1
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Harvey M, Lane B, Cisek R, Veres SP, Kreplak L, Tokarz D. Histological staining alters circular dichroism SHG measurements of collagen. OPTICS LETTERS 2024; 49:3705-3708. [PMID: 38950247 DOI: 10.1364/ol.523689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 05/28/2024] [Indexed: 07/03/2024]
Abstract
Circular dichroism second harmonic generation microscopy (CDSHG) is a powerful imaging technique, which allows three-dimensional visualization of collagen fibril orientation in tissues. However, recent publications have obtained contradictory results on whether CDSHG can be used to reveal the relative out-of-plane polarity of collagen fibrils. Here we compare CDSHG images of unstained tendon and tendon which has been stained with hematoxylin and eosin. We find significant differences in the CDSHG between these two conditions, which explain the recent contradictory results within the literature.
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2
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Lee YR, Kim DY, Jo Y, Kim M, Choi W. Exploiting volumetric wave correlation for enhanced depth imaging in scattering medium. Nat Commun 2023; 14:1878. [PMID: 37015941 PMCID: PMC10073116 DOI: 10.1038/s41467-023-37467-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 03/16/2023] [Indexed: 04/06/2023] Open
Abstract
Imaging an object embedded within a scattering medium requires the correction of complex sample-induced wave distortions. Existing approaches have been designed to resolve them by optimizing signal waves recorded in each 2D image. Here, we present a volumetric image reconstruction framework that merges two fundamental degrees of freedom, the wavelength and propagation angles of light waves, based on the object momentum conservation principle. On this basis, we propose methods for exploiting the correlation of signal waves from volumetric images to better cope with multiple scattering. By constructing experimental systems scanning both wavelength and illumination angle of the light source, we demonstrated a 32-fold increase in the use of signal waves compared with that of existing 2D-based approaches and achieved ultrahigh volumetric resolution (lateral resolution: 0.41 [Formula: see text], axial resolution: 0.60 [Formula: see text]) even within complex scattering medium owing to the optimal coherent use of the broad spectral bandwidth (225 nm).
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Affiliation(s)
- Ye-Ryoung Lee
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, 02841, Korea
- Department of Physics, Korea University, Seoul, 02841, Korea
- Institute of Basic Science, Korea University, Seoul, 02841, Korea
- Department of Physics, Konkuk University, Seoul, 05029, Korea
| | - Dong-Young Kim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, 02841, Korea
- Department of Physics, Korea University, Seoul, 02841, Korea
| | - Yonghyeon Jo
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, 02841, Korea
- Department of Physics, Korea University, Seoul, 02841, Korea
| | - Moonseok Kim
- Department of Medical Life Sciences, College of Medicine, The Catholic University of Korea, Seoul, 06591, Korea
- Department of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, 06591, Korea
| | - Wonshik Choi
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, 02841, Korea.
- Department of Physics, Korea University, Seoul, 02841, Korea.
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3
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Yamanaka M, Hayakawa N, Nishizawa N. High-spatial-resolution deep tissue imaging with spectral-domain optical coherence microscopy in the 1700-nm spectral band. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-4. [PMID: 31364330 PMCID: PMC6995893 DOI: 10.1117/1.jbo.24.7.070502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 07/10/2019] [Indexed: 05/25/2023]
Abstract
We present three-dimensional (3-D) high-resolution spectral-domain optical coherence microscopy (SD-OCM) by using a supercontinuum (SC) fiber laser source with 300-nm spectral bandwidth (full-width at half-maximum) in the 1700-nm spectral band. By using low-coherence interferometry with SC light and a confocal detection scheme, we realized lateral and axial resolutions of 3.4 and 3.8 μm in tissue (n = 1.38), respectively. This is, to the best of our knowledge, the highest 3-D spatial resolution reported among those of Fourier-domain optical coherence imaging techniques in the 1700-nm spectral band. In our SD-OCM, to enhance the imaging depth, a full-range method was implemented, which suppressed the formation of a coherent ghost image and allowed us to set the zero-delay position inside the samples. We demonstrated the 3-D high-resolution imaging capability of 1700-nm SD-OCM through the measurement of an interference signal from a mirror surface and imaging of a single 200-nm polystyrene bead and a pig thyroid gland. Deep tissue imaging at a depth of up to 1.8 mm was also demonstrated. This is the first demonstration of 3-D high-resolution SD-OCM in the 1700-nm spectral band.
