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Wang H, Blanke N, Gong D, Ortug A, Alatorre Warren JL, Clickner C, Ammon W, Nolan J, Cotronis Z, van der Kouwe A, Takahashi E. Imaging of developing human brains with ex vivo PSOCT and dMRI. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.27.605383. [PMID: 39211119 PMCID: PMC11361116 DOI: 10.1101/2024.07.27.605383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
The human brain undergoes substantial developmental changes in the first five years of life. Particularly in the white matter, myelination of axons occurs near birth and continues at a rapid pace during the first 2 to 3 years. Diffusion MRI (dMRI) has revolutionized our understanding of developmental trajectories in white matter. However, the mm-resolution of in vivo techniques bears significant limitation in revealing the microstructure of the developing brain. Polarization sensitive optical coherence tomography (PSOCT) is a three-dimensional (3D) optical imaging technique that uses polarized light interferometry to target myelinated fiber tracts with micrometer resolution. Previous studies have shown that PSOCT contributes significantly to the elucidation of myelin content and quantification of fiber orientation in adult human brains. In this study, we utilized the PSOCT technique to study developing brains during the first 5 years of life in combination with ex vivo dMRI. The results showed that the optical properties of PSOCT quantitatively reveal the myelination process in young children. The imaging contrast of the optic axis orientation is a sensitive measure of fiber orientations in largely unmyelinated brains as young as 3-months-old. The micrometer resolution of PSOCT provides substantially enriched information about complex fiber networks and complements submillimeter dMRI. This new optical tool offers great potential to reveal the white matter structures in normal neurodevelopment and developmental disorders in unprecedented detail.
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Blanke N, Chang S, Novoseltseva A, Wang H, Boas DA, Bigio IJ. Multiscale label-free imaging of myelin in human brain tissue with polarization-sensitive optical coherence tomography and birefringence microscopy. BIOMEDICAL OPTICS EXPRESS 2023; 14:5946-5964. [PMID: 38021128 PMCID: PMC10659784 DOI: 10.1364/boe.499354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/03/2023] [Accepted: 09/06/2023] [Indexed: 12/01/2023]
Abstract
The combination of polarization-sensitive optical coherence tomography (PS-OCT) and birefringence microscopy (BRM) enables multiscale assessment of myelinated axons in postmortem brain tissue, and these tools are promising for the study of brain connectivity and organization. We demonstrate label-free imaging of myelin structure across the mesoscopic and microscopic spatial scales by performing serial-sectioning PS-OCT of a block of human brain tissue and periodically sampling thin sections for high-resolution imaging with BRM. In co-registered birefringence parameter maps, we observe good correspondence and demonstrate that BRM enables detailed validation of myelin (hence, axonal) organization, thus complementing the volumetric information content of PS-OCT.
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Affiliation(s)
- Nathan Blanke
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Shuaibin Chang
- Department of Electrical & Computer Engineering, Boston University, 8 St. Mary’s St., Boston, MA 02215, USA
| | - Anna Novoseltseva
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Hui Wang
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, 149 13th St., Charlestown, MA 02129, USA
| | - David A. Boas
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Irving J. Bigio
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
- Department of Electrical & Computer Engineering, Boston University, 8 St. Mary’s St., Boston, MA 02215, USA
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3
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Liu CJ, Ammon W, Jones RJ, Nolan JC, Gong D, Maffei C, Edlow BL, Augustinack JC, Magnain C, Yendiki A, Villiger M, Fischl B, Wang H. Quantitative imaging of three-dimensional fiber orientation in the human brain via two illumination angles using polarization-sensitive optical coherence tomography. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.20.563298. [PMID: 37961162 PMCID: PMC10634685 DOI: 10.1101/2023.10.20.563298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The accurate measurement of three-dimensional (3D) fiber orientation in the brain is crucial for reconstructing fiber pathways and studying their involvement in neurological diseases. Optical imaging methods such as polarization-sensitive optical coherence tomography (PS-OCT) provide important tools to directly quantify fiber orientation at micrometer resolution. However, brain imaging based on the optic axis by PS-OCT so far has been limited to two-dimensional in-plane orientation, preventing the comprehensive study of connectivity in 3D. In this work, we present a novel method to obtain the 3D fiber orientation in full angular space with only two illumination angles. We measure the optic axis orientation and the apparent birefringence by PS-OCT from a normal and a 15 deg tilted illumination, and then apply a computational method yielding the 3D optic axis orientation and true birefringence. We verify that our method accurately recovers a large range of through-plane orientations from -85 deg to 85 deg with a high angular precision. We further present 3D fiber orientation maps of entire coronal sections of human cerebrum and brainstem with 10 μm in-plane resolution, revealing unprecedented details of fiber configurations. We envision that further development of our method will open a promising avenue towards large-scale 3D fiber axis mapping in the human brain and other complex fibrous tissues at microscopic level.
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4
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Baroni A, Bouchama L, Dorizzi B, Gottesman Y. Angularly resolved polarization microscopy for birefringent materials with Fourier ptychography. OPTICS EXPRESS 2022; 30:38984-38994. [PMID: 36258450 DOI: 10.1364/oe.469377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/11/2022] [Indexed: 06/16/2023]
Abstract
Polarization light microscopy is a very popular approach for structural imaging in optics. So far these methods mainly probe the sample at a fixed angle of illumination. They are consequently only sensitive to the polarization properties along the microscope optical axis. This paper presents a novel method to resolve angularly the polarization properties of birefringent materials, by retrieving quantitatively the spatial variation of their index ellipsoids. Since this method is based on Fourier ptychography microscopy the latter properties are retrieved with a spatial super-resolution factor. An adequate formalism for the Fourier ptychography forward model is introduced to cope with angularly resolved polarization properties. The inverse problem is solved using an unsupervised deep neural network approach that is proven efficient thanks to its performing regularization properties together with its automatic differentiation. Simulated results are reported showing the feasibility of the methods.
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Yendiki A, Aggarwal M, Axer M, Howard AF, van Cappellen van Walsum AM, Haber SN. Post mortem mapping of connectional anatomy for the validation of diffusion MRI. Neuroimage 2022; 256:119146. [PMID: 35346838 PMCID: PMC9832921 DOI: 10.1016/j.neuroimage.2022.119146] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 03/02/2022] [Accepted: 03/23/2022] [Indexed: 01/13/2023] Open
Abstract
Diffusion MRI (dMRI) is a unique tool for the study of brain circuitry, as it allows us to image both the macroscopic trajectories and the microstructural properties of axon bundles in vivo. The Human Connectome Project ushered in an era of impressive advances in dMRI acquisition and analysis. As a result of these efforts, the quality of dMRI data that could be acquired in vivo improved substantially, and large collections of such data became widely available. Despite this progress, the main limitation of dMRI remains: it does not image axons directly, but only provides indirect measurements based on the diffusion of water molecules. Thus, it must be validated by methods that allow direct visualization of axons but that can only be performed in post mortem brain tissue. In this review, we discuss methods for validating the various features of connectional anatomy that are extracted from dMRI, both at the macro-scale (trajectories of axon bundles), and at micro-scale (axonal orientations and other microstructural properties). We present a range of validation tools, including anatomic tracer studies, Klingler's dissection, myelin stains, label-free optical imaging techniques, and others. We provide an overview of the basic principles of each technique, its limitations, and what it has taught us so far about the accuracy of different dMRI acquisition and analysis approaches.
