Publications by Gabriel Girard

A Riemannian framework for incorporating white matter bundle prior in orientation distribution function based tractography algorithms

Diffusion magnetic resonance imaging (dMRI) tractography is a powerful approach to study brain structural connectivity. However, its reliability in a clinical context is still highly debated. Recent studies have shown that most classical algorithms achieve ...

2025

Neurotransmitter-informed connectivity maps and their application for outcome inference after stroke

Gabriel Girard

Neuroscience has evolved by framing numerous neuropsychiatric conditions as network diseases. Alterations within neurotransmitter (NT) systems are central to the development of these diseases. Recently, normative data on whole-brain NT fingerprints derived ...

Oxford University Press (OUP)2025

Probabilistic tractography

Gabriel Girard

Tractography techniques map white matter bundles in the brain using diffusion magnetic resonance imaging (dMRI) data. These techniques use models to calculate paths where water molecule diffusion is least hindered, assuming these paths approximate the unde ...

Elsevier2025

White adipose tissue distribution and amount are associated with increased white matter connectivity

Jean-Philippe Thiran, Elda Fischi Gomez, Gabriel Girard, Philipp Johannes Koch, Liana Okudzhava

Obesity represents a significant public health concern and is linked to various comorbidities and cognitive impairments. Previous research indicates that elevated body mass index (BMI) is associated with structural changes in white matter (WM). However, a ...

Wiley2024

The interplay between white adipose tissue, adipokines, and structural gray matter changes

Jean-Philippe Thiran, Elda Fischi Gomez, Gabriel Girard, Liana Okudzhava

The growing global obesity issue emphasizes the importance of understanding its health implications. Previous research has identified consistent alterations in gray matter (GM) volume in connection with obesity. Given the various implications of distinct f ...

Wiley2024

Spatial Prior Informed Constrained Spherical Deconvolution in Super Resolution Variation

Jean-Philippe Thiran, Gabriel Girard, Erick Jorge Canales Rodriguez, Juan Luis Villarreal Haro

Constrained Spherical Deconvolution (CSD) is a state-of-the-art technique for unraveling complex fiber configurations of white matter from diffusion MRI data. Despite its ability to identify multiple fiber orientations, it faces difficulties in resolving f ...

Springer Nature2024

Comparing Steam and PGSE Diffusion MRI Signal of RAT Lymph Nodes Using In-Silico Simulations

Jean-Philippe Thiran, Elda Fischi Gomez, Gabriel Girard, Erick Jorge Canales Rodriguez, Rémy Marc M Gardier, Juan Luis Villarreal Haro

Diffusion magnetic resonance imaging (dMRI) has demonstrated great capabilities to quantify tissue microstructure using biophysical diffusion models. Over the years, various gradient sequences have been proposed to provide sensitivity and specificity to va ...

IEEE Computer Society2024

Tractography passes the test: Results from the diffusion-simulated connectivity (disco) challenge

Jean-Philippe Thiran, Alessandro Daducci, Ying-Chia Lin, Sara Sedlar, Caio Seguin, Gabriel Girard, Erick Jorge Canales Rodriguez, Alonso Ramirez Manzanares, Marco Pizzolato, Juan Luis Villarreal Haro, Kenji Marshall, Yang Ji

Estimating structural connectivity from diffusion-weighted magnetic resonance imaging is a challenging task, partly due to the presence of false-positive connections and the misestimation of connection weights. Building on previous efforts, the MICCAI-CDMR ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2023

Cellular EXchange Imaging (CEXI): Evaluation of a diffusion model including water exchange in cells using numerical phantoms of permeable spheres

Jean-Philippe Thiran, Ileana Ozana Jelescu, Gabriel Girard, Jonathan Rafael Patino Lopez, Erick Jorge Canales Rodriguez, Rémy Marc M Gardier, Juan Luis Villarreal Haro

Purpose Biophysical models of diffusion MRI have been developed to characterize microstructure in various tissues, but existing models are not suitable for tissue composed of permeable spherical cells. In this study we introduce Cellular Exchange Imaging ( ...

Wiley2023

Differential Impact of Brain Network Efficiency on Poststroke Motor and Attentional Deficits

Dimitri Nestor Alice Van De Ville, Philip Egger, Nathalie Heidi Meyer, Elena Beanato, Gabriel Girard, Julia Brügger, Friedhelm Christoph Hummel, Takuya Morishita, Maximilian Jonas Wessel, Philipp Johannes Koch, Giorgia Giulia Evangelista, Andéol Geoffroy Cadic-Melchior, Lisa Aïcha Mireille Julie Fleury

Background:Most studies on stroke have been designed to examine one deficit in isolation; yet, survivors often have multiple deficits in different domains. While the mechanisms underlying multiple-domain deficits remain poorly understood, network-theoretic ...

2023

Why is the winner the best?

Adrien Raphaël Depeursinge, Jian Wang, Ho Ling Li, Gabriel Girard, Yong Yang, Fan Xia, Xiao Wang, Hui Wang, Jing Li

International benchmarking competitions have become fundamental for the comparative performance assessment of image analysis methods. However, little attention has been given to investigating what can be learnt from these competitions. Do they really gener ...

