High-resolution extended source optical coherence tomography

High resolution optical coherence tomography (OCT) is capable of providing detailed tissue microstructures that are critical for disease diagnosis, yet its sensitivity is usually degraded since the system key components are typically not working at their respective center wavelengths. We developed a...

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Main Authors: Yu, Xiaojun, Liu, Xinyu, Chen, Si, Luo, Yuemei, Wang, Xianghong, Liu, Linbo
Other Authors: School of Chemical and Biomedical Engineering
Format: Article
Language:English
Published: 2016
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Online Access:https://hdl.handle.net/10356/81673
http://hdl.handle.net/10220/40954
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-816732020-03-07T11:35:19Z High-resolution extended source optical coherence tomography Yu, Xiaojun Liu, Xinyu Chen, Si Luo, Yuemei Wang, Xianghong Liu, Linbo School of Chemical and Biomedical Engineering School of Electrical and Electronic Engineering Optical coherence tomography Medical and biological imaging High resolution optical coherence tomography (OCT) is capable of providing detailed tissue microstructures that are critical for disease diagnosis, yet its sensitivity is usually degraded since the system key components are typically not working at their respective center wavelengths. We developed a novel imaging system that achieves enhanced sensitivity without axial resolution degradation by the use of a spectrally encoded extended source (SEES) technique; it allows larger sample power without exceeding the maximum permissible exposure (MPE). In this study, we demonstrate a high-resolution extended source (HRES) OCT system, which is capable of providing a transverse resolution of 4.4 µm and an axial resolution of 2.1 µm in air with the SEES technique. We first theoretically show a sensitivity advantage of 6-dB of the HRES-OCT over that of its point source counterpart using numerical simulations, and then experimentally validate the applicability of the SEES technique to high-resolution OCT (HR-OCT) by comparing the HRES-OCT with an equivalent point-source system. In the HRES-OCT system, a dispersive prism was placed in the infinity space of the sample arm optics to spectrally extend the visual angle (angular subtense) of the light source to 10.3 mrad. This extended source allowed ~4 times larger MPE than its point source counterpart, which results in an enhancement of ~6 dB in sensitivity. Specifically, to solve the unbalanced dispersion between the sample and the reference arm optics, we proposed easy and efficient methods for system calibration and dispersion correction, respectively. With a maximum scanning speed reaching up to 60K A-lines/s, we further conducted imaging experiments with HRES-OCT using the human fingertip in vivo and the swine eye tissues ex vivo. Results demonstrate that the HRES-OCT is able to achieve significantly larger penetration depth than its conventional point source OCT counterpart. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) NMRC (Natl Medical Research Council, S’pore) Accepted version 2016-07-18T05:30:13Z 2019-12-06T14:35:53Z 2016-07-18T05:30:13Z 2019-12-06T14:35:53Z 2015 Journal Article Yu, X., Liu, X., Chen, S., Luo, Y., Wang, X., & Liu, L. (2015). High-resolution extended source optical coherence tomography. Optics Express, 23(20), 26399-26413. 1094-4087 https://hdl.handle.net/10356/81673 http://hdl.handle.net/10220/40954 10.1364/OE.23.026399 en Optics Express © 2015 Optical Society of America. This is the author created version of a work that has been peer reviewed and accepted for publication by Optics Express, Optical Society of America. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1364/OE.23.026399]. 17 p. application/pdf
institution Nanyang Technological University
building NTU Library
country Singapore
collection DR-NTU
language English
topic Optical coherence tomography
Medical and biological imaging
spellingShingle Optical coherence tomography
Medical and biological imaging
Yu, Xiaojun
Liu, Xinyu
Chen, Si
Luo, Yuemei
Wang, Xianghong
Liu, Linbo
High-resolution extended source optical coherence tomography
description High resolution optical coherence tomography (OCT) is capable of providing detailed tissue microstructures that are critical for disease diagnosis, yet its sensitivity is usually degraded since the system key components are typically not working at their respective center wavelengths. We developed a novel imaging system that achieves enhanced sensitivity without axial resolution degradation by the use of a spectrally encoded extended source (SEES) technique; it allows larger sample power without exceeding the maximum permissible exposure (MPE). In this study, we demonstrate a high-resolution extended source (HRES) OCT system, which is capable of providing a transverse resolution of 4.4 µm and an axial resolution of 2.1 µm in air with the SEES technique. We first theoretically show a sensitivity advantage of 6-dB of the HRES-OCT over that of its point source counterpart using numerical simulations, and then experimentally validate the applicability of the SEES technique to high-resolution OCT (HR-OCT) by comparing the HRES-OCT with an equivalent point-source system. In the HRES-OCT system, a dispersive prism was placed in the infinity space of the sample arm optics to spectrally extend the visual angle (angular subtense) of the light source to 10.3 mrad. This extended source allowed ~4 times larger MPE than its point source counterpart, which results in an enhancement of ~6 dB in sensitivity. Specifically, to solve the unbalanced dispersion between the sample and the reference arm optics, we proposed easy and efficient methods for system calibration and dispersion correction, respectively. With a maximum scanning speed reaching up to 60K A-lines/s, we further conducted imaging experiments with HRES-OCT using the human fingertip in vivo and the swine eye tissues ex vivo. Results demonstrate that the HRES-OCT is able to achieve significantly larger penetration depth than its conventional point source OCT counterpart.
author2 School of Chemical and Biomedical Engineering
author_facet School of Chemical and Biomedical Engineering
Yu, Xiaojun
Liu, Xinyu
Chen, Si
Luo, Yuemei
Wang, Xianghong
Liu, Linbo
format Article
author Yu, Xiaojun
Liu, Xinyu
Chen, Si
Luo, Yuemei
Wang, Xianghong
Liu, Linbo
author_sort Yu, Xiaojun
title High-resolution extended source optical coherence tomography
title_short High-resolution extended source optical coherence tomography
title_full High-resolution extended source optical coherence tomography
title_fullStr High-resolution extended source optical coherence tomography
title_full_unstemmed High-resolution extended source optical coherence tomography
title_sort high-resolution extended source optical coherence tomography
publishDate 2016
url https://hdl.handle.net/10356/81673
http://hdl.handle.net/10220/40954
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