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Affiliation(s)
- Anastasia Yendiki
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States,Corresponding author (A. Yendiki)
| | - Manisha Aggarwal
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Markus Axer
- Forschungszentrum Jülich, Institute of Neuroscience and Medicine, Jülich, Germany,Department of Physics, University of Wuppertal Germany
| | - Amy F.D. Howard
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Anne-Marie van Cappellen van Walsum
- Department of Medical Imaging, Anatomy, Radboud University Medical Center, Nijmegen, the Netherland,Cognition and Behaviour, Donders Institute for Brain, Nijmegen, the Netherland
| | - Suzanne N. Haber
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, United States,McLean Hospital, Belmont, MA, United States
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Jones R, Maffei C, Augustinack J, Fischl B, Wang H, Bilgic B, Yendiki A. High-fidelity approximation of grid- and shell-based sampling schemes from undersampled DSI using compressed sensing: Post mortem validation. Neuroimage 2021; 244:118621. [PMID: 34587516 PMCID: PMC8631240 DOI: 10.1016/j.neuroimage.2021.118621] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/02/2021] [Accepted: 09/24/2021] [Indexed: 12/31/2022] Open
Abstract
While many useful microstructural indices, as well as orientation distribution functions, can be obtained from multi-shell dMRI data, there is growing interest in exploring the richer set of microstructural features that can be extracted from the full ensemble average propagator (EAP). The EAP can be readily computed from diffusion spectrum imaging (DSI) data, at the cost of a very lengthy acquisition. Compressed sensing (CS) has been used to make DSI more practical by reducing its acquisition time. CS applied to DSI (CS-DSI) attempts to reconstruct the EAP from significantly undersampled q-space data. We present a post mortem validation study where we evaluate the ability of CS-DSI to approximate not only fully sampled DSI but also multi-shell acquisitions with high fidelity. Human brain samples are imaged with high-resolution DSI at 9.4T and with polarization-sensitive optical coherence tomography (PSOCT). The latter provides direct measurements of axonal orientations at microscopic resolutions, allowing us to evaluate the mesoscopic orientation estimates obtained from diffusion MRI, in terms of their angular error and the presence of spurious peaks. We test two fast, dictionary-based, L2-regularized algorithms for CS-DSI reconstruction. We find that, for a CS acceleration factor of R=3, i.e., an acquisition with 171 gradient directions, one of these methods is able to achieve both low angular error and low number of spurious peaks. With a scan length similar to that of high angular resolution multi-shell acquisition schemes, this CS-DSI approach is able to approximate both fully sampled DSI and multi-shell data with high accuracy. Thus it is suitable for orientation reconstruction and microstructural modeling techniques that require either grid- or shell-based acquisitions. We find that the signal-to-noise ratio (SNR) of the training data used to construct the dictionary can have an impact on the accuracy of CS-DSI, but that there is substantial robustness to loss of SNR in the test data. Finally, we show that, as the CS acceleration factor increases beyond R=3, the accuracy of these reconstruction methods degrade, either in terms of the angular error, or in terms of the number of spurious peaks. Our results provide useful benchmarks for the future development of even more efficient q-space acceleration techniques.
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Affiliation(s)
- Robert Jones
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA 02129, USA.
| | - Chiara Maffei
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA 02129, USA
| | - Jean Augustinack
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA 02129, USA
| | - Bruce Fischl
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA 02129, USA; Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Hui Wang
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA 02129, USA
| | - Berkin Bilgic
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA 02129, USA; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anastasia Yendiki
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA 02129, USA
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7
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Goodwin M, Workman J, Thambyah A, Vanholsbeeck F. Impact-induced cartilage damage assessed using polarisation-sensitive optical coherence tomography. J Mech Behav Biomed Mater 2021; 117:104326. [PMID: 33578298 DOI: 10.1016/j.jmbbm.2021.104326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/10/2020] [Accepted: 01/06/2021] [Indexed: 10/22/2022]
Abstract
Non-invasive determination of structural changes in articular cartilage immediately after impact and rehydration provides insight into the response and recovery of the soft tissue, as well as provides a potential methodology for clinicians to quantify early degenerative changes. In this study, we use polarisation-sensitive optical coherence tomography (PS-OCT) to examine subtle alterations of the optical properties in healthy and early-stage degenerate articular cartilage immediately after impact loading to identify structurally relevant metrics required for understanding the mechanical factors of osteoarthritic initiation and progression. A custom-designed impact testing rig was used to deliver 0.9 J and 1.4 J impact energies to bovine articular cartilage. A total of 52 (n=26 healthy, n=26 mildly degenerate) cartilage-on-bone samples were imaged before, immediately after, and 3 h after impact. PS-OCT images were analyzed to assess changes relating to surface irregularity, optical attenuation, and birefringence. Mildly degenerate cartilage exhibits a significant change in birefringence following 1.4 J impact energies compared to healthy samples which is believed to be attributable to degenerate cartilage being unable to fully utilise the fluid phase to distribute and dampen the energy. After rehydration, the polarisation-sensitive images appear to 'optically-recover' reducing the reliability of birefringence as an absolute metric. Surface irregularity and optical attenuation encode diagnostically relevant information and may serve as markers to predict the mechanical response of articular cartilage. PS-OCT with its ability to non-invasively image the sub-surface microstructural abnormalities of cartilage presents as an ideal modality for cartilage degeneration assessment and identification of mechanically vulnerable tissue.
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Affiliation(s)
- Matthew Goodwin
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, The University of Auckland, Auckland, 1010, New Zealand; Department of Chemical and Materials Engineering, The University of Auckland, Auckland, 1010, New Zealand.
| | - Joshua Workman
- Department of Chemical and Materials Engineering, The University of Auckland, Auckland, 1010, New Zealand
| | - Ashvin Thambyah
- Department of Chemical and Materials Engineering, The University of Auckland, Auckland, 1010, New Zealand
| | - Frédérique Vanholsbeeck
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Physics, The University of Auckland, Auckland, 1010, New Zealand
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8
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McLean JP, Fang S, Gallos G, Myers KM, Hendon CP. Three-dimensional collagen fiber mapping and tractography of human uterine tissue using OCT. BIOMEDICAL OPTICS EXPRESS 2020; 11:5518-5541. [PMID: 33149968 PMCID: PMC7587264 DOI: 10.1364/boe.397041] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/23/2020] [Accepted: 07/30/2020] [Indexed: 05/10/2023]
Abstract
Automatic quantification and visualization of 3-D collagen fiber architecture using Optical Coherence Tomography (OCT) has previously relied on polarization information and/or prior knowledge of tissue-specific fiber architecture. This study explores image processing, enhancement, segmentation, and detection algorithms to map 3-D collagen fiber architecture from OCT images alone. 3-D fiber mapping, histogram analysis, and 3-D tractography revealed fiber groupings and macro-organization previously unseen in uterine tissue samples. We applied our method on centimeter-scale mosaic OCT volumes of uterine tissue blocks from pregnant and non-pregnant specimens revealing a complex, patient-specific network of fibrous collagen and myocyte bundles.
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Affiliation(s)
- James P. McLean
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
| | - Shuyang Fang
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA
| | - George Gallos
- Department of Anesthesiology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Kristin M. Myers
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA
| | - Christine P. Hendon
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
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9
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Jones R, Grisot G, Augustinack J, Magnain C, Boas DA, Fischl B, Wang H, Yendiki A. Insight into the fundamental trade-offs of diffusion MRI from polarization-sensitive optical coherence tomography in ex vivo human brain. Neuroimage 2020; 214:116704. [PMID: 32151760 PMCID: PMC8488979 DOI: 10.1016/j.neuroimage.2020.116704] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 02/16/2020] [Accepted: 03/03/2020] [Indexed: 11/25/2022] Open
Abstract
In the first study comparing high angular resolution diffusion MRI (dMRI) in the human brain to axonal orientation measurements from polarization-sensitive optical coherence tomography (PSOCT), we compare the accuracy of orientation estimates from various dMRI sampling schemes and reconstruction methods. We find that, if the reconstruction approach is chosen carefully, single-shell dMRI data can yield the same accuracy as multi-shell data, and only moderately lower accuracy than a full Cartesian-grid sampling scheme. Our results suggest that current dMRI reconstruction approaches do not benefit substantially from ultra-high b-values or from very large numbers of diffusion-encoding directions. We also show that accuracy remains stable across dMRI voxel sizes of 1 mm or smaller but degrades at 2 mm, particularly in areas of complex white-matter architecture. We also show that, as the spatial resolution is reduced, axonal configurations in a dMRI voxel can no longer be modeled as a small set of distinct axon populations, violating an assumption that is sometimes made by dMRI reconstruction techniques. Our findings have implications for in vivo studies and illustrate the value of PSOCT as a source of ground-truth measurements of white-matter organization that does not suffer from the distortions typical of histological techniques.
