Publications by Tobias Kober | EPFL Graph Search

Related publications (147)

Data-driven myelin water imaging based on T-1 and T-2 relaxometry

Tobias Kober, Tom Hilbert, Erick Jorge Canales Rodriguez, Marco Pizzolato

Long acquisition times preclude the application of multiecho spin echo (MESE) sequences for myelin water fraction (MWF) mapping in daily clinical practice. In search of alternative methods, previous studies of interest explored the biophysical modeling of ...

WILEY2021

Revisiting the T-2 spectrum imaging inverse problem: Bayesian regularized non-negative least squares

Jean-Philippe Thiran, Tobias Kober, Tom Hilbert, Erick Jorge Canales Rodriguez, Marco Pizzolato, Thomas Yu

Multi-echo T-2 magnetic resonance images contain information about the distribution of T-2 relaxation times of compartmentalized water, from which we can estimate relevant brain tissue properties such as the myelin water fraction (MWF). Regularized non-neg ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2021

Methanol Poisoning as an Acute Toxicological Basal Ganglia Lesion Model: Evidence from Brain Volumetry and Cognition

Bénédicte Marie Maréchal, Tobias Kober

Background Acute methanol poisoning leads to optic neuropathy and necrotic lesions of basal ganglia (BG) and subcortical white matter. Survivors of methanol poisoning exhibit long-term executive and memory deficits. Associations between brain volumetry par ...

WILEY2019

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

Periventricular gradient of T1 tissue alterations in multiple sclerosis

Bénédicte Marie Maréchal, Tobias Kober, Tom Hilbert, Veronica Lily Ravano, Gian Franco Piredda

Objective: Pathology in multiple sclerosis is not homogenously distributed. Recently, it has been shown that structures adjacent to CSF are more severely affected. A gradient of brain tissue involvement was shown with more severe pathology in periventricul ...

ELSEVIER SCI LTD2022

Advancing Thalamic Nuclei Segmentation: The Impact of Compressed Sensing on MRI Processing

Tobias Kober, Tom Hilbert

The thalamus is a collection of gray matter nuclei that play a crucial role in sensorimotor processing and modulation of cortical activity. Characterizing thalamic nuclei non-invasively with structural MRI is particularly relevant for patient populations w ...

Wiley2024

Submillimeter T-1 atlas for subject-specific abnormality detection at 7T

Jean-Philippe Thiran, Bénédicte Marie Maréchal, Tobias Kober, Tom Hilbert, Ricardo Alberto Corredor Jerez, Gian Franco Piredda, Samuele Caneschi

Purpose: Studies at 3T have shown that T-1 relaxometry enables characterization of brain tissues at the single-subject level by comparing individual physical properties to a normative atlas. In this work, an atlas of normative T-1 values at 7T is introduce ...

WILEY2022

CVSnet: A machine learning approach for automated central vein sign assessment in multiple sclerosis

Jonas Richiardi, Meritxell Bach Cuadra, Reto Meuli, Tobias Kober, Cristina Granziera, João Pedro Forjaco Jorge, Francesco La Rosa

The central vein sign (CVS) is an efficient imaging biomarker for multiple sclerosis (MS) diagnosis, but its application in clinical routine is limited by inter-rater variability and the expenditure of time associated with manual assessment. We describe a ...

2020

Micro-Structural Brain Alterations in Aviremic HIV+ Patients with Minor Neurocognitive Disorders: A Multi-Contrast Study at High Field

Djalel Eddine Meskaldji, Reto Meuli, François Lazeyras, Gunnar Krüger, Tobias Kober, Cristina Granziera, Alessandro Daducci, Alexis Roche

Objective Mild neurocognitive disorders (MND) affect a subset of HIV+ patients under effective combination antiretroviral therapy (cART). In this study, we used an innovative multi-contrast magnetic resonance imaging (MRI) approach at high-field to assess ...

