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Gunnar Krüger

Cette personne a quitté l’EPFL

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Publications associées (60)

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Automatic quality assessment in structural brain magnetic resonance imaging

Jean-Philippe Thiran, Reto Meuli, Gunnar Krüger, Bénédicte Marie Maréchal

MRI has evolved into an important diagnostic technique in medical imaging. However, reliability of the derived diagnosis can be degraded by artifacts, which challenge both radiologists and automatic computer-aided diagnosis. This work proposes a fully-auto ...

Wiley2009

On the Convergence of EM-Like Algorithms for Image Segmentation using Markov Random Fields

Meritxell Bach Cuadra, Gunnar Krüger, Alexis Roche, Delphine Ribes Lemay

Inference of Markov random field images segmentation models is usually performed using iterative methods which adapt the well-known expectation-maximization (EM) algorithm for independent mixture models. However, some of these adaptations are ad-hoc and ma ...

2011

Automatic quality assessment in structural brain magnetic resonance imaging

Jean-Philippe Thiran, Reto Meuli, Gunnar Krüger, Bénédicte Marie Maréchal

Quality assessment of MRI is of great importance to derive reliable diagnostic information. As automated quantitative image analysis is being increasingly used in routine, automated measures of quality are needed. Based on a single magnitude image, we prop ...

2009

Volume-based vs. voxel-based brain morphometry in Alzheimer's disease prediction

Meritxell Bach Cuadra, Alessandro Daducci, Reto Meuli, Gunnar Krüger, Bénédicte Marie Maréchal, Cristina Granziera, Alexis Roche, Delphine Ribes Lemay, Daniel Andreas Schmitter

Voxel-based morphometry from conventional T1-weighted images has proved effective to quantify Alzheimer's disease (AD) related brain atrophy and to enable accurate automated classification of AD patients, mild cognitive impaired (MCI) patients and elderly ...

Proceedings of 23rd International Society for Magnetic Resonance in Medicine (ISMRM) Conference2014

Diffusion Spectrum Imaging after stroke shows structural changes in the contra-lateral motor network correlating with functional recovery

Jean-Philippe Thiran, Reto Meuli, Alessandro Daducci, Cristina Granziera, Gunnar Krüger, Leila Cammoun, Djalel Eddine Meskaldji, Xavier Gigandet, Leila Faiza Ben Hamida Cammoun

There is growing interest in understanding the role of the non-injured contra-lateral hemisphere in stroke recovery. In the experimental field, histological evidence has been reported that structural changes occur in the contra-lateral connectivity and cir ...

2011

Magnetization transfer-based 3D visualization of foot peripheral nerves

Cristina Granziera, Gunnar Krüger, Bénédicte Marie Maréchal, Giulio Gambarota

PURPOSE: To investigate magnetization transfer (MT) effects as a new source of contrast for imaging and tracking of peripheral foot nerves. MATERIALS AND METHODS: Two sets of 3D spoiled gradient-echo images acquired with and without a saturation pulse were ...

Wiley-Blackwell2013

Who said fat is bad? Skull-stripping benefits from additional fat image

Tobias Kober, Reto Meuli, Gunnar Krüger, Delphine Ribes Lemay

Being a preliminary step for many clinical applications and analyses, accurate skull-stripping is a key challenge in MR brain imaging. One of its major difficulties arises from the contrast similarities at brain/non-brain tissue interfaces, in particular b ...

2011

Multiple Sclerosis Lesion Fingerprint Using Multicontrast MRI

Jean-Philippe Thiran, Cristina Granziera, Gunnar Krüger, Djalel Eddine Meskaldji, Gloria Menegaz, David Paul Roger Romascano, Alexis Roche, Guillaume Bonnier, Ying-Chia Lin

Conventional magnetic resonance imaging (MRI) measures of multiple sclerosis patients provide limited information about the nature and the extent of brain damage and repair. We established a clinically compatible protocol including quantitative MRI techniq ...

2014

3D Residual Eddy Current Field Characterisation: applied to Diffusion Weighted Magnetic Resonance Imaging

Rolf Gruetter, Alessandro Daducci, Gunnar Krüger, François Lazeyras, Kieran O'Brien

Clinical use of the Stejskal-Tanner diffusion weighted images is hampered by the geometric distortions that result from the large residual 3D eddy current field induced. In this work we aimed to predict, using linear response theory, the residual 3D eddy c ...