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Affiliation(s)
- Robert Jones
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA, USA
| | | | - Jean Augustinack
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA, USA
| | - Caroline Magnain
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA, USA
| | - David A Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Bruce Fischl
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA, USA
| | - Hui Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA, USA
| | - Anastasia Yendiki
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital & Harvard Medical School, Charlestown, MA, USA.
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Servin‐Vences MR, Poole K, Sporbert A, Lewin GR, Margineanu A. Collagen Organization Within the Cartilage of
Trpv4
−/−
Mice Studied with Two‐Photon Microscopy and Polarized Second Harmonic Generation. Cytometry A 2019; 97:504-514. [DOI: 10.1002/cyto.a.23900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/19/2019] [Accepted: 09/09/2019] [Indexed: 02/06/2023]
Affiliation(s)
| | - Kate Poole
- Molecular Physiology of Somatic SensationMax Delbrück Centrum Berlin Germany
| | - Anje Sporbert
- Advanced Light MicroscopyMax Delbrück Centrum Berlin Germany
| | - Gary R. Lewin
- Molecular Physiology of Somatic SensationMax Delbrück Centrum Berlin Germany
| | - Anca Margineanu
- Advanced Light MicroscopyMax Delbrück Centrum Berlin Germany
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11
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Li W, Narice BF, Anumba DO, Matcher SJ. Polarization-sensitive optical coherence tomography with a conical beam scan for the investigation of birefringence and collagen alignment in the human cervix. BIOMEDICAL OPTICS EXPRESS 2019; 10:4190-4206. [PMID: 31453004 PMCID: PMC6701558 DOI: 10.1364/boe.10.004190] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/27/2019] [Accepted: 05/29/2019] [Indexed: 05/19/2023]
Abstract
By measuring the phase retardance of a cervical extracellular matrix, our in-house polarization-sensitive optical coherence tomography (PS-OCT) was shown to be capable of (1) mapping the distribution of collagen fibers in the non-gravid cervix, (2) accurately determining birefringence, and (3) measuring the distinctive depolarization of the cervical tissue. A conical beam scan strategy was also employed to explore the 3D orientation of the collagen fibers in the cervix by interrogating the samples with an incident light at 45° and successive azimuthal rotations of 0-360°. Our results confirmed previous observations by X-ray diffraction, suggesting that in the non-gravid human cervix collagen fibers adjacent to the endocervical canal and in the outermost areas tend to arrange in a longitudinal fashion whereas in the middle area they are oriented circumferentially. PS-OCT can assess the microstructure of the human cervical collagen in vitro and holds the potential to help us better understand cervical remodeling prior to birth pending the development of an in vivo probe.
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Affiliation(s)
- Wei Li
- Biophotonics Group, Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield, S3 7HQ, UK
- Co-first authors with equal contribution
| | - Brenda F. Narice
- Reproductive and Developmental Medicine, Department of Oncology and Metabolism, University of Sheffield, Sheffield, S10 2SF, UK
- Co-first authors with equal contribution
| | - Dilly O. Anumba
- Reproductive and Developmental Medicine, Department of Oncology and Metabolism, University of Sheffield, Sheffield, S10 2SF, UK
| | - Stephen J. Matcher
- Biophotonics Group, Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield, S3 7HQ, UK
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12
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McLean JP, Gan Y, Lye TH, Qu D, Lu HH, Hendon CP. High-speed collagen fiber modeling and orientation quantification for optical coherence tomography imaging. OPTICS EXPRESS 2019; 27:14457-14471. [PMID: 31163895 PMCID: PMC6825605 DOI: 10.1364/oe.27.014457] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/18/2019] [Accepted: 04/24/2019] [Indexed: 05/03/2023]
Abstract
Quantifying collagen fiber architecture has clinical and scientific relevance across a variety of tissue types and adds functionality to otherwise largely qualitative imaging modalities. Optical coherence tomography (OCT) is uniquely suited for this task due to its ability to capture the collagen microstructure over larger fields of view than traditional microscopy. Existing image processing techniques for quantifying fiber architecture, while accurate and effective, are very slow for processing large datasets and tend to lack structural specificity. We describe here a computationally efficient method for quantifying and visualizing collagen fiber organization. The algorithm is demonstrated on swine atria, bovine anterior cruciate ligament, and human cervical tissue samples. Additionally, we show an improved performance for images with crimped fiber textures and low signal to noise when compared to similar methods.
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Affiliation(s)
- James P. McLean
- Electrical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, 1300 West 120th Street, New York, NY 10025,
USA
| | - Yu Gan
- Electrical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, 1300 West 120th Street, New York, NY 10025,
USA
| | - Theresa H. Lye
- Electrical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, 1300 West 120th Street, New York, NY 10025,
USA
| | - Dovina Qu
- Biomedical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, 1300 West 120th Street, New York, NY 10025,
USA
| | - Helen H. Lu
- Biomedical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, 1300 West 120th Street, New York, NY 10025,
USA
| | - Christine P. Hendon
- Electrical Engineering, Fu Foundation School of Engineering and Applied Science, Columbia University, 1300 West 120th Street, New York, NY 10025,
USA
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13
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Ravanfar M, Yao G. Measurement of biaxial optical birefringence in articular cartilage. APPLIED OPTICS 2019; 58:2021-2027. [PMID: 30874069 DOI: 10.1364/ao.58.002021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 02/16/2019] [Indexed: 05/24/2023]
Abstract
Optical birefringence is a valuable parameter in evaluating collagen organization and assessing collagen degeneration in articular cartilage. A uniaxial birefringent model is implied when using existing methods such as polarized light microscopy in characterizing birefringence in cartilage. However, some studies suggest the existence of a sheet-like collagen organization in articular cartilage, which requires a biaxial birefringence model to describe. In this study, we applied a multi-incident birefringence measurement procedure to investigate the biaxial birefringence in articular cartilage. The results supported the existence of a small yet significant biaxial birefringence effect, which was in agreement with the expectation from a sheet-like collagen organization.
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14
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Zhou X, Ju MJ, Huang L, Tang S. Slope-based segmentation of articular cartilage using polarization-sensitive optical coherence tomography phase retardation image. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-14. [PMID: 30873765 PMCID: PMC6975236 DOI: 10.1117/1.jbo.24.3.036006] [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: 09/18/2018] [Accepted: 01/02/2019] [Indexed: 05/14/2023]
Abstract
A segmentation method based on phase retardation measurements from polarization-sensitive optical coherence tomography (PS-OCT) is developed to differentiate the structural zones of articular cartilage. The organization of collagen matrix in articular cartilage varies over the different structural zones, generating different tissue birefringence. Analyzing the slope of the accumulated phase retardation at different depths can detect the variation in tissue birefringence and be used to segment the structural zones. The method is validated on phantoms composed of layers of different materials. Articular cartilage samples from adult swine are segmented with the method. The characteristics in each segmented zone are also examined by histology and high-resolution second-harmonic generation imaging, showing distinctive properties that match with the anatomical structure of articular cartilage. The segmentation algorithm is also applied on PS-OCT images acquired at multiple illumination angles, where the angular dependence of tissue birefringence in the deep zone is detected. This method offers a noninvasive imaging approach to differentiating the structural zones of articular cartilage, as well as a quantification approach based on the phase retardation measurements of PS-OCT. This method has great potential in studying depth-related progression of cartilage degeneration.
