Portrait of Julien Cohen-Adad

Julien Cohen-Adad

Associate Academic Member
Associate Professor, Polytechnique Montréal, Electrical Engineering Department
Adjunct Professor, Université de Montréal, Department of Neuroscience
Research Topics
Medical Machine Learning

Biography

Julien Cohen-Adad is a professor at Polytechnique Montréal and the associate director of the Neuroimaging Functional Unit at Université de Montréal. He is also the Canada Research Chair in Quantitative Magnetic Resonance Imaging.

His research focuses on advancing neuroimaging methods with the help of AI. Some examples of projects are:

- Multi-modal training for medical imaging tasks (segmentation of pathologies, diagnosis, etc.)

- Adding prior from MRI physics to improve model generalization

- Incorporating uncertainty measures to deal with inter-rater variability

- Continuous learning strategies when data sharing is restricted

- Bringing AI methods into clinical radiology routine via user-friendly software solutions

Cohen-Adad also leads multiple open-source software projects that are benefiting the research and clinical community (see neuro.polymtl.ca/software.html). In short, he loves MRI with strong magnets, neuroimaging, programming and open science!

Current Students

Collaborating Alumni - Polytechnique Montréal
Co-supervisor :
PhD - Polytechnique Montréal
Co-supervisor :
PhD - Polytechnique Montréal
Master's Research - Polytechnique Montréal
Master's Research - Polytechnique Montréal
PhD - Polytechnique Montréal
PhD - Polytechnique Montréal
Collaborating researcher
Master's Research - Université de Montréal
Master's Research - Polytechnique Montréal
Postdoctorate - Polytechnique Montréal