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Affiliation(s)
| | - Naoki Hayakawa
- Nagoya University, Department of Electronics, Nagoya, Aichi, Japan
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4
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Dubois A, Levecq O, Azimani H, Siret D, Barut A, Suppa M, Del Marmol V, Malvehy J, Cinotti E, Rubegni P, Perrot JL. Line-field confocal optical coherence tomography for high-resolution noninvasive imaging of skin tumors. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-9. [PMID: 30353716 DOI: 10.1117/1.jbo.23.10.106007] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/01/2018] [Indexed: 05/06/2023]
Abstract
An optical technique called line-field confocal optical coherence tomography (LC-OCT) is introduced for high-resolution, noninvasive imaging of human skin in vivo. LC-OCT combines the principles of time-domain optical coherence tomography and confocal microscopy with line illumination and detection using a broadband laser and a line-scan camera. LC-OCT measures the echo-time delay and amplitude of light backscattered from cutaneous microstructures through low-coherence interferometry associated with confocal spatial filtering. Multiple A-scans are acquired simultaneously while dynamically adjusting the focus. The resulting cross-sectional B-scan image is produced in real time at 10 frame / s. With an isotropic spatial resolution of ∼1 μm, the LC-OCT images reveal a comprehensive structural mapping of skin at the cellular level down to a depth of ∼500 μm. LC-OCT has been applied to the imaging of various skin lesions, in vivo, including carcinomas and melanomas. LC-OCT images are found to strongly correlate with conventional histopathological images. The use of LC-OCT as an adjunct tool in medical practice could significantly improve clinical diagnostic accuracy while reducing the number of biopsies of benign lesions.
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Affiliation(s)
- Arnaud Dubois
- Université Paris-Saclay, Institut d'Optique Graduate School, Laboratoire Charles Fabry, Palaiseau, France
| | | | | | | | | | - Mariano Suppa
- Hôpital Erasme, Université Libre de Bruxelles, Department of Dermatology, Brussels, Belgium
| | - Véronique Del Marmol
- Hôpital Erasme, Université Libre de Bruxelles, Department of Dermatology, Brussels, Belgium
| | - Josep Malvehy
- University Hospital Clinic of Barcelona, Barcelona, Spain
| | - Elisa Cinotti
- University of Siena, Department of Medical, Surgical and Neurological Sciences, Dermatology Unit, Si, Italy
| | - Pietro Rubegni
- University of Siena, Department of Medical, Surgical and Neurological Sciences, Dermatology Unit, Si, Italy
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5
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Chen Y, Trinh LA, Fingler J, Fraser SE. 3D in vivo imaging with extended-focus optical coherence microscopy. JOURNAL OF BIOPHOTONICS 2017; 10:1411-1420. [PMID: 28417564 DOI: 10.1002/jbio.201700008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/02/2017] [Accepted: 03/06/2017] [Indexed: 05/22/2023]
Abstract
Optical coherence microscopy (OCM) has unique advantages of non-invasive 3D imaging without the need of exogenous labels for studying biological samples. However, the imaging depth of this technique is limited by the tradeoff between the depth of focus (DOF) and high lateral resolution in Gaussian optics. To overcome this limitation, we have developed an extended-focus OCM (xf-OCM) imaging system using quasi-Bessel beam illumination to extend the DOF to ∼100 μm, about 3-fold greater than standard OCM. High lateral resolution of 1.6 μm ensured detailed identification of structures within live animal samples. The insensitivity to spherical aberrations strengthened the capability of our xf-OCM system in 3D biological imaging.
