Prof. Frédéric Leblond Profile

Significance: The practicality of optical methods detecting tissue optical contrast (absorption, elastic and inelastic scattering, fluorescence) for surgical guidance is limited by interferences from blood pooling and the resulting partial or complete inability to interrogate cortex and blood vessels. Aim: A multispectral diffuse reflectance technique was developed for intraoperative brain imaging of hemodynamic activity to automatically discriminate blood vessels, cortex, and bleeding at the brain surface. Approach: A manual segmentation of blood pooling, cortex, and vessels allowed the identification of a frequency range in hemoglobin concentration variations associated with high optical signal in blood vessels and cortex but not in bleeding. Reflectance spectra were then used to automatically segment areas with and without hemodynamic activity as well as to discriminate blood from cortical areas. Results: The frequency range associated with low-frequency hemodynamics and respiratory rate (0.03 to 0.3 Hz) exhibits the largest differences in signal amplitudes for bleeding, blood vessels, and cortex. A segmentation technique based on simulated reflectance spectra initially allowed discrimination of blood (bleeding and vessels) from cortical tissue. Then, a threshold applied to the low-frequency components from deoxyhemoglobin allowed the segmentation of bleeding from vessels. A study on the minimum acquisition time needed to discriminate all three components determined that ∼25 s was necessary to detect changes in the low-frequency range. Other frequency ranges such as heartbeat (1 to 1.7 Hz) can be used to reduce the acquisition time to few seconds but would necessitate optimizing instrumentation to ensure larger signal-to-noise ratios are achieved. Conclusions: A method based on multispectral reflectance signals and low-frequency hemoglobin concentration changes can be used to distinguish bleeding, blood vessels, and cortex. This could be integrated into fiber optic probes to enhance signal specificity by providing users an indication of whether measurements are corrupted by blood pooling, an important confounding factor in biomedical optics applied to surgery.

DOWNLOAD PAPER

SPIE Journal Paper | 27 October 2020

Experimental validation of a spectroscopic Monte Carlo light transport simulation technique and Raman scattering depth sensing analysis in biological tissue

Alireza Akbarzadeh, Ehsan Edjlali, Guillaume Sheehy, Juliette Selb, Rajeev Agarwal, Jessie Weber, Frédéric Leblond

JBO Vol. 25 Issue 10

Read Abstract +

Significance: Raman spectroscopy (RS) applied to surgical guidance is attracting attention among scientists in biomedical optics. Offering a computational platform for studying depth-resolved RS and probing molecular specificity of different tissue layers is of crucial importance to increase the precision of these techniques and facilitate their clinical adoption. Aim: The aim of this work was to present a rigorous analysis of inelastic scattering depth sampling and elucidate the relationship between sensing depth of the Raman effect and optical properties of the tissue under interrogation. Approach: A new Monte Carlo (MC) package was developed to simulate absorption, fluorescence, elastic, and inelastic scattering of light in tissue. The validity of the MC algorithm was demonstrated by comparison with experimental Raman spectra in phantoms of known optical properties using nylon and polydimethylsiloxane as Raman-active compounds. A series of MC simulations were performed to study the effects of optical properties on Raman sensing depth for an imaging geometry consistent with single-point detection using a handheld fiber optics probe system. Results: The MC code was used to estimate the Raman sensing depth of a handheld fiber optics system. For absorption and reduced scattering coefficients of 0.001 and 1 mm − 1, the sensing depth varied from 105 to 225 μm for a range of Raman probabilities from 10 − 6 to 10 − 3. Further, for a realistic Raman probability of 10 − 6, the sensing depth ranged between 10 and 600 μm for the range of absorption coefficients 0.001 to 1.4 mm − 1 and reduced scattering coefficients of 0.5 to 30 mm − 1. Conclusions: A spectroscopic MC light transport simulation platform was developed and validated against experimental measurements in tissue phantoms and used to predict depth sensing in tissue. It is hoped that the current package and reported results provide the research community with an effective simulating tool to improve the development of clinical applications of RS.

DOWNLOAD PAPER

SPIE Journal Paper | 1 May 2020

Rise of Raman spectroscopy in neurosurgery: a review

Damon DePaoli, Émile Lemoine, Katherine Ember, Martin Parent, Michel Prud’homme, Léo Cantin, Kevin Petrecca, Frédéric Leblond, Daniel Côté

JBO Vol. 25 Issue 05

KEYWORDS: Raman spectroscopy, Tissues, Brain, Tissue optics, Remote sensing, Imaging systems, Chromium, Tumors, Signal processing, Biopsy

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 21 April 2020

Quantitative spectral quality assessment technique validated using intraoperative in vivo Raman spectroscopy measurements

Frédérick Dallaire, Fabien Picot, Jean-Philippe Tremblay, Guillaume Sheehy, Émile Lemoine, Rajeev Agarwal, Samuel Kadoury, Dominique Trudel, Frédéric Lesage, Kevin Petrecca, Frédéric Leblond

JBO Vol. 25 Issue 04

KEYWORDS: Raman spectroscopy, Tissues, Signal to noise ratio, In vivo imaging, Cancer, Brain, Data acquisition, Luminescence, Tissue optics, Visualization

