Research project title
Realtime compensation of magnetic field variation in MRI
Education level
Master or doctorate
Director/co-director
Director: Julien Cohen-Adad
End of display
June 23, 2025
Areas of expertise
Instrumentation and measurements
Unit(s) and department(s)
Department of Electrical Engineering
Biomedical Science and Technologies Research Centre (GRSTB)
Unité de Neuroimagerie Fonctionnelle
Martinos Center for Biomedical Imaging
Montreal Neurological Institute
Detailed description

- Description: To obtain a nice image inside the body, an MRI device assumes that the main magnetic field (B0) is homogeneous and stable over time. Unfortunately (or fortunately for the subject), subjects breathe while in the scanner. When subjects breathe, the B0 field varies in time and space. The NeuroPoly laboratory, in collaboration with Dr. Stockmann (Harvard/MIT), has developed hardware and software methods to compensate for these variations. The principle is based on the development of so-called "shim" coils, in which a direct current circulates, generating a magnetic field (Biot-Savart law) which compensates for the inhomogeneities of the B0 field. To orchestrate these complex experiments, the NeuroPoly laboratory has also developed free software: https://shimming-toolbox.org. We recruit Master/PhD/Postdoc students to work on real-time shimming projects. Examples of projects: implementation of optimization methods to find the right shim current combinations for each coil element (taking into account physical constraints, such as the maximum allowed current and dB/dt), experimentation with human subjects at 3T and 7T (taking measurements, image analysis), comparison and implementation of robust methods to map the B0 field, dynamic and real-time shimming of the spinal cord at 7T. The research will be conducted at the NeuroPoly laboratory (Polytechnique, Université de Montréal, www.neuro.polymtl.ca), at the Montreal Neurological Institute (MNI, McGill University) and in collaboration with the Martinos Center (Harvard/MIT).
- Skills: Ultra-high field MRI | MRI acquisition | Image analysis
- More details here
- Contact: Julien Cohen-Adad

Julien Cohen-Adad
Full Professor