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Affiliation(s)
- Yu Chen
- Translational Imaging Center, University of Southern California, Los Angeles, 90089, CA
- Department of Biomedical Engineering, University of Southern California, Los Angeles, 90089, CA
| | - Le A Trinh
- Translational Imaging Center, University of Southern California, Los Angeles, 90089, CA
- Molecular and Computational Biology, University of Southern California, Los Angeles, 90089, CA
| | - Jeff Fingler
- Varocto Inc., 1586 N Batavia St, Orange, 92867, CA
| | - Scott E Fraser
- Translational Imaging Center, University of Southern California, Los Angeles, 90089, CA
- Department of Biomedical Engineering, University of Southern California, Los Angeles, 90089, CA
- Molecular and Computational Biology, University of Southern California, Los Angeles, 90089, CA
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6
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Chen Y, Fingler J, Fraser SE. Multi-shaping technique reduces sidelobe magnitude in optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2017; 8:5267-5281. [PMID: 29188119 PMCID: PMC5695969 DOI: 10.1364/boe.8.005267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 10/22/2017] [Accepted: 10/23/2017] [Indexed: 05/15/2023]
Abstract
Shaping methods that are commonly used in Fourier-domain optical coherence tomography (FD-OCT) can suppress sidelobe artifacts in the axial direction, but they typically broaden the mainlobe of the point spread function (PSF) and reduce the axial resolution. To improve OCT image quality without this tradeoff, we have developed a multi-shaping technique that reduces the axial sidelobe magnitude dramatically and achieves better axial resolution than conventional shaping methods. This technique is robust and compatible in various FD-OCT imaging systems. Testing of multi-shaping in three experimental settings shows that it reduced the axial sidelobe contribution by more than 8 dB and improved the contrast to noise by at least 30% and up to three-fold. Multi-shaping enables accurate image analysis and is potentially useful in many OCT applications.
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Affiliation(s)
- Yu Chen
- Translational Imaging Center, University of Southern California, Los Angeles, CA 90089, USA
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Varocto Inc, 1586 N Batavia St., Orange, CA 92867, USA
| | - Jeff Fingler
- Varocto Inc, 1586 N Batavia St., Orange, CA 92867, USA
| | - Scott E. Fraser
- Translational Imaging Center, University of Southern California, Los Angeles, CA 90089, USA
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA
- Molecular and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA
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7
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Determination on the Coefficient of Thermal Expansion in High-Power InGaN-based Light-emitting Diodes by Optical Coherence Tomography. Sci Rep 2017; 7:14390. [PMID: 29089538 PMCID: PMC5663912 DOI: 10.1038/s41598-017-14689-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 10/16/2017] [Indexed: 11/09/2022] Open
Abstract
The coefficient of thermal expansion (CTE) is a physical quantity that indicates the thermal expansion value of a material upon heating. For advanced thermal management, the accurate and immediate determination of the CTE of packaging materials is gaining importance because the demand for high-power lighting-emitting diodes (LEDs) is currently increasing. In this study, we used optical coherence tomography (OCT) to measure the CTE of an InGaN-based (λ = 450 nm) high-power LED encapsulated in polystyrene resin. The distances between individual interfaces of the OCT images were observed and recorded to derive the instantaneous CTE of the packaged LED under different injected currents. The LED junction temperature at different injected currents was established with the forward voltage method. Accordingly, the measured instantaneous CTE of polystyrene resin varied from 5.86 × 10−5 °C−1 to 14.10 × 10−5 °C−1 in the junction temperature range 25–225 °C and exhibited a uniform distribution in an OCT scanning area of 200 × 200 μm. Most importantly, this work validates the hypothesis that OCT can provide an alternative way to directly and nondestructively determine the spatially resolved CTE of the packaged LED device, which offers significant advantages over traditional CTE measurement techniques.