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 1 April 2020 Presentation

Data compatibility across point probe Raman spectroscopy systems and its impact on statistical models portability (Conference Presentation)

Fabien Picot, Guillaume Sheehy, Frédéric Dallaire, Jean-Phillipe Tremblay, François Daoust, Émile Lemoine, Layal Chaikho, Théophile Bégin, Kevin Petrecca, Samuel Kadoury, Frédéric Leblond

Proc. SPIE. 11362, Clinical Biophotonics

Read Abstract +

Proceedings Article | 10 March 2020 Presentation

In situ molecular characterization and brain cancer detection using macroscopic spontaneous Raman spectroscopy imaging (Conference Presentation)

Frédéric Leblond

Proc. SPIE. 11253, Biomedical Applications of Light Scattering X

KEYWORDS: Cancer, Data modeling, Tissues, Brain cancer, Imaging spectroscopy, Raman spectroscopy, Molecular spectroscopy, Spatial resolution, Systems modeling, Brain

Read Abstract +

Proceedings Article | 9 March 2020 Presentation

Large field of view macroscopic Raman line-scanning imaging system for neuro-oncology applications (Conference Presentation)

Francois Daoust, Patrick Orsini, Jacques Bismuth, Marie-Maude de Denus-Baillargeon, Israel Veilleux, Alexandre Wetter, Philippe McKoy, Isabelle Dicaire, Maroun Massabki, Kevin Petrecca, Frédéric Leblond

Proc. SPIE. 11236, Biomedical Vibrational Spectroscopy 2020: Advances in Research and Industry

KEYWORDS: Coherence imaging, Real time imaging, Imaging systems, Cameras, Endoscopes, Raman spectroscopy, In vivo imaging, Spatial resolution, RGB color model, Neuro-oncology

Read Abstract +

Proceedings Article | 11 July 2019 Paper

Multimodal imaging platform for surgical guidance during epilepsy surgery

Audrey Laurence, Emile Beaulieu, Dang Nguyen, Alain Bouthillier, Dominique Trudel, Frederic Leblond

Proc. SPIE. 11074, Diffuse Optical Spectroscopy and Imaging VII

KEYWORDS: Hyperspectral imaging, Microscopes, Multimodal imaging, Optical properties, Surgery, Imaging systems, Luminescence, Hemodynamics, Epilepsy, Auto-fluorescence imaging

Read Abstract +

SPIE Journal Paper | 23 April 2019

Interstitial imaging with multiple diffusive reflectance spectroscopy projections for in vivo blood vessels detection during brain needle biopsy procedures

Fabien Picot, Andréanne Goyette, Sami Obaid, Joannie Desroches, Simon Lessard, Marie-André Tremblay, Mathias Strupler, Brian Wilson, Kevin Petrecca, Gilles Soulez, Frédéric Leblond

NPh Vol. 6 Issue 02

KEYWORDS: Biopsy, Brain, Blood vessels, Neuroimaging, Tissue optics, In vivo imaging, Computed tomography, Tissues, Absorption, Imaging systems

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 4 March 2019 Presentation

Post-prostatectomy spatial frequency domain imaging for positive margins identification using endogenous tissue fluorescence, absorption and scattering (Conference Presentation)

Emile Beaulieu, Audrey Laurence, Mathieu Latour, Roula Albadine, Dominique Trudel, Frédéric Leblond

Proc. SPIE. 10871, Multimodal Biomedical Imaging XIV

KEYWORDS: Cancer, Tissues, Imaging systems, Scattering, Luminescence, Light scattering, Laser scattering, Prostate, Laser tissue interaction, Absorption

Read Abstract +

Proceedings Article | 4 March 2019 Presentation

Wide-field intraoperative Raman imaging technique to guide cytoreductive surgery for advanced stages of ovarian cancer (Conference Presentation)

Sandryne David, Guillaume Sheehy, Kayla Simeone, Jean-Phillipe Tremblay, Fred Saad, Anne-Marie Mes-Masson, Daniel Côté, Frédéric Leblond

Proc. SPIE. 10890, Label-free Biomedical Imaging and Sensing (LBIS) 2019

KEYWORDS: Tumor growth modeling, Cancer, Tissues, Surgery, Imaging systems, Remote sensing, Raman spectroscopy, Optical inspection, Tissue optics, Ovarian cancer

Read Abstract +

SPIE Journal Paper | 14 February 2019

Integration of a Raman spectroscopy system to a robotic-assisted surgical system for real-time tissue characterization during radical prostatectomy procedures

Michael Pinto, Kevin Zorn, Jean-Philippe Tremblay, Joannie Desroches, Frédérick Dallaire, Kelly Aubertin, Eric Marple, Chris Kent, Frederic Leblond, Dominique Trudel, Frederic Lesage

JBO Vol. 24 Issue 02

KEYWORDS: Raman spectroscopy, Prostate, Robotic systems, Tissue optics, Tissues, Surgery, Spectroscopy, In vivo imaging, Robotics, Prostate cancer

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 24 May 2018 Presentation

Quantitative subsurface fluorescence imaging enabled by spatial frequency domain imaging for enhanced fluorescence-guided surgery (Conference Presentation)

