1
|
Kendall WY, Tian Q, Zhao S, Mirminachi S, O'Kane E, Joseph A, Dufault D, Miller DA, Shi C, Roper J, Wax A. Deep learning classification of ex vivo human colon tissues using spectroscopic optical coherence tomography. JOURNAL OF BIOPHOTONICS 2024:e202400082. [PMID: 38955358 DOI: 10.1002/jbio.202400082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/27/2024] [Accepted: 05/21/2024] [Indexed: 07/04/2024]
Abstract
Screening for colorectal cancer (CRC) with colonoscopy has improved patient outcomes; however, it remains the third leading cause of cancer-related mortality, novel strategies to improve screening are needed. Here, we propose an optical biopsy technique based on spectroscopic optical coherence tomography (OCT). Depth resolved OCT images are analyzed as a function of wavelength to measure optical tissue properties and used as input to machine learning algorithms. Previously, we used this approach to analyze mouse colon polyps. Here, we extend the approach to examine human biopsied colonic epithelial tissue samples ex vivo. Optical properties are used as input to a novel deep learning architecture, producing accuracy of up to 97.9% in discriminating tissue type. SOCT parameters are used to create false colored en face OCT images and deep learning classifications are used to enable visual classification by tissue type. This study advances SOCT toward clinical utility for analysis of colonic epithelium.
Collapse
Affiliation(s)
- Wesley Y Kendall
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
| | - Qinyi Tian
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
| | - Shi Zhao
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
| | - Seyedbabak Mirminachi
- Division of Gastroenterology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Erin O'Kane
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
| | - Abel Joseph
- Division of Gastroenterology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Darin Dufault
- Division of Gastroenterology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - David A Miller
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
| | - Chanjuan Shi
- Department of Pathology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Jatin Roper
- Division of Gastroenterology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina, USA
| | - Adam Wax
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
| |
Collapse
|
2
|
Kendall WY, Tian Q, Zhao S, Mirminachi S, Joseph A, Dufault D, Shi C, Roper J, Wax A. Deep learning classification of ex vivo human colon tissues using spectroscopic OCT. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.04.555974. [PMID: 37732221 PMCID: PMC10508742 DOI: 10.1101/2023.09.04.555974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Screening programs for colorectal cancer (CRC) have had a profound impact on the morbidity and mortality of this disease by detecting and removing early cancers and precancerous adenomas with colonoscopy. However, CRC continues to be the third leading cause of cancer-related mortality in both men and woman, partly because of limitations in colonoscopy-based screening. Thus, novel strategies to improve the efficiency and effectiveness of screening colonoscopy are urgently needed. Here, we propose to address this need using an optical biopsy technique based on spectroscopic optical coherence tomography (OCT). The depth resolved images obtained with OCT are analyzed as a function of wavelength to measure optical tissue properties. The optical properties can be used as input to machine learning algorithms as a means to classify adenomatous tissue in the colon. In this study, biopsied tissue samples from the colonic epithelium are analyzed ex vivo using spectroscopic OCT and tissue classifications are generated using a novel deep learning architecture, informed by machine learning methods including LSTM and KNN. The overall classification accuracy obtained was 88.9%, 76.0% and 97.9% in discriminating tissue type for these methods. Further, we apply an approach using false coloring of en face OCT images based on SOCT parameters and deep learning predictions to enable visual identification of tissue type. This study advances the spectroscopic OCT towards clinical utility for analyzing colonic epithelium for signs of adenoma.
Collapse
|
3
|
Kuttippurath V, Slijkhuis N, Liu S, van Soest G. Spectroscopic optical coherence tomography at 1200 nm for lipid detection. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:096002. [PMID: 37692562 PMCID: PMC10492233 DOI: 10.1117/1.jbo.28.9.096002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 08/13/2023] [Accepted: 08/18/2023] [Indexed: 09/12/2023]
Abstract
Significance Spectroscopic analysis of optical coherence tomography (OCT) data can yield added information about the sample's chemical composition, along with high-resolution images. Typical commercial OCT systems operate at wavelengths that may not be optimal for identifying lipid-containing samples based on absorption features. Aim The main aim of this study was to develop a 1200 nm spectroscopic OCT (SOCT) for the classification of lipid-based and water-based samples by extracting the lipid absorption peak at 1210 nm from the OCT data. Approach We developed a 1200 nm OCT system and implemented a signal processing algorithm that simultaneously retrieves spectroscopic and structural information from the sample. In this study, we validated the performance of our OCT system by imaging weakly scattering phantoms with and without lipid absorption features. An orthogonal projections to latent structures-discriminant analysis (OPLS-DA) model was developed and applied to classify weakly scattering samples based on their absorption features. Results The OCT system achieved an axial resolution of 7.2 μ m and a sensitivity of 95 dB. The calibrated OPLS-DA model on weakly scattering samples with lipid and water-based absorption features correctly classified 19/20 validation samples. Conclusions The 1200 nm SOCT system can discriminate the lipid-containing weakly scattering samples from water-based weakly scattering samples with good predictive ability.
Collapse
Affiliation(s)
- Vivek Kuttippurath
- Erasmus University Medical Center, Department of Cardiology, Rotterdam, The Netherlands
| | - Nuria Slijkhuis
- Erasmus University Medical Center, Department of Cardiology, Rotterdam, The Netherlands
| | - Shengnan Liu
- Erasmus University Medical Center, Department of Cardiology, Rotterdam, The Netherlands
| | - Gijs van Soest
- Delft University of Technology, Department of Precision and Microsystems Engineering, Faculty of Mechanical Engineering, Delft, The Netherlands
| |
Collapse
|
4
|
Jelly ET, Zhao Y, Chu KK, Price H, Crose M, Steelman ZA, Wax A. Deep imaging with 1.3 µm dual-axis optical coherence tomography and an enhanced depth of focus. BIOMEDICAL OPTICS EXPRESS 2021; 12:7689-7702. [PMID: 35003860 PMCID: PMC8713684 DOI: 10.1364/boe.438621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 10/01/2021] [Accepted: 11/03/2021] [Indexed: 06/14/2023]
Abstract
For many clinical applications, such as dermatology, optical coherence tomography (OCT) suffers from limited penetration depth due primarily to the highly scattering nature of biological tissues. Here, we present a novel implementation of dual-axis optical coherence tomography (DA-OCT) that offers improved depth penetration in skin imaging at 1.3 µm compared to conventional OCT. Several unique aspects of DA-OCT are examined here, including the requirements for scattering properties to realize the improvement and the limited depth of focus (DOF) inherent to the technique. To overcome this limitation, our approach uses a tunable lens to coordinate focal plane selection with image acquisition to create an enhanced DOF for DA-OCT. This improvement in penetration depth is quantified experimentally against conventional on-axis OCT using tissue phantoms and mouse skin. The results presented here suggest the potential use of DA-OCT in situations where a high degree of scattering limits depth penetration in OCT imaging.
Collapse
Affiliation(s)
- Evan T. Jelly
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Yang Zhao
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Kengyeh K. Chu
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Hillel Price
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | | | - Zachary A. Steelman
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Adam Wax
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| |
Collapse
|
5
|
Imaging Hypoxia. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00074-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
6
|
Zhou KC, Qian R, Farsiu S, Izatt JA. Spectroscopic optical coherence refraction tomography. OPTICS LETTERS 2020; 45:2091-2094. [PMID: 32236076 DOI: 10.1364/ol.389703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 03/05/2020] [Indexed: 05/24/2023]
Abstract
In optical coherence tomography (OCT), the axial resolution is often superior to the lateral resolution, which is sacrificed for long imaging depths. To address this anisotropy, we previously developed optical coherence refraction tomography (OCRT), which uses images from multiple angles to computationally reconstruct an image with isotropic resolution, given by the OCT axial resolution. On the other hand, spectroscopic OCT (SOCT), an extension of OCT, trades axial resolution for spectral resolution and hence often has superior lateral resolution. Here, we present spectroscopic OCRT (SOCRT), which uses SOCT images from multiple angles to reconstruct a spectroscopic image with isotropic spatial resolution limited by the OCT lateral resolution. We experimentally show that SOCRT can estimate bead size based on Mie theory at simultaneously high spectral and isotropic spatial resolution. We also applied SOCRT to a biological sample, achieving axial resolution enhancement limited by the lateral resolution.
