Publications by David Paul Roger Romascano

Successful MRI-Guided Focused Ultrasound Thalamotomy after Ipsilateral Gamma Knife Radiosurgery for Essential Tremor: A Case Report with Video

David Paul Roger Romascano, Damien Schneider, Constantin Tuleasca

We report the case of a 67-year-old left-handed female patient with disabling medically refractory essential tremor who underwent successful right-sided magnetic resonance-guided focused ultrasound (MRgFUS) of the ventral intermediate nucleus after ipsilat ...

Karger2023

Bundle-Specific Axon Diameter Index as a New Contrast to Differentiate White Matter Tracts

Jean-Philippe Thiran, Giorgio Innocenti, David Paul Roger Romascano, Cristina Granziera, Alessandro Daducci, Muhamed Barakovic, Gabriel Girard, Maxime Descoteaux

In the central nervous system of primates, several pathways are characterized by different spectra of axon diameters. In vivo methods, based on diffusion-weighted magnetic resonance imaging, can provide axon diameter index estimates non-invasively. However ...

2021

ActiveAx(ADD): Toward non-parametric and orientationally invariant axon diameter distribution mapping using PGSE

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci, Muhamed Barakovic, Jonathan Rafael Patino Lopez, Tim Bjørn Dyrby

Purpose Non-invasive axon diameter distribution (ADD) mapping using diffusion MRI is an ill-posed problem. Current ADD mapping methods require knowledge of axon orientation before performing the acquisition. Instead, ActiveAx uses a 3D sampling scheme to e ...

Wiley2020

Tractostorm: The what, why, and how of tractography dissection reproducibility

David Paul Roger Romascano, Alessandro Daducci, Muhamed Barakovic, Gabriel Girard, Maxime Descoteaux

Investigative studies of white matter (WM) brain structures using diffusion MRI (dMRI) tractography frequently require manual WM bundle segmentation, often called "virtual dissection." Human errors and personal decisions make these manual segmentations har ...

Wiley2020

Robust Monte-Carlo Simulations in Diffusion-MRI: Effect of the Substrate Complexity and Parameter Choice on the Reproducibility of Results

Jean-Philippe Thiran, David Paul Roger Romascano, Gabriel Girard, Jonathan Rafael Patino Lopez, Erick Jorge Canales Rodriguez, Alonso Ramirez Manzanares

Monte-Carlo Diffusion Simulations (MCDS) have been used extensively as a ground truth tool for the validation of microstructure models for Diffusion-Weighted MRI. However, methodological pitfalls in the design of the biomimicking geometrical configurations ...

2020

Sparse wars: A survey and comparative study of spherical deconvolution algorithms for diffusion MRI

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci, Muhamed Barakovic, Gabriel Girard, Gaëtan Olivier D Rensonnet, Jonathan Rafael Patino Lopez, Erick Jorge Canales Rodriguez, Marco Pizzolato

Spherical deconvolution methods are widely used to estimate the brain's white-matter fiber orientations from diffusion MRI data. In this study, eight spherical deconvolution algorithms were implemented and evaluated. These included two model selection tech ...

2019

Towards non-parametric reconstruction of axon diameter distributions using diffusion MRI and regularized discrete linear modeling

David Paul Roger Romascano

The distribution of axon diameters (ADD) is an important white matter feature: it influences action potential speed, it has been shown to evolve during development, and also to be affected during pathological processes. Diffusion Magnetic Resonance Imaging ...

EPFL2019

Assessing feasibility and reproducibility of a bundle-specific framework on in vivo axon diameter estimates at 300mT/m

Jean-Philippe Thiran, Giorgio Innocenti, David Paul Roger Romascano, Alessandro Daducci, Muhamed Barakovic, Gabriel Girard, Maxime Descoteaux, Jonathan Rafael Patino Lopez

In vivo quantitative estimation of axon diameter in the white matter could bring new tools to study the structural and functional architecture of the brain. Recently, the feasibility of axon diameter estimation with diffusion-weighted MRI (DW-MRI) has been ...

2018

Voxel size matters: big voxels are required to generate realistic extra-axonal dMRI signals from Monte Carlo simulations

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci, Muhamed Barakovic, Ileana Ozana Jelescu, Jonathan Rafael Patino Lopez, Tim Bjørn Dyrby

2018

Non-parametric axon diameter distribution mapping with PGSE: reconstruction of uni- and multimodal distributions

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci, Muhamed Barakovic, Jonathan Rafael Patino Lopez, Tim Bjørn Dyrby

2018

Central nervous system microbleeds in the acute phase are associated with structural integrity by DTI one year after mild traumatic brain injury: A longitudinal study

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci, Pietro Bontempi

Introduction: Several imaging modalities are under investigation to unravel the pathophysiological mystery of delayed performance deficits in patients after mild traumatic brain injury (mTBI). Although both imaging and neuropsychological studies have been ...