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8
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Lee HC, Ahsen OO, Liu JJ, Tsai TH, Huang Q, Mashimo H, Fujimoto JG. Assessment of the radiofrequency ablation dynamics of esophageal tissue with optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:76001. [PMID: 28687822 PMCID: PMC5499807 DOI: 10.1117/1.jbo.22.7.076001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 06/08/2017] [Indexed: 05/08/2023]
Abstract
Radiofrequency ablation (RFA) is widely used for the eradication of dysplasia and the treatment of early stage esophageal carcinoma in patients with Barrett’s esophagus (BE). However, there are several factors, such as variation of BE epithelium (EP) thickness among individual patients and varying RFA catheter-tissue contact, which may compromise RFA efficacy. We used a high-speed optical coherence tomography (OCT) system to identify and monitor changes in the esophageal tissue architecture from RFA. Two different OCT imaging/RFA application protocols were performed using an <italic<ex vivo</italic< swine esophagus model: (1) post-RFA volumetric OCT imaging for quantitative analysis of the coagulum formation using RFA applications with different energy settings, and (2) M-mode OCT imaging for monitoring the dynamics of tissue architectural changes in real time during RFA application. Post-RFA volumetric OCT measurements showed an increase in the coagulum thickness with respect to the increasing RFA energies. Using a subset of the specimens, OCT measurements of coagulum and coagulum + residual EP thickness were shown to agree with histology, which accounted for specimen shrinkage during histological processing. In addition, we demonstrated the feasibility of OCT for real-time visualization of the architectural changes during RFA application with different energy settings. Results suggest feasibility of using OCT for RFA treatment planning and guidance.
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Affiliation(s)
- Hsiang-Chieh Lee
- Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Cambridge, Massachusetts, United States
| | - Osman O. Ahsen
- Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Cambridge, Massachusetts, United States
| | - Jonathan J. Liu
- Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Cambridge, Massachusetts, United States
| | - Tsung-Han Tsai
- Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Cambridge, Massachusetts, United States
| | - Qin Huang
- Veterans Affairs Boston Healthcare System, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - Hiroshi Mashimo
- Veterans Affairs Boston Healthcare System, Boston, Massachusetts, United States
- Harvard Medical School, Boston, Massachusetts, United States
| | - James G. Fujimoto
- Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, Cambridge, Massachusetts, United States
- Address all correspondence to: James G. Fujimoto, E-mail:
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9
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Wan S, Lee HC, Huang X, Xu T, Xu T, Zeng X, Zhang Z, Sheikine Y, Connolly JL, Fujimoto JG, Zhou C. Integrated local binary pattern texture features for classification of breast tissue imaged by optical coherence microscopy. Med Image Anal 2017; 38:104-116. [PMID: 28327449 DOI: 10.1016/j.media.2017.03.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 03/06/2017] [Accepted: 03/07/2017] [Indexed: 12/20/2022]
Abstract
This paper proposes a texture analysis technique that can effectively classify different types of human breast tissue imaged by Optical Coherence Microscopy (OCM). OCM is an emerging imaging modality for rapid tissue screening and has the potential to provide high resolution microscopic images that approach those of histology. OCM images, acquired without tissue staining, however, pose unique challenges to image analysis and pattern classification. We examined multiple types of texture features and found Local Binary Pattern (LBP) features to perform better in classifying tissues imaged by OCM. In order to improve classification accuracy, we propose novel variants of LBP features, namely average LBP (ALBP) and block based LBP (BLBP). Compared with the classic LBP feature, ALBP and BLBP features provide an enhanced encoding of the texture structure in a local neighborhood by looking at intensity differences among neighboring pixels and among certain blocks of pixels in the neighborhood. Fourty-six freshly excised human breast tissue samples, including 27 benign (e.g. fibroadenoma, fibrocystic disease and usual ductal hyperplasia) and 19 breast carcinoma (e.g. invasive ductal carcinoma, ductal carcinoma in situ and lobular carcinoma in situ) were imaged with large field OCM with an imaging area of 10 × 10 mm2 (10, 000 × 10, 000 pixels) for each sample. Corresponding H&E histology was obtained for each sample and used to provide ground truth diagnosis. 4310 small OCM image blocks (500 × 500 pixels) each paired with corresponding H&E histology was extracted from large-field OCM images and labeled with one of the five different classes: adipose tissue (n = 347), fibrous stroma (n = 2,065), breast lobules (n = 199), carcinomas (pooled from all sub-types, n = 1,127), and background (regions outside of the specimens, n = 572). Our experiments show that by integrating a selected set of LBP and the two new variant (ALBP and BLBP) features at multiple scales, the classification accuracy increased from 81.7% (using LBP features alone) to 93.8% using a neural network classifier. The integrated feature was also used to classify large-field OCM images for tumor detection. A receiver operating characteristic (ROC) curve was obtained with an area under the curve value of 0.959. A sensitivity level of 100% and specificity level of 85.2% was achieved to differentiate benign from malignant samples. Several other experiments also demonstrate the complementary nature of LBP and the two variants (ALBP and BLBP features) and the significance of integrating these texture features for classification. Using features from multiple scales and performing feature selection are also effective mechanisms to improve accuracy while maintaining computational efficiency.