Collapse
|
7
|
Harper DJ, Konegger T, Augustin M, Schützenberger K, Eugui P, Lichtenegger A, Merkle CW, Hitzenberger CK, Glösmann M, Baumann B. Hyperspectral optical coherence tomography for in vivo visualization of melanin in the retinal pigment epithelium. JOURNAL OF BIOPHOTONICS 2019; 12:e201900153. [PMID: 31334610 PMCID: PMC7065636 DOI: 10.1002/jbio.201900153] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/19/2019] [Accepted: 07/18/2019] [Indexed: 05/09/2023]
Abstract
Previous studies for melanin visualization in the retinal pigment epithelium (RPE) have exploited either its absorption properties (using photoacoustic tomography or photothermal optical coherence tomography [OCT]) or its depolarization properties (using polarization sensitive OCT). However, these methods are only suitable when the melanin concentration is sufficiently high. In this work, we present the concept of hyperspectral OCT for melanin visualization in the RPE when the concentration is low. Based on white light OCT, a hyperspectral stack of 27 wavelengths (440-700 nm) was created in post-processing for each depth-resolved image. Owing to the size and shape of the melanin granules in the RPE, the variations in backscattering coefficient as a function of wavelength could be identified-a result which is to be expected from Mie theory. This effect was successfully identified both in eumelanin-containing phantoms and in vivo in the low-concentration Brown Norway rat RPE.
Collapse
Affiliation(s)
- Danielle J. Harper
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Thomas Konegger
- Institute of Chemical Technologies and Analytics, TU WienViennaAustria
| | - Marco Augustin
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Kornelia Schützenberger
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Pablo Eugui
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Antonia Lichtenegger
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | - Conrad W. Merkle
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| | | | - Martin Glösmann
- Core Facility for Research and TechnologyUniversity of Veterinary MedicineViennaAustria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
| |
Collapse
|
8
|
Steelman ZA, Ho DS, Chu KK, Wax A. Light scattering methods for tissue diagnosis. OPTICA 2019; 6:479-489. [PMID: 33043100 PMCID: PMC7544148 DOI: 10.1364/optica.6.000479] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Light scattering has become a common biomedical research tool, enabling diagnostic sensitivity to myriad tissue alterations associated with disease. Light-tissue interactions are particularly attractive for diagnostics due to the variety of contrast mechanisms that can be used, including spectral, angle-resolved, and Fourier-domain detection. Photonic diagnostic tools offer further benefit in that they are non-ionizing, non-invasive, and give real-time feedback. In this review, we summarize recent innovations in light scattering technologies, with a focus on clinical achievements over the previous ten years.
Collapse
|
9
|
Zhao Y, Chu KK, Eldridge WJ, Jelly ET, Crose M, Wax A. Real-time speckle reduction in optical coherence tomography using the dual window method. BIOMEDICAL OPTICS EXPRESS 2018; 9:616-622. [PMID: 29552398 PMCID: PMC5854063 DOI: 10.1364/boe.9.000616] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/06/2018] [Accepted: 01/08/2018] [Indexed: 05/19/2023]
Abstract
Speckle is an intrinsic noise of interferometric signals which reduces contrast and degrades the quality of optical coherence tomography (OCT) images. Here, we present a frequency compounding speckle reduction technique using the dual window (DW) method. Using the DW method, speckle noise is reduced without the need to acquire multiple frames. A ~25% improvement in the contrast-to-noise ratio (CNR) was achieved using the DW speckle reduction method with only minimal loss (~17%) in axial resolution. We also demonstrate that real-time speckle reduction can be achieved at a B-scan rate of ~21 frames per second using a graphic processing unit (GPU). The DW speckle reduction technique can work on any existing OCT instrument without further system modification or extra components. This makes it applicable both in real-time imaging systems and during post-processing.
Collapse
|
10
|
Bailey MJ, Verma N, Fradkin L, Lam S, MacAulay C, Poh C, Markey MK, Sokolov K. Detection of precancerous lesions in the oral cavity using oblique polarized reflectance spectroscopy: a clinical feasibility study. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:65002. [PMID: 28609512 PMCID: PMC5469421 DOI: 10.1117/1.jbo.22.6.065002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 05/18/2017] [Indexed: 05/20/2023]
Abstract
We developed a multifiber optical probe for oblique polarized reflectance spectroscopy (OPRS) in vivo and evaluated its performance in detection of dysplasia in the oral cavity. The probe design allows the implementation of a number of methods to enable depth resolved spectroscopic measurements including polarization gating, source–detector separation, and differential spectroscopy; this combination was evaluated in carrying out binary classification tasks between four major diagnostic categories: normal, benign, mild dysplasia (MD), and severe dysplasia (SD). Multifiber OPRS showed excellent performance in the discrimination of normal from benign, MD, SD, and MD plus SD yielding sensitivity/specificity values of 100%/93%, 96%/95%, 100%/98%, and 100%/100%, respectively. The classification of benign versus dysplastic lesions was more challenging with sensitivity and specificity values of 80%/93%, 71%/93%, and 74%/80% in discriminating benign from SD, MD, and SD plus MD categories, respectively; this challenge is most likely associated with a strong and highly variable scattering from a keratin layer that was found in these sites. Classification based on multiple fibers was significantly better than that based on any single detection pair for tasks dealing with benign versus dysplastic sites. This result indicates that the multifiber probe can perform better in the detection of dysplasia in keratinized tissues.
Collapse
Affiliation(s)
- Maria J. Bailey
- University of Texas M.D. Anderson Cancer Center, Department of Imaging Physics, Houston, Texas, United States
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Nishant Verma
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Leonid Fradkin
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Sylvia Lam
- British Columbia Cancer Agency, Integrative Oncology Department, Vancouver, British Columbia, Canada
| | - Calum MacAulay
- British Columbia Cancer Agency, Integrative Oncology Department, Vancouver, British Columbia, Canada
| | - Catherine Poh
- British Columbia Cancer Agency, Integrative Oncology Department, Vancouver, British Columbia, Canada
| | - Mia K. Markey
- University of Texas M.D. Anderson Cancer Center, Department of Imaging Physics, Houston, Texas, United States
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Konstantin Sokolov
- University of Texas M.D. Anderson Cancer Center, Department of Imaging Physics, Houston, Texas, United States
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
- Rice University, Department of Bioengineering, Houston, Texas, United States
| |
Collapse
|
11
|
Kassinopoulos M, Bousi E, Zouvani I, Pitris C. Correlation of the derivative as a robust estimator of scatterer size in optical coherence tomography (OCT). BIOMEDICAL OPTICS EXPRESS 2017; 8:1598-1606. [PMID: 28663852 PMCID: PMC5480567 DOI: 10.1364/boe.8.001598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/23/2016] [Accepted: 12/29/2016] [Indexed: 05/18/2023]
Abstract
The size-dependent spectral variations, predicted by Mie theory, have already been considered as a contrast enhancement mechanism in optical coherence tomography. In this work, a new spectroscopic metric, the bandwidth of the correlation of the derivative, was developed for estimating scatterer size which is more robust and accurate compared to existing methods. Its feasibility was demonstrated using phantoms containing polystyrene microspheres as well as images of normal and cancerous human colon. The results are very promising, suggesting that the proposed metric could be utilized for measuring nuclear size distribution, a diagnostically valuable marker, in human tissues.
