 separate days. The rb-BMS algorithm improved within-visit repeatability and between-visit reproducibility of CD compared with a global-threshold measurement algorithm. Using the rb-BMS algorithm, the CD results were less affected by RSS and the population variation was reduced. Motion-induced line artifacts were also reduced. Conclusions: The rb-BMS algorithm improved the reliability of perfusion quantification in OCTA on both Food and Drug Administration–cleared spectral-domain OCTA systems. Translational Relevance: The rb-BMS method helped reduce the inter-scan variability by generating accurate vessel maps, improving the reliability of retinal perfusion quantification.
| Original language | English (US) |
|---|---|
| Article number | 20 |
| Journal | Translational Vision Science and Technology |
| Volume | 7 |
| Issue number | 6 |
| DOIs | |
| State | Published - Nov 1 2018 |
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Keywords
- Motion artifacts
- OCTA
- Vessel density
ASJC Scopus subject areas
- Biomedical Engineering
- Ophthalmology
Cite this
Enhanced quantification of retinal perfusion by improved discrimination of blood flow from bulk motion signal in OCTA. / Camino, Acner; Zhang, Miao; Liu, Liang; Wang, Jie; Yali, Jia; Huang, David.
In: Translational Vision Science and Technology, Vol. 7, No. 6, 20, 01.11.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Enhanced quantification of retinal perfusion by improved discrimination of blood flow from bulk motion signal in OCTA
AU - Camino, Acner
AU - Zhang, Miao
AU - Liu, Liang
AU - Wang, Jie
AU - Yali, Jia
AU - Huang, David
PY - 2018/11/1
Y1 - 2018/11/1
N2 - Purpose: Quantification of optical coherence tomography angiography (OCTA) is confounded by the prevalence of bulk motion. We have previously developed a regression-based bulk motion subtraction (rb-BMS) algorithm that estimates bulk motion velocity and corrects for its effect on flow signal. Here, we aim to investigate its ability to improve the reliability of capillary density (CD) quantification. Methods: Two spectral-domain systems (70-kHz Avanti/AngioVue and 68-kHz Cirrus/ AngioPlex) acquired 6 × 6-mm OCTA scans. The rb-BMS algorithm was applied on each OCTA volume. Regression analysis of angiographic versus reflectance signal of avascular A-lines in B-frames was used to set an optimized reflectance-adjusted threshold for discriminating vascular versus nonvascular voxels. The CD was calculated from en face maximum projections of the superficial vascular complex in macular scans and the nerve fiber layer plexus in disc scans, excluding large vessels. The retinal signal strength (RSS) was calculated by averaging the logarithmic-scale OCT reflectance signal, and its correlation with CD was investigated. Results: Eight healthy eyes were scanned with each instrument on 2 separate days. The rb-BMS algorithm improved within-visit repeatability and between-visit reproducibility of CD compared with a global-threshold measurement algorithm. Using the rb-BMS algorithm, the CD results were less affected by RSS and the population variation was reduced. Motion-induced line artifacts were also reduced. Conclusions: The rb-BMS algorithm improved the reliability of perfusion quantification in OCTA on both Food and Drug Administration–cleared spectral-domain OCTA systems. Translational Relevance: The rb-BMS method helped reduce the inter-scan variability by generating accurate vessel maps, improving the reliability of retinal perfusion quantification.
AB - Purpose: Quantification of optical coherence tomography angiography (OCTA) is confounded by the prevalence of bulk motion. We have previously developed a regression-based bulk motion subtraction (rb-BMS) algorithm that estimates bulk motion velocity and corrects for its effect on flow signal. Here, we aim to investigate its ability to improve the reliability of capillary density (CD) quantification. Methods: Two spectral-domain systems (70-kHz Avanti/AngioVue and 68-kHz Cirrus/ AngioPlex) acquired 6 × 6-mm OCTA scans. The rb-BMS algorithm was applied on each OCTA volume. Regression analysis of angiographic versus reflectance signal of avascular A-lines in B-frames was used to set an optimized reflectance-adjusted threshold for discriminating vascular versus nonvascular voxels. The CD was calculated from en face maximum projections of the superficial vascular complex in macular scans and the nerve fiber layer plexus in disc scans, excluding large vessels. The retinal signal strength (RSS) was calculated by averaging the logarithmic-scale OCT reflectance signal, and its correlation with CD was investigated. Results: Eight healthy eyes were scanned with each instrument on 2 separate days. The rb-BMS algorithm improved within-visit repeatability and between-visit reproducibility of CD compared with a global-threshold measurement algorithm. Using the rb-BMS algorithm, the CD results were less affected by RSS and the population variation was reduced. Motion-induced line artifacts were also reduced. Conclusions: The rb-BMS algorithm improved the reliability of perfusion quantification in OCTA on both Food and Drug Administration–cleared spectral-domain OCTA systems. Translational Relevance: The rb-BMS method helped reduce the inter-scan variability by generating accurate vessel maps, improving the reliability of retinal perfusion quantification.
KW - Motion artifacts
KW - OCTA
KW - Vessel density
UR - http://www.scopus.com/inward/record.url?scp=85059255844&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85059255844&partnerID=8YFLogxK
U2 - 10.1167/tvst.7.6.20
DO - 10.1167/tvst.7.6.20
M3 - Article
AN - SCOPUS:85059255844
VL - 7
JO - Translational Vision Science and Technology
JF - Translational Vision Science and Technology
SN - 2164-2591
IS - 6
M1 - 20
ER -