Public Library of Science2013

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

Prospective head motion correction using FID-guided on-demand image navigators

Reto Meuli, Rolf Gruetter, Bénédicte Marie Maréchal, Guillaume Bonnier, Gunnar Krüger, Tobias Kober, Tom Hilbert, Maryna Volodimirivna Waszak, Pavel Falkovskiy

PURPOSE: We suggest a motion correction concept that employs free-induction-decay (FID) navigator signals to continuously monitor motion and to guide the acquisition of image navigators for prospective motion correction following motion detection. METHODS: ...

Wiley-Blackwell2017

Fast refacing of MR images with a generative neural network lowers re-identification risk and preserves volumetric consistency

Jean-Philippe Thiran, Bénédicte Marie Maréchal, Tobias Kober

With the rise of open data, identifiability of individuals based on 3D renderings obtained from routine structural magnetic resonance imaging (MRI) scans of the head has become a growing privacy concern. To protect subject privacy, several algorithms have ...

Wiley2024

Model-informed machine learning for multi-component T2 relaxometry

Jean-Philippe Thiran, Meritxell Bach Cuadra, Tobias Kober, Elda Fischi Gomez, Cristina Granziera, Tom Hilbert, Muhamed Barakovic, Gian Franco Piredda, Erick Jorge Canales Rodriguez, Marco Pizzolato, Thomas Yu

Recovering the distribution from multi-echo magnetic resonance (MR) signals is challenging but has high potential as it provides biomarkers characterizing the tissue micro-structure, such as the myelin water fraction (MWF). In this work, we propose to comb ...

2020

Episodic memory decline in Parkinson' s disease: relation with white matter hyperintense lesions and influence of quantification method

Meritxell Bach Cuadra, Bénédicte Marie Maréchal, Tobias Kober

The relation of white matter hyperintense lesions to episodic memory impairment in patients with Parkinson's disease (PD) is still controversial. We aimed at evaluating the relation between white matter hyperintense lesions and episodic memory decline in p ...

SPRINGER2019

Compressed sensing with signal averaging for improved sensitivity and motion artifact reduction in fluorine-19 MRI

Jérôme Yerly, Ruud van Heeswijk, Tobias Kober, Tom Hilbert

Fluorine-19 (F-19) MRI of injected perfluorocarbon emulsions (PFCs) allows for the non-invasive quantification of inflammation and cell tracking, but suffers from a low signal-to-noise ratio and extended scan time. To address this limitation, we tested the ...

WILEY2020

Quantifying brain development in the HEALthy Brain and Child Development (HBCD) Study: The magnetic resonance imaging and spectroscopy protocol

Tobias Kober, Tom Hilbert

The HEALthy Brain and Child Development (HBCD) Study, a multi-site prospective longitudinal cohort study, will examine human brain, cognitive, behavioral, social, and emotional development beginning prenatally and planned through early childhood. The acqui ...

ELSEVIER SCI LTD2024

Probing myelin content of the human brain with MRI: A review

Jean-Philippe Thiran, Tobias Kober, Tom Hilbert, Gian Franco Piredda

Rapid and efficient transmission of electric signals among neurons of vertebrates is ensured by myelin-insulating sheaths surrounding axons. Human cognition, sensation, and motor functions rely on the integrity of these layers, and demyelinating diseases o ...

WILEY2021

Serum GFAP in multiple sclerosis: correlation with disease type and MRI markers of disease severity

Bénédicte Marie Maréchal, Tobias Kober, Ricardo Alberto Corredor Jerez

Neurofilament light chain (NfL) has been demonstrated to correlate with multiple sclerosis disease severity as well as treatment response. Nevertheless, additional serum biomarkers are still needed to better differentiate disease activity from disease prog ...

Nature Research2020

Clinical correlates of white matter lesions in Parkinson's disease using automated multi-modal segmentation measures

Bénédicte Marie Maréchal, Tobias Kober

Background: Age-related white matter lesions (WML) are common, impact neuronal connectivity, and affect motor function and cognition. In addition to pathological nigrostriatal losses, WML are also common co morbidities in Parkinson's disease (PD) that affe ...

ELSEVIER2021

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

Jonas Richiardi, Reto Meuli, Bénédicte Marie Maréchal, Tobias Kober

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