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Maltais-Tariant R, Itzamna Becerra-Deana R, Brais-Brunet S, Dehaes M, Boudoux C. Speckle contrast reduction through the use of a modally-specific photonic lantern for optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2023; 14:6250-6259. [PMID: 38420311 PMCID: PMC10898554 DOI: 10.1364/boe.504861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/31/2023] [Accepted: 11/02/2023] [Indexed: 03/02/2024]
Abstract
A few-mode optical coherence tomography (FM-OCT) system was developed around a 2 × 1 modally-specific photonic lantern (MSPL) centered at 1310 nm. The MSPL allowed FM-OCT to acquire two coregistered images with uncorrelated speckle patterns generated by their specific coherent spread function. Here, we showed that averaging such images in vitro and in vivo reduced the speckle contrast by up to 28% and increased signal-to-noise ratio (SNR) by up to 48% with negligible impact on image spatial resolution. This method is compatible with other speckle reduction techniques to further improve OCT image quality.
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Affiliation(s)
| | | | - Simon Brais-Brunet
- Research Centre, CHU Sainte-Justine, Montréal, Canada
- Université de Montréal, Institute of Biomedical Engineering, Montréal, Canada
| | - Mathieu Dehaes
- Research Centre, CHU Sainte-Justine, Montréal, Canada
- Université de Montréal, Institute of Biomedical Engineering, Montréal, Canada
- Université de Montréal, Department of Radiology, Radio-oncology and Nuclear Medicine, Montréal, Canada
| | - Caroline Boudoux
- Polytechnique Montréal, Department of Engineering Physics, Montréal, Canada
- Castor Optics, Saint-Laurent, Canada
- Research Centre, CHU Sainte-Justine, Montréal, Canada
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Fang Y, Shao X, Liu B, Lv H. Optical coherence tomography image despeckling based on tensor singular value decomposition and fractional edge detection. Heliyon 2023; 9:e17735. [PMID: 37449117 PMCID: PMC10336597 DOI: 10.1016/j.heliyon.2023.e17735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 07/18/2023] Open
Abstract
Optical coherence tomography (OCT) imaging is a technique that is frequently used to diagnose medical conditions. However, coherent noise, sometimes referred to as speckle noise, can dramatically reduce the quality of OCT images, which has an adverse effect on how OCT images are used. In order to enhance the quality of OCT images, a speckle noise reduction technique is developed, and this method is modelled as a low-rank tensor approximation issue. The grouped 3D tensors are first transformed into the transform domain using tensor singular value decomposition (t-SVD). Then, to cut down on speckle noise, transform coefficients are thresholded. Finally, the inverse transform can be used to produce images with speckle suppression. To further enhance the despeckling results, a feature-guided thresholding approach based on fractional edge detection and an adaptive backward projection technique are also presented. Experimental results indicate that the presented algorithm outperforms several comparison methods in relation to speckle suppression, objective metrics, and edge preservation.
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Affiliation(s)
- Ying Fang
- School of Information Technology, Shangqiu Normal University, Shangqiu, 476000, China
| | - Xia Shao
- School of Information Technology, Shangqiu Normal University, Shangqiu, 476000, China
| | - Bangquan Liu
- College of Digital Technology and Engineering, Ningbo University of Finance and Economics, Ningbo, 315100, China
| | - Hongli Lv
- School of Information Technology, Shangqiu Normal University, Shangqiu, 476000, China
- College of Big Data and Software Engineering, Zhejiang Wanli University, Ningbo, 315100, China
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Zhao J, Winetraub Y, Yuan E, Chan WH, Aasi SZ, Sarin KY, Zohar O, de la Zerda A. Angular compounding for speckle reduction in optical coherence tomography using geometric image registration algorithm and digital focusing. Sci Rep 2020; 10:1893. [PMID: 32024946 PMCID: PMC7002526 DOI: 10.1038/s41598-020-58454-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 01/15/2020] [Indexed: 11/09/2022] Open
Abstract
Optical coherence tomography (OCT) suffers from speckle noise due to the high spatial coherence of the utilized light source, leading to significant reductions in image quality and diagnostic capabilities. In the past, angular compounding techniques have been applied to suppress speckle noise. However, existing image registration methods usually guarantee pure angular compounding only within a relatively small field of view in the focal region, but produce spatial averaging in the other regions, resulting in resolution loss and image blur. This work develops an image registration model to correctly localize the real-space location of every pixel in an OCT image, for all depths. The registered images captured at different angles are fused into a speckle-reduced composite image. Digital focusing, based on the convolution of the complex OCT images and the conjugate of the point spread function (PSF), is studied to further enhance lateral resolution and contrast. As demonstrated by experiments, angular compounding with our improved image registration techniques and digital focusing, can effectively suppress speckle noise, enhance resolution and contrast, and reveal fine structures in ex-vivo imaged tissue.