Collapse
Affiliation(s)
- M. Kassinopoulos
- KIOS Research Center, Department of Electrical and Computer Engineering, University of Cyprus, Nicosia, Cyprus
| | - E. Bousi
- KIOS Research Center, Department of Electrical and Computer Engineering, University of Cyprus, Nicosia, Cyprus
| | - I. Zouvani
- Nicosia General Hospital, Nicosia, Cyprus
| | - C. Pitris
- KIOS Research Center, Department of Electrical and Computer Engineering, University of Cyprus, Nicosia, Cyprus
| |
Collapse
|
12
|
Robles FE, Zhou KC, Fischer MC, Warren WS. Stimulated Raman scattering spectroscopic optical coherence tomography. OPTICA 2017; 4:243-246. [PMID: 29302608 PMCID: PMC5749255 DOI: 10.1364/optica.4.000243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We integrate spectroscopic optical coherence tomography (SOCT) with stimulated Raman scattering (SRS) to enable simultaneously multiplexed spatial and spectral imaging with sensitivity to many endogenous biochemical species that play an important role in biology and medicine. The combined approach, termed SRS-SOCT, overcomes the limitations of each individual method. Ultimately, SRS-SOCT has the potential to achieve fast, volumetric, and highly sensitive label-free molecular imaging. We demonstrate the approach by imaging excised human adipose tissue and detecting the lipids' Raman signatures in the high-wavenumber region.
Collapse
Affiliation(s)
- Francisco E. Robles
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
- Currently at Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory School of Medicine, tlanta, Georgia 30332, USA
| | - Kevin C. Zhou
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Martin C. Fischer
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Warren S. Warren
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| |
Collapse
|
13
|
Zhao Y, Maher JR, Ibrahim MM, Chien JS, Levinson H, Wax A. Deep imaging of absorption and scattering features by multispectral multiple scattering low coherence interferometry. BIOMEDICAL OPTICS EXPRESS 2016; 7:3916-3926. [PMID: 27867703 PMCID: PMC5102527 DOI: 10.1364/boe.7.003916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/18/2016] [Accepted: 09/03/2016] [Indexed: 05/05/2023]
Abstract
We have developed frequency domain multispectral multiple scattering low coherence interferometry (ms2/LCI) for deep imaging of absorption and scattering contrast. Using tissue-mimicking phantoms that match the full scattering phase function of human dermal tissue, we demonstrate that ms2/LCI can provide a signal/noise ratio (SNR) improvement of 15.4 dB over conventional OCT at an imaging depth of 1 mm. The enhanced SNR and penetration depth provided by ms2/LCI could be leveraged for a variety of clinical applications including the assessment of burn injuries where current clinical classification of severity only provides limited accuracy. The utility of the approach was demonstrated by imaging a tissue phantom simulating a partial-thickness burn revealing good spectroscopic contrast between healthy and injured tissue regions deep below the sample surface. Finally, healthy rat skin was imaged in vivo with both a commercial OCT instrument and our custom ms2/LCI system. The results demonstrate that ms2/LCI is capable of obtaining spectroscopic information far beyond the penetration depth provided by conventional OCT.
Collapse
Affiliation(s)
- Yang Zhao
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Jason R. Maher
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Mohamed M. Ibrahim
- Department of Surgery, Duke University Medical Center, Durham, NC 27708, USA
| | - Jennifer S. Chien
- Department of Surgery, Duke University Medical Center, Durham, NC 27708, USA
| | - Howard Levinson
- Department of Surgery, Duke University Medical Center, Durham, NC 27708, USA
- Department of Pathology, Duke University Medical Center, Durham, NC 27708, USA
| | - Adam Wax
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| |
Collapse
|
14
|
Ryczkowski P, Turunen J, Friberg AT, Genty G. Experimental Demonstration of Spectral Intensity Optical Coherence Tomography. Sci Rep 2016; 6:22126. [PMID: 26916668 PMCID: PMC4768261 DOI: 10.1038/srep22126] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 02/03/2016] [Indexed: 11/21/2022] Open
Abstract
We demonstrate experimentally spectral-domain intensity optical coherence tomography using a Mach-Zehnder interferometer with balanced detection. We show that the technique allows for a point spread function with reduced full-width at half maximum compared to conventional optical coherence tomography. The method further provides benefits similar to those of chirped-pulse interferometry in terms of dispersion cancellation but only requires a broadband incoherent source and standard detectors. The measurements are in excellent agreement with the theoretical predictions. Finally, we propose an approach that enables the elimination of potential artefacts arising from multiple interfaces.
Collapse
Affiliation(s)
- Piotr Ryczkowski
- Optics Laboratory, Department of Physics, Tampere University of Technology, 33720 Tampere, Finland
| | - Jari Turunen
- Institute of Photonics, University of Eastern Finland, P. O. Box 111, FI-80101 Joensuu, Finland
| | - Ari T Friberg
- Institute of Photonics, University of Eastern Finland, P. O. Box 111, FI-80101 Joensuu, Finland
| | - Goëry Genty
- Optics Laboratory, Department of Physics, Tampere University of Technology, 33720 Tampere, Finland
| |
Collapse
|
15
|
Robles FE, Fischer MC, Warren WS. Dispersion-based stimulated Raman scattering spectroscopy, holography, and optical coherence tomography. OPTICS EXPRESS 2016; 24:485-98. [PMID: 26832279 PMCID: PMC4741354 DOI: 10.1364/oe.24.000485] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Stimulated Raman scattering (SRS) enables fast, high resolution imaging of chemical constituents important to biological structures and functional processes, both in a label-free manner and using exogenous biomarkers. While this technology has shown remarkable potential, it is currently limited to point scanning and can only probe a few Raman bands at a time (most often, only one). In this work we take a fundamentally different approach to detecting the small nonlinear signals based on dispersion effects that accompany the loss/gain processes in SRS. In this proof of concept, we demonstrate that the dispersive measurements are more robust to noise compared to amplitude-based measurements, which then permit spectral or spatial multiplexing (potentially both, simultaneously). Finally, we illustrate how this method may enable different strategies for biochemical imaging using phase microscopy and optical coherence tomography.
Collapse
|
16
|
Zhao Y, Maher JR, Kim J, Selim MA, Levinson H, Wax A. Evaluation of burn severity in vivo in a mouse model using spectroscopic optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2015; 6:3339-45. [PMID: 26417505 PMCID: PMC4574661 DOI: 10.1364/boe.6.003339] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/07/2015] [Accepted: 08/10/2015] [Indexed: 05/09/2023]
Abstract
Clinical management of burn injuries depends upon an accurate assessment of the depth of the wound. Current diagnostic methods rely primarily on subjective visual inspection, which can produce variable results. In this study, spectroscopic optical coherence tomography was used to objectively evaluate burn injuries in vivo in a mouse model. Significant spectral differences were observed and correlated with the depth of the injury as determined by histopathology. The relevance of these results to clinical burn management in human tissues is discussed.
Collapse
Affiliation(s)
- Yang Zhao
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- These authors contributed equally to this work
| | - Jason R. Maher
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- These authors contributed equally to this work
| | - Jina Kim
- Department of Surgery, Duke University Medical Center, Durham, NC 27708, USA
| | | | - Howard Levinson
- Department of Surgery, Duke University Medical Center, Durham, NC 27708, USA
- Department of Pathology, Duke University Medical Center, Durham, NC 27708, USA
| | - Adam Wax
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| |
Collapse
|
17
|
Deutsch B, Reddy R, Mayerich D, Bhargava R, Carney PS. Compositional prior information in computed infrared spectroscopic imaging. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2015; 32:1126-1131. [PMID: 26367047 DOI: 10.1364/josaa.32.001126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Compositional prior information is used to bridge a gap in the theory between optical coherence tomography (OCT), which provides high-resolution structural images by neglecting spectral variation, and imaging spectroscopy, which provides only spectral information without significant regard to structure. A constraint is proposed in which it is assumed that a sample is composed of N distinct materials with known spectra, allowing the structural and spectral composition of the sample to be determined with a number of measurements on the order of N. We present a forward model for a sample with heterogeneities along the optical axis and show through simulation that the N-species constraint allows unambiguous inversion of Fourier transform interferometric data within the spatial frequency passband of the optical system. We then explore the stability and limitations of this model and extend it to a general 3D heterogeneous sample.