Mira Sibai, Dennis Wirth, Frédéric Leblond, David Roberts, Brian Wilson

Proc. SPIE. 10685, Biophotonics: Photonic Solutions for Better Health Care VI

KEYWORDS: Hyperspectral imaging, Tumors, Modulation, Optical properties, Tissues, Surgery, Imaging systems, Luminescence, Fluorescence spectroscopy, Tissue optics

Read Abstract +

Intra-operative fluorescence-guided resection (FGR) enables maximum safe resection of glioma by providing real-time tumor contrast. In its most widely used form, FGR is mediated by the preferential overproduction of the fluorophore protoporphyrinIX (PpIX) in malignant tissue after an oral dose of its precursor 5-Aminolevulinic Acid (ALA)1. ALA-PpIX-FGR has been shown to significantly increase completeness of tumor resection. However, the subjective visual assessment and the variable intrinsic optical attenuation of tissue limit this technique to delineating only high-grade tumors that display strong fluorescence residing at the tissue surface. We have shown that wide-field quantitative assessment by extracting 2D maps of PpIX concentration in the tissue, [PpIX], significantly improves the accuracy in detecting diffuse tumors, thereby potentially extending FGR to patients with low-grade tumors. In this approach, hyperspectral fluorescence imaging is coupled to a custom-built spatial frequency domain imaging (SFDI) system. SFDI enables the recovery of tissue optical properties maps, μ_a and μ_s^'. These are used to correct the fluorescence images. The corrected hyperspectral fluorescence images are then spectrally unmixed to separate true PpIX fluorescence from that of its photoproducts and from autofluorescence. Quantitative fluorescence imaging was validated against the clinically used spectroscopic probe by comparing the recovered optical properties and [PpIX] in vivo of a rat brain tumor model. This quantitative approach was also applied to a near infrared fluorophore ZW-800 on tissue-simulating phantoms. ALA-PpIX-FGR, as it is currently implemented, is inaccessible to infiltrative residuals lying beyond the resection cavity because of the limited penetration depth of the blue excitation light used. This is problematic as these infiltrative tumors are the main cause of reccurence. Enhanced sub-surface tumor detection was shown feasible by exciting PpIX’s secondary absorption peak of 635 nm intra-operatively on patients with various intra-cranial pathologies. However, resolving strong fluorescence of a deep-seated tumor from weak fluorescence of a shallow tumor was not possible. That is because the detected fluorescence intensity is heavily dependent on fluorophore concentration, depth, and fluorophore distribution, while also being convolved with tissue turbidity. The aim of this work, therefore, is to extend quantitative ALA-PpIX-FGR to identify sub-surface tumors by resolving tumor depth from fluorophore concentration. This should assist the surgeon in making an informed decision as for whether to further resect or not. A new quantitative depth imaging method was developed by exploiting SFDI’s depth-encoding capabilities in fluorescence mode. The result is a series of spatially modulated fluorescence images, where the modulation amplitude decays with increasing spatial frequency at a rate dependent on fluorophore depth. After recovering depth, a diffusion-based fluorescent light transport model is applied to extract fluorophore concentration. The algorithm was validated using tissue-simulating phantoms and an ex vivo tissue model indicating that the maximum depth recovered is highly dependent on fluorophore concentration as well as on tissue turbidity. For the [PpIX] and optical property maps relevant for glioma tissue, our quantitative depth fluorescence technique can predict depths up to 9 mm ± 0.4 mm, while recovering [PpIX] with an accuracy of 15% for concentrations as low as 2.5 µg/ml.

Proceedings Article | 5 April 2018 Presentation

Integrated Raman biopsy probe for high yield targeted brain cancer biopsies (Conference Presentation)

Joannie Desroches, Michael Jermyn, Eric Marple, Kirk Urmey, Gilles Soulez, Marie-Christine Guiot, Brian Wilson, Kevin Petrecca, Frédéric Leblond

Proc. SPIE. 10484, Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XVI

KEYWORDS: Cancer, Tumors, Magnetic resonance imaging, Brain cancer, Remote sensing, Raman spectroscopy, Biopsy, Computed tomography, Tissue optics, Brain

Read Abstract +

Proceedings Article | 14 March 2018 Presentation

Label-free optical spectroscopy techniques for targeted, real time and informed in situ cancer diagnosis (Conference Presentation)

Frédéric Leblond

Proc. SPIE. 10478, Molecular-Guided Surgery: Molecules, Devices, and Applications IV

KEYWORDS: Oncology, Cancer, Fiber optics, Surgery, Brain cancer, Luminescence, Raman spectroscopy, Optical spectroscopy, Prostate cancer, Tissue optics

Read Abstract +

SPIE Journal Paper | 6 March 2018

Challenges and opportunities in clinical translation of biomedical optical spectroscopy and imaging

Brian Wilson, Michael Jermyn, Frédéric Leblond

JBO Vol. 23 Issue 03

KEYWORDS: Tissue optics, Clinical trials, Biomedical optics, Tumors, Prototyping, Luminescence, Imaging spectroscopy, Raman spectroscopy, Biopsy, Surgery

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 12 October 2017

Dimension reduction technique using a multilayered descriptor for high-precision classification of ovarian cancer tissue using optical coherence tomography: a feasibility study