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Affiliation(s)
- Jingjing Zhao
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California, 94305, USA
| | - Yonatan Winetraub
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California, 94305, USA
- Biophysics Program at Stanford, Stanford, California, 94305, USA
- Molecular Imaging Program at Stanford, Stanford, California, 94305, USA
- The Bio-X Program, Stanford, California, 94305, USA
| | - Edwin Yuan
- Department of Applied Physics, Stanford University, Stanford, California, 94305, USA
| | - Warren H Chan
- Department of Dermatology, Stanford University School of Medicine, Stanford, California, 94305, USA
| | - Sumaira Z Aasi
- Department of Dermatology, Stanford University School of Medicine, Stanford, California, 94305, USA
| | - Kavita Y Sarin
- Department of Dermatology, Stanford University School of Medicine, Stanford, California, 94305, USA
| | - Orr Zohar
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California, 94305, USA
| | - Adam de la Zerda
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California, 94305, USA.
- Biophysics Program at Stanford, Stanford, California, 94305, USA.
- Molecular Imaging Program at Stanford, Stanford, California, 94305, USA.
- The Bio-X Program, Stanford, California, 94305, USA.
- The Chan Zuckerberg Biohub, San Francisco, California, 94158, USA.
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Winetraub Y, Wu C, Collins GP, Chu S, de la Zerda A. Upper limit for angular compounding speckle reduction. APPLIED PHYSICS LETTERS 2019; 114:211101. [PMID: 32549585 PMCID: PMC7195867 DOI: 10.1063/1.5088709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 05/06/2019] [Indexed: 06/11/2023]
Abstract
Angular compounding is a technique for reducing speckle noise in optical coherence tomography that is claimed to significantly improve the signal-to-noise ratio (SNR) of images without impairing their spatial resolution. Here, we examine how focal point movements caused by optical aberrations in an angular compounding system may produce unintended spatial averaging and concomitant loss of spatial resolution. Experimentally, we accounted for such aberrations by aligning our system and measuring distortions in images and found that when the distortions were corrected, the speckle reduction by angular compounding was limited. Our theoretical analysis using Monte Carlo simulations indicates that "pure" angular compounding (i.e., with no spatial averaging) over our full numerical aperture (13° in air) can improve the SNR by not more than a factor of 1.3. Illuminating only a partial aperture cannot improve this factor compared to a spatial averaging system with equivalent loss of resolution. We conclude that speckle reduction using angular compounding is equivalent to spatial averaging. Nonetheless, angular compounding may be useful for improving images in applications where the depth of field is important. The distortions tend to be the greatest off the focal plane, and so angular compounding combined with our correction technique can reduce speckle with a minimal loss of resolution across a large depth of field.
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Shi W, Chen C, Jivraj J, Dobashi Y, Gao W, Yang VX. 2D MEMS-based high-speed beam-shifting technique for speckle noise reduction and flow rate measurement in optical coherence tomography. OPTICS EXPRESS 2019; 27:12551-12564. [PMID: 31052795 DOI: 10.1364/oe.27.012551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 04/01/2019] [Indexed: 06/09/2023]
Abstract
In this manuscript, a two-dimensional (2D) micro-electro-mechanical system (MEMS)-based, high-speed beam-shifting spectral domain optical coherence tomography (MHB-SDOCT) is proposed for speckle noise reduction and absolute flow rate measurement. By combining a zigzag scanning protocol, the frame rates of 45.2 Hz for speckle reduction and 25.6 Hz for flow rate measurement are achieved for in-vivo tissue imaging. Phantom experimental results have shown that by setting the incident beam angle to ϕ = 4.76° (between optical axis of objective lens and beam axis) and rotating the beam about the optical axis in 17 discrete angular positions, 91% of speckle noise in the structural images can be reduced. Furthermore, a precision of 0.0032 µl/s is achieved for flow rate measurement with the same beam angle, using three discrete angular positions around the optical axis. In-vivo experiments on human skin and chicken embryo were also implemented to further verify the performance of speckle noise reduction and flow rate measurement of MHB-SDOCT.
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