51
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Efficient Detection of Ventricular Late Potentials on ECG Signals Based on Wavelet Denoising and SVM Classification. INFORMATION 2019. [DOI: 10.3390/info10110328] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The analysis of cardiac signals is still regarded as attractive by both the academic community and industry because it helps physicians in detecting abnormalities and improving the diagnosis and therapy of diseases. Electrocardiographic signal processing for detecting irregularities related to the occurrence of low-amplitude waveforms inside the cardiac signal has a considerable workload as cardiac signals are heavily contaminated by noise and other artifacts. This paper presents an effective approach for the detection of ventricular late potential occurrences which are considered as markers of sudden cardiac death risk. Three stages characterize the implemented method which performs a beat-to-beat processing of high-resolution electrocardiograms (HR-ECG). Fifteen lead HR-ECG signals are filtered and denoised for the improvement of signal-to-noise ratio. Five features were then extracted and used as inputs of a classifier based on a machine learning approach. For the performance evaluation of the proposed method, a HR-ECG database consisting of real ventricular late potential (VLP)-negative and semi-simulated VLP-positive patterns was used. Experimental results show that the implemented system reaches satisfactory performance in terms of sensitivity, specificity accuracy, and positive predictivity; in fact, the respective values equal to 98.33%, 98.36%, 98.35%, and 98.52% were achieved.
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52
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Ultrahigh Resolution Polarization Sensitive Optical Coherence Tomography of the Human Cornea with Conical Scanning Pattern and Variable Dispersion Compensation. APPLIED SCIENCES-BASEL 2019; 9:4245. [PMID: 31915537 PMCID: PMC6949131 DOI: 10.3390/app9204245] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Noninvasive corneal imaging is essential for the diagnosis and treatment control of various diseases affecting the anterior segment of the eye. This study presents an ultrahigh resolution polarization sensitive optical coherence tomography instrument operating in the 840 nm wavelength band that incorporates a conical scanning design for large field of view imaging of the cornea. As the conical scanning introduces a dispersion mismatch depending on the scanning angle, this study implemented variable, location dependent, numerical dispersion compensation in order to achieve high axial resolution throughout the imaged volume. The corneal images were recorded in vivo in healthy volunteers showing various details of corneal structures.
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53
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Xiong Q, Wang N, Liu X, Chen S, Braganza CS, Bouma BE, Liu L, Villiger M. Constrained polarization evolution simplifies depth-resolved retardation measurements with polarization-sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2019; 10:5207-5222. [PMID: 31646042 PMCID: PMC6788597 DOI: 10.1364/boe.10.005207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/28/2019] [Accepted: 08/31/2019] [Indexed: 05/24/2023]
Abstract
We observed that the polarization state of light after round-trip propagation through a birefringent medium frequently aligns with the employed input polarization state 'mirrored' by the horizontal plane of the Poincaré sphere. We explored the predisposition for this mirror state and evidence that it constrains the evolution of polarization states as a function of the round-trip depth into weakly scattering birefringent samples, as measured with polarization-sensitive optical coherence tomography (PS-OCT). Combined with spectral variations in the polarization state transmitted through system components, we demonstrate how this constraint enables measurement of depth-resolved birefringence using only a single input polarization state, which offers a critical simplification compared to conventional PS-OCT employing two input states.