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Affiliation(s)
- Sunhua Wan
- Department of Computer Science and Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Hsiang-Chieh Lee
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, MIT, Cambridge, MA 02139, USA
| | - Xiaolei Huang
- Department of Computer Science and Engineering, Lehigh University, Bethlehem, PA 18015, USA.
| | - Ting Xu
- Department of Computer Science and Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Tao Xu
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA
| | - Xianxu Zeng
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA; The Third Affiliated Hospital of Zhengzhou University, Henan, China
| | - Zhan Zhang
- The Third Affiliated Hospital of Zhengzhou University, Henan, China
| | - Yuri Sheikine
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - James L Connolly
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - James G Fujimoto
- Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics, MIT, Cambridge, MA 02139, USA
| | - Chao Zhou
- Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA; Center for Photonics and Nanoelectronics, Lehigh University, Bethlehem, PA 18015, USA; Bioengineering Program, Lehigh University, Bethlehem, PA 18015, USA.
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10
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Chen Y, Trinh LA, Fingler J, Fraser SE. Phase variance optical coherence microscopy for label-free imaging of the developing vasculature in zebrafish embryos. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:126022. [PMID: 28036094 DOI: 10.1117/1.jbo.21.12.126022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/05/2016] [Indexed: 06/06/2023]
Abstract
A phase variance optical coherence microscope (pvOCM) has been created to image blood flow in the microvasculature of zebrafish embryos, without the use of exogenous labels. The pvOCM imaging system has axial and lateral resolutions of 2.8 ?? ? m in tissue and imaging depth of more than 100 ?? ? m . Images of 2 to 5 days postfertilization zebrafish embryos identified the detailed anatomical structure based on OCM intensity contrast. Phase variance contrast offered visualization of blood flow in the arteries, veins, and capillaries. The pvOCM images of the vasculature were confirmed by direct comparisons with fluorescence microscopy images of transgenic embryos in which the vascular endothelium is labeled with green fluorescent protein. The ability of pvOCM to capture activities of regional blood flow permits it to reveal functional information that is of great utility for the study of vascular development.
