Louis Gagnon

Summary

Affiliation: Harvard University
Country: USA

Publications

  1. pmc Improved recovery of the hemodynamic response in diffuse optical imaging using short optode separations and state-space modeling
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
    Neuroimage 56:1362-71. 2011
  2. pmc Validation and optimization of hypercapnic-calibrated fMRI from oxygen-sensitive two-photon microscopy
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA Department of Medicine, Laval University, Quebec City, Quebec, Canada Deparment of Electrical Engineering, Ecole Polytechnique Montreal, Montreal, Quebec, Canada
    Philos Trans R Soc Lond B Biol Sci 371:. 2016
  3. pmc Quantifying the microvascular origin of BOLD-fMRI from first principles with two-photon microscopy and an oxygen-sensitive nanoprobe
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, Harvard MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139
    J Neurosci 35:3663-75. 2015
  4. pmc Further improvement in reducing superficial contamination in NIRS using double short separation measurements
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA Harvard MIT Division of Health Sciences and Technology, Cambridge, MA, USA Electronic address
    Neuroimage 85:127-35. 2014
  5. pmc Quantification of the cortical contribution to the NIRS signal over the motor cortex using concurrent NIRS-fMRI measurements
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
    Neuroimage 59:3933-40. 2012
  6. pmc Short separation channel location impacts the performance of short channel regression in NIRS
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
    Neuroimage 59:2518-28. 2012
  7. pmc Double-layer estimation of intra- and extracerebral hemoglobin concentration with a time-resolved system
    Louis Gagnon
    Institut de Génie Biomédical, Ecole Polytechnique de Montreal, C P 6079, Succ Centre Ville, Montreal, Quebec H3C 3A7, Canada
    J Biomed Opt 13:054019. 2008
  8. pmc Large arteriolar component of oxygen delivery implies a safe margin of oxygen supply to cerebral tissue
    Sava Sakadzic
    Optics Division, MHG MIT HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA
    Nat Commun 5:5734. 2014
  9. pmc Validation of the hypercapnic calibrated fMRI method using DOT-fMRI fusion imaging
    Meryem A Yucel
    MGH HST Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, 02129 MA, USA Electronic address
    Neuroimage 102:729-35. 2014
  10. pmc Calibrating the BOLD signal during a motor task using an extended fusion model incorporating DOT, BOLD and ASL data
    Meryem A Yucel
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
    Neuroimage 61:1268-76. 2012

