Common approach for compensation of axial motion artifacts in swept-source OCT and dispersion in Fourier-domain OCT

• Published in: Optics express Vol. 20; no. 6; pp. 6761 - 6776
• Main Authors: Hillmann, Dierck, Bonin, Tim, Lührs, Christian, Franke, Gesa, Hagen-Eggert, Martin, Koch, Peter, Hüttmann, Gereon
• Format: Journal Article
• Language: English
• Published: United States 12.03.2012
• Subjects: Algorithms; Fourier Analysis; Image Enhancement - methods; Image Interpretation, Computer-Assisted - methods; Motion; Reproducibility of Results; Sensitivity and Specificity; Tomography, Optical Coherence - methods
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/oe.20.006761

Swept-source optical coherence tomography (SS-OCT) is sensitive to sample motion during the wavelength sweep, which leads to image blurring and image artifacts. In line-field and full-field SS-OCT parallelization is achieved by using a line or area detector, respectively. Thus, approximately 1000 lines or images at different wavenumbers are acquired. The sweep duration is identically with the acquisition time of a complete B-scan or volume, rendering parallel SS-OCT more sensitive to motion artifacts than scanning OCT. The effect of axial motion on the measured spectra is similar to the effect of non-balanced group velocity dispersion (GVD) in the interferometer arms. It causes the apparent optical path lengths in the sample arm to vary with the wavenumber. Here we propose the cross-correlation of sub-bandwidth reconstructions (CCSBR) as a new algorithm that is capable of detecting and correcting the artifacts induced by axial motion in line-field or full-field SS-OCT as well as GVD mismatch in any Fourier-domain OCT (FD-OCT) setup. By cross-correlating images which were reconstructed from a limited spectral range of the interference signal, a phase error is determined which is used to correct the spectral modulation prior to the calculation of the A-scans. Performance of the algorithm is demonstrated on in vivo full-field SS-OCT images of skin and scanning FD-OCT of skin and retina.