Publications associées à Microstructure informed tractography: pitfalls and open challenges

The inductive bias of deep learning: Connecting weights and functions

Years of a fierce competition have naturally selected the fittest deep learning algorithms. Yet, although these models work well in practice, we still lack a proper characterization of why they do so. This poses serious questions about the robustness, trus ...

EPFL2023

Axial and radial axonal diffusivities and radii from single encoding strongly diffusion-weighted MRI

Erick Jorge Canales Rodriguez, Marco Pizzolato, Tim Bjørn Dyrby

We enable the estimation of the per-axon axial diffusivity from single encoding, strongly diffusion-weighted, pulsed gradient spin echo data. Additionally, we improve the estimation of the per-axon radial diffusivity compared to estimates based on spherica ...

ELSEVIER2023

Mapping of Structure-Function Age-Related Connectivity Changes on Cognition Using Multimodal MRI

Dimitri Nestor Alice Van De Ville, Maria Giulia Preti

The relationship between age-related changes in brain structural connectivity (SC) and functional connectivity (FC) with cognition is not well understood. Furthermore, it is not clear whether cognition is represented via a similar spatial pattern of FC and ...

FRONTIERS MEDIA SA2022

Validating atlas-based lesion disconnectomics in multiple sclerosis: A retrospective multi-centric study

Jonas Richiardi, Reto Meuli, Bénédicte Marie Maréchal, Tobias Kober, Mario Joao Fartaria de Oliveira

The translational potential of MR-based connectivity modelling is limited by the need for advanced diffusion imaging, which is not part of clinical protocols for many diseases. In addition, where diffusion data is available, brain connectivity analyses rel ...

2021

Intra- and inter-hemispheric structural connectome in agenesis of the corpus callosum

Dimitri Nestor Alice Van De Ville, Lorena Gonçalves de Alcântara e Freitas Krikler, Vanessa Siffredi, Minghui Shi

Agenesis of the corpus callosum (AgCC) is a congenital brain malformation characterized by the complete or partial failure to develop the corpus callosum. Despite missing the largest white matter bundle connecting the left and right hemispheres of the brai ...

2021

Dynamic spatiotemporal patterns of brain connectivity reorganize across development

Patric Hagmann, Marie Schaer, Alessandra Griffa, Emeline Mullier

Late human development is characterized by the maturation of high-level functional processes, which rely on reshaping of white matter connections, as well as synaptic density. However, the relationship between the whole-brain dynamics and the underlying wh ...

MIT PRESS2020

Exploring dynamic functional connectivity by incorporating prior knowledge of brain structure

Anjali Bagunu Tarun

The synchronized firing of distant neuronal populations gives rise to a wide array of functional brain networks that underlie human brain function. Given the enormous perception, learning, and cognition potential of the human brain, it is not surprising th ...

EPFL2020

Towards quantitative brain connectomics: microstructure informed tractography via convex optimization

Muhamed Barakovic

Tractography is the only non-invasive technique which is used to reconstruct the white mat- ter structural connectivity of the human brain. It relies on a specific Magnetic Resonance Imaging (MRI) acquisition, called diffusion MRI, which is sensitive to th ...

EPFL2019

Validation strategies for the interpretation of microstructure imaging using diffusion MRI

Giorgio Innocenti, Tim Bjørn Dyrby

Extracting microanatomical information beyond the image resolution of MRI would provide valuable tools for diagnostics and neuroscientific research. A number of mathematical models already suggest microstructural interpretations of diffusion MRI (dMRI) dat ...

2018

Diffusion-weighted imaging evidence of altered white matter development from late childhood to early adulthood in Autism Spectrum Disorder

Djalel Eddine Meskaldji, Fikret Isik Karahanoglu

Autism Spectrum Disorder (ASD) is thought to reflect disrupted development of brain connectivity characterized by white matter abnormalities and dyscoordination of activity across brain regions that give rise to core features. But there is little consensus ...