Catherine St. Pierre, Wendy-Julie Madore, Étienne De Montigny, Dominique Trudel, Caroline Boudoux, Nicolas Godbout, Anne-Marie Mes-Masson, Kurosh Rahimi, Frédéric Leblond

JMI Vol. 4 Issue 04

KEYWORDS: Optical coherence tomography, Tissues, Image classification, Cancer, Ovarian cancer, Tissue optics, Multilayers, Binary data, Dimension reduction, Image segmentation

Read Abstract +

SPIE Journal Paper | 11 July 2017

Preclinical evaluation of spatial frequency domain-enabled wide-field quantitative imaging for enhanced glioma resection

Mira Sibai, Carl Fisher, Israel Veilleux, Jonathan Elliott, Frederic Leblond, David Roberts, Brian Wilson

JBO Vol. 22 Issue 07

KEYWORDS: Tumors, Tissue optics, Spatial frequencies, Fiber optics tests, Fiber optics, Neuroimaging, Brain, Visualization, Visual optics, Signal attenuation

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 2 May 2017 Presentation

Raman spectroscopy for prostate cancer detection and characterization (Conference Presentation)

Kelly Aubertin, Quoc-Huy Trinh, Michael Jermyn, Catherine St-Pierre, Maria-Claudia Vladoiu, Andrée-Anne Grosset, Fred Saad, Dominique Trudel, Frédéric Leblond

Proc. SPIE. 10038, Therapeutics and Diagnostics in Urology: Lasers, Robotics, Minimally Invasive, and Advanced Biomedical Devices

KEYWORDS: Microscopes, Laser therapeutics, Cancer, Tumors, Tissues, Collagen, Raman spectroscopy, Machine learning, Prostate, Prostate cancer

Read Abstract +

Proceedings Article | 1 May 2017 Presentation

Taking label-free optical spectroscopy techniques into the operating theatre: biopsy needles and surgical guidance probes (Conference Presentation)

Frédéric Leblond

Proc. SPIE. 10060, Optical Biopsy XV: Toward Real-Time Spectroscopic Imaging and Diagnosis

KEYWORDS: Oncology, Cancer, Tissues, Surgery, Raman spectroscopy, Biopsy, Optical spectroscopy, Colorectal cancer, Prostate, Brain

Read Abstract +

SPIE Journal Paper | 12 October 2016

Intraoperative video-rate hemodynamic response assessment in human cortex using snapshot hyperspectral optical imaging

Julien Pichette, Audrey Laurence, Leticia Angulo, Frederic Lesage, Alain Bouthillier, Dang Khoa Nguyen, Frédéric Leblond

NPh Vol. 3 Issue 04

KEYWORDS: Hemodynamics, Tissue optics, Brain, Absorption, Optical imaging, Cameras, Hyperspectral imaging, Imaging systems, Calibration, Microscopes

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 8 September 2016

Neural networks improve brain cancer detection with Raman spectroscopy in the presence of operating room light artifacts

Michael Jermyn, Joannie Desroches, Jeanne Mercier, Marie-Andrée Tremblay, Karl St-Arnaud, Marie-Christine Guiot, Kevin Petrecca, Frédéric Leblond

JBO Vol. 21 Issue 09

KEYWORDS: Raman spectroscopy, Light, Brain, Cancer, Tissue optics, Neurons, Brain cancer, Microscopes, Tissues, Light sources

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 27 April 2016 Presentation

Multimodal optical biopsy probe to improve the safety and diagnostic yield of brain needle biopsies (Conference Presentation)

Joannie Desroches, Julien Pichette, Andréanne Goyette, Marie-Andrée Tremblay, Michael Jermyn, Kevin Petrecca, Frédéric Leblond

Proc. SPIE. 9698, Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XIV

KEYWORDS: Safety, Tissues, Blood vessels, Diagnostics, Raman spectroscopy, Biopsy, Integrated optics, Tissue optics, Yield improvement, Brain

Read Abstract +

Proceedings Article | 26 April 2016 Presentation

Intraoperative brain hemodynamic response assessment with real-time hyperspectral optical imaging (Conference Presentation)

Audrey Laurence, Julien Pichette, Leticia Angulo-Rodríguez, Catherine Saint Pierre, Frédéric Lesage, Alain Bouthillier, Dang Khoa Nguyen, Frédéric Leblond

Proc. SPIE. 9690, Clinical and Translational Neurophotonics; Neural Imaging and Sensing; and Optogenetics and Optical Manipulation

KEYWORDS: Optical imaging, Hyperspectral imaging, Surgery, Imaging systems, Hemodynamics, Cerebral blood flow, Neuroimaging, Mosaic detectors, Brain mapping, Brain

Read Abstract +

Proceedings Article | 26 April 2016 Presentation

An intraoperative spectroscopic imaging system for quantification of Protoporphyrin IX during glioma surgery (Conference Presentation)

Leticia Angulo-Rodríguez, Audrey Laurence, Michael Jermyn, Guillaume Sheehy, Mira Sibai, Kevin Petrecca, David Roberts, Keith Paulsen, Brian Wilson, Frédéric Leblond

Proc. SPIE. 9690, Clinical and Translational Neurophotonics; Neural Imaging and Sensing; and Optogenetics and Optical Manipulation

