Dr. Mark Hewko Profile

Dr. Mark Hewko

Research Council Officer at National Research Council Canada

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Author

Publications (31)

Proceedings Article | 5 March 2018 Paper

Fast detection of vascular plaque in optical coherence tomography images using a reduced feature set

Ammu Prakash, Mariano Ocana Macias, Mark Hewko, Michael Sowa, Sherif Sherif

Proceedings Volume 10591, 105910P (2018) https://doi.org/10.1117/12.2283017

KEYWORDS: Optical coherence tomography, Tissue optics, Image segmentation, Genetic algorithms, Optimization (mathematics), Feature selection

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Proceedings Article | 19 April 2017 Presentation

Ex-vivo evaluation of an early caries detector based on integrated OCT and polarized Raman spectroscopy (Conference Presentation)

Guy Lamouche, Christian Padioleau, Mark Hewko, Michael S. Smith, Bernie Schattka, Crystal Fulton, Bruno Gauthier, André Beauchesne, Alex Ko, Lin-P'ing Choo-Smith, Michael Sowa

Proceedings Volume 10044, 1004405 (2017) https://doi.org/10.1117/12.2253224

KEYWORDS: Dental caries, Raman spectroscopy, Optical coherence tomography, Sensors, Teeth, Space reconnaissance, Microelectromechanical systems, Image processing, Laser dentistry, Spectroscopes

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Proceedings Article | 28 February 2014 Paper

Evaluating collagen morphology and pathological lipid deposition using multiphoton image statistics

Leila Mostaço-Guidolin, Alex C.-T. Ko, Fei Wang, Hong Tian, Mark Hewko, Masashi Shiomi, Arkady Major, Michael Sowa

Proceedings Volume 8948, 89482A (2014) https://doi.org/10.1117/12.2038232

KEYWORDS: Collagen, Second-harmonic generation, Tissues, Image classification, Particles, Image analysis, Microscopy, Arteries, Microscopes, Statistical analysis

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Proceedings Article | 18 June 2013 Paper

Texture based segmentation method to detect atherosclerotic plaque from optical tomography images

Ammu Prakash, Mark Hewko, Michael Sowa, Sherif Sherif

Proceedings Volume 8802, 88020S (2013) https://doi.org/10.1117/12.2032197

KEYWORDS: Image segmentation, Optical coherence tomography, Photography, Tissue optics, Tissues, Optical tomography, Coherence imaging, Vascular diseases, Arteries, Intravascular ultrasound

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Proceedings Article | 24 October 2012 Paper

Detection of atherosclerotic vascular tissue from optical coherence tomography images

Ammu Prakash, Mark Hewko, Mike Sowa, Sherif Sherif

Proceedings Volume 8412, 841204 (2012) https://doi.org/10.1117/12.981916

KEYWORDS: Optical coherence tomography, Arteries, Tissues, Feature extraction, Feature selection, Tissue optics, Sensors, Statistical analysis, Image classification, Optical inspection

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Proceedings Article | 2 March 2011 Paper

Detection of inflating balloon in optical coherence tomography images of a porcine artery in a beating heart experiment

Hamed Azarnoush, Sébastien Vergnole, Mark Hewko, Benoit Boulet, Mike Sowa, Guy Lamouche

Proceedings Volume 7964, 79641V (2011) https://doi.org/10.1117/12.878000

KEYWORDS: Arteries, Optical coherence tomography, Heart, Blood, Image segmentation, Prisms, Edge detection, Detection and tracking algorithms, Polymers, Image processing

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Proceedings Article | 23 February 2011 Paper

Using multimodal femtosecond CARS imaging to determine plaque burden in luminal atherosclerosis

Alex C-T. Ko, Leila Mostaço-Guidolin, Andrew Ridsdale, Adrian Pegoraro, Michael S. Smith, Aaron Slepkov, Mark Hewko, Elicia Kohlenberg, Bernie Schattka, Albert Stolow, Michael Sowa

Proceedings Volume 7903, 790318 (2011) https://doi.org/10.1117/12.873867

KEYWORDS: Second-harmonic generation, Collagen, Femtosecond phenomena, CARS tomography, Arteries, Tissues, Image analysis, Microscopes, Microscopy, Statistical analysis