2018

Reducing false positives in tractography with microstructural and anatomical priors

Jean-Philippe Thiran, Alessandro Daducci, Muhamed Barakovic, Gabriel Girard, Maxime Descoteaux

Tractography has proven particularly effective for studying noninvasively the neuronal architecture of the brain but recent studies have showed that the high incidence of false positives can significantly bias any connectivity analysis. We present a novel ...

2018

Exploring the role of white matter connectivity in cortex maturation

Patric Hagmann, Alessandra Griffa, Petra Susan Hüppi

The maturation of the cortical gray matter (GM) and white matter (WM) are described as sequential processes following multiple, but distinct rules. However, neither the mechanisms driving brain maturation processes, nor the relationship between GM and WM m ...

2017

Structural Brain Connectivity in School-Age Preterm Infants Provides Evidence for Impaired Networks Relevant for Higher Order Cognitive Skills and Social Cognition

Jean-Philippe Thiran, Djalel Eddine Meskaldji, Patric Hagmann, François Lazeyras, Elda Fischi Gomez

Extreme prematurity and pregnancy conditions leading to intrauterine growth restriction (IUGR) affect thousands of newborns every year and increase their risk for poor higher order cognitive and social skills at school age. However, little is known about t ...

Oxford University Press2015

On evaluating the accuracy and biological plausibility of diffusion MRI tractograms

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci

One of the major limitations of diffusion MRI tractography is that the tractograms, i.e. set of fiber tracts, recovered by existing algorithms are not truly quantitative. Hence, the structural connectivity between different brain regions, a.k.a. connectomi ...

2015

Global tractography with embedded anatomical priors and microstructure information for quantitative connectomics

Alia Lemkaddem

Over the last decades new technologies have shed the light on an improved understanding of brain structure and function. Recently, an imaging modality referred to as diffusion Magnetic Resonance Imaging (dMRI) has emerged. By exploiting the natural motion ...

EPFL2015

Global tractography with embedded anatomical priors for quantitative connectivity analysis

Jean-Philippe Thiran, Alia Lemkaddem, Alessandro Daducci, Didrik Hans Malcolm Skiöldebrand

Tractography algorithms provide us with the ability to non-invasively reconstruct fiber pathways in the white matter (WM) by exploiting the directional information described with diffusion magnetic resonance. These methods could be divided into two major c ...

2014

Whole-brain structural connectivity in temporal lobe epilepsy: a Diffusion Spectrum Imaging study

Jean-Philippe Thiran, François Lazeyras, Alia Lemkaddem, Alessandra Griffa, Alessandro Daducci

Introduction: Medial Temporal Lobe Epilepsy (mTLE) with hippocampal sclerosis is the most frequent cause of drug-resistant focal epilepsy in adults. These patients suffer from widespread subtle white matter abnormalities and abnormal functional connectivit ...

2012

White matter maturation reshapes structural connectivity in the late developing human brain

Jean-Philippe Thiran, Patric Hagmann, Reto Meuli, Van Jay Wedeen, Leila Cammoun, Olaf Sporns

From toddler to late teenager, the macroscopic pattern of axonal projections in the human brain remains largely unchanged while undergoing dramatic functional modifications that lead to network refinement. These functional modifications are mediated by inc ...

National Academy of Sciences2010

Essays on individual decision making under uncertainty

Elise Le Nestour

This research project is an experimental study of decision-making in very difficult contexts resembling those encountered in financial markets. The starting point was the empirical observation that financial assets are objects of a very complex kind. Speci ...

EPFL2009

Global brain connectivity analysis by diffusion MR tractography : algorithms, validation and applications

Xavier Gigandet

The human cerebral cortex consists of approximately 1010 neurons that are organized into a complex network of local circuits and long-range connections. During the past years there has been an increasing interest from the neuro-scientific community towards ...

EPFL2009