KEYWORDS: Cancer, Tumors, Tissues, Surgery, Imaging systems, Spectroscopy, Luminescence, Imaging spectroscopy, Tissue optics, Brain

Read Abstract +

Proceedings Article | 9 March 2016 Presentation + Paper

Neural networks improve brain cancer detection with Raman spectroscopy in the presence of light artifacts

Michael Jermyn, Joannie Desroches, Jeanne Mercier, Karl St-Arnaud, Marie-Christine Guiot, Kevin Petrecca, Frederic Leblond

Proc. SPIE. 9690, Clinical and Translational Neurophotonics; Neural Imaging and Sensing; and Optogenetics and Optical Manipulation

KEYWORDS: Cancer, Surgery, Brain cancer, Raman spectroscopy, Neural networks, Machine learning, Tissue optics, Neurons, Light, Brain

Read Abstract +

Proceedings Article | 29 February 2016 Paper

Spectroscopic imaging system for high-throughput viability assessment of ovarian spheroids or microdissected tumor tissues (MDTs) in a microfluidic chip

A. St-Georges-Robillard, M. Masse, J. Kendall-Dupont, M. Strupler, B. Patra, M. Jermyn, A.-M. Mes-Masson, F. Leblond, T. Gervais

Proc. SPIE. 9689, Photonic Therapeutics and Diagnostics XII

KEYWORDS: Microfluidics, Medicine, Cancer, Tumors, Fluorescence spectroscopy, Imaging spectroscopy, Fluorescent markers, Spectral calibration, Tunable filters, Ovarian cancer

Read Abstract +

SPIE Journal Paper | 20 March 2015

Macroscopic-imaging technique for subsurface quantification of near-infrared markers during surgery

Michael Jermyn, Kolbein Kolste, Julien Pichette, Guillaume Sheehy, Leticia Angulo-Rodríguez, Keith Paulsen, Brian Wilson, Kevin Petrecca, Frederic Leblond

JBO Vol. 20 Issue 03

KEYWORDS: Luminescence, Tissue optics, Tumors, Tissues, Natural surfaces, Surgery, Reconstruction algorithms, Microscopes, Fluorescence spectroscopy, Fluorescent markers

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 5 March 2015 Paper

Intraoperative detection of glioma invasion beyond MRI enhancement with Raman spectroscopy in humans

Michael Jermyn, Kelvin Mok, Jeanne Mercier, Joannie Desroches, Julien Pichette, Karl Saint-Arnaud, Marie-Christine Guiot, Kevin Petrecca, Frédéric Leblond

Proc. SPIE. 9318, Optical Biopsy XIII: Toward Real-Time Spectroscopic Imaging and Diagnosis

KEYWORDS: Visible radiation, Cancer, Tumors, Visualization, Tissues, Surgery, Magnetic resonance imaging, Brain cancer, Raman spectroscopy, Brain

Read Abstract +

Proceedings Article | 4 March 2015 Paper

Quantitative fluorescence imaging enabled by spatial frequency domain optical-property mapping in the sub-diffusive regime for surgical guidance

Mira Sibai, Israel Veilleux, Jonathan Elliott, Frederic Leblond, David Roberts, Brian Wilson

Proc. SPIE. 9311, Molecular-Guided Surgery: Molecules, Devices, and Applications

KEYWORDS: Diffuse reflectance spectroscopy, Tumors, Optical properties, Tissues, Spatial frequencies, Scattering, Luminescence, Reflectivity, Tissue optics, Absorption

Read Abstract +

SPIE Journal Paper | 4 February 2015

Macroscopic optical imaging technique for wide-field estimation of fluorescence depth in optically turbid media for application in brain tumor surgical guidance

Kolbein Kolste, Stephen Kanick, Pablo Valdés, Michael Jermyn, Brian Wilson, David Roberts, Keith Paulsen, Frederic Leblond

JBO Vol. 20 Issue 02

KEYWORDS: Luminescence, Optical properties, Tissue optics, Error analysis, Tissues, Monte Carlo methods, Tumors, Brain, Scattering, Optical imaging

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 20 March 2014 Paper

Quantitative spectrally resolved intraoperative fluorescence imaging for neurosurgical guidance in brain tumor surgery: pre-clinical and clinical results

Pablo Valdés, Valerie Jacobs, Frederic Leblond, Brian Wilson, Keith Paulsen, David Roberts

Proc. SPIE. 8928, Optical Techniques in Neurosurgery, Neurophotonics, and Optogenetics

KEYWORDS: Microscopes, Tumors, Tissues, Surgery, Imaging systems, Signal attenuation, Luminescence, Tissue optics, Signal detection, Brain

Read Abstract +

Proceedings Article | 25 March 2013 Paper

An overview of time-domain diffuse fluorescence imaging: instrumentation and applications

Kenneth Tichauer, Robert Holt, Frederic Leblond, Brian Pogue

Proc. SPIE. 8578, Optical Tomography and Spectroscopy of Tissue X

KEYWORDS: Light sources, Imaging systems, Sensors, Dispersion, Luminescence, Photons, Charge-coupled devices, Tissue optics, Signal detection, Pulsed laser operation

