Dr. Mark Hewko Profile

Dr. Mark Hewko

Research Council Officer at National Research Council Canada

SPIE Involvement:

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

Proc. SPIE. 10591, 2nd Canterbury Conference on OCT with Emphasis on Broadband Optical Sources

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

Read Abstract +

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

Proc. SPIE. 10044, Lasers in Dentistry XXIII

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

Read Abstract +

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

Proc. SPIE. 8948, Multiphoton Microscopy in the Biomedical Sciences XIV

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

Read Abstract +

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

Proc. SPIE. 8802, Optical Coherence Tomography and Coherence Techniques VI

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

Read Abstract +

Proceedings Article | 24 October 2012 Paper

Detection of atherosclerotic vascular tissue from optical coherence tomography images

Ammu Prakash, Mark Hewko, Mike Sowa, Sherif Sherif

Proc. SPIE. 8412, Photonics North 2012

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

Read Abstract +

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

Proc. SPIE. 7964, Medical Imaging 2011: Visualization, Image-Guided Procedures, and Modeling

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

Read Abstract +

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

Proc. SPIE. 7903, Multiphoton Microscopy in the Biomedical Sciences XI

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

Read Abstract +

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

Proc. SPIE. 7884, Lasers in Dentistry XVII

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

Read Abstract +

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

Proc. SPIE. 7883, Photonic Therapeutics and Diagnostics VII

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

Read Abstract +

SPIE Journal Paper | 1 July 2010

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

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

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 1 March 2010

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

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

Read Abstract +

DOWNLOAD PAPER

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

Proc. SPIE. 7386, Photonics North 2009

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

Read Abstract +

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

Proc. SPIE. 7182, Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues VII

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

Read Abstract +

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

Proc. SPIE. 7162, Lasers in Dentistry XV

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

Read Abstract +

SPIE Journal Paper | 1 September 2008

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

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

Read Abstract +

DOWNLOAD PAPER

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

Proc. SPIE. 6864, Biomedical Applications of Light Scattering II

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

Read Abstract +

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

Proc. SPIE. 6424, Photonic Therapeutics and Diagnostics III

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

Read Abstract +

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

Proc. SPIE. 6429, Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine XI

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

Read Abstract +

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

Proc. SPIE. 6343, Photonics North 2006

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

Read Abstract +

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

Proc. SPIE. 6343, Photonics North 2006

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

Read Abstract +

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

Proc. SPIE. 6093, Biomedical Vibrational Spectroscopy III: Advances in Research and Industry

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

Read Abstract +

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

Proc. SPIE. 6078, Photonic Therapeutics and Diagnostics II

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

Read Abstract +

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

Proc. SPIE. 6137, Lasers in Dentistry XII

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

Read Abstract +

SPIE Journal Paper | 1 May 2005

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

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

Read Abstract +

DOWNLOAD PAPER

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

Proc. SPIE. 5687, Lasers in Dentistry XI

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

Read Abstract +

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

Proc. SPIE. 4959, Spectral Imaging: Instrumentation, Applications, and Analysis II

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

Read Abstract +

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

Proc. SPIE. 4259, Biomarkers and Biological Spectral Imaging

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

Read Abstract +

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

Proc. SPIE. 3918, Biomedical Spectroscopy: Vibrational Spectroscopy and Other Novel Techniques

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

Read Abstract +

SPIE Journal Paper | 1 October 1999

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

Michael Sowa, Jeri Payette, Mark Hewko, Henry Mantsch

JBO Vol. 4 Issue 04

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

DOWNLOAD PAPER

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

Proc. SPIE. 3257, Infrared Spectroscopy: New Tool in Medicine

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

Read Abstract +

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

Proc. SPIE. 3257, Infrared Spectroscopy: New Tool in Medicine

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

Read Abstract +

Showing 5 of 31 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years