Collapse
|
18
|
Liu HY, Jonas E, Tian L, Zhong J, Recht B, Waller L. 3D imaging in volumetric scattering media using phase-space measurements. OPTICS EXPRESS 2015; 23:14461-14471. [PMID: 26072807 DOI: 10.1364/oe.23.014461] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We demonstrate the use of phase-space imaging for 3D localization of multiple point sources inside scattering material. The effect of scattering is to spread angular (spatial frequency) information, which can be measured by phase space imaging. We derive a multi-slice forward model for homogenous volumetric scattering, then develop a reconstruction algorithm that exploits sparsity in order to further constrain the problem. By using 4D measurements for 3D reconstruction, the dimensionality mismatch provides significant robustness to multiple scattering, with either static or dynamic diffusers. Experimentally, our high-resolution 4D phase-space data is collected by a spectrogram setup, with results successfully recovering the 3D positions of multiple LEDs embedded in turbid scattering media.
Collapse
|
19
|
Kim J, Brown W, Maher JR, Levinson H, Wax A. Functional optical coherence tomography: principles and progress. Phys Med Biol 2015; 60:R211-37. [PMID: 25951836 PMCID: PMC4448140 DOI: 10.1088/0031-9155/60/10/r211] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In the past decade, several functional extensions of optical coherence tomography (OCT) have emerged, and this review highlights key advances in instrumentation, theoretical analysis, signal processing and clinical application of these extensions. We review five principal extensions: Doppler OCT (DOCT), polarization-sensitive OCT (PS-OCT), optical coherence elastography (OCE), spectroscopic OCT (SOCT), and molecular imaging OCT. The former three have been further developed with studies in both ex vivo and in vivo human tissues. This review emphasizes the newer techniques of SOCT and molecular imaging OCT, which show excellent potential for clinical application but have yet to be well reviewed in the literature. SOCT elucidates tissue characteristics, such as oxygenation and carcinogenesis, by detecting wavelength-dependent absorption and scattering of light in tissues. While SOCT measures endogenous biochemical distributions, molecular imaging OCT detects exogenous molecular contrast agents. These newer advances in functional OCT broaden the potential clinical application of OCT by providing novel ways to understand tissue activity that cannot be accomplished by other current imaging methodologies.
Collapse
Affiliation(s)
- Jina Kim
- Department of Surgery, Duke University, Durham, NC 27710, USA
| | | | | | | | | |
Collapse
|
20
|
Chong SP, Merkle CW, Leahy C, Radhakrishnan H, Srinivasan VJ. Quantitative microvascular hemoglobin mapping using visible light spectroscopic Optical Coherence Tomography. BIOMEDICAL OPTICS EXPRESS 2015; 6:1429-50. [PMID: 25909026 PMCID: PMC4399681 DOI: 10.1364/boe.6.001429] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 02/19/2015] [Accepted: 03/14/2015] [Indexed: 05/18/2023]
Abstract
Quantification of chromophore concentrations in reflectance mode remains a major challenge for biomedical optics. Spectroscopic Optical Coherence Tomography (SOCT) provides depth-resolved spectroscopic information necessary for quantitative analysis of chromophores, like hemoglobin, but conventional SOCT analysis methods are applicable only to well-defined specular reflections, which may be absent in highly scattering biological tissue. Here, by fitting of the dynamic scattering signal spectrum in the OCT angiogram using a forward model of light propagation, we quantitatively determine hemoglobin concentrations directly. Importantly, this methodology enables mapping of both oxygen saturation and total hemoglobin concentration, or alternatively, oxyhemoglobin and deoxyhemoglobin concentration, simultaneously. Quantification was verified by ex vivo blood measurements at various pO2 and hematocrit levels. Imaging results from the rodent brain and retina are presented. Confounds including noise and scattering, as well as potential clinical applications, are discussed.
Collapse
|
21
|
Maher JR, Jaedicke V, Medina M, Levinson H, Selim MA, Brown WJ, Wax A. In vivo analysis of burns in a mouse model using spectroscopic optical coherence tomography. OPTICS LETTERS 2014; 39:5594-7. [PMID: 25360936 PMCID: PMC4370176 DOI: 10.1364/ol.39.005594] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Spectroscopic analysis of biological tissues can provide insight into changes in structure and function due to disease or injury. Depth-resolved spectroscopic measurements can be implemented for tissue imaging using optical coherence tomography (OCT). Here, spectroscopic OCT is applied to in vivo measurement of burn injury in a mouse model. Data processing and analysis methods are compared for their accuracy. Overall accuracy in classifying burned tissue was found to be as high as 91%, producing an area under the curve of a receiver operating characteristic curve of 0.97. The origins of the spectral changes are identified by correlation with histopathology.
Collapse
Affiliation(s)
- Jason R. Maher
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Volker Jaedicke
- Photonics and Terahertz Technology, Ruhr-Universität Bochum, Universitätsstr 150, 44780 Bochum, Germany
| | - Manuel Medina
- Department of Surgery, Duke University Medical Center, Durham, NC 27708
| | - Howard Levinson
- Department of Surgery, Duke University Medical Center, Durham, NC 27708
- Department of Pathology, Duke University Medical Center, Durham, NC 27708
| | | | - William J. Brown
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
| | - Adam Wax
- Department of Biomedical Engineering, Duke University, Durham, NC 27708
- Corresponding author:
| |
Collapse
|
22
|
Kraszewski M, Trojanowski M, Strąkowski MR. Comment on "Quantitative comparison of analysis methods for spectroscopic optical coherence tomography". BIOMEDICAL OPTICS EXPRESS 2014; 5:3023-3033. [PMID: 25401015 PMCID: PMC4230851 DOI: 10.1364/boe.5.003023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 05/30/2014] [Accepted: 06/01/2014] [Indexed: 05/29/2023]
Abstract
In a recent paper by Bosschaart et al. [Biomed. Opt. Express 4, 2570 (2013)] various algorithms of time-frequency signal analysis have been tested for their performance in blood analysis with spectroscopic optical coherence tomography (sOCT). The measurement of hemoglobin concentration and oxygen saturation based on blood absorption spectra have been considered. Short time Fourier transform (STFT) was found as the best method for the measurement of blood absorption spectra. STFT was superior to other methods, such as dual window Fourier transform. However, the algorithm proposed by Bosschaart et al. significantly underestimates values of blood oxygen saturation. In this comment we show that this problem can be solved by thorough design of STFT algorithm. It requires the usage of a non-gaussian shape of STFT window that may lead to an excellent reconstruction of blood absorption spectra from OCT interferograms. Our study shows that sOCT can be potentially used for estimating oxygen saturation of blood with the accuracy below 1% and the spatial resolution of OCT image better than 20 μm.
Collapse
|
23
|
Alexandrov SA, Subhash HM, Zam A, Leahy M. Nano-sensitive optical coherence tomography. NANOSCALE 2014; 6:3545-9. [PMID: 24595392 DOI: 10.1039/c3nr06132a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Depth resolved label-free detection of structural changes with nanoscale sensitivity is an outstanding problem in the biological and physical sciences and has significant applications in both the fundamental research and healthcare diagnostics arenas. Here we experimentally demonstrate a novel label-free depth resolved sensing technique based on optical coherence tomography (OCT) to detect structural changes at the nanoscale. Structural components of the 3D object, spectrally encoded in the remitted light, are transformed from the Fourier domain into each voxel of the 3D OCT image without compromising sensitivity. Spatial distribution of the nanoscale structural changes in the depth direction is visualized in just a single OCT scan. This label free approach provides new possibilities for depth resolved study of pathogenic and physiologically relevant molecules in the body with high sensitivity and specificity. It offers a powerful opportunity for early diagnosis and treatment of diseases. Experimental results show the ability of the approach to differentiate structural changes of 30 nm in nanosphere aggregates, located at different depths, from a single OCT scan, and structural changes less than 30 nm in time from two OCT scans. Application for visualization of the structure of human skin in vivo is also demonstrated.