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Proceedings Article | 22 February 2011 Paper

Enhancing caries resistance in occlusal fissures with a short-pulsed CO2 9.6 μm laser: an in vitro pH-cycling study, preliminary results

Daniel Charland, Crystal Fulton, Beate Rechmann, Mark Hewko, John Featherstone, Lin-P'ing Choo-Smith, Peter Rechmann

Proceedings Volume 7884, 78840G (2011) https://doi.org/10.1117/12.881705

KEYWORDS: Carbon dioxide lasers, Teeth, Minerals, Optical coherence tomography, Luminescence, Dental caries, Raman spectroscopy, Carbon dioxide, In vitro testing, Backscatter

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Proceedings Article | 18 February 2011 Paper

Tools for experimental characterization of the non-uniform rotational distortion in intravascular OCT probes

Marc Dufour, Charles-Etienne Bisaillon, Guy Lamouche, Sebastien Vergnole, Mark Hewko, Frédéric D'Amours, Christian Padioleau, Michael Sowa

Proceedings Volume 7883, 788339 (2011) https://doi.org/10.1117/12.874705

KEYWORDS: Arteries, Optical coherence tomography, Distortion, Image segmentation, Heart, Image processing, Intravascular ultrasound, Visualization, Ions, Cardiovascular magnetic resonance imaging

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SPIE Journal Paper | 1 July 2010 Open Access

Intravascular optical coherence tomography on a beating heart model

Guy Lamouche, Marc Dufour, Mark Hewko, Sébastien Vergnole, Bruno Gauthier, Charles-Etienne Bisaillon, Jean-Pierre Monchalin, Michael Sowa

JBO, Vol. 15, Issue 04, 046023, (July 2010) https://doi.org/10.1117/12.10.1117/1.3475960

KEYWORDS: Heart, Optical coherence tomography, Arteries, Blood, In vivo imaging, Imaging systems, Animal model studies, Polymers, Video, GRIN lenses

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SPIE Journal Paper | 1 March 2010 Open Access

Multimodal nonlinear optical imaging of atherosclerotic plaque development in myocardial infarction-prone rabbits

Alex Ko, Andrew Ridsdale, Michael Smith, Leila Mostaço-Guidolin, Mark Hewko, Adrian Pegoraro, Elicia Kohlenberg, Bernhard Schattka, Masashi Shiomi, Albert Stolow, Michael Sowa

JBO, Vol. 15, Issue 02, 020501, (March 2010) https://doi.org/10.1117/12.10.1117/1.3353960

KEYWORDS: Collagen, Microscopes, Femtosecond phenomena, Nonlinear optics, Tissues, CARS tomography, Objectives, Multimodal imaging, Optical imaging, Tissue optics

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Proceedings Article | 5 August 2009 Paper

A single-photon fluorescence and multi-photon spectroscopic study of atherosclerotic lesions

Michael S. D. Smith, Alex C. T. Ko, Andrew Ridsdale, Bernie Schattka, Adrian Pegoraro, Mark Hewko, Masashi Shiomi, Albert Stolow, Michael Sowa

Proceedings Volume 7386, 73860I (2009) https://doi.org/10.1117/12.840500

KEYWORDS: Luminescence, Tissues, Second-harmonic generation, Spectroscopy, Tissue optics, Microscopes, Single photon, Mirrors, Fluorescence spectroscopy, Multiphoton spectroscopy

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Proceedings Article | 24 February 2009 Paper

Label-free imaging of arterial tissues using photonic crystal fiber (PCF) based nonlinear optical microscopic system

Alex C. Ko, Andrew Ridsdale, Adrian Pegoraro, Michael S. Smith, Leila Mostaço-Guidolin, Mark Hewko, Elicia Kohlenberg, Bernie Schattka, Masashi Shiomi, Albert Stolow, Michael Sowa

Proceedings Volume 7182, 718204 (2009) https://doi.org/10.1117/12.809361

KEYWORDS: Tissues, Imaging systems, Collagen, Microscopes, Nonlinear optics, Photonic crystal fibers, Natural surfaces, Second-harmonic generation, Objectives, Complex systems