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Affiliation(s)
- Xin Zhou
- University of British Columbia, Department of Electrical and Computer Engineering, Vancouver, British Columbia, Canada
| | - Myeong Jin Ju
- Simon Fraser University, School of Engineering Science, Burnaby, British Columbia, Canada
- Beckman Laser Institute-Korea, Dankook University, Cheonan, Chungnam, South Korea
| | - Lin Huang
- University of British Columbia, Department of Electrical and Computer Engineering, Vancouver, British Columbia, Canada
| | - Shuo Tang
- University of British Columbia, Department of Electrical and Computer Engineering, Vancouver, British Columbia, Canada
- Address all correspondence to Shuo Tang, E-mail:
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15
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Chue-Sang J, Gonzalez M, Pierre A, Laughrey M, Saytashev I, Novikova T, Ramella-Roman JC. Optical phantoms for biomedical polarimetry: a review. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-12. [PMID: 30851015 PMCID: PMC6975228 DOI: 10.1117/1.jbo.24.3.030901] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 01/29/2019] [Indexed: 05/04/2023]
Abstract
Calibration, quantification, and standardization of the polarimetric instrumentation, as well as interpretation and understanding of the obtained data, require the development and use of well-calibrated phantoms and standards. We reviewed the status of tissue phantoms for a variety of applications in polarimetry; more than 500 papers are considered. We divided the phantoms into five groups according to their origin (biological/nonbiological) and fundamental polarimetric properties of retardation, depolarization, and diattenuation. We found that, while biological media are generally depolarizing, retarding, and diattenuating, only one of all the phantoms reviewed incorporated all these properties, and few considered at least combined retardation and depolarization. Samples derived from biological tissue, such as tendon and muscle, remain extremely popular to quickly ascertain a polarimetric system, but do not provide quantifiable results aside from relative direction of their principal optical axis. Microspheres suspensions are the most utilized phantoms for depolarization, and combined with theoretical models can offer true quantification of depolarization or degree of polarization. There is a real paucity of birefringent phantoms despite the retardance being one of the most interesting parameters measurable with polarization techniques. Therefore, future work should be directed at generating truly reliable and repeatable phantoms for this metric determination. Diattenuating phantoms are rare and application-specific. Given that diattenuation is considered to be low in most biological tissues, the lack of such phantoms is seen as less problematic. The heterogeneity of the phantoms reviewed points to a critical need for standardization in this field. Ultimately, all research groups involved in polarimetric studies and instruments development would benefit from sharing a limited set of standardized polarimetric phantoms, as is done earlier in the round robin investigations in ellipsometry.
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Affiliation(s)
- Joseph Chue-Sang
- Florida International University, Department of Biomedical Engineering, Miami, Florida, United States
| | - Mariacarla Gonzalez
- Florida International University, Department of Biomedical Engineering, Miami, Florida, United States
| | - Angie Pierre
- Florida International University, Department of Biomedical Engineering, Miami, Florida, United States
| | - Megan Laughrey
- Florida International University, Department of Biomedical Engineering, Miami, Florida, United States
| | - Ilyas Saytashev
- Florida International University, Herbert Wertheim College of Medicine, Miami, Florida, United States
| | - Tatiana Novikova
- LPICM Laboratoire de Physique des Interfaces et Couches Minces, CNRS, Ecole Polytechnique, Palaiseau, France
| | - Jessica C. Ramella-Roman
- Florida International University, Department of Biomedical Engineering, Miami, Florida, United States
- Florida International University, Herbert Wertheim College of Medicine, Miami, Florida, United States
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16
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Mansfield JC, Mandalia V, Toms A, Winlove CP, Brasselet S. Collagen reorganization in cartilage under strain probed by polarization sensitive second harmonic generation microscopy. J R Soc Interface 2019; 16:20180611. [PMID: 30958161 PMCID: PMC6364654 DOI: 10.1098/rsif.2018.0611] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 12/20/2018] [Indexed: 11/12/2022] Open
Abstract
Type II collagen fibril diameters in cartilage are beneath the diffraction limit of optical microscopy, which makes the assessment of collagen organization very challenging. In this work we use polarization sensitive second harmonic generation (P-SHG) imaging to map collagen organization in articular cartilage, addressing in particular its behaviour under strain and changes which occur in osteoarthritis. P-SHG yields two parameters, molecular order and orientation, which provide measures of the degree of organization both at the molecular scale (below the diffraction limit) and above a few hundred nanometres (at the image pixel size). P-SHG clearly demonstrates the zonal collagen architecture and reveals differences in the structure of the fibrils around chondrocytes. P-SHG also reveals sub-micron scale fibril re-organization in cartilage strips exposed to tensile loading, with an increase in local organization in the superficial zone which weakly correlates with tensile modulus. Finally, P-SHG is used to investigate osteoarthritic cartilage from total knee replacement surgery, and reveals widespread heterogeneity across samples both microscale fibril orientations and their sub-micron organization. By addressing collagen fibril structure on scales intermediate between conventional light and electron microscopy, this study provides new insights into collagen micromechanics and mechanisms of degradation.
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Affiliation(s)
- Jessica C. Mansfield
- Physics, College of Engineering Mathematics and Physical Sciences, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Vipul Mandalia
- Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Barrack Road, Exeter EX2 5DW, UK
| | - Andrew Toms
- Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Barrack Road, Exeter EX2 5DW, UK
| | - C. Peter Winlove
- Physics, College of Engineering Mathematics and Physical Sciences, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
| | - Sophie Brasselet
- Institut Fresnel, CNRS, Aix Marseille Univ, Centrale Marseille, 13013 Marseille, France
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17
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Collier TA, Nash A, Birch HL, de Leeuw NH. Relative orientation of collagen molecules within a fibril: a homology model for homo sapiens type I collagen. J Biomol Struct Dyn 2018; 37:537-549. [PMID: 29380684 DOI: 10.1080/07391102.2018.1433553] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Type I collagen is an essential extracellular protein that plays an important structural role in tissues that require high tensile strength. However, owing to the molecule's size, to date no experimental structural data are available for the Homo sapiens species. Therefore, there is a real need to develop a reliable homology model and a method to study the packing of the collagen molecules within the fibril. Through the use of the homology model and implementation of a novel simulation technique, we have ascertained the orientations of the collagen molecules within a fibril, which is currently below the resolution limit of experimental techniques. The longitudinal orientation of collagen molecules within a fibril has a significant effect on the mechanical and biological properties of the fibril, owing to the different amino acid side chains available at the interface between the molecules.
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Affiliation(s)
- Thomas A Collier
- a Institute of Natural and Mathematical Sciences , Massey University , Auckland 0632 , New Zealand
| | - Anthony Nash
- b Department of Physiology, Anatomy and Genetics , University of Oxford , South Parks Road, Oxford OX1 3QX , UK
| | - Helen L Birch
- c Institute of Orthopaedics and Musculoskeletal Science, UCL, RNOH Stanmore Campus , London , UK
| | - Nora H de Leeuw
- d School of Chemistry , Cardiff University , Main Building, Park Place, Cardiff CF10 3AT , UK
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18
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Wang H, Magnain C, Wang R, Dubb J, Varjabedian A, Tirrell LS, Stevens A, Augustinack JC, Konukoglu E, Aganj I, Frosch MP, Schmahmann JD, Fischl B, Boas DA. as-PSOCT: Volumetric microscopic imaging of human brain architecture and connectivity. Neuroimage 2018; 165:56-68. [PMID: 29017866 PMCID: PMC5732037 DOI: 10.1016/j.neuroimage.2017.10.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 10/05/2017] [Accepted: 10/06/2017] [Indexed: 01/21/2023] Open
Abstract
Polarization sensitive optical coherence tomography (PSOCT) with serial sectioning has enabled the investigation of 3D structures in mouse and human brain tissue samples. By using intrinsic optical properties of back-scattering and birefringence, PSOCT reliably images cytoarchitecture, myeloarchitecture and fiber orientations. In this study, we developed a fully automatic serial sectioning polarization sensitive optical coherence tomography (as-PSOCT) system to enable volumetric reconstruction of human brain samples with unprecedented sample size and resolution. The 3.5 μm in-plane resolution and 50 μm through-plane voxel size allow inspection of cortical layers that are a single-cell in width, as well as small crossing fibers. We show the abilities of as-PSOCT in quantifying layer thicknesses of the cerebellar cortex and creating microscopic tractography of intricate fiber networks in the subcortical nuclei and internal capsule regions, all based on volumetric reconstructions. as-PSOCT provides a viable tool for studying quantitative cytoarchitecture and myeloarchitecture and mapping connectivity with microscopic resolution in the human brain.