Read Abstract +

Proceedings Article | 25 March 2013 Paper

Optimized methodology for low-contrast fluorescence recovery using a new approach for reference tracer normalization

Robert Holt, Kenneth Tichauer, Fadi El-Ghussein, Jason Gunn, Frederic Leblond, Brian Pogue

Proc. SPIE. 8578, Optical Tomography and Spectroscopy of Tissue X

KEYWORDS: Liver, Data modeling, Tumors, Sensors, Luminescence, Image restoration, Tomography, Reconstruction algorithms, Signal detection, Fluorescence tomography

Read Abstract +

Proceedings Article | 13 March 2013 Paper

Toward ideal imaging geometry for recovery independence in fluorescence molecular tomography

Robert Holt, Frederic Leblond, Brian Pogue

Proc. SPIE. 8574, Multimodal Biomedical Imaging VIII

KEYWORDS: Modulation, Imaging systems, Sensors, Luminescence, Fourier transforms, Optical testing, Tomography, Projection systems, Charge-coupled devices, Fluorescence tomography

Read Abstract +

SPIE Journal Paper | 4 January 2013

Dual-tracer background subtraction approach for fluorescent molecular tomography

Kenneth Tichauer, Robert Holt, Fadi El-Ghussein, Scott Davis, Kimberley Samkoe, Jason Gunn, Frederic Leblond, Brian Pogue

JBO Vol. 18 Issue 01

KEYWORDS: Luminescence, Tumors, Fourier transforms, Tomography, Image restoration, Imaging systems, In vivo imaging, Optical properties, Data modeling, Tissues

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 4 May 2012

Spatial frequency domain tomography of protoporphyrin IX fluorescence in preclinical glioma models

Soren Konecky, Tyler Rice, Bruce Tromberg, Chris Owen, Pablo Valdes, David Roberts, Kolbein Kolste, Frederic Leblond, Keith Paulsen, Brian Wilson

JBO Vol. 17 Issue 5

KEYWORDS: Luminescence, Tumors, Tomography, Tissue optics, Scattering, Skull, Tissues, In vivo imaging, Brain, Optical properties

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 1 November 2011

Combined fluorescence and reflectance spectroscopy for in vivo quantification of cancer biomarkers in low- and high-grade glioma surgery

Pablo Valdes, Frederic Leblond, Keith Paulsen, Anthony Kim, Brian Wilson, Olga Conde, Brent Harris, David Roberts

JBO Vol. 16 Issue 11

KEYWORDS: Tumors, Luminescence, Tissue optics, Tissues, Diagnostics, Scattering, Algorithm development, Surgery, Absorption, Brain

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 1 March 2011 Paper

Application of spectral derivative data in spectral near infrared tomography

Hamid Dehghani, Frederic Leblond, Brian Pogue, Fabien Chauchard

Proc. SPIE. 7896, Optical Tomography and Spectroscopy of Tissue IX

KEYWORDS: Near infrared, Tissues, Scattering, Sensors, Calibration, Spectroscopy, Imaging spectroscopy, Tomography, Tissue optics, Absorption

Read Abstract +

Proceedings Article | 18 February 2011 Paper

ALA-induced PpIX spectroscopy for brain tumor image-guided surgery

Pablo Valdes, Frederic Leblond, Anthony Kim, Brent Harris, Brian Wilson, Keith Paulsen, David Roberts

Proc. SPIE. 7883, Photonic Therapeutics and Diagnostics VII

KEYWORDS: Microscopes, Tumors, Tissues, Surgery, Spectroscopy, Luminescence, Reflectivity, Diagnostics, Tissue optics, Brain

Read Abstract +

Proceedings Article | 17 February 2011 Paper

Development and evaluation of a time-resolved near-infrared fluorescence finite element model

Qun Zhu, Frederic Leblond, Fadi El-Ghussein, Brian Pogue, Hamid Dehghani

Proc. SPIE. 7896, Optical Tomography and Spectroscopy of Tissue IX

KEYWORDS: Data modeling, Scattering, Sensors, Luminescence, Photons, Diffusion, 3D modeling, Monte Carlo methods, Finite element methods, Absorption

Read Abstract +

Proceedings Article | 17 February 2011 Paper

Imaging sub-nanomolar concentrations through more than five centimeters of tissue with time-domain diffuse fluorescence tomography?

Kenneth Tichauer, Frederic Leblond, Robert Holt, Fadi El-Ghussein, Brian Pogue

Proc. SPIE. 7896, Optical Tomography and Spectroscopy of Tissue IX

KEYWORDS: Data modeling, Optical properties, Tissues, Imaging systems, Luminescence, Fluorescence spectroscopy, Image restoration, Head, Transmittance, Fluorescence tomography

Read Abstract +

Proceedings Article | 10 February 2011 Paper

A hybrid approach combining microCT and fluorescence tomography: imaging workflow and system of coordinate registration

Robert Holt, Fadi El-Ghussein, Kenneth Tichauer, Frederic Leblond, Brian Pogue

Proc. SPIE. 7892, Multimodal Biomedical Imaging VI

KEYWORDS: Imaging systems, Luminescence, Diffusion, Image restoration, Image registration, Optical phantoms, Finite element methods, Software development, Binary data, Fluorescence tomography