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Affiliation(s)
- Yu Chen
- University of Southern California, Translational Imaging Center, Los Angeles, California 90089, United StatesbUniversity of Southern California, Department of Biomedical Engineering, Los Angeles, California 90089, United States
| | - Le A Trinh
- University of Southern California, Translational Imaging Center, Los Angeles, California 90089, United States
| | - Jeff Fingler
- Varocto Inc., 1586 North Batavia Street, Orange, California 92867, United States
| | - Scott E Fraser
- University of Southern California, Translational Imaging Center, Los Angeles, California 90089, United StatesbUniversity of Southern California, Department of Biomedical Engineering, Los Angeles, California 90089, United States
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11
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High Resolution Optical Coherence Tomography for Bio-Imaging. FRONTIERS IN BIOPHOTONICS FOR TRANSLATIONAL MEDICINE 2016. [DOI: 10.1007/978-981-287-627-0_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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12
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Xu J, Wei X, Yu L, Zhang C, Xu J, Wong KKY, Tsia KK. High-performance multi-megahertz optical coherence tomography based on amplified optical time-stretch. BIOMEDICAL OPTICS EXPRESS 2015; 6:1340-50. [PMID: 25909017 PMCID: PMC4399672 DOI: 10.1364/boe.6.001340] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 03/16/2015] [Accepted: 03/16/2015] [Indexed: 05/18/2023]
Abstract
As the key prerequisite of high-speed volumetric structural and functional tissue imaging in real-time, scaling the A-scan rate beyond MHz has been one of the major pursuits in the development of optical coherence tomography (OCT). Along with a handful of techniques enabling multi-MHz, amplified optical time-stretch OCT (AOT-OCT) has recently been demonstrated as a viable alternative for ultrafast swept-source OCT well above MHz without the need for the mechanical wavelength-tuning mechanism. In this paper, we report a new generation of AOT-OCT demonstrating superior performance to its older generation and all other time-stretch-based OCT modalities in terms of shot-to-shot stability, sensitivity (~90dB), roll-off performance (>4 mm/dB) and A-scan rate (11.5 MHz). Such performance is mainly attributed to the combined contribution from the stable operation of the broadband and compact mode-locked fiber laser as well as the optical amplification in-line with the time-stretch process. The system allows us, for the first time, to deliver volumetric time-stretch-based OCT of biological tissues with the single-shot A-scan rate beyond 10 MHz. Comparing with the existing high-speed OCT systems, the inertia-free AOT-OCT shows promises to realize high-performance 3D OCT imaging at video rate.
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13
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Liang K, Traverso G, Lee HC, Ahsen OO, Wang Z, Potsaid B, Giacomelli M, Jayaraman V, Barman R, Cable A, Mashimo H, Langer R, Fujimoto JG. Ultrahigh speed en face OCT capsule for endoscopic imaging. BIOMEDICAL OPTICS EXPRESS 2015; 6:1146-63. [PMID: 25909001 PMCID: PMC4399656 DOI: 10.1364/boe.6.001146] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 05/18/2023]
Abstract
Depth resolved and en face OCT visualization in vivo may have important clinical applications in endoscopy. We demonstrate a high speed, two-dimensional (2D) distal scanning capsule with a micromotor for fast rotary scanning and a pneumatic actuator for precision longitudinal scanning. Longitudinal position measurement and image registration were performed by optical tracking of the pneumatic scanner. The 2D scanning device enables high resolution imaging over a small field of view and is suitable for OCT as well as other scanning microscopies. Large field of view imaging for screening or surveillance applications can also be achieved by proximally pulling back or advancing the capsule while scanning the distal high-speed micromotor. Circumferential en face OCT was demonstrated in living swine at 250 Hz frame rate and 1 MHz A-scan rate using a MEMS tunable VCSEL light source at 1300 nm. Cross-sectional and en face OCT views of the upper and lower gastrointestinal tract were generated with precision distal pneumatic longitudinal actuation as well as proximal manual longitudinal actuation. These devices could enable clinical studies either as an adjunct to endoscopy, attached to an endoscope, or as a swallowed tethered capsule for non-endoscopic imaging without sedation. The combination of ultrahigh speed imaging and distal scanning capsule technology could enable both screening and surveillance applications.