Collaborators

Detail Information

Publications16

  1. pmc Improved recovery of the hemodynamic response in diffuse optical imaging using short optode separations and state-space modeling
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
    Neuroimage 56:1362-71. 2011
    ..05) in both HbO and HbR recovery using our Kalman filter dynamic estimator compared to the traditional adaptive filter, the static estimator and the standard GLM technique...
  2. pmc Validation and optimization of hypercapnic-calibrated fMRI from oxygen-sensitive two-photon microscopy
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA Department of Medicine, Laval University, Quebec City, Quebec, Canada Deparment of Electrical Engineering, Ecole Polytechnique Montreal, Montreal, Quebec, Canada
    Philos Trans R Soc Lond B Biol Sci 371:. 2016
    ..This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'. ..
  3. pmc Quantifying the microvascular origin of BOLD-fMRI from first principles with two-photon microscopy and an oxygen-sensitive nanoprobe
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, Harvard MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139
    J Neurosci 35:3663-75. 2015
    ..This framework is then used to quantify the contribution of individual vascular compartments and other factors to the BOLD signal for different magnet strengths and pulse sequences. ..
  4. pmc Further improvement in reducing superficial contamination in NIRS using double short separation measurements
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA Harvard MIT Division of Health Sciences and Technology, Cambridge, MA, USA Electronic address
    Neuroimage 85:127-35. 2014
    ..While the implementation of short separation sources presents some difficulties experimentally, the improvement in noise reduction is significant enough to justify the practical challenges. ..
  5. pmc Quantification of the cortical contribution to the NIRS signal over the motor cortex using concurrent NIRS-fMRI measurements
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
    Neuroimage 59:3933-40. 2012
    ..While different stimuli will result in different pial vein contributions, our finger tapping results do reveal the importance of considering the pial contribution...
  6. pmc Short separation channel location impacts the performance of short channel regression in NIRS
    Louis Gagnon
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
    Neuroimage 59:2518-28. 2012
    ..Using small separations located farther than 2 cm away resulted in mild or negligible improvements only...
  7. pmc Double-layer estimation of intra- and extracerebral hemoglobin concentration with a time-resolved system
    Louis Gagnon
    Institut de Génie Biomédical, Ecole Polytechnique de Montreal, C P 6079, Succ Centre Ville, Montreal, Quebec H3C 3A7, Canada
    J Biomed Opt 13:054019. 2008
    ..We observed a noticeable intersubject variability of the hemoglobin concentrations, but constant values for the cerebral hemoglobin oxygen saturation...
  8. pmc Large arteriolar component of oxygen delivery implies a safe margin of oxygen supply to cerebral tissue
    Sava Sakadzic
    Optics Division, MHG MIT HMS Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA
    Nat Commun 5:5734. 2014
    ....
  9. pmc Validation of the hypercapnic calibrated fMRI method using DOT-fMRI fusion imaging
    Meryem A Yucel
    MGH HST Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, 02129 MA, USA Electronic address
    Neuroimage 102:729-35. 2014
    ....
  10. pmc Calibrating the BOLD signal during a motor task using an extended fusion model incorporating DOT, BOLD and ASL data
    Meryem A Yucel
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
    Neuroimage 61:1268-76. 2012
    ..Our method yields an independent measurement of M, which provides an alternative measurement to validate the hypercapnic calibration of the BOLD signal...
  11. pmc Magnetic resonance fingerprinting based on realistic vasculature in mice
    Philippe Pouliot
    Dept of Electrical Engineering, Ecole Polytechnique Montreal, Montreal, QC, Canada Research Centre, Montreal Heart Institute, Montreal Electronic address
    Neuroimage . 2016
    ..Further validation work is essential before vMRF can gain wider application...
  12. pmc The utility of near-infrared spectroscopy in the regression of low-frequency physiological noise from functional magnetic resonance imaging data
    R J Cooper
    Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
    Neuroimage 59:3128-38. 2012
    ..The RETROICOR model did not provide a significant change in MSE. By each of the metrics calculated, NIRS recording is shown to be of significant benefit to the regression of low-frequency physiological noise from fMRI data...
  13. pmc Modeling of Cerebral Oxygen Transport Based on In vivo Microscopic Imaging of Microvascular Network Structure, Blood Flow, and Oxygenation
    Louis Gagnon
    Optics Division, Department of Radiology, MHG MIT HMS Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School Charlestown, MA, USA
    Front Comput Neurosci 10:82. 2016
    ..These "bottom-up" models are essential for the understanding of the processes governing brain oxygenation in normal and disease states and for eventual translation of the lessons learned from animal studies to humans. ..
  14. pmc A systematic comparison of motion artifact correction techniques for functional near-infrared spectroscopy
    Robert J Cooper
    Department of Radiology, Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School Charlestown, MA, USA
    Front Neurosci 6:147. 2012
    ..On the basis of this analysis, we recommend the routine application of motion correction techniques (particularly spline interpolation or wavelet analysis) to minimize the impact of motion artifacts on functional NIRS data...
  15. ncbi request reprint Investigation of diffuse correlation spectroscopy in multi-layered media including the human head
    Louis Gagnon
    Institut de Génie Biomédical, Ecole Polytechnique de Montreal, C P 6079, Succ Centre Ville, Montreal, QC, H3C 3A7, Canada
    Opt Express 16:15514-30. 2008
    ..Experimental measurements with a two-layered dynamical phantom confirm the ability of the two-layered analytical model to distinguish flow increase in each layer...
  16. doi request reprint A fNIRS investigation of switching and inhibition during the modified Stroop task in younger and older adults
    Maude Laguë-Beauvais
    Universite du Quebec a Montreal, Departement de Psychologie, CP 8888, Succursale Centre Ville, Montreal, Quebec, Canada H3C 3P8
    Neuroimage 64:485-95. 2013
    ....