Publications by Gian Franco Piredda

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

Deep multiple sclerosis lesion phenotyping using multimodal quantitative MRI

Tobias Kober, Tom Hilbert, Gian Franco Piredda

Sage Publications Ltd2023

Variability and reproducibility of multi-echo T2 relaxometry: Insights from multi-site, multi-session and multi-subject MRI acquisitions

Jean-Philippe Thiran, Tobias Kober, Elda Fischi Gomez, Alessandro Daducci, Tom Hilbert, Elena Beanato, Gabriel Girard, Julia Brügger, Gian Franco Piredda, Friedhelm Christoph Hummel, Takuya Morishita, Maximilian Jonas Wessel, Philipp Johannes Koch, Erick Jorge Canales Rodriguez, Marco Pizzolato, Andéol Geoffroy Cadic-Melchior, Thomas Yu, Chang-Hyun Park

Quantitative magnetic resonance imaging (qMRI) can increase the specificity and sensitivity of conventional weighted MRI to underlying pathology by comparing meaningful physical or chemical parameters, measured in physical units, with normative values acqu ...

2022

Compressed sensing (CS) MP2RAGE versus standard MPRAGE: A of derived brain volume measurements

Tobias Kober, Tom Hilbert, Gian Franco Piredda

Purpose: T1 Magnetization Prepared Two Rapid Acquisition Gradient Echo (MP2RAGE) with compress sensing (CS) has been proposed as an improvement of the standard MPRAGE sequence with multiple advantages including reduced acquisition time needed to provide a ...

ELSEVIER SCI LTD2022

First evidence on the utility of T-1 mapping of the optic nerve to investigate differences between MS and NMOSD

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

SAGE PUBLICATIONS LTD2022

Evaluating reproducibility and subject-specificity of microstructure-informed connectivity

Jean-Philippe Thiran, Tobias Kober, Elda Fischi Gomez, Tom Hilbert, Elena Beanato, Gabriel Girard, Julia Brügger, Gian Franco Piredda, Friedhelm Christoph Hummel, Takuya Morishita, Maximilian Jonas Wessel, Philipp Johannes Koch, Erick Jorge Canales Rodriguez, Marco Pizzolato, Andéol Geoffroy Cadic-Melchior, Chang-Hyun Park

Tractography enables identifying and evaluating the healthy and diseased brain's white matter pathways from diffusion-weighted magnetic resonance imaging data. As previous evaluation studies have reported significant false-positive estimation biases, recen ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

Towards better characterization of spinal cord pathology in early stages of multiple sclerosis using T1 mapping

Bénédicte Marie Maréchal, Tobias Kober, Tom Hilbert, Veronica Lily Ravano, Gian Franco Piredda

SAGE PUBLICATIONS LTD2022

Periventricular gradient of T1 tissue alterations in multiple sclerosis

Bénédicte Marie Maréchal, Tobias Kober, Tom Hilbert, Veronica Lily Ravano, Gian Franco Piredda

Objective: Pathology in multiple sclerosis is not homogenously distributed. Recently, it has been shown that structures adjacent to CSF are more severely affected. A gradient of brain tissue involvement was shown with more severe pathology in periventricul ...

ELSEVIER SCI LTD2022

Submillimeter T-1 atlas for subject-specific abnormality detection at 7T

Jean-Philippe Thiran, Bénédicte Marie Maréchal, Tobias Kober, Tom Hilbert, Ricardo Alberto Corredor Jerez, Gian Franco Piredda

Purpose: Studies at 3T have shown that T-1 relaxometry enables characterization of brain tissues at the single-subject level by comparing individual physical properties to a normative atlas. In this work, an atlas of normative T-1 values at 7T is introduce ...

WILEY2022

Comparison of non-parametric T2 relaxometry methods for myelin water quantification

Jean-Philippe Thiran, Nicolas Kunz, Tobias Kober, Alessandro Daducci, Tom Hilbert, Gian Franco Piredda, Erick Jorge Canales Rodriguez, Marco Pizzolato, Thomas Yu

Multi-component T2 relaxometry allows probing tissue microstructure by assessing compartment-specific T2 relaxation times and water fractions, including the myelin water fraction. Non-negative least squares (NNLS) with zero-order Tikhonov regularization is ...