Institute of Electrical and Electronics Engineers2013

MP2RAGE, a self bias-field corrected sequence for improved segmentation and T-1-mapping at high field

Rolf Gruetter, Tobias Kober, José Pedro Rebelo Ferreira Marques, Wietske Van der Zwaag, Gunnar Krüger

The large spatial inhomogeneity in transmit B, field (B-1(+)) observable in human MR images at hi h static magnetic fields (B-0) severely impairs image quality. To overcome this effect in brain T-1-weighted images the, MPRAGE sequence was modified to gener ...

Elsevier2010

Eddy current effects on a clinical 7T-68 cm bore scanner

Rolf Gruetter, Tobias Kober, José Pedro Rebelo Ferreira Marques, Wietske Van der Zwaag, Gunnar Krüger

Eddy currents induced by switching of magnetic field gradients can lead to distortions in short echo-time spectroscopy or diffusion weighted imaging. In small bore magnets, such as human head-only systems, minimization of eddy current effects is more deman ...

2010

Surface-based characteristics of the cerebellar cortex visualized with ultra-high field MRI

Wietske Van der Zwaag, Cristina Granziera, Gunnar Krüger, Guillaume Bonnier, Kieran O'Brien, Yohan Boillat

Although having a relatively homogeneous cytoarchitectonic organization, the cerebellar cortex is a heterogeneous region characterized by different amounts of myelin, iron and protein expression profiles. In this study, we used quantitative T1 and T2* mapp ...

2018

An evaluation of volume-based morphometry for prediction of mild cognitive impairment and Alzheimer's disease

Reto Meuli, Meritxell Bach Cuadra, Alessandro Daducci, Gunnar Krüger, Cristina Granziera, Bénédicte Marie Maréchal, Daniel Andreas Schmitter, Alexis Roche, Delphine Ribes Lemay

Voxel-based morphometry from conventional T1-weighted images has proved effective to quantify Alzheimer’s disease (AD) related brain atrophy and to enable fairly accurate automated classification of AD patients, mild cognitive impaired patients (MCI) and e ...

Elsevier2015

In vivo measurement of glycine with short echo-time H-1 MRS in human brain at 7 T

Rolf Gruetter, Lijing Xin, Wietske Van der Zwaag, Gunnar Krüger, Giulio Gambarota

To determine whether glycine can be measured at 7 T in human brain with H-1 magnetic resonance spectroscopy (MRS). ...

2009

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

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

Fast model-based T-2 mapping using SAR-reduced simultaneous multislice excitation

Jean-Philippe Thiran, Tobias Kober, José Pedro Rebelo Ferreira Marques, Gunnar Krüger, Tom Hilbert

Purpose To obtain whole-brain high-resolution T-2 maps in 2 minutes by combining simultaneous multislice excitation and low-power PINS (power independent of number of slices) refocusing pulses with undersampling and a model-based reconstruction. Methods A ...

WILEY2019

Motion detection using FID navigator signals of MRI coil array elements

Rolf Gruetter, Tobias Kober, José Pedro Rebelo Ferreira Marques, Gunnar Krüger

We propose a motion-detection technique which, in contrast to previously suggested methods, is based on motion-induced free induction decay (FID) signal changes in receive coil arrays with negligible impact on scanning performance. ...

2009

Multicontrats MRI Improved the Clinico-Radiological Correlation in Early Multiple Sclerosis Patients with Minor Deficits

Jean-Philippe Thiran, Cristina Granziera, Gunnar Krüger, Djalel Eddine Meskaldji, Gloria Menegaz, David Paul Roger Romascano, Alexis Roche, Guillaume Bonnier, Ying-Chia Lin

Conventional magnetic resonance imaging (MRI) of patients with multiple sclerosis provides only limited insights into the nature of brain tissue damage with modest clinical-radiological correlations. In this study, quantitative and semi-quantitative MRI te ...

2014

Microstructural alterations in the brain of well treated HIV+ patients with minor neurocognitive disorders: a multi-contrast MRI study at 3T

Alessandro Daducci, Cristina Granziera, Gunnar Krüger, Djalel Eddine Meskaldji, Alexis Roche

2012

FID-guided retrospective motion correction based on autofocusing

Rolf Gruetter, Tobias Kober, Gunnar Krüger, Cristina Granziera, Maryna Volodimirivna Waszak

This work investigates the possibility of using FID navigator signals to improve the performance of a recently proposed autofocusing-based retrospective motion correction technique. FID navigators were incorporated into an MP-RAGE sequence and 3 subjects w ...

2014