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Affiliation(s)
- Kaicheng Liang
- Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA,
USA
| | - Giovanni Traverso
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge MA,
USA
- Division of Gastroenterology, Massachusetts General Hospital, Boston MA,
USA
- Harvard Medical School, Boston MA,
USA
| | - Hsiang-Chieh Lee
- Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA,
USA
| | - Osman Oguz Ahsen
- Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA,
USA
| | - Zhao Wang
- Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA,
USA
| | - Benjamin Potsaid
- Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA,
USA
- Advanced Imaging Group, Thorlabs Inc., Newton NJ,
USA
| | - Michael Giacomelli
- Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA,
USA
| | | | - Ross Barman
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge MA,
USA
| | - Alex Cable
- Advanced Imaging Group, Thorlabs Inc., Newton NJ,
USA
| | - Hiroshi Mashimo
- Harvard Medical School, Boston MA,
USA
- Veterans Affairs Boston Healthcare System, Boston MA,
USA
| | - Robert Langer
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge MA,
USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge MA,
USA
| | - James G. Fujimoto
- Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge MA,
USA
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14
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Grulkowski I, Szulzycki K, Wojtkowski M. Microscopic OCT imaging with focus extension by ultrahigh-speed acousto-optic tunable lens and stroboscopic illumination. OPTICS EXPRESS 2014; 22:31746-60. [PMID: 25607144 DOI: 10.1364/oe.22.031746] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We develop high-resolution optical coherence tomography (OCT) system with high-speed acousto-optic tunable lens. Stroboscopic pulsed illumination is used for the first time to perform time-resolved OCT imaging with acousto-optic tunable focusing. The operation of ultrahigh-speed tunable acousto-optic lens is demonstrated theoretically and experimentally. Focal position tuning at MHz frequency range is experimentally shown in the imaging system leading to OCT images with extended depth of focus. Imaging with active optical elements is helpful for improvement of photon collection efficiency, depth of focus and enhancement of the image quality.
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Li F, Song Y, Dryer A, Cogguillo W, Berdichevsky Y, Zhou C. Nondestructive evaluation of progressive neuronal changes in organotypic rat hippocampal slice cultures using ultrahigh-resolution optical coherence microscopy. NEUROPHOTONICS 2014; 1:025002. [PMID: 25750928 PMCID: PMC4350448 DOI: 10.1117/1.nph.1.2.025002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 07/22/2014] [Accepted: 07/25/2014] [Indexed: 05/25/2023]
Abstract
Three-dimensional tissue cultures have been used as effective models for studying different diseases, including epilepsy. High-throughput, nondestructive techniques are essential for rapid assessment of disease-related processes, such as progressive cell death. An ultrahigh-resolution optical coherence microscopy (UHR-OCM) system with [Formula: see text] axial resolution and [Formula: see text] transverse resolution was developed to evaluate seizure-induced neuronal injury in organotypic rat hippocampal cultures. The capability of UHR-OCM to visualize cells in neural tissue was confirmed by comparison of UHR-OCM images with confocal immunostained images of the same cultures. In order to evaluate the progression of neuronal injury, UHR-OCM images were obtained from cultures on 7, 14, 21, and 28 days in vitro (DIVs). In comparison to DIV 7, statistically significant reductions in three-dimensional cell count and culture thickness from UHR-OCM images were observed on subsequent time points. In cultures treated with kynurenic acid, significantly less reduction in cell count and culture thickness was observed compared to the control specimens. These results demonstrate the capability of UHR-OCM to perform rapid, label-free, and nondestructive evaluation of neuronal death in organotypic hippocampal cultures. UHR-OCM, in combination with three-dimensional tissue cultures, can potentially prove to be a promising tool for high-throughput screening of drugs targeting various disorders.