2021

Multi-Compartment Diffusion Mri, T2 Relaxometry And Myelin Water Imaging As Neuroimaging Descriptors For Anomalous Tissue Detection

Jean-Philippe Thiran, Elda Fischi Gomez, Gian Franco Piredda, Jonathan Rafael Patino Lopez, Erick Jorge Canales Rodriguez, Marco Pizzolato

Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease characterized by diffuse and focal areas of tissue loss. Conventional MRI techniques such as T1-weighted and T2-weighted scans are generally used in the diagnosis and prognosis of the ...

IEEE2021

Quantitative Microstructural Imaging for Clinical Use

Gian Franco Piredda

Today, Magnetic Resonance Imaging (MRI) is a well-established medical imaging modality thanks to its excellent soft tissue contrast. Conventional MR image contrasts can be weighted towards one or more physical properties that discriminate different tissues ...

EPFL2021

Model-informed machine learning for multi-component T2 relaxometry

Jean-Philippe Thiran, Meritxell Bach Cuadra, Tobias Kober, Elda Fischi Gomez, Cristina Granziera, Tom Hilbert, Muhamed Barakovic, Gian Franco Piredda, Erick Jorge Canales Rodriguez, Marco Pizzolato, Thomas Yu

Recovering the distribution from multi-echo magnetic resonance (MR) signals is challenging but has high potential as it provides biomarkers characterizing the tissue micro-structure, such as the myelin water fraction (MWF). In this work, we propose to comb ...

2020

Normal volumetric and T1 relaxation time values at 1.5 T in segmented pediatric brain MRI using a MP2RAGE acquisition

Jean-Philippe Thiran, Bénédicte Marie Maréchal, Tobias Kober, Tom Hilbert, Gian Franco Piredda

Objectives This study introduced a tailored MP2RAGE-based brain acquisition for a comprehensive assessment of the normal maturing brain. Methods Seventy normal patients (35 girls and 35 boys) from 1 to 16 years of age were recruited within a prospective mo ...

SPRINGER2021

Probing myelin content of the human brain with MRI: A review

Jean-Philippe Thiran, Tobias Kober, Tom Hilbert, Gian Franco Piredda

Rapid and efficient transmission of electric signals among neurons of vertebrates is ensured by myelin-insulating sheaths surrounding axons. Human cognition, sensation, and motor functions rely on the integrity of these layers, and demyelinating diseases o ...

WILEY2021

Fast and high-resolution myelin water imaging: Accelerating multi-echo GRASE with CAIPIRINHA

Jean-Philippe Thiran, Reto Meuli, Tobias Kober, Alessandro Daducci, Tom Hilbert, Gian Franco Piredda, Erick Jorge Canales Rodriguez, Marco Pizzolato

Purpose Although several MRI methods have been explored to achievein vivomyelin quantification, imaging the whole brain in clinically acceptable times and sufficiently high resolution remains challenging. To address this problem, this work investigates the ...

Wiley2021

Model-based super-resolution reconstruction of T-2 maps

Jean-Philippe Thiran, Reto Meuli, Mohammad Golbabaee, Tobias Kober, Tom Hilbert, Gian Franco Piredda, Wajiha Bano

Purpose High-resolution isotropic T-2 mapping of the human brain with multi-echo spin-echo (MESE) acquisitions is challenging. When using a 2D sequence, the resolution is limited by the slice thickness. If used as a 3D acquisition, specific absorption rate ...

Wiley2020

Quantitative brain relaxation atlases for personalized detection and characterization of brain pathology

Jean-Philippe Thiran, Reto Meuli, Guillaume Bonnier, Tobias Kober, Cristina Granziera, Tom Hilbert, Gian Franco Piredda

Purpose To exploit the improved comparability and hardware independency of quantitative MRI, databases of MR physical parameters in healthy tissue are required, to which tissue properties of patients can be compared. In this work, normative values for long ...

WILEY2020