Collapse
Affiliation(s)
- Sergey A Alexandrov
- NBIPI Tissue Optics & Microcirculation Imaging Group, School of Physics, National University of Ireland, Galway, Ireland.
| | | | | | | |
Collapse
|
24
|
Turzhitsky V, Qiu L, Itzkan I, Novikov AA, Kotelev MS, Getmanskiy M, Vinokurov VA, Muradov AV, Perelman LT. Spectroscopy of scattered light for the characterization of micro and nanoscale objects in biology and medicine. APPLIED SPECTROSCOPY 2014; 68:133-54. [PMID: 24480270 DOI: 10.1366/13-07395] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The biomedical uses for the spectroscopy of scattered light by micro and nanoscale objects can broadly be classified into two areas. The first, often called light scattering spectroscopy (LSS), deals with light scattered by dielectric particles, such as cellular and sub-cellular organelles, and is employed to measure their size or other physical characteristics. Examples include the use of LSS to measure the size distributions of nuclei or mitochondria. The native contrast that is achieved with LSS can serve as a non-invasive diagnostic and scientific tool. The other area for the use of the spectroscopy of scattered light in biology and medicine involves using conducting metal nanoparticles to obtain either contrast or electric field enhancement through the effect of the surface plasmon resonance (SPR). Gold and silver metal nanoparticles are non-toxic, they do not photobleach, are relatively inexpensive, are wavelength-tunable, and can be labeled with antibodies. This makes them very promising candidates for spectrally encoded molecular imaging. Metal nanoparticles can also serve as electric field enhancers of Raman signals. Surface enhanced Raman spectroscopy (SERS) is a powerful method for detecting and identifying molecules down to single molecule concentrations. In this review, we will concentrate on the common physical principles, which allow one to understand these apparently different areas using similar physical and mathematical approaches. We will also describe the major advancements in each of these areas, as well as some of the exciting recent developments.
Collapse
Affiliation(s)
- Vladimir Turzhitsky
- Center for Advanced Biomedical Imaging fnd Photonics, Beth Israel Deaconess Medical Center, Harvard University, Boston, Massachusetts 02215 Usa
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Matthews TE, Giacomelli MG, Brown WJ, Wax A. Fourier domain multispectral multiple scattering low coherence interferometry. APPLIED OPTICS 2013; 52:8220-8. [PMID: 24513821 DOI: 10.1364/ao.52.008220] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 10/15/2013] [Indexed: 05/22/2023]
Abstract
We have implemented multispectral multiple scattering low coherence interferometry (ms2/LCI) with Fourier domain data collection. The ms2/LCI system is designed to localize features with spectroscopic contrast with millimeter resolution up to 1 cm deep in scattering samples by using photons that have undergone multiple low-angle (forward) scattering events. Fourier domain detection both increases the data acquisition speed of the system and gives access to rich spectroscopic information, compared to the previous single channel, time-domain implementation. Separate delivery and detection angular apertures reduce collection of the diffuse background signal in order to isolate localized spectral features from deeper in scattering samples than would be possible with traditional spectroscopic optical coherence tomography. Light from a supercontinuum source is used to acquire absorption spectra of chromophores in the visible range within a tissue-like scattering phantom. An intensity modulation and digital lock-in detection scheme is implemented to mitigate relative intensity and spectral noise inherent in supercontinuum sources. The technical parameters of the system and comparative analysis are presented.
Collapse
|
26
|
Wax A, Meiri A, Arumugam S, Rinehart MT. Comparative review of interferometric detection of plasmonic nanoparticles. BIOMEDICAL OPTICS EXPRESS 2013; 4:2166-78. [PMID: 24156072 PMCID: PMC3799674 DOI: 10.1364/boe.4.002166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 09/04/2013] [Accepted: 09/05/2013] [Indexed: 05/26/2023]
Abstract
Noble metal nanoparticles exhibit enhanced scattering and absorption at specific wavelengths due to a localized surface plamson resonance. This unique property can be exploited to enable the use of plasmonic nanoparticles as contrast agents in optical imaging. A range of optical techniques have been developed to detect nanoparticles in order to implement imaging schemes. Here we review several different approaches for using optical interferometry to detect the presence and concentration of nanoparticles. The strengths and weaknesses of the various approaches are discussed and quantitative comparisons of the achievable signal to noise ratios are presented. The benefits of each approach are outlined as they relate to specific application goals.
Collapse
|
27
|
Yin B, Kuranov RV, McElroy AB, Kazmi S, Dunn AK, Duong TQ, Milner TE. Dual-wavelength photothermal optical coherence tomography for imaging microvasculature blood oxygen saturation. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:56005. [PMID: 23640076 PMCID: PMC3642243 DOI: 10.1117/1.jbo.18.5.056005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A swept-source dual-wavelength photothermal (DWP) optical coherence tomography (OCT) system is demonstrated for quantitative imaging of microvasculature oxygen saturation. DWP-OCT is capable of recording three-dimensional images of tissue and depth-resolved phase variation in response to photothermal excitation. A 1,064-nm OCT probe and 770-nm and 800-nm photothermal excitation beams are combined in a single-mode optical fiber to measure microvasculature hemoglobin oxygen saturation (SO(2)) levels in phantom blood vessels with a range of blood flow speeds (0 to 17 mm/s). A 50-μm-diameter blood vessel phantom is imaged, and SO(2) levels are measured using DWP-OCT and compared with values provided by a commercial oximeter at various blood oxygen concentrations. The influences of blood flow speed and mechanisms of SNR phase degradation on the accuracy of SO(2) measurement are identified and investigated.
Collapse
Affiliation(s)
- Biwei Yin
- University of Texas at Austin, Departments of Electrical and Computer Engineering, 1 University Station C0803, Austin, Texas 78712
| | - Roman V. Kuranov
- University of Texas Health Science Center at San Antonio, Department of Ophthalmology, 7703 Floyd Curl Drive, San Antonio, Texas 78229
- Address all correspondence to: Roman V. Kuranov, University of Texas Health Science Center at San Antonio, Department of Ophthalmology, 7703 Floyd Curl Drive, San Antonio, Texas 78229. Tel: 210-567-8402; Fax: 210-567-8413; E-mail:
| | - Austin B. McElroy
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712
| | - Shams Kazmi
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712
| | - Andrew K. Dunn
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712
| | - Timothy Q. Duong
- University of Texas Health Science Center at San Antonio, Department of Ophthalmology, 7703 Floyd Curl Drive, San Antonio, Texas 78229
| | - Thomas E. Milner
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712
| |
Collapse
|
28
|
Bosschaart N, van Leeuwen TG, Aalders MCG, Faber DJ. Quantitative comparison of analysis methods for spectroscopic optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2013; 4:2570-84. [PMID: 24298417 PMCID: PMC3829551 DOI: 10.1364/boe.4.002570] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 09/28/2013] [Accepted: 10/15/2013] [Indexed: 05/09/2023]
Abstract
Spectroscopic optical coherence tomography (sOCT) enables the mapping of chromophore concentrations and image contrast enhancement in tissue. Acquisition of depth resolved spectra by sOCT requires analysis methods with optimal spectral/spatial resolution and spectral recovery. In this article, we quantitatively compare the available methods, i.e. the short time Fourier transform (STFT), wavelet transforms, the Wigner-Ville distribution and the dual window method through simulations in tissue-like media. We conclude that all methods suffer from the trade-off in spectral/spatial resolution, and that the STFT is the optimal method for the specific application of the localized quantification of hemoglobin concentration and oxygen saturation.