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Affiliation(s)
- Qiaozhou Xiong
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- These authors contributed equally
| | - Nanshuo Wang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- These authors contributed equally
| | - Xinyu Liu
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- Singapore Eye Research Institute, Singapore, 169856, Singapore
- These authors contributed equally
| | - Si Chen
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Cilwyn S Braganza
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Brett E Bouma
- Harvard Medical School and Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts 02114, USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Linbo Liu
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, 637459, Singapore
- These authors contributed equally
- Corresponding author:
| | - Martin Villiger
- Harvard Medical School and Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts 02114, USA
- These authors contributed equally
- Corresponding author:
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54
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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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55
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Byers R, Matcher S. Attenuation of stripe artifacts in optical coherence tomography images through wavelet-FFT filtering. BIOMEDICAL OPTICS EXPRESS 2019; 10:4179-4189. [PMID: 31453003 PMCID: PMC6701519 DOI: 10.1364/boe.10.004179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/16/2019] [Accepted: 05/29/2019] [Indexed: 05/04/2023]
Abstract
The use of polarization-maintaining (PM) fibers for polarization-sensitive optical coherence tomography (PS-OCT) can result in numerous image artifacts which degrade the reliability of birefringence measurements. Similar artifacts can also arise in conventional OCT, due to stray reflections from optical surfaces, a problem which is increasing in tandem with the steady rise in source coherence lengths. Here, a recently presented wavelet-FFT filter[Opt. Express17(10), 8567 (2009).] is combined with surface flattening displacement fields in order to suppress ghost artifacts following either a duplicate or inverse profile to that of the sample surface. In addition, horizontal coherence stripes originating from Fresnel reflections of optical components are suppressed in order to facilitate accurate surface detection. The result is an improved visualization of the phase-retardance profile within tissue, which may improve the reliability of curve-fitting methods for localized birefringence estimation. While the results are presented with a focus towards PS-OCT, the filtering method can also be applied to the removal of stray reflection artifacts in conventional OCT images.
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Affiliation(s)
- Robert Byers
- Dept. of Infection & Immunity & Cardiovascular Disease, Univ. of Sheffield, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Stephen Matcher
- Dept. of Electronic and Electrical Engineering, Univ. of Sheffield, Broad Lane, Sheffield, S3 7HQ, UK
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56
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Yashin KS, Kiseleva EB, Gubarkova EV, Moiseev AA, Kuznetsov SS, Shilyagin PA, Gelikonov GV, Medyanik IA, Kravets LY, Potapov AA, Zagaynova EV, Gladkova ND. Cross-Polarization Optical Coherence Tomography for Brain Tumor Imaging. Front Oncol 2019; 9:201. [PMID: 31001471 PMCID: PMC6455095 DOI: 10.3389/fonc.2019.00201] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/11/2019] [Indexed: 12/23/2022] Open
Abstract
This paper considers valuable visual assessment criteria for distinguishing between tumorous and non-tumorous tissues, intraoperatively, using cross-polarization OCT (CP OCT)—OCT with a functional extension, that enables detection of the polarization properties of the tissues in addition to their conventional light scattering. Materials and Methods: The study was performed on 176 ex vivo human specimens obtained from 30 glioma patients. To measure the degree to which the typical parameters of CP OCT images can be matched to the actual histology, 100 images of tumors and white matter were selected for visual analysis to be undertaken by three “single-blinded” investigators. An evaluation of the inter-rater reliability between the investigators was performed. Application of the identified visual CP OCT criteria for intraoperative use was performed during brain tumor resection in 17 patients. Results: The CP OCT image parameters that can typically be used for visual assessment were separated: (1) signal intensity; (2) homogeneity of intensity; (3) attenuation rate; (4) uniformity of attenuation. The degree of match between the CP OCT images and the histology of the specimens was significant for the parameters “signal intensity” in both polarizations, and “homogeneity of intensity” as well as the “uniformity of attenuation” in co-polarization. A test based on the identified criteria showed a diagnostic accuracy of 87–88%. Intraoperative in vivo CP OCT images of white matter and tumors have similar signals to ex vivo ones, whereas the cortex in vivo is characterized by indicative vertical striations arising from the “shadows” of the blood vessels; these are not seen in ex vivo images or in the case of tumor invasion. Conclusion: Visual assessment of CP OCT images enables tumorous and non-tumorous tissues to be distinguished. The most powerful aspect of CP OCT images that can be used as a criterion for differentiation between tumorous tissue and white matter is the signal intensity. In distinguishing white matter from tumors the diagnostic accuracy using the identified visual CP OCT criteria was 87–88%. As the CP OCT data is easily associated with intraoperative neurophysiological and neuronavigation findings this can provide valuable complementary information for the neurosurgeon tumor resection.