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Proceedings Article | 18 February 2009 Paper

Ex vivo imaging of early dental caries within the interproximal space

Lin-P'ing Choo-Smith, Mark Hewko, Marc Dufour, Crystal Fulton, Pingli Qiu, Bruno Gauthier, Christian Padioleau, Charles-Etienne Bisaillon, Cecilia Dong, Blaine Cleghorn, Guy Lamouche, Michael Sowa

Proceedings Volume 7162, 716206 (2009) https://doi.org/10.1117/12.809553

KEYWORDS: Teeth, Optical coherence tomography, Dental caries, Imaging systems, Calculus, Space reconnaissance, Visualization, In vivo imaging, Tissues, Photography

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SPIE Journal Paper | 1 September 2008 Open Access

Assessment of early demineralization in teeth using the signal attenuation in optical coherence tomography images

Dan Popescu, Michael Sowa, Mark Hewko, Lin-P'ing Choo-Smith

JBO, Vol. 13, Issue 05, 054053, (September 2008) https://doi.org/10.1117/12.10.1117/1.2992129

KEYWORDS: Signal attenuation, Optical coherence tomography, Teeth, Dental caries, Light scattering, Statistical analysis, Binary data, Scattering, Signal detection, Biomedical optics

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Proceedings Article | 22 February 2008 Paper

Propagation properties of 1300-nm light in blood-saline mixtures determined through optical coherence tomography

Dan Popescu, Bernhard Schattka, Mark Hewko, Jeri Friesen, Michael Sowa

Proceedings Volume 6864, 686408 (2008) https://doi.org/10.1117/12.764074

KEYWORDS: Optical coherence tomography, Blood, Signal detection, Light scattering, Scattering, Signal attenuation, Monte Carlo methods, Speckle, Interfaces, Tissue optics

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Proceedings Article | 23 March 2007 Paper

Broadband coherent anti-Stokes Raman scattering (CARS): a potential tool for atherosclerosis diagnostic imaging

J.-F. Cormier, A. Ko, L.-P. Choo-Smith, J. Werner, E. Kohlenberg, M. Hewko, J. Fréchette, M. Fortin, I. Noiseux, J. P. Bouchard, David Gay, P. Desroches, Francois Roy-Moisan, Marie-Eve Bourgault, M. Sowa, M. Vernon

Proceedings Volume 6424, 64241X (2007) https://doi.org/10.1117/12.701243

KEYWORDS: Raman spectroscopy, Control systems, Tissues, CARS tomography, Arteries, Spectroscopy, Collagen, Luminescence, Principal component analysis, Molecules

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Proceedings Article | 7 February 2007 Paper

Optical delay line using rotating rhombic prisms

G. Lamouche, M. Dufour, B. Gauthier, V. Bartulovic, M. Hewko, J.-P. Monchalin

Proceedings Volume 6429, 64292G (2007) https://doi.org/10.1117/12.701047

KEYWORDS: Prisms, Mirrors, Geometrical optics, Optical coherence tomography, Tissue optics, Optical components, Imaging systems, Biomedical optics, Real time imaging, Optical alignment

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Proceedings Article | 8 September 2006 Paper

Dental caries detection by optical spectroscopy: a polarized Raman approach with fibre-optic coupling

A. C.-T. Ko, L.-P. Choo-Smith, J. Werner, M. Hewko, M. Sowa, C. Dong, B. Cleghorn

Proceedings Volume 6343, 634303 (2006) https://doi.org/10.1117/12.706544

KEYWORDS: Raman spectroscopy, Dental caries, Teeth, Polarization, Anisotropy, Fiber couplers, Spectroscopy, Microscopes, Objectives, Photomicroscopy

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Proceedings Article | 8 September 2006 Paper

Surface inspection of hard to reach industrial parts using low-coherence interferometry