Collapse
Affiliation(s)
- Nienke Bosschaart
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, P.O Box 22700, NL-1100 DE Amsterdam, The Netherlands
| | - Ton G. van Leeuwen
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, P.O Box 22700, NL-1100 DE Amsterdam, The Netherlands
| | - Maurice C. G. Aalders
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, P.O Box 22700, NL-1100 DE Amsterdam, The Netherlands
| | - Dirk J. Faber
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, P.O Box 22700, NL-1100 DE Amsterdam, The Netherlands
| |
Collapse
|
29
|
Jaedicke V, Agcaer S, Robles FE, Steinert M, Jones D, Goebel S, Gerhardt NC, Welp H, Hofmann MR. Comparison of different metrics for analysis and visualization in spectroscopic optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2013; 4:2945-61. [PMID: 24409393 PMCID: PMC3862158 DOI: 10.1364/boe.4.002945] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 11/08/2013] [Accepted: 11/10/2013] [Indexed: 05/03/2023]
Abstract
Spectroscopic Optical Coherence Tomography (S-OCT) extracts depth resolved spectra that are inherently available from OCT signals. The back scattered spectra contain useful functional information regarding the sample, since the light is altered by wavelength dependent absorption and scattering caused by chromophores and structures of the sample. Two aspects dominate the performance of S-OCT: (1) the spectral analysis processing method used to obtain the spatially-resolved spectroscopic information and (2) the metrics used to visualize and interpret relevant sample features. In this work, we focus on the second aspect, where we will compare established and novel metrics for S-OCT. These concepts include the adaptation of methods known from multispectral imaging and modern signal processing approaches such as pattern recognition. To compare the performance of the metrics in a quantitative manner, we use phantoms with microsphere scatterers of different sizes that are below the system's resolution and therefore cannot be differentiated using intensity based OCT images. We show that the analysis of the spectral features can clearly separate areas with different scattering properties in multi-layer phantoms. Finally, we demonstrate the performance of our approach for contrast enhancement in bovine articular cartilage.
Collapse
Affiliation(s)
- Volker Jaedicke
- Photonics and Terahertz Technology, Ruhr-University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Semih Agcaer
- Photonics and Terahertz Technology, Ruhr-University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Francisco E. Robles
- Department of Chemistry, Duke University, 2303 French Family Science Center, 124 Science Drive, Durham, NC 27708, USA
| | - Marian Steinert
- Institute for Experimental Orthopaedics and Biomechanics, Philipps-University Marburg, Baldingerstr. 35043 Marburg, Germany
| | - David Jones
- Institute for Experimental Orthopaedics and Biomechanics, Philipps-University Marburg, Baldingerstr. 35043 Marburg, Germany
| | - Sebastian Goebel
- Department of Electrical Engineering and Information Technology, University of Applied Science Georg Agricola, Herner Str 45, 44787 Bochum, Germany
| | - Nils C. Gerhardt
- Photonics and Terahertz Technology, Ruhr-University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Hubert Welp
- Department of Electrical Engineering and Information Technology, University of Applied Science Georg Agricola, Herner Str 45, 44787 Bochum, Germany
| | - Martin R. Hofmann
- Photonics and Terahertz Technology, Ruhr-University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| |
Collapse
|
30
|
Tay BCM, Chow TH, Ng BK, Loh TKS. Dual-Window Dual-Bandwidth Spectroscopic Optical Coherence Tomography Metric for Qualitative Scatterer Size Differentiation in Tissues. IEEE Trans Biomed Eng 2012; 59:2439-48. [DOI: 10.1109/tbme.2012.2202391] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
31
|
Bosschaart N, Aalders MCG, van Leeuwen TG, Faber DJ. Spectral domain detection in low-coherence spectroscopy. BIOMEDICAL OPTICS EXPRESS 2012; 3:2263-72. [PMID: 23024918 PMCID: PMC3447566 DOI: 10.1364/boe.3.002263] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 08/06/2012] [Accepted: 08/13/2012] [Indexed: 05/22/2023]
Abstract
Low-coherence spectroscopy (LCS) offers the valuable possibility to measure quantitative and wavelength resolved optical property spectra within a tissue volume of choice that is controllable both in size and in depth. Until now, only time domain detection was investigated for LCS (tdLCS), but spectral domain detection offers a theoretical speed/sensitivity advantage over tdLCS. In this article, we introduce a method for spectral domain detection in LCS (sdLCS), with optimal sensitivity as a function of measurement depth. We validate our method computationally in a simulation and experimentally on a phantom with known optical properties. The attenuation, absorption and scattering coefficient spectra from the phantom that were measured by sdLCS agree well with the expected optical properties and the measured optical properties by tdLCS.
Collapse
Affiliation(s)
- Nienke Bosschaart
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, P.O. Box 22700, NL-1100 DE Amsterdam, The Netherlands
| | - Maurice C. G. Aalders
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, P.O. Box 22700, NL-1100 DE Amsterdam, The Netherlands
| | - Ton G. van Leeuwen
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, P.O. Box 22700, NL-1100 DE Amsterdam, The Netherlands
- Biomedical Photonic Imaging Group, University of Twente, P.O. Box 217, NL-7500 AE Enschede, The Netherlands
| | - Dirk J. Faber
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, P.O. Box 22700, NL-1100 DE Amsterdam, The Netherlands
| |
Collapse
|
32
|
Li YL, Seekell K, Yuan H, Robles FE, Wax A. Multispectral nanoparticle contrast agents for true-color spectroscopic optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2012; 3:1914-23. [PMID: 22876354 PMCID: PMC3409709 DOI: 10.1364/boe.3.001914] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 07/18/2012] [Accepted: 07/18/2012] [Indexed: 05/18/2023]
Abstract
We have recently developed a novel dual window scheme for processing spectroscopic OCT images to provide spatially resolved true color imaging of chromophores in scattering samples. Here we apply this method to measure the extinction spectra of plasmonic nanoparticles at various concentrations for potential in vivo applications. We experimentally demonstrate sub-nanomolar sensitivity in the measurement of nanoparticle concentrations, and show that colorimetric imaging with multiple species of nanoparticles produces enhanced contrast for spectroscopic OCT in both tissue phantom and cell studies.
Collapse
Affiliation(s)
- You Leo Li
- Department of Biomedical Engineering and Fitzpatrick Institute for Photonics, Duke University, Durham NC 27708, USA
| | - Kevin Seekell
- Department of Biomedical Engineering and Fitzpatrick Institute for Photonics, Duke University, Durham NC 27708, USA
| | - Hsiangkuo Yuan
- Department of Biomedical Engineering and Fitzpatrick Institute for Photonics, Duke University, Durham NC 27708, USA
| | | | - Adam Wax
- Department of Biomedical Engineering and Fitzpatrick Institute for Photonics, Duke University, Durham NC 27708, USA
| |
Collapse
|
33
|
Robles FE, Wilson C, Grant G, Wax A. Molecular imaging true-colour spectroscopic optical coherence tomography. NATURE PHOTONICS 2011; 5:744-747. [PMID: 23144652 PMCID: PMC3491993 DOI: 10.1038/nphoton.2011.257] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Molecular imaging holds a pivotal role in medicine due to its ability to provide invaluable insight into disease mechanisms at molecular and cellular levels. To this end, various techniques have been developed for molecular imaging, each with its own advantages and disadvantages(1-4). For example, fluorescence imaging achieves micrometre-scale resolution, but has low penetration depths and is mostly limited to exogenous agents. Here, we demonstrate molecular imaging of endogenous and exogenous chromophores using a novel form of spectroscopic optical coherence tomography. Our approach consists of using a wide spectral bandwidth laser source centred in the visible spectrum, thereby allowing facile assessment of haemoglobin oxygen levels, providing contrast from readily available absorbers, and enabling true-colour representation of samples. This approach provides high spectral fidelity while imaging at the micrometre scale in three dimensions. Molecular imaging true-colour spectroscopic optical coherence tomography (METRiCS OCT) has significant implications for many biomedical applications including ophthalmology, early cancer detection, and understanding fundamental disease mechanisms such as hypoxia and angiogenesis.