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Affiliation(s)
- Konstantin S Yashin
- Microneurosurgery Group, University Clinic, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Elena B Kiseleva
- Laboratory of Optical Coherence Tomography, Research Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Ekaterina V Gubarkova
- Laboratory of Optical Coherence Tomography, Research Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Alexander A Moiseev
- Laboratory of High-Sensitivity Optical Measurements, Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Sergey S Kuznetsov
- Department of Anatomical Pathology, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Pavel A Shilyagin
- Laboratory of High-Sensitivity Optical Measurements, Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Grigory V Gelikonov
- Laboratory of High-Sensitivity Optical Measurements, Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Igor A Medyanik
- Microneurosurgery Group, University Clinic, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Leonid Ya Kravets
- Microneurosurgery Group, University Clinic, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Alexander A Potapov
- Federal State Autonomous Institution "N.N. Burdenko National Scientific and Practical Center for Neurosurgery" of the Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Elena V Zagaynova
- Research Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Natalia D Gladkova
- Laboratory of Optical Coherence Tomography, Research Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
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Walther J, Li Q, Villiger M, Farah CS, Koch E, Karnowski K, Sampson DD. Depth-resolved birefringence imaging of collagen fiber organization in the human oral mucosa in vivo. BIOMEDICAL OPTICS EXPRESS 2019; 10:1942-1956. [PMID: 31086712 PMCID: PMC6484997 DOI: 10.1364/boe.10.001942] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/02/2018] [Accepted: 01/09/2019] [Indexed: 05/18/2023]
Abstract
Stromal collagen organization has been identified as a potential prognostic indicator in a variety of cancers and other diseases accompanied by fibrosis. Changes in the connective tissue are increasingly considered for grading dysplasia and progress of oral squamous cell carcinoma, investigated mainly ex vivo by histopathology. In this study, polarization-sensitive optical coherence tomography (PS-OCT) with local phase retardation imaging is used for the first time to visualize depth-resolved (i.e., local) birefringence of healthy human oral mucosa in vivo. Depth-resolved birefringence is shown to reveal the expected local collagen organization. To demonstrate proof-of-principle, 3D image stacks were acquired at labial and lingual locations of the oral mucosa, chosen as those most commonly affected by cancerous alterations. To enable an intuitive evaluation of the birefringence images suitable for clinical application, color depth-encoded en-face projections were generated. Compared to en-face views of intensity or conventional cumulative phase retardation, we show that this novel approach offers improved visualization of the mucosal connective tissue layer in general, and reveals the collagen fiber architecture in particular. This study provides the basis for future prospective pathological and comparative in vivo studies non-invasively assessing stromal changes in conspicuous and cancerous oral lesions at different stages.
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Affiliation(s)
- Julia Walther
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Department of Medical Physics and Biomedical Engineering, 01307 Dresden, Germany
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Anesthesiology and Intensive Care Medicine, Clinical Sensoring and Monitoring, 01307 Dresden, Germany
| | - Qingyun Li
- Optical + Biomedical Engineering Laboratory, Department of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia
| | - Martin Villiger
- Harvard Medical School and Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, MA, USA
| | - Camile S. Farah
- UWA Dental School, The University of Western Australia, Perth, WA 6009, Australia
- Australian Centre for Oral Oncology Research and Education, Perth, WA 6009, Australia
| | - Edmund Koch
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Anesthesiology and Intensive Care Medicine, Clinical Sensoring and Monitoring, 01307 Dresden, Germany
| | - Karol Karnowski
- Optical + Biomedical Engineering Laboratory, Department of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia
| | - David D. Sampson
- Optical + Biomedical Engineering Laboratory, Department of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia
- University of Surrey, Guilford, Surrey GU2 7XH, United Kingdom
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Abstract
Artificial intelligence is changing the healthcare industry from many perspectives: diagnosis, treatment, and follow-up. A wide range of techniques has been proposed in the literature. In this special issue, 13 selected and peer-reviewed original research articles contribute to the application of artificial intelligence (AI) approaches in various real-world problems. Papers refer to the following main areas of interest: feature selection, high dimensionality, and statistical approaches; heart and cardiovascular diseases; expert systems and e-health platforms.