Publications

Rootlets-based registration to the PAM50 spinal cord template
Sandrine Bédard
Valeria Oliva
Kenneth A. Weber
Abstract Spinal cord functional MRI studies require precise localization of spinal levels for reliable voxel-wise group analyses. Traditiona… (see more)l template-based registration of the spinal cord uses intervertebral discs for alignment. However, substantial anatomical variability across individuals exists between vertebral and spinal levels. This study proposes a novel registration approach that leverages spinal nerve rootlets to improve alignment accuracy and reproducibility across individuals. We developed a registration method leveraging dorsal cervical rootlets segmentation and aligning them non-linearly with the PAM50 spinal cord template. Validation was performed on a multi-subject, multi-site dataset (n = 267, 44 sites) and a multi-subject dataset with various neck positions (n = 10, 3 sessions). We further validated the method on task-based functional MRI (n = 23) to compare group-level activation maps using rootlet-based registration to traditional disc-based methods. Rootlet-based registration showed superior alignment across individuals compared with the traditional disc-based method on n = 226 individuals, and on n = 176 individuals for morphological analyses. Notably, rootlet positions were more stable across neck positions. Group-level analysis of task-based functional MRI using rootlet-based registration increased Z scores and activation cluster size compared with disc-based registration (number of active voxels from 3292 to 7978). Rootlet-based registration enhances both inter- and intra-subject anatomical alignment and yields better spatial normalization for group-level fMRI analyses. Our findings highlight the potential of rootlet-based registration to improve the precision and reliability of spinal cord neuroimaging group analysis.
Cervical Spinal Cord Magnetization Transfer Ratio and Its Relationship With Clinical Outcomes in Multiple Sclerosis
Lisa Eunyoung Lee
Irene M. Vavasour
Melanie Guenette
Katherine Sawicka
Neda Rashidi‐Ranjbar
Nathan Churchill
Akash Chopra
Adelia Adelia
Pierre-Louis Benveniste
Anthony Traboulsee
Nathalie Arbour
Fabrizio Giuliani
Larry D. Lynd
Scott B. Patten
Alexandre Prat
Alice Schabas
Penelope Smyth
Roger Tam
Yunyan Zhang … (see 6 more)
Simon J. Graham
Mojgan Hodaie
Anthony Feinstein
Shannon Kolind
Tom A. Schweizer
Jiwon Oh
Monitoring morphometric drift in lifelong learning segmentation of the spinal cord
Enamundram Naga Karthik
Sandrine Bédard
Christoph S. Aigner
Elise Bannier
Josef Bednařík
Virginie Callot
Anna Combes
Armin Curt
Gergely David
Falk Eippert
Lynn Farner
Michael G Fehlings
Patrick Freund
Tobias Granberg
Cristina Granziera
Rhscir Network Imaging Group
Ulrike Horn
Tomáš Horák … (see 36 more)
Suzanne Humphreys
Markus Hupp
Anne Kerbrat
Nawal Kinany
Shannon Kolind
Anna Lebret
Petr Kudlička
Lisa Eunyoung Lee
Caterina Mainero
Allan R. Martin
Megan McGrath
Govind Nair
Kristin P. O’Grady
Jiwon Oh
Russell Ouellette
Nikolai Pfender
Dario Pfyffer
P. Pradat
Alexandre Prat
Emanuele Pravatà
Daniel S. Reich
Ilaria Ricchi
Naama Rotem-Kohavi
Simon Schading-Sassenhausen
Maryam Seif
Andrew C. Smith
Seth Aaron Smith
Grace Sweeney
Roger Tam
Anthony Traboulsee
Constantina A. Treaba
Charidimos Tsagkas
Zachary Vavasour
Dimitri Van De Ville
Kenneth A. Weber
Ultrasound and MRI-based evaluation of relationships between morphological and mechanical properties of the lower lumbar multifidus muscle in chronic low back pain.
Neda Naghdi
Sara Masi
Cléo Bertrand
Brent Rosenstein
Hassan Rivaz
Mathieu Roy
Maryse Fortin
Multi-center benchmarking of cervical spinal cord RF coils for 7 T MRI: A traveling spines study
Eva Alonso‐Ortiz
Daniel Papp
Robert L. Barry
Kyota Poëti
Alan C. Seifert
Kyle M. Gilbert
Nibardo Lopez‐Rios
Jan Paska
Falk Eippert
Nikolaus Weiskopf
Laura Beghini
Nadine Graedel
Robert Trampel
Martina F Callaghan
Christoph S. Aigner
Patrick Freund
Maryam Seif
Aurélien Destruel
Virginie Callot
Johanna Vannesjo … (see 1 more)
Multi‐center benchmarking of cervical spinal cord <scp>RF</scp> coils for 7 T <scp>MRI</scp>: A traveling spines study
Eva Alonso‐Ortiz
Daniel Papp
Robert L. Barry
Kyota Poëti
Alan C. Seifert
Kyle M. Gilbert
Nibardo Lopez‐Rios
Jan Paska
Falk Eippert
Nikolaus Weiskopf
Laura Beghini
Nadine Graedel
Robert Trampel
Martina F Callaghan
Christoph S. Aigner
Patrick Freund
Maryam Seif
Aurélien Destruel
Virginie Callot
Johanna Vannesjo … (see 1 more)
Influence of scanning plane on Human Spinal Cord functional Magnetic Resonance echo planar imaging
Marta Moraschi
Silvia Tommasin
Laura Maugeri
Mauro DiNuzzo
Marco Masullo
Fabio Mangini
Lorenzo Giovannelli
Daniele Mascali
Tommaso Gili
Valerio Pisani
Ugo Nocentini
Federico Giove
Michela Fratini
BACKGROUND: Functional Magnetic Resonance Imaging (fMRI) is based on the Blood Oxygenation Level Dependent contrast and has been exploited f… (see more)or the indirect study of the neuronal activity within both the brain and the spinal cord. However, the interpretation of spinal cord fMRI (scfMRI) is still controversial and its diffusion is rather limited because of technical limitations. Overcoming these limitations would have a beneficial effect for the assessment and follow-up of spinal injuries and neurodegenerative diseases. PURPOSE: This study was aimed at systematically verify whether sagittal scanning in scfMRI using EPI readout is a viable alternative to the more common axial scanning, and at optimizing a pipeline for EPI-based scfMRI data analysis, based on Spinal Cord Toolbox (SCT). METHODS: Forty-five healthy subjects underwent MRI acquisition in a Philips Achieva 3T MRI scanner. T2*-weighted fMRI data were acquired using a GE-EPI sequence along sagittal and axial planes during an isometric motor task. Differences on benchmarks were assessed via paired two-sample t-test at p=0.05. RESULTS: We investigated the impact of the acquisition strategy by means of various metrics such as Temporal Signal to Noise Ratio (tSNR), Dice Coefficient to assess geometric distortions, Reproducibility and Sensitivity. tSNR was higher in axial than in sagittal scans, as well as reproducibility within the whole cord mask (t=7.4, p0.01) and within the GM mask (t=4.2, p0.01). The other benchmarks, associated with distortion and functional response, showed no differenc
Monitoring morphometric drift in lifelong learning segmentation of the spinal cord
Enamundram Naga Karthik
Sandrine B'edard
Jan Valovsek
Christoph Aigner
Elise Bannier
Josef Bednavr'ik
Virginie Callot
Anna Combes
Armin Curt
Gergely David
Falk Eippert
Lynn Farner
M. G. Fehlings
Patrick Freund
Tobias Granberg
Cristina Granziera
Rhscir Network Imaging Group
Ulrike Horn
Tom'avs Hor'ak
Suzanne Humphreys … (see 36 more)
Markus Hupp
Anne Kerbrat
Nawal Kinany
Shannon Kolind
Petr Kudlivcka
Anna Lebret
Lisa Eunyoung Lee
Caterina Mainero
Allan R. Martin
Megan McGrath
Govind Nair
Kristin P. O’Grady
Jiwon Oh
Russell Ouellette
Nikolai Pfender
Dario Pfyffer
P. Pradat
Alexandre Prat
Emanuele Pravatà
D. S. Reich
Ilaria Ricchi
Naama Rotem-Kohavi
Simon Schading-Sassenhausen
Maryam Seif
Andrew C. Smith
Seth Aaron Smith
Grace Sweeney
Roger Tam
Anthony Traboulsee
Constantina A. Treaba
Charidimos Tsagkas
Zachary Vavasour
Dimitri Van De Ville
Kenneth A. Weber
Impact of through‐slice gradient optimization for dynamic slice‐wise shimming in the cervico‐thoracic spinal cord
Arnaud Breheret
Alexandre D'Astous
Yixin Ma
Jason P. Stockmann
Rootlets-based registration to the spinal cord PAM50 template
Sandrine Bédard
Valeria Oliva
Kenneth A. Weber
Spinal Cord Tract Integrity in Degenerative Cervical Myelopathy.
Newton Cho
Abdul Al-Shawwa
W. Bradley Jacobs
Nathan Evaniew
Jacques Bouchard
Steven Casha
Stephan duPlessis
Peter Lewkonia
Fred Nicholls
Alex Soroceanu
Ganesh Swamy
Kenneth C. Thomas
Michael M.H. Yang
David W. Cadotte
Addressing Missing Modality Challenges in MRI Images: A Comprehensive Review
Reza Azad
Mohammad Dehghanmanshadi
Nika Khosravi
Dorit Merhof