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Affiliation(s)
- Hui Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA.
| | - Caroline Magnain
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Ruopeng Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Jay Dubb
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Ani Varjabedian
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Lee S Tirrell
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Allison Stevens
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Jean C Augustinack
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Ender Konukoglu
- Computer Vision Laboratory, ETH Zurich, 8092 Zurich, Switzerland
| | - Iman Aganj
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
| | - Matthew P Frosch
- C.S. Kubik Laboratory for Neuropathology, Pathology Service, Massachusetts General Hospital, Boston, MA 02115, USA
| | - Jeremy D Schmahmann
- Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02114, USA
| | - Bruce Fischl
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA; MIT Computer Science and AI Lab, Cambridge, MA 02139, USA
| | - David A Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
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19
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Ravanfar M, Pfeiffer FM, Bozynski CC, Wang Y, Yao G. Parametric imaging of collagen structural changes in human osteoarthritic cartilage using optical polarization tractography. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-10. [PMID: 29197177 DOI: 10.1117/1.jbo.22.12.121708] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/14/2017] [Indexed: 05/18/2023]
Abstract
Collagen degeneration is an important pathological feature of osteoarthritis. The purpose of this study is to investigate whether the polarization-sensitive optical coherence tomography (PSOCT)-based optical polarization tractography (OPT) can be useful in imaging collagen structural changes in human osteoarthritic cartilage samples. OPT eliminated the banding artifacts in conventional PSOCT by calculating the depth-resolved local birefringence and fiber orientation. A close comparison between OPT and PSOCT showed that OPT provided improved visualization and characterization of the zonal structure in human cartilage. Experimental results obtained in this study also underlined the importance of knowing the collagen fiber orientation in conventional polarized light microscopy assessment. In addition, parametric OPT imaging was achieved by quantifying the surface roughness, birefringence, and fiber dispersion in the superficial zone of the cartilage. These quantitative parametric images provided complementary information on the structural changes in cartilage, which can be useful for a comprehensive evaluation of collagen damage in osteoarthritic cartilage.
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Affiliation(s)
- Mohammadreza Ravanfar
- University of Missouri, Department of Bioengineering, Columbia, Missouri, United States
| | - Ferris M Pfeiffer
- University of Missouri, Department of Bioengineering, Columbia, Missouri, United States
- University of Missouri, Department of Orthopedic Surgery, Columbia, Missouri, United States
| | - Chantelle C Bozynski
- University of Missouri, Department of Orthopedic Surgery, Columbia, Missouri, United States
| | - Yuanbo Wang
- University of Missouri, Department of Bioengineering, Columbia, Missouri, United States
| | - Gang Yao
- University of Missouri, Department of Bioengineering, Columbia, Missouri, United States
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20
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Polarization Sensitive Optical Coherence Tomography: A Review of Technology and Applications. APPLIED SCIENCES-BASEL 2017. [DOI: 10.3390/app7050474] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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21
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de Boer JF, Hitzenberger CK, Yasuno Y. Polarization sensitive optical coherence tomography - a review [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:1838-1873. [PMID: 28663869 PMCID: PMC5480584 DOI: 10.1364/boe.8.001838] [Citation(s) in RCA: 200] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 02/16/2017] [Accepted: 02/16/2017] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT) is now a well-established modality for high-resolution cross-sectional and three-dimensional imaging of transparent and translucent samples and tissues. Conventional, intensity based OCT, however, does not provide a tissue-specific contrast, causing an ambiguity with image interpretation in several cases. Polarization sensitive (PS) OCT draws advantage from the fact that several materials and tissues can change the light's polarization state, adding an additional contrast channel and providing quantitative information. In this paper, we review basic and advanced methods of PS-OCT and demonstrate its use in selected biomedical applications.
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Affiliation(s)
- Johannes F. de Boer
- Department of Physics and Astronomy, LaserLaB Amsterdam, VU University, Amsterdam, The Netherlands
- Authors were listed in alphabetical order and contributed equally to the manuscript
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Authors were listed in alphabetical order and contributed equally to the manuscript
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tsukuba, Japan
- Authors were listed in alphabetical order and contributed equally to the manuscript
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22
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Yao X, Wang Y, Ravanfar M, Pfeiffer FM, Duan D, Yao G. Nondestructive imaging of fiber structure in articular cartilage using optical polarization tractography. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:116004. [PMID: 27819110 DOI: 10.1117/1.jbo.21.11.116004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/17/2016] [Indexed: 05/18/2023]
Abstract
Collagen fiber orientation plays an important role in determining the structure and function of the articular cartilage. However, there is currently a lack of nondestructive means to image the fiber orientation from the cartilage surface. The purpose of this study is to investigate whether the newly developed optical polarization tractography (OPT) can image fiber structure in articular cartilage. OPT was applied to obtain the depth-dependent fiber orientation in fresh articular cartilage samples obtained from porcine phalanges. For comparison, we also obtained collagen fiber orientation in the superficial zone of the cartilage using the established split-line method. The direction of each split-line was quantified using image processing. The orientation measured in OPT agreed well with those obtained from the split-line method. The correlation analysis of a total of 112 split-lines showed a greater than 0.9 coefficient of determination (R2) between the split-line results and OPT measurements obtained between 40 and 108???m in depth. In addition, the thickness of the superficial layer can also be assessed from the birefringence images obtained in OPT. These results support that OPT provides a nondestructive way to image the collagen fiber structure in articular cartilage. This technology may be valuable for both basic cartilage research and clinical orthopedic applications.
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Affiliation(s)
- Xuan Yao
- University of Missouri, Department of Bioengineering, 1406 E. Rollins Street, Columbia 65211, United States
| | - Yuanbo Wang
- University of Missouri, Department of Bioengineering, 1406 E. Rollins Street, Columbia 65211, United States
| | - Mohammadreza Ravanfar
- University of Missouri, Department of Bioengineering, 1406 E. Rollins Street, Columbia 65211, United States
| | - Ferris M Pfeiffer
- University of Missouri, Department of Bioengineering, 1406 E. Rollins Street, Columbia 65211, United StatesbUniversity of Missouri, Department of Orthopedic Surgery, 1100 Virginia Avenue, Columbia 65212, United States
| | - Dongsheng Duan
- University of Missouri, Department of Bioengineering, 1406 E. Rollins Street, Columbia 65211, United StatescUniversity of Missouri, Department of Molecular Microbiology and Immunology, One Hospital Drive, Columbia 65212, United States
| | - Gang Yao
- University of Missouri, Department of Bioengineering, 1406 E. Rollins Street, Columbia 65211, United States
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23
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Liu CJ, Black AJ, Wang H, Akkin T. Quantifying three-dimensional optic axis using polarization-sensitive optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:70501. [PMID: 27387702 DOI: 10.1117/1.jbo.21.7.070501] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 06/16/2016] [Indexed: 05/23/2023]
Abstract
The optic axis of birefringent samples indicates the direction of optical anisotropy, which should be described in three-dimensional (3-D) space. We present a method to quantify the complete 3-D optic axis orientation calculated from in-plane optic axis measurements from a polarization-sensitive optical coherence tomography system. The in-plane axis orientations with different illumination angles allow the calculation of the necessary polar angle. The method then provides the information to produce the actual birefringence. The method and results from a biological sample are presented.
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Abstract
Osteoarthritis (OA) is the most common chronic disease of our joints, manifested by a dynamically increasing degeneration of hyaline articular cartilage (AC). While currently no therapy can reverse this process, the few available treatment options are hampered by the inability of early diagnosis. Loss of cartilage surface, or extracellular matrix (ECM), integrity is considered the earliest sign of OA. Despite the increasing number of imaging modalities surprisingly few imaging biomarkers exist. In this narrative review, recent developments in optical coherence tomography are critically evaluated for their potential to assess different aspects of AC quality as biomarkers of OA. Special attention is paid to imaging surface irregularities, ECM organization and the evaluation of posttraumatic injuries by light-based modalities.