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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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Quantitative nontumorous and tumorous human brain tissue assessment using microstructural co- and cross-polarized optical coherence tomography. Sci Rep 2019; 9:2024. [PMID: 30765763 PMCID: PMC6375924 DOI: 10.1038/s41598-019-38493-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 12/31/2018] [Indexed: 01/09/2023] Open
Abstract
Optical coherence tomography (OCT) is a promising method for detecting cancer margins during tumor resection. This study focused on differentiating tumorous from nontumorous tissues in human brain tissues using cross-polarization OCT (CP OCT). The study was performed on fresh ex vivo human brain tissues from 30 patients with high- and low-grade gliomas. Different tissue types that neurosurgeons should clearly distinguish during surgery, such as the cortex, white matter, necrosis and tumorous tissue, were separately analyzed. Based on volumetric CP OCT data, tumorous and normal brain tissue were differentiated using two optical coefficients — attenuation and forward cross-scattering. Compared with white matter, tumorous tissue without necrotic areas had significantly lower optical attenuation and forward cross-scattering values. The presence of particular morphological patterns, such as necrosis and injured myelinated fibers, can lead to dramatic changes in coefficient values and create some difficulties in differentiating between tissues. Color-coded CP OCT maps based on optical coefficients provided a visual assessment of the tissue. This study demonstrated the high translational potential of CP OCT in differentiating tumorous tissue from white matter. The clinical use of CP OCT during surgery in patients with gliomas could increase the extent of tumor resection and improve overall and progression-free survival.
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Real E, Icardo JM, Fernández-Barreras G, Revuelta JM, Calvo Díez M, Pontón A, Gutiérrez JF, López Higuera JM, Conde OM. Identification of Human Pathological Mitral Chordae Tendineae Using Polarization-sensitive Optical Coherence Tomography. SENSORS 2019; 19:s19030543. [PMID: 30696054 PMCID: PMC6386950 DOI: 10.3390/s19030543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/24/2019] [Accepted: 01/26/2019] [Indexed: 12/14/2022]
Abstract
Defects of the mitral valve complex imply heart malfunction. The chordae tendineae (CTs) are tendinous strands connecting the mitral and tricuspid valve leaflets to the papillary muscles. These CTs are composed of organized, wavy collagen bundles, making them a strongly birefringent material. Disorder of the collagen structure due to different diseases (rheumatic, degenerative) implies the loss or reduction of tissue birefringence able to be characterized with Polarization Sensitive Optical Coherence Tomography (PS-OCT). PS-OCT is used to discriminate healthy from diseased chords, as the latter must be excised and replaced in clinical conventional interventions. PS-OCT allows to quantify birefringence reduction in human CTs affected by degenerative and rheumatic pathologies. This tissue optical property is proposed as a diagnostic marker for the identification of degradation of tendinous chords to guide intraoperative mitral valve surgery.
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Affiliation(s)
- Eusebio Real
- Photonics Engineering Group, Department TEISA, University of Cantabria, 39005 Santander, Spain.
- Instituto de Investigación Marqués de Valdecilla (IDIVAL), 39011 Santander, Spain.
| | - José Manuel Icardo
- Department of Anatomy and Cell Biology, University of Cantabria, 39011 Santander, Spain.
| | | | | | - Marta Calvo Díez
- Cardiovascular Surgery Service, Marqués de Valdecilla University Hospital, 39011 Santander, Spain.
| | - Alejandro Pontón
- Cardiovascular Surgery Service, Marqués de Valdecilla University Hospital, 39011 Santander, Spain.
| | - José Francisco Gutiérrez
- Cardiovascular Surgery Service, Marqués de Valdecilla University Hospital, 39011 Santander, Spain.
| | - José Miguel López Higuera
- Photonics Engineering Group, Department TEISA, University of Cantabria, 39005 Santander, Spain.