ELSEVIER URBAN & PARTNER SP Z O O2018

Realistic 3D Fiber Crossing Phantom Models for Monte Carlo Diffusion Simulations

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci, Muhamed Barakovic, Gabriel Girard, Gaëtan Olivier D Rensonnet, Jonathan Rafael Patino Lopez

2018

In-vivo Bundle-Specific Axon Diameter Distributions Estimation across the Corpus Callosum

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci, Muhamed Barakovic, Gabriel Girard, Maxime Descoteaux

Over the last decade microstructure imaging has become commonly endorsed to estimate quantitative features of neuronal tissue. However, those techniques estimate the microstructure only locally. Microstructure informed tractography was recently proposed to ...

2017

When does a volume of a bundle achieve saturation? A microstructure informed tractography study

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci, Muhamed Barakovic, Gabriel Girard, Maxime Descoteaux

Volumetric analysis of bundles derived from tractography is a popular statistical measure used in neurological disorder studies. Recent research performed by Gauvin shows that different bundles saturate with different tractography parameters, however, to a ...

2017

Orientation invariant and non-parametric Axon Diameter Distribution mapping using PGSE and regularized discrete linear modeling

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci, Anna Auria Rasclosa, Muhamed Barakovic, Tim Bjørn Dyrby

Axon Diameter Distributions (ADDs) change during brain development and are altered in several brain pathologies. Mapping ADDs non-invasively using dMRI could provide a useful biomarker, but existing methods are either parametric, orientation dependent, sur ...

2017

Reducing acquisition time for axon diameter mapping using global optimization in the spatial-angular-microstructure space

Jean-Philippe Thiran, Yves Wiaux, David Paul Roger Romascano, Alessandro Daducci, Anna Auria Rasclosa, Erick Jorge Canales Rodriguez, Tim Bjørn Dyrby

State-of-the-art microstructure imaging methods usually fit biophysical models to the diffusion MRI data on a voxel-by-voxel basis using non-linear procedures that require both long acquisitions and processing time. We recently introduced AMICO, a framewor ...

2016

Reducing acquisition time for microstructure imaging with spatially-regularized global optimization

Jean-Philippe Thiran, Yves Wiaux, David Paul Roger Romascano, Alessandro Daducci, Anna Auria Rasclosa, Erick Jorge Canales Rodriguez, Tim Bjørn Dyrby

Microstructure imaging with diffusion MRI (dMRI) is usually based on fitting models to the data using voxelwise nonlinear procedures that (i) are time consuming and (ii) need long acquisitions. Recently, we introduced the AMICO framework to accelerate the ...

2016

On evaluating the accuracy and biological plausibility of diffusion MRI tractograms

Jean-Philippe Thiran, David Paul Roger Romascano, Alessandro Daducci

One of the major limitations of diffusion MRI tractography is that the tractograms, i.e. set of fiber tracts, recovered by existing algorithms are not truly quantitative. Hence, the structural connectivity between different brain regions, a.k.a. connectomi ...

2015

Multicontrast connectometry: A new tool to assess cerebellum alterations in early relapsing‐remitting multiple sclerosis

Jonas Richiardi, Gloria Menegaz, Jean-Philippe Thiran, Djalel Eddine Meskaldji, Dimitri Nestor Alice Van De Ville, Guillaume Bonnier, David Paul Roger Romascano, Gunnar Krüger, Cristina Granziera, Alessandro Daducci, Alexis Roche, Ying-Chia Lin

Background: Cerebellar pathology occurs in late multiple sclerosis (MS) but little is known about cerebellar changes during early disease stages. In this study, we propose a new multicontrast “connectometry” approach to assess the structural and functional ...

Wiley-Blackwell2015

Multicontrast MRI Quantification of Focal Inflammation and Degeneration in Multiple Sclerosis

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

Introduction. Local microstructural pathology in multiple sclerosis patients might influence their clinical performance. This study applied multicontrast MRI to quantify inflammation and neurodegeneration in MS lesions. We explored the impact of MRI-based ...

Hindawi Publishing Corporation2015