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Affiliation(s)
- Holger Jahr
- a Department of Orthopaedic Surgery , University Hospital RWTH Aachen University , Aachen , Germany
| | - Nicolai Brill
- b Fraunhofer Institute for Production Technology , Aachen , Germany , and
| | - Sven Nebelung
- a Department of Orthopaedic Surgery , University Hospital RWTH Aachen University , Aachen , Germany .,c Department of Anatomy and Cell Biology , University Hospital RWTH Aachen University , Aachen , Germany
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25
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Matcher SJ. What can biophotonics tell us about the 3D microstructure of articular cartilage? Quant Imaging Med Surg 2015; 5:143-58. [PMID: 25694964 DOI: 10.3978/j.issn.2223-4292.2014.12.03] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 12/02/2014] [Indexed: 12/30/2022]
Abstract
Connective tissues such as articular cartilage have been the subject of study using novel optical techniques almost since the invention of polarized light microscopy (PLM). Early studies of polarized light micrographs were the main evidential basis for the establishment of quantitative models of articular cartilage collagen structure by Benninghoff and others. Even now, state of the art optical techniques including quantitative polarized light microscopy (qPLM), optical coherence tomography (OCT), polarization-sensitive optical coherence tomography (PS-OCT), second harmonic generation (SHG) microscopy, Fourier-transform infrared (FTIR) microscopy, Raman and optical hyperspectral reflectance and fluorescence imaging are providing new insights into articular cartilage structure from the nanoscale through to the mesoscale. New insights are promised by emerging modalities such as optical elastography. This short review highlights some key recent results from modern optical techniques.
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Affiliation(s)
- Stephen J Matcher
- 1 Department of Materials Science and Engineering, 2 INSIGNEO Institute for in-silico medicine, University of Sheffield, North Campus, Broad Lane, Sheffield, S3 7HQ, UK
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26
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Puhakka PH, Ylärinne JH, Lammi MJ, Saarakkala S, Tiitu V, Kröger H, Virén T, Jurvelin JS, Töyräs J. Dependence of light attenuation and backscattering on collagen concentration and chondrocyte density in agarose scaffolds. Phys Med Biol 2014; 59:6537-48. [PMID: 25310088 DOI: 10.1088/0031-9155/59/21/6537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Optical coherence tomography (OCT) has been applied for high resolution imaging of articular cartilage. However, the contribution of individual structural elements of cartilage on OCT signal has not been thoroughly studied. We hypothesize that both collagen and chondrocytes, essential structural components of cartilage, act as important light scatterers and that variation in their concentrations can be detected by OCT through changes in backscattering and attenuation. To evaluate this hypothesis, we established a controlled model system using agarose scaffolds embedded with variable collagen concentrations and chondrocyte densities. Using OCT, we measured the backscattering coefficient (µb) and total attenuation coefficient (µt) in these scaffolds. Along our hypothesis, light backscattering and attenuation in agarose were dependent on collagen concentration and chondrocyte density. Significant correlations were found between µt and chondrocyte density (ρ = 0.853, p < 0.001) and between µt and collagen concentration (ρ = 0.694, p < 0.001). µb correlated significantly with chondrocyte density (ρ = 0.504, p < 0.001) but not with collagen concentration (ρ = 0.103, p = 0.422) of the scaffold. Thus, quantitation of light backscattering and, especially, attenuation could be valuable when evaluating the integrity of soft tissues, such as articular cartilage with OCT.
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Affiliation(s)
- P H Puhakka
- Department of Applied Physics, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland. Department of Clinical Neurophysiology, Kuopio University Hospital, PO Box 1777, FI-70029 Kuopio, Finland
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27
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Lu Z, Kasaragod D, Matcher SJ. Conical scan polarization-sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2014; 5:752-62. [PMID: 24688811 PMCID: PMC3959841 DOI: 10.1364/boe.5.000752] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 11/29/2013] [Accepted: 12/20/2013] [Indexed: 05/18/2023]
Abstract
We report on a new articular cartilage imaging technique with potential for clinical arthroscopic use, by supplementing the variable-incidence-angle polarization-sensitive optical coherence tomography method previously developed by us with a conical beam scan protocol. The technique is validated on bovine tendon by comparing experimental data with simulated data generated using the extended Jones matrix calculus. A unique capability of this new optical technique is that it can locate the "brushing direction" of collagen fibers in articular cartilage, which is structural information that extends beyond established methods such as split-line photography or birefringent fast-axis measurement in that it is uniquely defined over the full azimuthal-angle range of (-π, + π). The mapping of this direction over the cartilage surface may offer insights into the optimal design of tissue-engineering scaffolds for cartilage repair.
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Affiliation(s)
- Zenghai Lu
- Department of Materials Science and Engineering, the Kroto Research Institute, University of Sheffield, North Campus, Broad Lane, Sheffield, S3 7HQ, UK
- Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK
| | - Deepa Kasaragod
- Department of Materials Science and Engineering, the Kroto Research Institute, University of Sheffield, North Campus, Broad Lane, Sheffield, S3 7HQ, UK
- Currently with the Computational Optics Group, University of Tsukuba, Tsukuba, Japan
| | - Stephen J Matcher
- Department of Materials Science and Engineering, the Kroto Research Institute, University of Sheffield, North Campus, Broad Lane, Sheffield, S3 7HQ, UK
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28
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Novakofski KD, Williams RM, Fortier LA, Mohammed HO, Zipfel WR, Bonassar LJ. Identification of cartilage injury using quantitative multiphoton microscopy. Osteoarthritis Cartilage 2014; 22:355-62. [PMID: 24185113 PMCID: PMC4117377 DOI: 10.1016/j.joca.2013.10.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/27/2013] [Accepted: 10/23/2013] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Cartilage injury can lead to post-traumatic osteoarthritis (PTOA). Immediate post-trauma cellular and structural changes are not widely understood. Furthermore, current cellular-resolution cartilage imaging techniques require sectioning of cartilage and/or use of dyes not suitable for patient imaging. In this study, we used multiphoton microscopy (MPM) data with FDA-approved sodium fluorescein to identify and evaluate the pattern of chondrocyte death after traumatic injury. METHOD Mature equine distal metacarpal or metatarsal osteochondral blocks (OCBs) were injured by 30 MPa compressive loading delivered over 1 s. Injured and control sites were imaged unfixed and in situ 1 h post-injury with sodium fluorescein using rasterized z-scanning. MPM data was quantified in MATLAB, reconstructed in 3-D, and projected in 2-D to determine the damage pattern. RESULTS MPM images (600 per sample) were reconstructed and analyzed for cell death. The overall distribution of cell death appeared to cluster into circular (n = 7) or elliptical (n = 4) patterns (p = 0.006). Dead cells were prevalent near cracks in the matrix, with only 26.3% (SE = 5.0%, p < 0.0001) of chondrocytes near cracks being viable. CONCLUSION This study demonstrates the first application of MPM for evaluating cellular-scale cartilage injury in situ in live tissue, with clinical potential for detecting early cartilage damage. With this technique, we were able to uniquely observe two death patterns resulting from the same compressive loading, which may be related to local variability in matrix structure. These results also demonstrate proof-of-concept MPM diagnostic use in detecting subtle and early cartilage damage not detectable in any other way.
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Affiliation(s)
- K D Novakofski
- Department of Clinical Sciences, Cornell University, Ithaca, NY, USA
| | - R M Williams
- Department of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - L A Fortier
- Department of Clinical Sciences, Cornell University, Ithaca, NY, USA
| | - H O Mohammed
- Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY 14853, USA
| | - W R Zipfel
- Department of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - L J Bonassar
- Department of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA.