- Instituto de Investigación Marqués de Valdecilla (IDIVAL), 39011 Santander, Spain.
- Centro de Investigación Biomédica en Red - Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain.
| | - Olga María Conde
- Photonics Engineering Group, Department TEISA, University of Cantabria, 39005 Santander, Spain.
- Instituto de Investigación Marqués de Valdecilla (IDIVAL), 39011 Santander, Spain.
- Centro de Investigación Biomédica en Red - Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), 28029 Madrid, Spain.
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Li Q, Karnowski K, Noble PB, Cairncross A, James A, Villiger M, Sampson DD. Robust reconstruction of local optic axis orientation with fiber-based polarization-sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2018; 9:5437-5455. [PMID: 30460138 PMCID: PMC6238922 DOI: 10.1364/boe.9.005437] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/10/2018] [Accepted: 09/12/2018] [Indexed: 05/19/2023]
Abstract
It is challenging to recover local optic axis orientation from samples probed with fiber-based polarization-sensitive optical coherence tomography (PS-OCT). In addition to the effect of preceding tissue layers, the transmission through fiber and system elements, and imperfect system alignment, need to be compensated. Here, we present a method to retrieve the required correction factors from measurements with depth-multiplexed PS-OCT, which accurately measures the full Jones matrix. The correction considers both retardation and diattenuation and is applied in the wavenumber domain, preserving the axial resolution of the system. The robustness of the method is validated by measuring a birefringence phantom with a misaligned system. Imaging ex-vivo lamb trachea and human bronchus demonstrates the utility of reconstructing the local optic axis orientation to assess smooth muscle, which is expected to be useful in the assessment of airway smooth muscle thickness in asthma, amongst other fiber-based applications.
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Affiliation(s)
- Qingyun Li
- Optical + Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA 6009,
Australia
| | - Karol Karnowski
- Optical + Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA 6009,
Australia
| | - Peter B. Noble
- School of Human Sciences, The University of Western Australia, Perth, WA 6009,
Australia
| | - Alvenia Cairncross
- School of Human Sciences, The University of Western Australia, Perth, WA 6009,
Australia
| | - Alan James
- Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital, Perth,
Australia
| | - Martin Villiger
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, Boston, MA,
USA
| | - David D. Sampson
- Optical + Biomedical Engineering Laboratory, Department of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA 6009,
Australia
- University of Surrey, Guildford, GU2 7XH, Surrey,
United Kingdom
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63
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Leitgeb RA, Baumann B. Multimodal Optical Medical Imaging Concepts Based on Optical Coherence Tomography. FRONTIERS IN PHYSICS 2018; 6. [PMID: 0 DOI: 10.3389/fphy.2018.00114] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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64
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Baumann B, Augustin M, Lichtenegger A, Harper D, Muck M, Eugui P, Wartak A, Pircher M, Hitzenberger C. Polarization-sensitive optical coherence tomography imaging of the anterior mouse eye. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-12. [PMID: 30168301 DOI: 10.1117/1.jbo.23.8.086005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 08/14/2018] [Indexed: 05/20/2023]
Abstract
Polarization-sensitive optical coherence tomography (PS-OCT) enables noninvasive, high-resolution imaging of tissue polarization properties. In the anterior segments of human eyes, PS-OCT allows the visualization of birefringent and depolarizing structures. We present the use of PS-OCT for imaging the murine anterior eye. Using a spectral domain PS-OCT setup operating in the 840-nm regime, we performed in vivo volumetric imaging in anesthetized C57BL/6 mice. The polarization properties of murine anterior eye structures largely replicated those known from human PS-OCT imagery, suggesting that the mouse eye may also serve as a model system under polarization contrast. However, dissimilarities were found in the depolarizing structure of the iris which, as we confirmed in postmortem histological sections, were caused by anatomical differences between both species. In addition to the imaging of tissues in the anterior chamber and the iridocorneal angle, we demonstrate longitudinal PS-OCT imaging of the murine anterior segment during mydriasis as well as birefringence imaging of corneal pathology in an aged mouse.
