TY - JOUR
T1 - Strip-based registration of serially acquired optical coherence tomography angiography
AU - Heisler, Morgan
AU - Lee, Sieun
AU - Mammo, Zaid
AU - Jian, Yifan
AU - Ju, Myeongjin
AU - Merkur, Andrew
AU - Navajas, Eduardo
AU - Balaratnasingam, Chandrakumar
AU - Beg, Mirza Faisal
AU - Sarunic, Marinko V.
N1 - Publisher Copyright:
© The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its.
PY - 2017/3/1
Y1 - 2017/3/1
N2 - The visibility of retinal microvasculature in optical coherence tomography angiography (OCT-A) images is negatively affected by the small dimension of the capillaries, pulsatile blood flow, and motion artifacts. Serial acquisition and time-averaging of multiple OCT-A images can enhance the definition of the capillaries and result in repeatable and consistent visualization. We demonstrate an automated method for registration and averaging of serially acquired OCT-A images. Ten OCT-A volumes from six normal control subjects were acquired using our prototype 1060-nm swept source OCT system. The volumes were divided into microsaccade-free en face angiogram strips, which were affine registered using scale-invariant feature transform keypoints, followed by nonrigid registration by pixel-wise local neighborhood matching. The resulting averaged images were presented of all the retinal layers combined, as well as in the superficial and deep plexus layers separately. The contrast-to-noise ratio and signal-to-noise ratio of the angiograms with all retinal layers (reported as average±standard deviation) increased from 0.52±0.22 and 19.58±4.04dB for a single image to 0.77±0.25 and 25.05±4.73dB, respectively, for the serially acquired images after registration and averaging. The improved visualization of the capillaries can enable robust quantification and study of minute changes in retinal microvasculature.
AB - The visibility of retinal microvasculature in optical coherence tomography angiography (OCT-A) images is negatively affected by the small dimension of the capillaries, pulsatile blood flow, and motion artifacts. Serial acquisition and time-averaging of multiple OCT-A images can enhance the definition of the capillaries and result in repeatable and consistent visualization. We demonstrate an automated method for registration and averaging of serially acquired OCT-A images. Ten OCT-A volumes from six normal control subjects were acquired using our prototype 1060-nm swept source OCT system. The volumes were divided into microsaccade-free en face angiogram strips, which were affine registered using scale-invariant feature transform keypoints, followed by nonrigid registration by pixel-wise local neighborhood matching. The resulting averaged images were presented of all the retinal layers combined, as well as in the superficial and deep plexus layers separately. The contrast-to-noise ratio and signal-to-noise ratio of the angiograms with all retinal layers (reported as average±standard deviation) increased from 0.52±0.22 and 19.58±4.04dB for a single image to 0.77±0.25 and 25.05±4.73dB, respectively, for the serially acquired images after registration and averaging. The improved visualization of the capillaries can enable robust quantification and study of minute changes in retinal microvasculature.
KW - image analysis
KW - image processing
KW - ophthalmology
KW - optical coherence tomography
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U2 - 10.1117/1.JBO.22.3.036007
DO - 10.1117/1.JBO.22.3.036007
M3 - Article
C2 - 28265647
AN - SCOPUS:85015758543
SN - 1083-3668
VL - 22
JO - Journal of biomedical optics
JF - Journal of biomedical optics
IS - 3
M1 - 036007
ER -