Read Abstract +

Proceedings Article | 10 February 2011 Paper

Acquisition and reconstruction of Raman and fluorescence signals for rat leg imaging

Jennifer-Lynn Demers, Brian Pogue, Frederic Leblond, Francis Esmonde-White, Paul Okagbare, Michael Morris

Proc. SPIE. 7892, Multimodal Biomedical Imaging VI

KEYWORDS: Data modeling, Tissues, Calibration, Luminescence, Diffusion, Bone, Raman spectroscopy, Data acquisition, Liquids, Animal model studies

Read Abstract +

SPIE Journal Paper | 1 May 2009

Imaging of glioma tumor with endogenous fluorescence tomography

Dax Kepshire, Summer Gibbs-Strauss, Julia O'Hara, Michael Hutchins, Niculae Mincu, Frederic Leblond, Mario Khayat, Hamid Dehghani, Subhadra Srinivasan, Brian Pogue

JBO Vol. 14 Issue 03

KEYWORDS: Tumors, Luminescence, Fluorescence tomography, Tomography, Imaging systems, Signal detection, Tissues, Calibration, Fluorescence spectroscopy, Single photon detectors

Read Abstract +

DOWNLOAD PAPER

SPIE Journal Paper | 1 May 2009

Errata: Imaging of glioma tumor with endogenous fluorescence tomography

Dax Kepshire, Summer Gibbs-Strauss, Julia O'Hara, Frederic Leblond, Subhadra Srinivasan, Brian Pogue, Michael Hutchins, Niculae Mincu, Mario Khayat, Hamid Dehghani

JBO Vol. 14 Issue 03

KEYWORDS: Tumors, Fluorescence tomography, Medical research, Physics, Roads, Diagnostics, Radiology

DOWNLOAD PAPER

Proceedings Article | 13 March 2009 Paper

Brain tumor resection guided by fluorescence imaging and MRI image guidance

Pablo Valdes, Brent Harris, Frederic Leblond, Kathryn Fontaine, Songbai Ji, Brian Pogue, Alex Hartov, David Roberts, Keith Paulsen

Proc. SPIE. 7261, Medical Imaging 2009: Visualization, Image-Guided Procedures, and Modeling

KEYWORDS: Microscopes, Tumors, Tissues, Surgery, Magnetic resonance imaging, Luminescence, Image analysis, Image enhancement, Gadolinium, Brain

Read Abstract +

Proceedings Article | 24 February 2009 Paper

Brain tumor resection guided by fluorescence imaging

Frederic Leblond, Kathryn Fontaine, Pablo Valdes, Songbai Ji, Brian Pogue, Alex Hartov, David Roberts, Keith Paulsen

Proc. SPIE. 7164, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XVIII

KEYWORDS: Microscopes, Tumors, Tissues, Surgery, Magnetic resonance imaging, Luminescence, Navigation systems, Neuroimaging, Brain, Clinical trials

Read Abstract +

Proceedings Article | 20 February 2009 Paper

Imaging protoporphyrin IX fluorescence with a time-domain FMT/microCT system

Frederic Leblond, Dax Kepshire, Julia O'Hara, Hamid Dehghani, Subha Srinivasan, N. Mincu, M. Hutchins, M. Khayat, B. Pogue

Proc. SPIE. 7171, Multimodal Biomedical Imaging IV

KEYWORDS: Imaging systems, Sensors, Luminescence, Diffusion, Quantum efficiency, Tomography, Data acquisition, Computed tomography, Signal detection, Natural surfaces

Read Abstract +

Proceedings Article | 21 February 2008 Paper

Diffuse optical tomography and spectroscopy performance assessment: phantoms and methodology

Niculae Mincu, Jean Brunette, Olga Guilman, Fréderic Leblond, Salim Djeziri, Zahia Ichalalène, Guobin Ma, Mario Khayat, Anader Benyamin-Seeyar

Proc. SPIE. 6870, Design and Performance Validation of Phantoms Used in Conjunction with Optical Measurements of Tissue

KEYWORDS: Refractive index, Titanium dioxide, Optical properties, Scattering, Water, Particles, Solids, Mie scattering, Liquids, Absorption

Read Abstract +

Proceedings Article | 20 February 2008 Paper

Full path Monte Carlo simulation of fluorescence in non-voxelized complex heterogeneous mouse model

Jean-Francois Delorme, Guobin Ma, Frederic Lesage, Frederic Leblond, Anader Benyamin-Seyar

Proc. SPIE. 6854, Optical Interactions with Tissue and Cells XIX

KEYWORDS: Refractive index, Reflection, Scattering, Luminescence, Diffusion, Computer simulations, 3D modeling, Monte Carlo methods, Refraction, Photon transport

Read Abstract +

Proceedings Article | 12 February 2008 Paper

Fluorescence lifetime estimation of multiple near-infrared dyes in mice

Guobin Ma, Simon Fortier, Muriel Jean-Jacques, Niculae Mincu, Frederic Leblond, Zahia Ichalalene, Anader Benyamin-Seeyar, Mario Khayat