Collapse
Affiliation(s)
- Francisco E. Robles
- Department of Biomedical Engineering and Fitzpatrick Institute for Photonics, Duke University, Durham, North Carolina 27708, USA
- Medical Physics Program, Duke University, Durham, North Carolina 27708, USA
| | - Christy Wilson
- Pediatric Neurosurgery, Duke University, Durham, North Carolina 27708, USA
| | - Gerald Grant
- Pediatric Neurosurgery, Duke University, Durham, North Carolina 27708, USA
| | - Adam Wax
- Department of Biomedical Engineering and Fitzpatrick Institute for Photonics, Duke University, Durham, North Carolina 27708, USA
- Medical Physics Program, Duke University, Durham, North Carolina 27708, USA
- Correspondence and requests for materials should be addressed to A.W.
| |
Collapse
|
34
|
Kuranov RV, Kazmi S, McElroy AB, Kiel JW, Dunn AK, Milner TE, Duong TQ. In vivo depth-resolved oxygen saturation by Dual-Wavelength Photothermal (DWP) OCT. OPTICS EXPRESS 2011; 19:23831-44. [PMID: 22109408 PMCID: PMC3482904 DOI: 10.1364/oe.19.023831] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Microvasculature hemoglobin oxygen saturation (SaO2) is important in the progression of various pathologies. Non-invasive depth-resolved measurement of SaO2 levels in tissue microvasculature has the potential to provide early biomarkers and a better understanding of the pathophysiological processes allowing improved diagnostics and prediction of disease progression. We report proof-of-concept in vivo depth-resolved measurement of SaO(2) levels in selected 30 µm diameter arterioles in the murine brain using Dual-Wavelength Photothermal (DWP) Optical Coherence Tomography (OCT) with 800 nm and 770 nm photothermal excitation wavelengths. Depth location of back-reflected light from a target arteriole was confirmed using Doppler and speckle contrast OCT images. SaO(2) measured in a murine arteriole with DWP-OCT is linearly correlated (R(2)=0.98) with systemic SaO(2) values recorded by a pulse-oximeter. DWP-OCT are steadily lower (10.1%) than systemic SaO(2) values except during pure oxygen breathing. DWP-OCT is insensitive to OCT intensity variations and is a candidate approach for in vivo depth-resolved quantitative imaging of microvascular SaO(2) levels.
Collapse
Affiliation(s)
- Roman V Kuranov
- Department of Ophthalmology, The University of Texas Health Science Center, San Antonio, Texas 78229, USA.
| | | | | | | | | | | | | |
Collapse
|
35
|
Bosschaart N, Faber DJ, van Leeuwen TG, Aalders MCG. In vivo low-coherence spectroscopic measurements of local hemoglobin absorption spectra in human skin. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:100504. [PMID: 22029343 DOI: 10.1117/1.3644497] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Localized spectroscopic measurements of optical properties are invaluable for diagnostic applications that involve layered tissue structures, but conventional spectroscopic techniques lack exact control over the size and depth of the probed tissue volume. We show that low-coherence spectroscopy (LCS) overcomes these limitations by measuring local attenuation and absorption coefficient spectra in layered phantoms. In addition, we demonstrate the first in vivo LCS measurements of the human epidermis and dermis only. From the measured absorption in two distinct regions of the dermal microcirculation, we determine total hemoglobin concentration (3.0±0.5 g∕l and 7.8±1.2 g∕l) and oxygen saturation.
Collapse
Affiliation(s)
- Nienke Bosschaart
- University of Amsterdam, Academic Medical Center, Department of Biomedical Engineering and Physics, P.O. Box 22700, NL-1100 DE Amsterdam, The Netherlands.
| | | | | | | |
Collapse
|
36
|
Gambichler T, Jaedicke V, Terras S. Optical coherence tomography in dermatology: technical and clinical aspects. Arch Dermatol Res 2011; 303:457-73. [DOI: 10.1007/s00403-011-1152-x] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2011] [Revised: 05/04/2011] [Accepted: 05/19/2011] [Indexed: 11/24/2022]
|
37
|
Kuranov RV, Qiu J, McElroy AB, Estrada A, Salvaggio A, Kiel J, Dunn AK, Duong TQ, Milner TE. Depth-resolved blood oxygen saturation measurement by dual-wavelength photothermal (DWP) optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2011; 2:491-504. [PMID: 21412455 PMCID: PMC3047355 DOI: 10.1364/boe.2.000491] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 01/24/2011] [Accepted: 01/29/2011] [Indexed: 05/03/2023]
Abstract
Non-invasive depth-resolved measurement of hemoglobin oxygen saturation (SaO(2)) levels in discrete blood vessels may have implications for diagnosis and treatment of various pathologies. We introduce a novel Dual-Wavelength Photothermal (DWP) Optical Coherence Tomography (OCT) for non-invasive depth-resolved measurement of SaO(2) levels in a blood vessel phantom. DWP OCT SaO(2) is linearly correlated with blood-gas SaO(2) measurements. We demonstrate 6.3% precision in SaO(2) levels measured a phantom blood vessel using DWP-OCT with 800 and 765 nm excitation wavelengths. Sources of uncertainty in SaO(2) levels measured with DWP-OCT are identified and characterized.
Collapse
Affiliation(s)
- Roman V. Kuranov
- Department of Ophthalmology, The University of Texas Health Science Center, San Antonio, Texas 78229, USA
- Dept. of Biomedical Engineering, The University of Texas at Austin, Texas 78712, USA
| | - Jinze Qiu
- Dept. of Biomedical Engineering, The University of Texas at Austin, Texas 78712, USA
| | - Austin B. McElroy
- Dept. of Biomedical Engineering, The University of Texas at Austin, Texas 78712, USA
| | - Arnold Estrada
- Dept. of Biomedical Engineering, The University of Texas at Austin, Texas 78712, USA
| | - Anthony Salvaggio
- Dept. of Biomedical Engineering, The University of Texas at Austin, Texas 78712, USA
| | - Jeffrey Kiel
- Department of Ophthalmology, The University of Texas Health Science Center, San Antonio, Texas 78229, USA
| | - Andrew K. Dunn
- Dept. of Biomedical Engineering, The University of Texas at Austin, Texas 78712, USA
| | - Timothy Q. Duong
- Department of Ophthalmology, The University of Texas Health Science Center, San Antonio, Texas 78229, USA
- South Texas Veterans Health Care System, San Antonio, Texas 78229, USA
| | - Thomas E. Milner
- Dept. of Biomedical Engineering, The University of Texas at Austin, Texas 78712, USA
| |
Collapse
|
38
|
Song C, Ahn M, Gweon D. Polarization-sensitive spectral-domain optical coherence tomography using a multi-line single camera spectrometer. OPTICS EXPRESS 2010; 18:23805-17. [PMID: 21164725 DOI: 10.1364/oe.18.023805] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We describe a polarization sensitive spectral domain optical coherence tomography technique based on a single camera spectrometer that includes a multiplexed custom grating, camera lenses, and a high-speed three-line CCD camera. Two orthogonally polarized beams could be separately taken by two lines of the camera as a result of vertically different incident angles. The system could provide the imaging capabilities of a full camera speed and increased measurable depth. The proposed optical coherence tomography system could make a distinction between the normal muscle and cancerous tissue from the chest of a DSred GFP mouse and the OCT images were compared with those of in vivo confocal microscopy.
