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Artéfact (erreur)

Publications associées (25)

An Elliptic Local Problem With Exponential Decay Of The Resonance Error For Numerical Homogenization

Assyr Abdulle, Doghonay Arjmand, Edoardo Paganoni

Numerical multiscale methods usually rely on some coupling between a macroscopic and a microscopic model. The macroscopic model is incomplete as effective quantities, such as the homogenized material coefficients or fluxes, are missing in the model. These ...

SIAM PUBLICATIONS2023

Medipix4, a high granularity four sides buttable pixel readout chip for high resolution spectroscopic X-ray imaging at rates compatible with medical CT scans

Viros Sriskaran

Medipix4 is the latest member in the Medipix/Timepix family of pixel detector chips aimed at high rate spectroscopic X-ray imaging using high-Z materials. The chip address the limitations of conventional hybrid pixel detectors for X-ray imaging. Its predec ...

EPFL2022

A parabolic local problem with exponential decay of the resonance error for numerical homogenization

Assyr Abdulle, Doghonay Arjmand, Edoardo Paganoni

This paper aims at an accurate and efficient computation of effective quantities, e.g. the homogenized coefficients for approximating the solutions to partial differential equations with oscillatory coefficients. Typical multiscale methods are based on a m ...

WORLD SCIENTIFIC PUBL CO PTE LTD2021

Ultrasound Imaging: From Physical Modeling to Deep Learning

Dimitris Perdios

Among the medical imaging modalities, ultrasound (US) imaging is one of the safest, most widespread, and least expensive method used in medical diagnosis. In the past decades, several technological advances enabled the advent of ultrafast US imaging, an ac ...

EPFL2021

CNN-Based Ultrasound Image Reconstruction for Ultrafast Displacement Tracking

Jean-Philippe Thiran, Dimitris Perdios, Marcel Arditi, Florian Martinez, Manuel Vonlanthen

Thanks to its capability of acquiring full-view frames at multiple kilohertz, ultrafast ultrasound imaging unlocked the analysis of rapidly changing physical phenomena in the human body, with pioneering applications such as ultrasensitive flow imaging in t ...

Institute of Electrical and Electronics Engineers2021

An objective comparison of detection and segmentation algorithms for artefacts in clinical endoscopy

Georges Wagnières

We present a comprehensive analysis of the submissions to the first edition of the Endoscopy Artefact Detection challenge (EAD). Using crowd-sourcing, this initiative is a step towards understanding the limitations of existing state-of-the-art computer vis ...

Nature Research2020

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

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

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

Exponential decay of the resonance error in numerical homogenization via parabolic and elliptic cell problems

Assyr Abdulle, Doghonay Arjmand, Edoardo Paganoni

This paper presents two new approaches for finding the homogenized coefficients of multiscale elliptic PDEs. Standard approaches for computing the homogenized coefficients sufer from the so-called resonance error, originating from a mismatch between the tr ...

ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER2019

Denoising ECG Signal by CSTFM Algorithm: Monitoring During Motorbike and Car Races

Guglielmo Frigo

mHealth technology, by using habitual devices, i.e., smartphones, improves prevention, diagnosis, treatment, monitoring, and management of health. Monitoring heart profile during intense sports activities allows to diagnose pathologies, not identifiable wi ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2019

Neurovascular stent artifacts in 3D-TOF and 3D-PCMRI: Influence of stent design on flow measurement

Mohamed Farhat, Pierre Bouillot

Purpose: The morphological and hemodynamic evaluations of neurovascular diseases treated with stents would benefit from noninvasive imaging techniques such as 3D time-of-flight MRI (3D-TOF) and 3D phase contrast MRI (3D-PCMRI). For this purpose, a comprehe ...

WILEY2019

No time for drifting: Comparing performance and applicability of signal detrending algorithms for real-time fMRI

Dimitri Nestor Alice Van De Ville, Frank Scharnowski, Yury Koush, Rotem Roza Kopel

As a consequence of recent technological advances in the field of functional magnetic resonance imaging (fMRI), results can now be made available in real-time. This allows for novel applications such as online quality assurance of the acquisition, intra-op ...

2019

Understanding ultrasound neuromodulation using a computationally efficient and interpretable model of intramembrane cavitation

Silvestro Micera, Esra Neufeld, Théo Lemaire

Objective. Low-intensity focused ultrasound stimulation (LIFUS) emerges as an attracting technology for noninvasive modulation of neural circuits, yet the underlying action mechanisms remain unclear. The neuronal intramembrane cavitation excitation (NICE) ...

2019

MRI artifact correction using sparse plus low-rank decomposition of annihilating filter-based hankel matrix

Kyong Hwan Jin

PurposeMagnetic resonance imaging (MRI) artifacts are originated from various sources including instability of an magnetic resonance (MR) system, patient motion, inhomogeneities of gradient fields, and so on. Such MRI artifacts are usually considered as ir ...

Wiley2017

A Robust Actin Filaments Image Analysis Framework

Giovanni Dietler, Sandor Kasas

The cytoskeleton is a highly dynamical protein network that plays a central role in numerous cellular physiological processes, and is traditionally divided into three components according to its chemical composition, i.e. actin, tubulin and intermediate fi ...

Public Library of Science2016

B1+-mapping and B1+ inhomogeneity correction at high field

Florent Eggenschwiler

Magnetic resonance images acquired at the highest strength of the main magnetic field B0 are of interest since they highly benefit from an increased signal to noise ratio. At ultra high field strengths (B0 > 7 Tesla) images with more contrast and higher re ...

EPFL2015

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

Improving T2 -weighted imaging at high field through the use of kT -points

Rolf Gruetter, José Pedro Rebelo Ferreira Marques, Kieran O'Brien, Florent Eggenschwiler

PURPOSE: At high magnetic field strengths (B0 >/= 3 T), the shorter radiofrequency wavelength produces an inhomogeneous distribution of the transmit magnetic field. This can lead to variable contrast across the brain which is particularly pronounced in T2 ...

Wiley-Blackwell2014

High Temporal Resolution Functional Magnetic Resonance Imaging at 7 Tesla

Mayur Narsude

Speed has always been a critical consideration in magnetic resonance imaging (MRI), promising dramatic gains in imaging speed, a reduction in motion and susceptibility artifacts, and ultimately increased throughput for clinical studies. This thesis present ...

EPFL2014

Analytic Sensing For Multi-Layer Spherical Models With Application To EEG Source Imaging

Dimitri Nestor Alice Van De Ville, Thierry Blu, Djano Kandaswamy

Source imaging maps back boundary measurements to underlying generators within the domain; e. g., retrieving the parameters of the generating dipoles from electrical potential measurements on the scalp such as in electroencephalography (EEG). Fitting such ...

Amer Inst Mathematical Sciences2013

High-Resolution Scanning Tunneling Microscopy Characterization of Mixed Monolayer Protected Gold Nanoparticles

Francesco Stellacci, Paulo Henrique Jacob Silva, Quy Ong Khac, Javier Reguera Gomez, Kellen Michael Harkness, Mauro Moglianetti

Gold nanoparticles protected by a binary mixture of thiolate molecules have a ligand shell that can spontaneously separate into nanoscale domains. Complex morphologies arise in such ligand shells, including striped, patchy, and Janus domains. Characterizat ...

American Chemical Society2013