Proc. SPIE. 6850, Multimodal Biomedical Imaging III

KEYWORDS: Optical properties, Tissues, Luminescence, Diffusion, Convolution, Fluorescence lifetime imaging, Biological research, In vivo imaging, Radiative transfer, Liquids

Read Abstract +

Proceedings Article | 12 July 2007 Paper

Diffuse optical tomography forward model refinements in media with heterogeneous optical properties

Simon Fortier, Frederic Leblond

Proc. SPIE. 6629, Diffuse Optical Imaging of Tissue

KEYWORDS: Statistical analysis, Data modeling, Optical properties, Scattering, Sensors, Luminescence, Tomography, Statistical modeling, Absorption, Diffuse optical tomography

Read Abstract +

Proceedings Article | 27 March 2007 Paper

Sensitivity and repeatability of diffuse optical tomography: toward breast cancer neoadjuvant treatment monitoring

Niculae Mincu, Salim Djeziri, Zahia Ichalalène, Fréderic Leblond, Mario Khayat

Proc. SPIE. 6434, Optical Tomography and Spectroscopy of Tissue VII

KEYWORDS: Breast, Breast cancer, Tumors, Scattering, Blood, Data acquisition, Reconstruction algorithms, Liquids, Absorption, Diffuse optical tomography

Read Abstract +

Proceedings Article | 20 February 2007 Paper

Diffuse optical fluorescence tomography using time-resolved data acquired in transmission

Frederic Leblond, Simon Fortier, Michael Friedlander

Proc. SPIE. 6431, Multimodal Biomedical Imaging II

KEYWORDS: Optical properties, Tissues, Scattering, Sensors, Luminescence, Diffusion, Data acquisition, Refraction, Absorption, Animal model studies

Read Abstract +

Proceedings Article | 20 February 2007 Paper

Optical tomography as adjunct to x-ray mammography: methods and results

Mario Khayat, Zahia Ichalalene, Niculae Mincu, Fredéric Leblond, Olga Guilman, Salim Djeziri

Proc. SPIE. 6431, Multimodal Biomedical Imaging II

KEYWORDS: Optical imaging, Breast, X-ray optics, Statistical analysis, Radio optics, Tissues, Scattering, X-rays, Mammography, Tissue optics

Read Abstract +

Proceedings Article | 13 February 2007 Paper

Numerical optix: a time-domain simulator of fluorescent-light diffusion in turbid medium

Guobin Ma, Jean-François Delorme, Olga Guilman, Frédéric Leblond, Mario Khayat

Proc. SPIE. 6434, Optical Tomography and Spectroscopy of Tissue VII

KEYWORDS: Light sources, Biomedical optics, Tissues, Sensors, Luminescence, Diffusion, Reflectivity, Computer simulations, Monte Carlo methods, In vivo imaging

Read Abstract +

Proceedings Article | 13 February 2007 Paper

Improved quantification of fluorescence in 3-D in a realistic mouse phantom

Subhadra Srinivasan, Brian Pogue, Scott Davis, Frederic Leblond

Proc. SPIE. 6434, Optical Tomography and Spectroscopy of Tissue VII

KEYWORDS: Tumors, Optical properties, Tissues, Scattering, Sensors, Luminescence, Diffusion, Image restoration, Absorption, Brain

Read Abstract +

Showing 5 of 60 publications

Conference Committee Involvement (25)

Clinical and Translational Neurophotonics 2022

22 January 2022 | San Francisco, California, United States

Molecular-Guided Surgery: Molecules, Devices, and Applications VII

22 January 2022 | San Francisco, California, United States

Translational Biophotonics: Diagnostics and Therapeutics

20 June 2021 | Online Only, Germany

Clinical and Translational Neurophotonics 2021

6 March 2021 | Online Only, California, United States

Optical Tomography and Spectroscopy of Tissue XIV

6 March 2021 | Online Only, California, United States

Molecular-Guided Surgery: Molecules, Devices, and Applications VII

6 March 2021 | Online Only, California, United States

Clinical Biophotonics

6 April 2020 | Online Only, France

Clinical and Translational Neurophotonics 2020

1 February 2020 | San Francisco, California, United States

Molecular-Guided Surgery: Molecules, Devices, and Applications VI

1 February 2020 | San Francisco, California, United States

Optical Tomography and Spectroscopy of Tissue XIII

4 February 2019 | San Francisco, California, United States

Clinical and Translational Neurophotonics 2019

2 February 2019 | San Francisco, California, United States

Molecular-Guided Surgery: Molecules, Devices, and Applications V

2 February 2019 | San Francisco, California, United States

Clinical and Translational Neurophotonics 2018

27 January 2018 | San Francisco, California, United States

Molecular-Guided Surgery: Molecules, Devices, and Applications IV

27 January 2018 | San Francisco, California, United States

Optical Tomography and Spectroscopy of Tissue XII

30 January 2017 | San Francisco, California, United States

Clinical and Translational Neurophotonics

28 January 2017 | San Francisco, California, United States

Molecular-Guided Surgery: Molecules, Devices, and Applications III

28 January 2017 | San Francisco, California, United States

Clinical and Translational Neurophotonics

13 February 2016 | San Francisco, California, United States

Optical Tomography and Spectroscopy of Tissue XI

9 February 2015 | San Francisco, California, United States