Collapse
Affiliation(s)
- Cheol Song
- Nano-Opto-Mechatronics Lab., Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
| | | | | |
Collapse
|
39
|
Robles FE, Wax A. Separating the scattering and absorption coefficients using the real and imaginary parts of the refractive index with low-coherence interferometry. OPTICS LETTERS 2010; 35:2843-5. [PMID: 20808343 PMCID: PMC3306185 DOI: 10.1364/ol.35.002843] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present an analytical method that yields the real and imaginary parts of the refractive index (RI) from low-coherence interferometry measurements, leading to the separation of the scattering and absorption coefficients of turbid samples. The imaginary RI is measured using time-frequency analysis, with the real part obtained by analyzing the nonlinear phase induced by a sample. A derivation relating the real part of the RI to the nonlinear phase term of the signal is presented, along with measurements from scattering and nonscattering samples that exhibit absorption due to hemoglobin.
Collapse
|
40
|
Robles FE, Zhu Y, Lee J, Sharma S, Wax A. Detection of early colorectal cancer development in the azoxymethane rat carcinogenesis model with Fourier domain low coherence interferometry. BIOMEDICAL OPTICS EXPRESS 2010; 1:736-745. [PMID: 21258505 PMCID: PMC3017982 DOI: 10.1364/boe.1.000736] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 08/16/2010] [Accepted: 08/20/2010] [Indexed: 05/03/2023]
Abstract
Fourier domain low coherence interferometry (fLCI) is an emerging optical technique used to quantitatively assess cell nuclear morphology in tissue as a means of detecting early cancer development. In this work, we use the azoxymethane rat carcinogenesis model, a well characterized and established model for colon cancer research, to demonstrate the ability of fLCI to distinguish between normal and preneoplastic ex-vivo colon tissue. The results show highly statistically significant differences between the measured cell nuclear diameters of normal and azoxymethane-treated tissues, thus providing strong evidence that fLCI may be a powerful tool for non-invasive, quantitative detection of early changes associated with colorectal cancer development.
Collapse
Affiliation(s)
- Francisco E. Robles
- Department of Biomedical Engineering and Fitzpatrick Institute for Photonics,
Duke University, Durham NC 27708, USA
- Medical Physics Program, Duke University, Durham NC 27708, USA
| | - Yizheng Zhu
- Department of Biomedical Engineering and Fitzpatrick Institute for Photonics,
Duke University, Durham NC 27708, USA
| | - Jin Lee
- The Hamner Institutes for Health, Research Triangle Park, NC 27709, USA
| | - Sheela Sharma
- The Hamner Institutes for Health, Research Triangle Park, NC 27709, USA
| | - Adam Wax
- Department of Biomedical Engineering and Fitzpatrick Institute for Photonics,
Duke University, Durham NC 27708, USA
- Medical Physics Program, Duke University, Durham NC 27708, USA
| |
Collapse
|
41
|
Robles FE, Chowdhury S, Wax A. Assessing hemoglobin concentration using spectroscopic optical coherence tomography for feasibility of tissue diagnostics. BIOMEDICAL OPTICS EXPRESS 2010; 1:310-317. [PMID: 21258468 DOI: 10.1364/boe.1.000310] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 07/16/2010] [Accepted: 07/16/2010] [Indexed: 05/18/2023]
Abstract
Hemoglobin (Hb) concentration and oxygen saturation levels are important biomarkers for various diseases, including cancer. Here, we investigate the ability to measure these parameters for tissue using spectroscopic optical coherence tomography (SOCT). A parallel frequency domain OCT system is used with detection spanning the visible region of the spectrum (450 nm to 700 nm). Oxygenated and deoxygenated Hb absorbing phantoms are analyzed. The results show that Hb concentrations as low as 1.2 g/L at 1 mm can be retrieved indicating that both normal and cancerous tissue measurements may be obtained. However, measurement of oxygen saturation levels may not be achieved with this approach.
Collapse
|
42
|
Giacomelli M, Zhu Y, Lee J, Wax A. Size and shape determination of spheroidal scatterers using two-dimensional angle resolved scattering. OPTICS EXPRESS 2010; 18:14616-26. [PMID: 20639947 PMCID: PMC3408918 DOI: 10.1364/oe.18.014616] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 06/20/2010] [Accepted: 06/21/2010] [Indexed: 05/18/2023]
Abstract
We demonstrate accurate determination of the size and shape of spherical and spheroidal scatterers through inverse analysis of two-dimensional solid-angle and depth resolved backscattered light intensities. Intensity of scattered light is measured over a wide range of solid angles using a novel scanning fiber optic interferometer from both individual and ensembles of scatterers. T-matrix based inverse analysis of these two-dimensional angular measurements yields completely unique size and aspect ratio determinations with subwavelength precision over a large range of possible scatterer geometries.
Collapse
|
43
|
Robles FE, Wax A. Measuring morphological features using light-scattering spectroscopy and Fourier-domain low-coherence interferometry. OPTICS LETTERS 2010; 35:360-2. [PMID: 20125721 PMCID: PMC2831473 DOI: 10.1364/ol.35.000360] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present measurements of morphological features in a thick turbid sample using light-scattering spectroscopy (LSS) and Fourier-domain low-coherence interferometry (fLCI) by processing with the dual-window (DW) method. A parallel frequency domain optical coherence tomography (OCT) system with a white-light source is used to image a two-layer phantom containing polystyrene beads of diameters 4.00 and 6.98 mum on the top and bottom layers, respectively. The DW method decomposes each OCT A-scan into a time-frequency distribution with simultaneously high spectral and spatial resolution. The spectral information from localized regions in the sample is used to determine scatterer structure. The results show that the two scatterer populations can be differentiated using LSS and fLCI.
Collapse
|
44
|
Fercher AF. Optical coherence tomography - development, principles, applications. Z Med Phys 2009; 20:251-76. [PMID: 21134630 DOI: 10.1016/j.zemedi.2009.11.002] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 10/09/2009] [Accepted: 11/18/2009] [Indexed: 12/17/2022]
Abstract
This paper presents a review of the development of optical coherence tomography (OCT), its principles and important applications. Basic OCT systems are described and the physical foundations of OCT signal properties and signal recording systems are reviewed. Recent examples of OCT applications in ophthalmology, cardiology, gastroenterology and dermatology outline the relevance of this advanced imaging modality in the medical field.
Collapse
Affiliation(s)
- Adolf Friedrich Fercher
- ZBMTP - Medizinische Physik, Medizinische Universität Wien, Währinger Straße 13, A-1090 Wien.
| |
Collapse
|
45
|
Graf RN, Robles FE, Chen X, Wax A. Detecting precancerous lesions in the hamster cheek pouch using spectroscopic white-light optical coherence tomography to assess nuclear morphology via spectral oscillations. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:064030. [PMID: 20059268 PMCID: PMC2803719 DOI: 10.1117/1.3269680] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 10/08/2009] [Accepted: 10/09/2009] [Indexed: 05/19/2023]
Abstract
We have developed a novel dual-window approach for spectroscopic optical coherence tomography (OCT) measurements and applied it to probe nuclear morphology in tissue samples drawn from the hamster cheek pouch carcinogenesis model. The dual-window approach enables high spectral and depth resolution simultaneously, allowing detection of spectral oscillations, which we isolate to determine the structure of cell nuclei in the basal layer of the epithelium. The measurements were executed with our parallel frequency domain OCT system, which uses light from a thermal source, providing high bandwidth and access to the visible portion of the spectrum. The structural measurements show a highly statistically significant difference between untreated (normal) and treated (hyperplastic/dysplastic) tissues, indicating the potential utility of this approach as a diagnostic method.
Collapse
Affiliation(s)
- Robert N Graf
- Duke University, Department of Biomedical Engineering, 136 Hudson Hall, Durham, North Carolina 27708, USA
| | | | | | | |
Collapse
|