Publications de Tobias Kober | EPFL Graph Search

Domain shift, domain adaptation, and generalization: A focus on MRI

Jonas Richiardi, Meritxell Bach Cuadra, Tobias Kober, Veronica Lily Ravano

Differences in acquisition protocols or hardware result in measurable changes in image characteristics. These differences affect distributional properties and can also affect the spatial and temporal characteristics of the images. Likewise, the distributio ...

Academic Press2025

A noninvasive accelerated quantitative MR technique to distinguish drug resistance in prolactinomas: Early results

Tobias Kober

Management of dopamine agonist (DA) resistance in prolactinoma (PRLoma) remains challenging due to the lack of detecting approach and reliable imaging marker. In this cross-sectional study, PRLoma patients were recruited prospectively from a single-center ...

2025

Diffusion Imaging Protocol Heterogeneity Biases Ischemic Core Volume, Location, and Clinical Associations in Acute Stroke

Tobias Kober, Veronica Lily Ravano

BACKGROUND: Diffusion-weighted magnetic resonance imaging is essential for diagnosing ischemic stroke and identifying targets for emergency revascularization. Apparent diffusion coefficient (ADC) maps derived from diffusion-weighted magnetic resonance imag ...

LIPPINCOTT WILLIAMS & WILKINS2025

To evaluate repaired rotator cuff morphologically and quantitatively in one GRAPPATINI MRI examination

Tobias Kober, Tom Hilbert

Background: GRAPPATINI is capable of originating synthetic T2 images (T2(synth)) and T2 maps in one magnetic resonance imaging (MRI) scan. Purpose: To evaluate GRAPPATINI's performance in providing simultaneous morphological assessment of repaired rotator ...

SAGE PUBLICATIONS LTD2025

Improved MR Detection of Optic Nerve Demyelination With MP2RAGE-FLAWS Compared With T2-Weighted Fat-Saturated Sequences

Tobias Kober

Objectives: Nonenhanced T1-w sequences such as magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) and derived fluid and white matter suppression (FLAWS) have demonstrated high performance for detecting brain parenchymal and cervical spine d ...

2024

Precision brain morphometry using cluster scanning

Tobias Kober, Tom Hilbert

Measurement error limits the statistical power to detect group differences and longitudinal change in structural MRI morphometric measures (e.g., hippocampal volume, prefrontal cortical thickness). Recent advances in scan acceleration enable extremely fast ...

2024

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

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

Normative volumes and relaxation times at 3T during brain development

Bénédicte Marie Maréchal, Tobias Kober, Tom Hilbert, Ricardo Alberto Corredor Jerez

While research has unveiled and quantified brain markers of abnormal neurodevelopment, clinicians still work with qualitative metrics for MRI brain investigation. The purpose of the current article is to bridge the knowledge gap between case-control cohort ...

Nature Portfolio2024

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

Deep Learning for Ischemic Penumbra Segmentation from MR Perfusion Maps: Robustness to the Deconvolution Algorithm

Bénédicte Marie Maréchal, Tobias Kober, Veronica Lily Ravano

Determining the penumbra, i.e., the at-risk but salvageable tissue, is crucial in the context of acute ischemic stroke imaging. Deep learning methods performing segmentation from perfusion parameter maps have shown promise in this regard. However, these me ...

Springer Nature (Switzerland)2024

Multiparametric Characterization and Spatial Distribution of Different MS Lesion Phenotypes

Tobias Kober, Tom Hilbert, Gian Franco Piredda

BACKGROUND AND PURPOSE: MS lesions exhibit varying degrees of axonal and myelin damage. A comprehensive description of lesion phenotypes could contribute to an improved radiologic evaluation of smoldering inflammation and remyelination processes. This stud ...

Amer Soc Neuroradiology2024

Automated Quantitative Susceptibility and Morphometry MR Study: Feasibility and Interrelation Between Clinical Score, Lesion Load, Deep Grey Matter and Normal-Appearing White Matter in Multiple Sclerosis

Meritxell Bach Cuadra, Bénédicte Marie Maréchal, Tobias Kober, Tom Hilbert

Lesion load (LL), deep gray matter (DGM) and normal-appearing white matter (NAWM) susceptibility and morphometry may help in monitoring brain changes in multiple sclerosis (MS) patients. We aimed at evaluating the feasibility of a fully automated segmentat ...

2024

Weighting Schemes for Federated Learning in Heterogeneous and Imbalanced Segmentation Datasets

Tobias Kober, Veronica Lily Ravano

Federated learning allows for training deep learning models from various sources (e.g., hospitals) without sharing patient information, but only the model weights. Two central problems arise when sending the updated weights to the central node in a federat ...

Springer International Publishing Ag2023

Perilesional tissue exhibits different T1 gradients depending on multiple sclerosis subtypes

Jean-Philippe Thiran, Bénédicte Marie Maréchal, Tobias Kober, Tom Hilbert, Veronica Lily Ravano

Sage Publications Ltd2023

Tract-wise microstructural analysis informs on current and future disability in early multiple sclerosis

Jean-Philippe Thiran, Bénédicte Marie Maréchal, Tobias Kober, Tom Hilbert, Veronica Lily Ravano

Objectives Microstructural characterization of patients with multiple sclerosis (MS) has been shown to correlate better with disability compared to conventional radiological biomarkers. Quantitative MRI provides effective means to characterize micro ...

Springer Heidelberg2023

Accurate Diagnosis of Cortical and Infratentorial Lesions in Multiple Sclerosis Using Accelerated Fluid and White Matter Suppression Imaging

Tobias Kober

Objectives: The precise location of multiple sclerosis (MS) cortical lesions can be very challenging at 3 T, yet distinguishing them from subcortical lesions is essential for the diagnosis and prognosis of the disease. Compressed sensing-accelerated fluid ...

LIPPINCOTT WILLIAMS & WILKINS2023

Feasibility of accelerated T2 mapping for the preoperative assessment of endometrial carcinoma

Tobias Kober, Tom Hilbert

ObjectiveThe application value of T2 mapping in evaluating endometrial carcinoma (EMC) features remains unclear. The aim of the study was to determine the quantitative T2 values in EMC using a novel accelerated T2 mapping, and evaluate them for detection, ...

FRONTIERS MEDIA SA2023

Deep multiple sclerosis lesion phenotyping using multimodal quantitative MRI

Tobias Kober, Tom Hilbert, Gian Franco Piredda

Sage Publications Ltd2023

Corpus callosum in children with neurodevelopmental delay: MRI standard qualitative assessment versus automatic quantitative analysis

Bénédicte Marie Maréchal, Tobias Kober

Background The corpus callosum (CC) is a key brain structure. In children with neurodevelopmental delay, we compared standard qualitative radiological assessments with an automatic quantitative tool. Methods We prospectively enrolled 73 child ...

Springer Wien2023