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Affiliation(s)
- Fengqiang Li
- Lehigh University, Department of Electrical and Computer Engineering, 19 Memorial Drive West, Bethlehem, Pennsylvania 18015, United States
- Lehigh University, Center for Photonics and Nanoelectronics, 7 ASA Drive, Bethlehem, Pennsylvania 18015, United States
| | - Yu Song
- Lehigh University, Bioengineering Program, 111 Research Drive, Bethlehem, Pennsylvania 18015, United States
| | - Alexandra Dryer
- Lehigh University, Department of Electrical and Computer Engineering, 19 Memorial Drive West, Bethlehem, Pennsylvania 18015, United States
| | - William Cogguillo
- Lehigh University, Bioengineering Program, 111 Research Drive, Bethlehem, Pennsylvania 18015, United States
| | - Yevgeny Berdichevsky
- Lehigh University, Department of Electrical and Computer Engineering, 19 Memorial Drive West, Bethlehem, Pennsylvania 18015, United States
- Lehigh University, Center for Photonics and Nanoelectronics, 7 ASA Drive, Bethlehem, Pennsylvania 18015, United States
- Lehigh University, Bioengineering Program, 111 Research Drive, Bethlehem, Pennsylvania 18015, United States
| | - Chao Zhou
- Lehigh University, Department of Electrical and Computer Engineering, 19 Memorial Drive West, Bethlehem, Pennsylvania 18015, United States
- Lehigh University, Center for Photonics and Nanoelectronics, 7 ASA Drive, Bethlehem, Pennsylvania 18015, United States
- Lehigh University, Bioengineering Program, 111 Research Drive, Bethlehem, Pennsylvania 18015, United States
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Xu J, Wei X, Yu L, Zhang C, Xu J, Wong KKY, Tsia KK. Performance of megahertz amplified optical time-stretch optical coherence tomography (AOT-OCT). OPTICS EXPRESS 2014; 22:22498-512. [PMID: 25321720 DOI: 10.1364/oe.22.022498] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Enabled by the ultrahigh-speed all-optical wavelength-swept mechanism and broadband optical amplification, amplified optical time-stretch optical coherence tomography (AOT-OCT) has recently been demonstrated as a practical alternative to achieve ultrafast A-scan rate of multi-MHz in OCT. With the aim of identifying the optimal scenarios for MHz operation in AOT-OCT, we here present a theoretical framework to evaluate its performance metric. In particular, the analysis discusses the unique features of AOT-OCT, such as its superior coherence length, and the relationship between the optical gain and the A-scan rate. More importantly, we evaluate the sensitivity of AOT-OCT in the MHz regime under the influence of the amplifier noise. Notably, the model shows that AOT-OCT is particularly promising when operated at the A-scan rate well beyond multi-MHz--not trivially achievable by any existing swept-source OCT platform. A sensitivity beyond 90 dB, close to the shot-noise limit, can be maintained in the range of 2 - 10 MHz with an optical net gain of ~10 dB. Experimental measurement also shows excellent agreement with the theoretical prediction. While distributed fiber Raman amplification is mainly considered in this paper, the theoretical model is generally applicable to any type of amplification schemes. As a result, our analysis serves as a useful tool for further optimization of AOT-OCT system--as a practical alternative to enable MHz OCT operation.
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Xu J, Zhang C, Xu J, Wong KKY, Tsia KK. Megahertz all-optical swept-source optical coherence tomography based on broadband amplified optical time-stretch. OPTICS LETTERS 2014; 39:622-5. [PMID: 24487881 DOI: 10.1364/ol.39.000622] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We demonstrate all-optical ultrahigh-speed swept-source optical coherence tomography (OCT) based on amplified optical time-stretch (AOT). Such an inertia-free wavelength-swept mechanism, via group velocity dispersion, enables us to realize OCT with an A-scan rate well above MHz. More importantly, the key significance of AOT-OCT is its simultaneous broadband Raman amplification during the time-stretch process-greatly enhancing the detection sensitivity compared with prior attempts to apply optical time-stretch to OCT. Here, we report on an AOT-OCT system which is operated at an A-scan rate of 7.14 MHz, a superior roll-off performance (>2 mm/dB), a record-high sensitivity of time-stretch-based OCT (>80 dB) with a broadband gain bandwidth of 80 nm, which results in an axial resolution of ∼15 μm. Our AOT-OCT system is thus able to, for the first time to the best of our knowledge, perform time-stretch-based OCT of biological tissue in vivo. It represents a major step forward in utilizing AOT as an alternative for achieving practical MHz OCT, without any long-term mechanical stability concerns as in typical swept-source OCT or bypassing the speed limitation of the image sensor employed in spectral-domain OCT.
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