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29
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Hariri LP, Villiger M, Applegate MB, Mino-Kenudson M, Mark EJ, Bouma BE, Suter MJ. Seeing beyond the bronchoscope to increase the diagnostic yield of bronchoscopic biopsy. Am J Respir Crit Care Med 2013; 187:125-9. [PMID: 23322794 DOI: 10.1164/rccm.201208-1483oe] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Lida P Hariri
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
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Chu CR, Williams AA, Coyle CH, Bowers ME. Early diagnosis to enable early treatment of pre-osteoarthritis. Arthritis Res Ther 2012; 14:212. [PMID: 22682469 PMCID: PMC3446496 DOI: 10.1186/ar3845] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Osteoarthritis is a prevalent and disabling disease affecting an increasingly large swathe of the world population. While clinical osteoarthritis is a late-stage condition for which disease-modifying opportunities are limited, osteoarthritis typically develops over decades, offering a long window of time to potentially alter its course. The etiology of osteoarthritis is multifactorial, showing strong associations with highly modifiable risk factors of mechanical overload, obesity and joint injury. As such, characterization of pre-osteoarthritic disease states will be critical to support a paradigm shift from palliation of late disease towards prevention, through early diagnosis and early treatment of joint injury and degeneration to reduce osteoarthritis risk. Joint trauma accelerates development of osteoarthritis from a known point in time. Human joint injury cohorts therefore provide a unique opportunity for evaluation of pre-osteoarthritic conditions and potential interventions from the earliest stages of degeneration. This review focuses on recent advances in imaging and biochemical biomarkers suitable for characterization of the pre-osteoarthritic joint as well as implications for development of effective early treatment strategies.
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Affiliation(s)
- Constance R Chu
- Cartilage Restoration Center, Department of Orthopaedic Surgery, University of Pittsburgh, Biomedical Science Tower E1640, 200 Lothrop Street, PA 15261, USA.
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Paxton JZ, Wudebwe UNG, Wang A, Woods D, Grover LM. Monitoring sinew contraction during formation of tissue-engineered fibrin-based ligament constructs. Tissue Eng Part A 2012; 18:1596-607. [PMID: 22439983 DOI: 10.1089/ten.tea.2011.0535] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The ability to study the gross morphological changes occurring during tissue formation is vital to producing tissue-engineered structures of clinically relevant dimensions in vitro. Here, we have used nondestructive methods of digital imaging and optical coherence tomography to monitor the early-stage formation and subsequent maturation of fibrin-based tissue-engineered ligament constructs. In addition, the effect of supplementation with essential promoters of collagen synthesis, ascorbic acid (AA) and proline (P), has been assessed. Contraction of the cell-seeded fibrin gel occurs unevenly within the first 5 days of culture around two fixed anchor points before forming a longitudinal ligament-like construct. AA+P supplementation accelerates gel contraction in the maturation phase of development, producing ligament-like constructs with a higher collagen content and distinct morphology to that of unsupplemented constructs. These studies highlight the importance of being able to control the methods of tissue formation and maturation in vitro to enable the production of tissue-engineered constructs with suitable replacement tissue characteristics for repair of clinical soft-tissue injuries.
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Affiliation(s)
- Jennifer Z Paxton
- School of Chemical Engineering, College of Physical Sciences and Engineering, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
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Lu Z, Kasaragod DK, Matcher SJ. Optic axis determination by fibre-based polarization-sensitive swept-source optical coherence tomography. Phys Med Biol 2011; 56:1105-22. [PMID: 21263175 DOI: 10.1088/0031-9155/56/4/014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We describe a fibre-based variable-incidence angle (VIA) polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) system to determine the 3D optical axis of birefringent biological tissues. Single-plane VIA-PS-OCT is also explored which requires measurement of the absolute fast-axis orientation. A state-of-the-art PS-SS-OCT system with some improvements both in hardware and software was used to determine the apparent optical birefringence of equine tendon for a number of different illumination directions. Polar and azimuthal angles of cut equine tendon were produced by the VIA method and compared with the nominal values. A quarter waveplate (QWP) and equine tendon were used as test targets to validate the fast-axis measurements using the system. Polar and azimuthal angles of cut equine tendon broadly agreed with the expected values within about 8% of the nominal values. A theoretical and experimental analysis of the effect of the sample arm fibre on determination of optical axis orientation using a proposed definition based on the orientation of the eigenpolarization ellipse experimentally confirms that this algorithm only works correctly for special settings of the sample arm fibre. A proposed algorithm based on the angle between Stokes vectors on the Poincaré sphere is confirmed to work for all settings of the sample arm fibre. A calibration procedure is proposed to remove the sign ambiguity of the measured orientation and was confirmed experimentally by using the QWP.
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Affiliation(s)
- Zenghai Lu
- Department of Materials Science and Engineering, The Kroto Research Institute, University of Sheffield, Sheffield, UK.
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Huang YP, Saarakkala S, Toyras J, Wang LK, Jurvelin JS, Zheng YP. Effects of optical beam angle on quantitative optical coherence tomography (OCT) in normal and surface degenerated bovine articular cartilage. Phys Med Biol 2010; 56:491-509. [PMID: 21191151 DOI: 10.1088/0031-9155/56/2/013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Quantitative measurement of articular cartilage using optical coherence tomography (OCT) is a potential approach for diagnosing the early degeneration of cartilage and assessing the quality of its repair. However, a non-perpendicular angle of the incident optical beam with respect to the tissue surface may cause uncertainty to the quantitative analysis, and therefore, significantly affect the reliability of measurement. This non-perpendicularity was systematically investigated in the current study using bovine articular cartilage with and without mechanical degradation. Ten fresh osteochondral disks were quantitatively measured before and after artificially induced surface degradation by mechanical grinding. The following quantitative OCT parameters were determined with a precise control of the surface inclination up to an angle of 10° using a step of 2°: optical reflection coefficient (ORC), variation of surface reflection (VSR) along the surface profile, optical roughness index (ORI) and optical backscattering (OBS). It was found that non-perpendicularity caused systematic changes to all of the parameters. ORC was the most sensitive and OBS the most insensitive to the inclination angle. At the optimal perpendicular angle, all parameters could detect significant changes after surface degradation (p < 0.01), except OBS (p > 0.05). Nonsignificant change of OBS after surface degradation was expected since OBS reflected properties of the internal cartilage tissue and was not affected by the superficial mechanical degradation. As a conclusion, quantitative OCT parameters are diagnostically potential for characterizing the cartilage degeneration. However, efforts through a better controlled operation or corrections based on computational compensation mechanism should be made to minimize the effects of non-perpendicularity of the incident optical beam when clinical use of quantitative OCT is considered for assessing the articular cartilage.
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Affiliation(s)
- Yan-Ping Huang
- Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hong Kong, People's Republic of China.
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Kan WC, Lee WS, Cheung WH, Wallace VP, Pickwell-MacPherson E. Terahertz pulsed imaging of knee cartilage. BIOMEDICAL OPTICS EXPRESS 2010; 1:967-974. [PMID: 21258522 PMCID: PMC3018044 DOI: 10.1364/boe.1.000967] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 09/16/2010] [Accepted: 09/17/2010] [Indexed: 05/05/2023]
Abstract
Osteoarthritis (OA) is a common form of arthritis caused by cartilage degeneration. In this paper, we investigate the potential use of terahertz (THz) pulsed imaging to quantitatively measure the early symptoms of OA in an animal model. THz images of excised rabbit femoral condyles were taken. We observe THz waves reflected off different layers within samples and demonstrate that the optical delay between reflections can give a quantitative measure of the thicknesses of particular tissues within cartilage.