M. Dufour, G. Lamouche, S. Vergnole, B. Gauthier, C. Padioleau, M. Hewko, S. Lévesque, V. Bartulovic

Proceedings Volume 6343, 63431Z (2006) https://doi.org/10.1117/12.707806

KEYWORDS: Inspection, Interferometers, Interferometry, Optical fibers, Reflection, Electrodes, Mirrors, Prisms, Optical inspection, Plasma

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Proceedings Article | 27 February 2006 Paper

Application of NIR Raman spectroscopy for detecting and characterizing early dental caries

A. Ko, L.-P. Choo-Smith, R. Zhu, M. Hewko, C. Dong, B. Cleghorn, M. Sowa

Proceedings Volume 6093, 60930L (2006) https://doi.org/10.1117/12.647159

KEYWORDS: Raman spectroscopy, Dental caries, Teeth, Polarization, Anisotropy, Near infrared, Lawrencium, Data modeling, Photomicroscopy, Spectroscopy

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Proceedings Article | 22 February 2006 Paper

Atherosclerosis diagnostic imaging by optical spectroscopy and optical coherence tomography

M. D. Hewko, L. P. Choo-Smith, A. C. T. Ko, M. S. D. Smith, E. M. Kohlenberg, E. R. Bock, L. Leonardi, M. G. Sowa

Proceedings Volume 6078, 60782E (2006) https://doi.org/10.1117/12.641438

KEYWORDS: Raman spectroscopy, Collagen, Arteries, Optical coherence tomography, Tissues, Near infrared, Diagnostics, Luminescence, Imaging spectroscopy, Optical imaging

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Atherosclerosis is traditionally viewed as a disease of uncontrolled plaque growth leading to arterial occlusion. More recently, however, occlusion of the arterial lumen is being viewed as an acute event triggered by plaque rupture and thrombosis. An atheromatous plaque becomes vulnerable to sudden activation and/or rupture when a constellation of processes are activated by various trigger mechanisms. There is growing evidence that the vulnerability (i.e. susceptibility to rupture) and thrombogenic nature of the plaque need to be taken into account in the planning and treatment of the disease. X-ray fluoroscopy and intravascular ultrasound, the current clinical diagnostic tools are not capable of the providing a complete histological picture of the plaque region. Intravascular diagnostic imaging of coronary atherosclerotic plaques by optical means to assess plaque, patient risk and assist in planning treatment strategies represents the future in angioplasty treatment by interventional cardiologists. The techniques which will enable a clinically acceptable and reliable intravascular diagnostic platform are currently being investigated and compared to the clinical standard of histology. Currently, we are investigating the use of a number of optical and imaging techniques for biochemical analysis of arterial tissue including Raman, near infrared and fluorescence spectroscopies. Biochemical imaging will provide compositional information on collagen, elastin, lipid and thrombogenic by-products as well as gauging inflammation and tissue remodeling activity levels. To complement the functional biochemical imaging, optical coherence tomography will be provide structural morphological imaging. The synergistic combination of functional and structural imagery will provide the interventional cardiologist with a complete clinical picture of the atherosclerotic plaque region. The clinician can use this diagnostic information to plan a personalized treatment procedure based on the entire clinical presentation.

Proceedings Article | 15 February 2006 Paper

Characterization of early dental caries by polarized Raman spectroscopy

Lin-P'ing Choo-Smith, Alex C.-T. Ko, Mark Hewko, Cecilia C. S. Dong, Blaine Cleghorn, Michael Sowa

Proceedings Volume 6137, 613706 (2006) https://doi.org/10.1117/12.646795

KEYWORDS: Raman spectroscopy, Teeth, Dental caries, Polarization, Linear polarizers, Dentistry, Apatite, Crystals, Near infrared, Microscopes

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SPIE Journal Paper | 1 May 2005 Open Access

Ex vivo detection and characterization of early dental caries by optical coherence tomography and Raman spectroscopy

Alex Ko, Lin-P'ing Choo-Smith, Mark Hewko, Lorenzo Leonardi, Michael Sowa, Cecilia Dong, Peter Williams, Blaine Cleghorn

JBO, Vol. 10, Issue 03, 031118, (May 2005) https://doi.org/10.1117/12.10.1117/1.1915488

