Publications de Alia Lemkaddem

Contactless Respiration Monitoring in Real-Time via a Video Camera

Martin Bertschinger, Olivier Grossenbacher, Alia Lemkaddem

Until today, vital signs monitoring in neonatal intensive care units (NICUs) is based on wired sensors, known to cause discomfort and false alarms. In view of overcoming such issues we investigate a contactless method for respiration monitoring by means of ...

SPRINGER-VERLAG SINGAPORE PTE LTD2018

Track Y. Smart Assistance Systems

Virginie Moser, Olivier Grossenbacher, Alia Lemkaddem, Fabian Braun

De Gruyter2016

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

COMMIT: Convex Optimization Modeling for Microstructure Informed Tractography

Jean-Philippe Thiran, Alia Lemkaddem, Alessandro Daducci

Tractography is a class of algorithms aiming at in vivo mapping the major neuronal pathways in the white matter from diffusion MRI data. These techniques offer a powerful tool to noninvasively investigate at the macroscopic scale the architecture of the ne ...

Institute of Electrical and Electronics Engineers2015

Anatomical Priors to improve Global Tractography

Jean-Philippe Thiran, Alia Lemkaddem, Alessandro Daducci

The main assumption of fiber-tracking algorithms is that fiber trajectories are represented by paths of highest diffusion, which is usually accomplished by following the principal diffusion directions in every voxel. The state-of-the-art approaches known a ...

2014

Connectivity and tissue microstructural alterations in right and left temporal lobe epilepsy revealed by diffusion spectrum imaging

Jean-Philippe Thiran, Nicolas Kunz, François Lazeyras, Alia Lemkaddem, Alessandro Daducci

Focal epilepsy is increasingly recognized as the result of an altered brain network, both on the structural and functional levels and the characterization of these widespread brain alterations is crucial for our understanding of the clinical manifestation ...

2014

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

Structural Graph Analysis of Left and Right Temporal Lobe Epilepsy using Diffusion Spectrum Imaging

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

Patients with Temporal Lobe Epilepsy (TLE) suffer from widespread subtle white matter abnormalities and abnormal functional connectivity extending beyond the affected lobe, as revealed by volumetric and functional MRI studies. Diffusion Magnetic Resonance ...

2014

A convex optimization framework for global tractography

Jean-Philippe Thiran, Alia Lemkaddem, Alessandro Daducci

In this article we present a novel approach for diffusion MRI global tractography. Our formulation models the signal in each voxel as a linear combination of fiber-tract basis func- tions, which consist of a comprehensive set of plausible fiber tracts that ...

2013

Altered structural connectivity in patients with medial temporal lobe epilepsy: A Diffusion Spectrum Imaging and Graph Analysis study

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

In this study we investigated the effect of medial temporal lobe epilepsy (MTLE) on the global characteristics of brain connectivity estimated by topological measures. We used DSI (Diffusion Spectrum Imaging) to construct a connectivity matrix where the no ...

2012

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

A multi-center study: Intra-scan and inter-scan variability of Diffusion Spectrum Imaging

Jean-Philippe Thiran, François Lazeyras, Alia Lemkaddem, Gunnar Krüger, Alessandro Daducci, Kieran O'Brien

The objective of this study was to investigate whether it is possible to pool together diffusion spectrum imaging data from four different scanners, located at three different sites. Two of the scanners had identical configuration whereas two did not. To m ...

Elsevier2012

The Connectome Mapper: an open-source processing pipeline to map connectomes with MRI

Jean-Philippe Thiran, Xavier Gigandet, Patric Hagmann, Reto Meuli, Alia Lemkaddem, Alessandra Griffa, Alessandro Daducci, Leila Cammoun

Researchers working in the field of global connectivity analysis using diffusion magnetic resonance imaging (MRI) can count on a wide selection of software packages for processing their data, with methods ranging from the reconstruction of the local intra- ...

Public Library of Science2012

The Connectome Viewer Toolkit: an open source framework to manage, analyze, and visualize connectomes

Jean-Philippe Thiran, Patric Hagmann, Reto Meuli, Alia Lemkaddem, Alessandro Daducci

Advanced neuroinformatics tools are required for methods of connectome mapping, analysis, and visualization. The inherent multi-modality of connectome datasets poses new challenges for data organization, integration, and sharing. We have designed and imple ...

Frontiers Research Foundation2011

Testing the variability of Diffusion Spectrum Imaging (DSI): Inter- and intra-site comparison on "identical" 3T scanners

Jean-Philippe Thiran, Reto Meuli, François Lazeyras, Alia Lemkaddem, Gunnar Krüger, Alessandro Daducci

Multi-center neuroimaging studies have more power than smaller ones to conduct sophisticated studies of basic neuroanatomy and clinical disorders. One important confound of combining images obtained from different scanners is the potential for scanner effe ...

2011

Towards a diffusion image processing validation and accuracy prediction framework

Gloria Menegaz, Jean-Philippe Thiran, Meritxell Bach Cuadra, Alia Lemkaddem, Cristina Granziera, Alessandro Daducci

Validation is the main bottleneck preventing the adoption of many medical image processing algorithms in the clinical practice. In the classical approach, a-posteriori analysis is performed based on some objective metrics. In this work, a different approac ...

2011

Shape prior based on statistical map for active contour segmentation

Valérie Duay, Jean-Philippe Thiran, Nawal Houhou, Alia Lemkaddem

We propose a new method for performing active contour segmentation based on the statistical prior knowledge of the object to detect. From a binary training set of objects, a statistical map describes the possible shapes of the object by computing the proba ...

2008