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Affiliation(s)
- Wai-Chi Kan
- Department of Electronic Engineering, Chinese University of Hong Kong, Hong Kong
| | - Win-Sze Lee
- Department of Orthopaedics & Traumatology, Chinese University of Hong Kong, Hong Kong
| | - Wing-Hoi Cheung
- Department of Orthopaedics & Traumatology, Chinese University of Hong Kong, Hong Kong
| | - Vincent P. Wallace
- School of Physics, University of Western Australia, Crawley,6009, Australia
| | - Emma Pickwell-MacPherson
- Electronic and Computer Engineering Department, Hong Kong University of Science and Technology, Hong Kong
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Fanjul-Vélez F, Pircher M, Baumann B, Götzinger E, Hitzenberger CK, Arce-Diego JL. Polarimetric analysis of the human cornea measured by polarization-sensitive optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:056004. [PMID: 21054098 DOI: 10.1117/1.3486540] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Corneal polarimetry measurement has been the object of several papers. The results of techniques like polarization-sensitive optical coherence tomography (PS-OCT), scanning laser polarimetry, or polarization microscopy are contradictory. Some studies propose a biaxial-like birefringence pattern, while others postulate that birefringence grows at corneal periphery. Several theoretical approaches were proposed for the interpretation of these measurements, but they usually lack accuracy and an adequate consideration of the nonnormal incidence on the tissue. We analyze corneal polarization effects measured by PS-OCT. In vivo and in vitro PS-OCT images of the human cornea are acquired. PS-OCT measurements are apparently not in agreement with the biaxial-like birefringence pattern. We present a polarimetric model of the human cornea based on the extended Jones matrix formalism applied to multilayered systems. We also apply the Poincaré equivalence theorem to extract optic axis orientation and birefringence. The results show that for a fibrils orientation pattern composed by alternating circular and radial fibrils, the birefringence is biaxial-like at the corneal center, and there is an almost circularly symmetric high-birefringence area at corneal periphery. The model could be useful for diagnosis of corneal diseases or corneal compensation in retinal polarimetric imaging.
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Affiliation(s)
- Félix Fanjul-Vélez
- University of Cantabria, Electronics Technology, Systems and Automation Engineering Department, Applied Optical Techniques Group, Avenida de los Castros S/N, Santander, Cantabria 39005 Spain.
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Wallenburg MA, Wood MFG, Ghosh N, Vitkin IA. Polarimetry-based method to extract geometry-independent metrics of tissue anisotropy. OPTICS LETTERS 2010; 35:2570-2. [PMID: 20680061 DOI: 10.1364/ol.35.002570] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Recently, we have used polarimetry as a method for assessing the linear retardance of infarcted myocardium. While linear retardance reflects tissue anisotropy, experimental geometry has a confounding effect due to dependence of the linear retardance on the orientation of the sample with respect to the probing beam. Here, polarimetry imaging of an 8mm diameter birefringent polystyrene sphere of known anisotropy axis was used to test a dual-projection method by which the anisotropy axis and its true magnitude can be reconstructed, thus eliminating the confounding effect of anisotropy axis orientation. Feasibility is demonstrated in ex-vivo tissue imaging.
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Affiliation(s)
- Marika A Wallenburg
- Ontario Cancer Institute, University Health Network, and Department of Medical Biophysics,University of Toronto, Toronto, Ontario, Canada M5G 2M9
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Thompson MS, Epari DR, Bieler F, Duda GN. In vitro models for bone mechanobiology: Applications in bone regeneration and tissue engineering. Proc Inst Mech Eng H 2010; 224:1533-41. [DOI: 10.1243/09544119jeim807] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Healthy bone healing is a remarkable, mechanically sensitive, scar-free process that leads rapidly to repair tissue of high mechanical quality and functionality, and knowledge of this process is essential for driving advances in bone tissue engineering and regeneration. Gaining this knowledge requires the use of models to probe and understand the detailed mechanisms of healing, and the tight coupling of biology and mechanics make it essential that both of these aspects are controlled and analysed together, using a mechanobiological approach. This article reviews the literature on in vitro models used for this purpose, beginning with two-dimensional (2D) cell culture models used for applying controlled mechanical stimuli to relevant cells, and detailing the analysis techniques required for understanding both substrate strain and fluid flow stimuli in sufficient detail to relate them to biological response. The additional complexity of three-dimensional (3D) models, enabling more faithful representation of the healing situation, can require correspondingly more sophisticated tools for mechanical and biological analysis, but has recently uncovered exciting evidence for the mechanical sensitivity of angiogenesis, essential for successful healing. Studies using explanted tissue continue to be vital in informing these approaches, providing additional evidence for the relevance of effects in biological and mechanical environments close to those in the living organism. Mechanobiology is essential for the proper analysis of models for bone regeneration, and has an exciting integrative role to play not only in advancing knowledge in this area, but also in ensuring successful translation of new tissue engineering and regenerative therapies to the clinic.
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Affiliation(s)
- M S Thompson
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, UK
- Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - D R Epari
- Institute for Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - F Bieler
- Julius Wolff Institut and Center for Musculoskeletal Surgery, Berlin/Brandenburg Center for Regenerative Therapies, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - G N Duda
- Julius Wolff Institut and Center for Musculoskeletal Surgery, Berlin/Brandenburg Center for Regenerative Therapies, Charité – Universitätsmedizin Berlin, Berlin, Germany
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Chu CR, Williams A, Tolliver D, Kwoh CK, Bruno S, Irrgang JJ. Clinical optical coherence tomography of early articular cartilage degeneration in patients with degenerative meniscal tears. ACTA ACUST UNITED AC 2010; 62:1412-20. [PMID: 20213801 DOI: 10.1002/art.27378] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Quantitative and nondestructive methods for clinical diagnosis and staging of articular cartilage degeneration are important to the evaluation of potential disease-modifying treatments in osteoarthritis (OA). Optical coherence tomography (OCT) is a novel imaging technology that can generate microscopic-resolution cross-sectional images of articular cartilage in near real-time. This study tested the hypotheses that OCT can be used clinically to identify early cartilage degeneration and that OCT findings correlate with magnetic resonance imaging (MRI) T2 values and arthroscopy results. METHODS Patients undergoing arthroscopy for degenerative meniscal tears were recruited under Institutional Review Board-approved protocols. Thirty consecutive subjects completing preoperative 3.0T MRI, arthroscopy, and intraoperative OCT comprised the study group. Qualitative and quantitative OCT results and MRI T2 values were compared with modified Outerbridge cartilage degeneration scores (0-4 scale) assigned at arthroscopy. RESULTS Arthroscopic grades showed cartilage abnormality in 23 of the 30 patients. OCT grades were abnormal in 28 of the 30 patients. Both qualitative and quantitative OCT strongly correlated with the arthroscopy results (P = 0.004 and P = 0.0002, respectively, by Kruskal-Wallis test). Neither the superficial nor the deep cartilage T2 values correlated with the arthroscopy results. The quantitative OCT results correlated with the T2 values in the superficial cartilage (Pearson's r = 0.39, P = 0.03). CONCLUSION These data show that OCT can be used clinically to provide qualitative and quantitative assessments of early articular cartilage degeneration that strongly correlate with arthroscopy results. The correlation between the quantitative OCT values and T2 values for the superficial cartilage further supports the utility of OCT as a clinical research tool, providing quantifiable microscopic resolution data on the articular cartilage structure. New technologies for nondestructive quantitative assessment of human articular cartilage degeneration may facilitate the development of strategies to delay or prevent the onset of OA.
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Affiliation(s)
- Constance R Chu
- Cartilage Restoration Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
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Fanjul-Vélez F, Arce-Diego JL. Polarimetry of birefringent biological tissues with arbitrary fibril orientation and variable incidence angle. OPTICS LETTERS 2010; 35:1163-5. [PMID: 20410953 DOI: 10.1364/ol.35.001163] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Polarimetric optical techniques such as polarization microscopy or polarization-sensitive optical coherence tomography normally assume that light is perpendicular to the sample surface and that fibrils of a birefringent biological tissue are arranged in a plane parallel to this surface. The approaches that describe quantitatively polarimetric data from tissues with nonparallel fibril orientation and/or off-axis incidence usually lack a rigorous theoretical analysis. We present a polarimetric model with arbitrary fibril orientation and/or variable incidence angle by means of the extended Jones matrix theory, the polar decomposition, and Poincaré equivalence theorem. The model, suitable for diagnosis or tissue structure analysis, is applied to articular cartilage.
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Affiliation(s)
- Félix Fanjul-Vélez
- Applied Optical Techniques Group, Electronics Technology, Systems and Automation Engineering Department,University of Cantabria, Avenida de los Castros S/N, 39005 Santander, Cantabria, Spain.
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Saarakkala S, Wang SZ, Huang YP, Zheng YP. Quantification of the optical surface reflection and surface roughness of articular cartilage using optical coherence tomography. Phys Med Biol 2009; 54:6837-52. [DOI: 10.1088/0031-9155/54/22/006] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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