KEYWORDS: Raman spectroscopy, Teeth, Dental caries, Optical coherence tomography, Fiber optics, Crystals, Luminescence, Imaging spectroscopy, Polarization, Spectroscopy

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Proceedings Article | 23 March 2005 Paper

OCT of early dental caries: a comparative study with histology and Raman spectroscopy

Mark Hewko, Lin-P'ing Choo-Smith, Alex Ko, Lorenzo Leonardi, Cecilia Dong, Blaine Cleghorn, Michael Sowa

Proceedings Volume 5687, (2005) https://doi.org/10.1117/12.590955

KEYWORDS: Optical coherence tomography, Teeth, Dental caries, Raman spectroscopy, Minerals, Imaging systems, Visualization, Imaging spectroscopy, Visible radiation, Bacteria

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Proceedings Article | 2 July 2003 Paper

Evaluating the health of compromised tissues using a near-infrared spectroscopic imaging system in clinical settings: lessons learned

Lorenzo Leonardi, Michael Sowa, Mark Hewko, Bernhard Schattka, Jeri Payette, Michelle Hastings, Trevor Posthumus, Henry Mantsch

Proceedings Volume 4959, (2003) https://doi.org/10.1117/12.479483

KEYWORDS: Tissues, Injuries, Near infrared, Near infrared spectroscopy, Spectroscopy, Imaging spectroscopy, Oxygen, Principal component analysis, Hemodynamics, Blood

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Proceedings Article | 2 July 2001 Paper

Near-infrared spectroscopic approach to assess tissue viability following a thermal injury

Lorenzo Leonardi, Michael Sowa, Jeri Payette, Mark Hewko, Bernhard Schattka, Anna Matas, Henry Mantsch

Proceedings Volume 4259, (2001) https://doi.org/10.1117/12.432478

KEYWORDS: Injuries, Spectroscopy, Imaging spectroscopy, Near infrared, Tissues, Near infrared spectroscopy, Principal component analysis, Factor analysis, Tissue optics, Skin

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Proceedings Article | 8 May 2000 Paper

Applications of visible near-infrared spectroscopy and imaging in burn injury assessment

Lorenzo Leonardi, Michael Sowa, Jeri Payette, Mark Hewko, Bernhard Schattka, Anna Matas, Henry Mantsch

Proceedings Volume 3918, (2000) https://doi.org/10.1117/12.384955

KEYWORDS: Injuries, Tissues, Spectroscopy, Near infrared spectroscopy, Factor analysis, Skin, Tissue optics, Data modeling, Infrared spectroscopy, Oxygen

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SPIE Journal Paper | 1 October 1999 Open Access

Visible-near infrared multispectral imaging of the rat dorsal skin flap

Michael Sowa, Jeri Payette, Mark Hewko, Henry Mantsch

JBO, Vol. 4, Issue 04, (October 1999) https://doi.org/10.1117/12.10.1117/1.429957

KEYWORDS: Multispectral imaging, Skin, Surgery, Reflectivity, Tissues, Doppler effect, Principal component analysis, Near infrared, Infrared radiation, Infrared imaging

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Proceedings Article | 24 April 1998 Paper

Assessment of tissue viability by near-IR spectroscopy and imaging

Michael Sowa, Jeri Payette, Miroslaw Stranc, Badr Abdulrauf, Mark Hewko, James Mansfield, Henry Mantsch

Proceedings Volume 3257, (1998) https://doi.org/10.1117/12.306084

KEYWORDS: Oxygen, Tissues, Surgery, Skin, Imaging spectroscopy, Absorption, Tissue optics, Reflectivity, Near infrared spectroscopy, Blood

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Proceedings Article | 24 April 1998 Paper

Hemodynamic information obtained by statistical analysis of near-IR spectroscopic images

Michael Sowa, Jeri Payette, Mark Hewko, James Mansfield, Henry Mantsch

Proceedings Volume 3257, (1998) https://doi.org/10.1117/12.306097

KEYWORDS: Multispectral imaging, Tissues, Reflectivity, Skin, Statistical analysis, Image segmentation, Principal component analysis, Absorption, Fuzzy logic, Hemodynamics

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Showing 5 of 31 publications

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