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Affiliation(s)
| | | | | | | | - Martina Muck
- Medizinische Univ. Wien, Austria
- Allgemeines Krankenhaus der Stadt Wien, Austria
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Harper DJ, Augustin M, Lichtenegger A, Eugui P, Reyes C, Glösmann M, Hitzenberger CK, Baumann B. White light polarization sensitive optical coherence tomography for sub-micron axial resolution and spectroscopic contrast in the murine retina. BIOMEDICAL OPTICS EXPRESS 2018; 9:2115-2129. [PMID: 29760974 PMCID: PMC5946775 DOI: 10.1364/boe.9.002115] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 03/29/2018] [Accepted: 03/30/2018] [Indexed: 05/03/2023]
Abstract
A white light polarization sensitive optical coherence tomography system has been developed, using a supercontinuum laser as the light source. By detecting backscattered light from 400 - 700 nm, an axial resolution of 1.0 µm in air was achieved. The system consists of a free-space interferometer and two homemade spectrometers that detect orthogonal polarization states. Following system specifications, images of a healthy murine retina as acquired by this non-contact system are presented, showing high resolution reflectivity images as well as spectroscopic and polarization sensitive contrast. Additional images of the very-low-density-lipoprotein-receptor (VLDLR) knockout mouse model were acquired. The high resolution allows the detection of small lesions in the retina.
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Affiliation(s)
- Danielle J. Harper
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Marco Augustin
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Antonia Lichtenegger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Pablo Eugui
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Carlos Reyes
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Martin Glösmann
- University of Veterinary Medicine Vienna, Core Facility for Research and Technology, Veterinaerplatz 1, 1210 Vienna,
Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20/4L, 1090 Vienna,
Austria
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66
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Wang Y, Ravanfar M, Zhang K, Duan D, Yao G. Automatic quantification of microscopic heart damage in a mouse model of Duchenne muscular dystrophy using optical polarization tractography. JOURNAL OF BIOPHOTONICS 2018; 11:e201700284. [PMID: 29314725 DOI: 10.1002/jbio.201700284] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/06/2017] [Accepted: 01/03/2018] [Indexed: 06/07/2023]
Abstract
Quantification of microscopic myocardium damage in a diseased heart is important in studying disease progression and evaluating treatment outcome. However, it is challenging to use traditional histology and existing medical imaging modalities to quantify all microscopic damages in a small animal heart. Here, a method was developed for fast visualization and quantification of focal tissue damage in the mouse heart based on the fiber alignment index of the local myofiber organization obtained in optical polarization tractography (OPT). This method was tested in freshly excised hearts of the mdx4cv mouse, a commonly used mouse model for studying Duchenne cardiomyopathy. The hearts of age-matched C57BL/6 mice were also imaged as the normal controls. The results revealed a significant amount of damage in the mdx4cv hearts. Histology comparisons confirmed the damage identified by OPT. This fast and automatic method may greatly enhance preclinical studies in murine models of heart diseases.
