Phase unwrapping for Doppler spectral domain optical coherence tomography flow measurement. Issue 2 (25th November 2019)

• Record Type: Journal Article
• Authors: Zhao, Yuqian; Ma, Yushu; Liu, Jian; Yu, Yao; Wang, Yi; Ma, Zhenhe
• Is Part Of: Journal of biophotonics. Volume 13:Issue 2(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-11-25
• Subjects: Doppler -- flow measurement -- medical and biological imaging -- optical coherence tomography -- phase unwrapping; Photonics -- Periodicals; Optical materials -- Periodicals; Optics -- Periodicals; Medical instruments and apparatus -- Periodicals; 621.3605
• DOI: 10.1002/jbio.201960064
• Languages: English
• ISSNs: 1864-063X

Abstract

Abstract: Doppler optical coherence tomography (OCT) offers additional flow velocity information, which extends the application of OCT. Phase wrapping is the inherent problem that limits measureable range of Doppler OCT. We propose a phase unwrapping method which is suitable for correcting phase in Doppler OCT images. Points (pixels) in flow region are divided into groups according to the radial distance. Points in the same group are supposed to have close velocity. Phase unwrapping algorithm begins at the boundary layer group and is performed sequentially toward the center. Using the proposed criterion, points in a group are separated into two categories, signal points and noise points. Wrapping rounds are determined for signal points phase unwrapping. Mean value of the corrected signal points replaces the noise points for noise reduction. The method is validated with capillary tube flow phantom and in vivo blood flow. Abstract : We propose a phase unwrapping method to correct the wrapping phase in Doppler optical coherence tomography image. Points in flow region are divided into groups according to the radial distance. For each point group, signal points are selected and corrected with phase unwrapping algorithm, while noise points are replaced with the mean value of the corrected points. The method is validated with flow in capillary tube and in vivo blood vessels.