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Peter Modregger

Cette personne a quitté l’EPFL

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Publications associées (23)

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A sensitive x-ray phase contrast technique for rapid imaging using a single phase grid analyzer

Peter Modregger

Phase contrast x-ray imaging (PCXI) is a promising imaging modality, capable of sensitively differentiating soft tissue structures at high spatial resolution. However, high sensitivity often comes at the cost of a long exposure time or multiple exposures p ...

Optical Society of America2013

Living-Engineered Valves for Transcatheter Venous Valve Repair

Peter Modregger

Background: Chronic venous insufficiency (CVI) represents a major global health problem with increasing prevalence and morbidity. CVI is due to an incompetence of the venous valves, which causes venous reflux and distal venous hypertension. Several studies ...

2014

Combining Monte Carlo methods with coherent wave optics for the simulation of phase-sensitive X-ray imaging

Peter Modregger

Phase-sensitive X-ray imaging shows a high sensitivity towards electron density variations, making it well suited for imaging of soft tissue matter. However, there are still open questions about the details of the image formation process. Here, a framework ...

International Union of Crystallography2014

Differential X-ray phase contrast tomography of Alzheimer plaques in mouse models: perspectives for drug development and clinical imaging techniques

Peter Modregger

Alzheimer's disease (AD) is a looming threat on an ever-ageing population, with devastating effects on the human intellect. A particular characteristic lesion - the extracellular amyloid plaque - accumulates in the brain of AD patients during the course of ...

Institute of Physics2013

Constrained regularized reconstruction of X-ray-DPCI tomograms with weighted-norm

Michaël Unser, Cédric René Jean Vonesch, Peter Modregger, Masih Nilchian, Stamatios Lefkimmiatis

In this paper we introduce a new reconstruction algorithm for X-ray differential phase-contrast Imaging (DPCI). Our approach is based on 1) a variational formulation with a weighted data term and 2) a variable-splitting scheme that allows for fast converge ...

Optical Society of America2013

Iterative FBP For Improved Reconstruction Of X-Ray Differential Phase-Contrast Tomograms

Michaël Unser, Cédric René Jean Vonesch, Peter Modregger, Masih Nilchian

X-ray differential phase-contrast tomography is a recently-developed modality for the imaging of low-contrast biological samples. Its mathematical model is based on the first derivative of the Radon transform and the images, in practice, are reconstructed ...

IEEE2013

A tilted grating interferometer for full vector field differential x-ray phase contrast tomography

Peter Modregger

We report on a setup for differential x-ray phase-contrast imaging and tomography, that measures the full 2D phase-gradient information. The setup uses a simple one-dimensional x-ray grating interferometer, in which the grating structures of the interferom ...

Optical Society of America2012

Simple merging technique for improving resolution in qualitative single image phase contrast tomography

Peter Modregger

For dynamic samples and/or for simple ease-of-use experiments, single-image phase contrast tomography is a very effective method for the 3D visualization of materials which would otherwise be indiscernible in attenuation based x-ray imaging. With binary sa ...

Optical Society of America2014

Imaging brain amyloid deposition using grating-based differential phase contrast tomography

Patrick Aebischer, Jean-Charles Bensadoun, Peter Modregger

One of the core pathological features of Alzheimer's disease (AD) is the accumulation of amyloid plaques in the brain. Current efforts of medical imaging research aim at visualizing amyloid plaques in living patients in order to evaluate the progression of ...

Elsevier2012

Dissecting abdominal aortic aneurysm in Ang II-infused mice: suprarenal branch ruptures and apparent luminal dilatation

Nikolaos Stergiopoulos, Bram Trachet, Alessandra Piersigilli, Peter Modregger, Jessica Sordet

Aims In this work, we provide novel insight into the morphology of dissecting abdominal aortic aneurysms in angiotensin II-infused mice. We demonstrate why they exhibit a large variation in shape and, unlike their human counterparts, are located suprarenal ...

Oxford University Press2015

Engineering of living autologous human umbilical cord cell-based septal occluder membranes using composite PGA-P4HB matrices

Peter Modregger

Interventional closure of intracardiac wall defects using occluder devices has evolved as a highly attractive treatment option. However, incomplete and delayed healing reactions often result in a major risk of residual defects, thromboembolism, or device f ...

2011

Prenatally engineered autologous amniotic fluid stem cell-based heart valves in the fetal circulation

Peter Modregger

Prenatal heart valve interventions aiming at the early and systematic correction of congenital cardiac malformations represent a promising treatment option in maternal-fetal care. However, definite fetal valve replacements require growing implants adaptive ...

2012

Fast iterative reconstruction of differential phase contrast X-ray tomograms

Michaël Unser, Cédric René Jean Vonesch, Masih Nilchian, Peter Modregger

Differential phase-contrast is a recent technique in the context of X-ray imaging. In order to reduce the specimen's exposure time, we propose a new iterative algorithm that can achieve the same quality as FBP-type methods, while using substantially fewer ...

Optical Society of America2013

Two-dimensional ultra-small angle X-ray scattering with grating interferometry

Peter Modregger

It was recently established that the pixel-wise ultra-small angle x-ray distribution can be retrieved with grating interferometry. However, in these one dimensional approaches the contrast was limited to the direction orthogonal to the structure of the lin ...

AIP American Institute of Physics2014

Simultaneous submicrometric 3D imaging of the micro-vascular network and the neuronal system in a mouse spinal cord

Peter Modregger

Faults in vascular (VN) and neuronal networks of spinal cord are responsible for serious neurodegenerative pathologies. Because of inadequate investigation tools, the lacking knowledge of the complete fine structure of VN and neuronal system represents a c ...

Nature Publishing Group2015

Off-the-shelf human decellularized tissue-engineered heart valves in a non-human primate model

Peter Modregger

Heart valve tissue engineering based on decellularized xenogenic or allogenic starter matrices has shown promising first clinical results. However, the availability of healthy homologous donor valves is limited and xenogenic materials are associated with i ...

Elsevier2013

Multiple Scattering Tomography

Peter Modregger

Multiple scattering represents a challenge for numerous modern tomographic imaging techniques. In this Letter, we derive an appropriate line integral that allows for the tomographic reconstruction of angular resolved scattering distributions, even in the p ...

Amer Physical Soc2014

Sensitivity of X-ray grating interferometry

Peter Modregger

It is known that the sensitivity of X-ray phase-contrast grating interferometry with regard to electron density variations present in the sample is related to the minimum detectable refraction angle. In this article a numerical framework is developed that ...

Optical Society of America2011

High resolution, large field of view x-ray differential phase contrast imaging on a compact setup

Peter Modregger

X-ray grating interferometry is a well established technique to perform differential phase contrast imaging on conventional x-ray tubes. So far, the application of this technique in commercial micro computed tomography scanners has remained a major challen ...

American Institute of Physics2011

Three-dimensional pore structure and ion conductivity of porous ceramic diaphragms

Andreas Züttel, Peter Modregger, Laura Victoria Suárez Murillo

Wiley-Blackwell2013