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Affiliation(s)
- Yuanbo Wang
- Department of Bioengineering, University of Missouri, Columbia, Missouri
| | | | - Keqing Zhang
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, Missouri
| | - Dongsheng Duan
- Department of Bioengineering, University of Missouri, Columbia, Missouri
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, Missouri
| | - Gang Yao
- Department of Bioengineering, University of Missouri, Columbia, Missouri
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67
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Walther J, Golde J, Kirsten L, Tetschke F, Hempel F, Rosenauer T, Hannig C, Koch E. In vivo imaging of human oral hard and soft tissues by polarization-sensitive optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-17. [PMID: 29264891 DOI: 10.1117/1.jbo.22.12.121717] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/27/2017] [Indexed: 05/21/2023]
Abstract
Since optical coherence tomography (OCT) provides three-dimensional high-resolution images of biological tissue, the benefit of polarization contrast in the field of dentistry is highlighted in this study. Polarization-sensitive OCT (PS OCT) with phase-sensitive recording is used for imaging dental and mucosal tissues in the human oral cavity in vivo. An enhanced polarization contrast of oral structures is reached by analyzing the signals of the co- and crosspolarized channels of the swept source PS OCT system quantitatively with respect to reflectivity, retardation, optic axis orientation, and depolarization. The calculation of these polarization parameters enables a high tissue-specific contrast imaging for the detailed physical interpretation of human oral hard and soft tissues. For the proof-of-principle, imaging of composite restorations and mineralization defects at premolars as well as gingival, lingual, and labial oral mucosa was performed in vivo within the anterior oral cavity. The achieved contrast-enhanced results of the investigated human oral tissues by means of polarization-sensitive imaging are evaluated by the comparison with conventional intensity-based OCT.
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Affiliation(s)
- Julia Walther
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Anesthesiology and Intensive Care Medicine, Clini, Germany
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Department of Medical Physics and Biomedical Engi, Germany
| | - Jonas Golde
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Anesthesiology and Intensive Care Medicine, Clini, Germany
| | - Lars Kirsten
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Anesthesiology and Intensive Care Medicine, Clini, Germany
| | - Florian Tetschke
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Anesthesiology and Intensive Care Medicine, Clini, Germany
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Policlinic of Operative and Pediatric Dentistry,, Germany
| | - Franz Hempel
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Anesthesiology and Intensive Care Medicine, Clini, Germany
| | - Tobias Rosenauer
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Policlinic of Operative and Pediatric Dentistry,, Germany
| | - Christian Hannig
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Policlinic of Operative and Pediatric Dentistry,, Germany
| | - Edmund Koch
- TU Dresden, Faculty of Medicine Carl Gustav Carus, Anesthesiology and Intensive Care Medicine, Clini, Germany
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68
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Liu X, Beaudette K, Wang X, Liu L, Bouma BE, Villiger M. Tissue-like phantoms for quantitative birefringence imaging. BIOMEDICAL OPTICS EXPRESS 2017; 8:4454-4465. [PMID: 29082077 PMCID: PMC5654792 DOI: 10.1364/boe.8.004454] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 08/27/2017] [Accepted: 08/29/2017] [Indexed: 05/07/2023]
Abstract
Birefringence imaging, including polarization sensitive optical coherence tomography (PS-OCT), can provide valuable insight into the microscopic structure and organization of many biological tissues. In this paper, we report on a method to fabricate tissue-like birefringence phantoms for such imaging modalities. We utilize the photo-elastic effect, wherein birefringence is induced by stretching a polymer sample after heating it above its glass-transition temperature. The cooled samples stably exhibit homogeneous birefringence, and were assembled into phantoms containing multiple well-defined regions of distinct birefringence. We present planar slab phantoms for microscopy applications and cylindrical phantoms for catheter-based imaging and demonstrate quantitative analysis of the birefringence within individual regions of interest. Birefringence phantoms enable testing, validating, calibrating, and improving PS-OCT acquisition systems and reconstruction strategies.
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Affiliation(s)
- Xinyu Liu
- School of Electrical & Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - Kathy Beaudette
- Polytechnique Montréal, Department of Engineering Physics, P.O. Box 6079 Station Centre-Ville, Montréal, Québec H3C 3A7, Canada
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, MA 02114, USA
| | - Xianghong Wang
- School of Electrical & Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - Linbo Liu
- School of Electrical & Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Dr, 637459, Singapore
| | - Brett E. Bouma
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, MA 02114, USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Martin Villiger
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, MA 02114, USA
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