Ieee Computer Soc2023

Microstructure estimation from diffusion-MRI: Compartmentalized models in permeable cellular tissue

Jean-Philippe Thiran, Gabriel Girard, Jonathan Rafael Patino Lopez, Erick Jorge Canales Rodriguez, Rémy Marc M Gardier, Juan Luis Villarreal Haro

Diffusion-weighted magnetic resonance imaging (DW-MRI) is used to characterize brain tissue microstructure employing tissue-specific biophysical models. A current limitation, however, is that most of the proposed models are based on the assumption of negli ...

2022

Slice Estimation in Diffusion MRI of Neonatal and Fetal Brains in Image and Spherical Harmonics Domains Using Autoencoders

Meritxell Bach Cuadra, Hamza Kebiri, Gabriel Girard, Erick Jorge Canales Rodriguez, Thomas Yu

Diffusion MRI (dMRI) of the developing brain can provide valuable insights into the white matter development. However, slice thickness in fetal dMRI is typically high (i.e., 3-5 mm) to freeze the in-plane motion, which reduces the sensitivity of the dMRI s ...

SPRINGER INTERNATIONAL PUBLISHING AG2022

NPTX1-related oculomotor apraxia: an intra-hemispheric disconnection disorder

Gabriel Girard, Philipp Johannes Koch

SPRINGER HEIDELBERG2022

Toward individualized medicine in stroke-The TiMeS project: Protocol of longitudinal, multi-modal, multi-domain study in stroke

Jean-Philippe Thiran, Dimitri Nestor Alice Van De Ville, Olaf Blanke, Philip Egger, Sylvain Jean-François Harquel, Silvestro Micera, Nathalie Heidi Meyer, Elena Beanato, Valérie Rita Madeleine Zufferey, Gabriel Girard, Julia Brügger, Friedhelm Christoph Hummel, Takuya Morishita, Maximilian Jonas Wessel, Philipp Johannes Koch, Estelle Emeline Raffin, Andéol Geoffroy Cadic-Melchior, Traian Popa, Pauline Menoud, Lisa Aïcha Mireille Julie Fleury

Despite recent improvements, complete motor recovery occurs in < 15% of stroke patients. To improve the therapeutic outcomes, there is a strong need to tailor treatments to each individual patient. However, there is a lack of knowledge concerning the preci ...

FRONTIERS MEDIA SA2022

Evaluating reproducibility and subject-specificity of microstructure-informed connectivity

Jean-Philippe Thiran, Tobias Kober, Elda Fischi Gomez, Tom Hilbert, Elena Beanato, Gabriel Girard, Julia Brügger, Gian Franco Piredda, Friedhelm Christoph Hummel, Takuya Morishita, Maximilian Jonas Wessel, Philipp Johannes Koch, Erick Jorge Canales Rodriguez, Marco Pizzolato, Andéol Geoffroy Cadic-Melchior, Chang-Hyun Park

Tractography enables identifying and evaluating the healthy and diseased brain's white matter pathways from diffusion-weighted magnetic resonance imaging data. As previous evaluation studies have reported significant false-positive estimation biases, recen ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

Through-Plane Super-Resolution With Autoencoders in Diffusion Magnetic Resonance Imaging of the Developing Human Brain

Meritxell Bach Cuadra, Hamza Kebiri, Gabriel Girard, Erick Jorge Canales Rodriguez

Fetal brain diffusion magnetic resonance images (MRI) are often acquired with a lower through-plane than in-plane resolution. This anisotropy is often overcome by classical upsampling methods such as linear or cubic interpolation. In this work, we employ a ...

FRONTIERS MEDIA SA2022

Variability and reproducibility of multi-echo T2 relaxometry: Insights from multi-site, multi-session and multi-subject MRI acquisitions

Jean-Philippe Thiran, Tobias Kober, Elda Fischi Gomez, Alessandro Daducci, Tom Hilbert, Elena Beanato, Gabriel Girard, Julia Brügger, Gian Franco Piredda, Friedhelm Christoph Hummel, Takuya Morishita, Maximilian Jonas Wessel, Philipp Johannes Koch, Erick Jorge Canales Rodriguez, Marco Pizzolato, Andéol Geoffroy Cadic-Melchior, Thomas Yu, Chang-Hyun Park

Quantitative magnetic resonance imaging (qMRI) can increase the specificity and sensitivity of conventional weighted MRI to underlying pathology by comparing meaningful physical or chemical parameters, measured in physical units, with normative values acqu ...

2022

Insights from the IronTract challenge: Optimal methods for mapping brain pathways from multi-shell diffusion MRI

Jean-Philippe Thiran, Elda Fischi Gomez, Gabriel Girard, Gaëtan Olivier D Rensonnet, Jonathan Rafael Patino Lopez, Erick Jorge Canales Rodriguez, Marco Pizzolato, Thomas Yu

Limitations in the accuracy of brain pathways reconstructed by diffusion MRI (dMRI) tractography have received considerable attention. While the technical advances spearheaded by the Human Connectome Project (HCP) led to significant improvements in dMRI da ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

Bundle-Specific Axon Diameter Index as a New Contrast to Differentiate White Matter Tracts

Jean-Philippe Thiran, Giorgio Innocenti, David Paul Roger Romascano, Cristina Granziera, Alessandro Daducci, Muhamed Barakovic, Gabriel Girard, Maxime Descoteaux

In the central nervous system of primates, several pathways are characterized by different spectra of axon diameters. In vivo methods, based on diffusion-weighted magnetic resonance imaging, can provide axon diameter index estimates non-invasively. However ...

2021