Related Experiment Video
Updated: Jan 29, 2026

A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia
Published on: September 16, 2017
3D-Spatial encoding with permanent magnets for ultra-low field magnetic resonance imaging
Michael W Vogel1, Ruben Pellicer Guridi2, Jiasheng Su2
1Centre for Advanced Imaging, University of Queensland, Brisbane, Queensland, Australia. michael.vogel@cai.uq.edu.au.
Abstract:
We describe with a theoretical and numerical analysis the use of small permanent magnets moving along prescribed helical paths for 3D spatial encoding and imaging without sample adjustment in ultra-low field magnetic resonance imaging (ULF-MRI). With our developed method the optimal magnet path and orientation for a given encoding magnet number and instrument architecture can be determined. As a proof-of-concept, we studied simple helical magnet paths and lengths for one and two encoding magnets to evaluate the imaging efficiency for a mechanically operated ULF-MRI instrument with permanent magnets. We demonstrate that a single encoding magnet moving around the sample in a single revolution suffices for the generation of a 3D image by back projection.
Related Concept Videos
Magnetic Resonance Imaging
Magnetic Fields
A magnetic field is defined by the force that a charged particle experiences...
Imaging Studies IV: Magnetic Resonance Imaging
Magnetic Field of a Solenoid
Consider a solenoid with 100 turns wrapped around a cylinder of...
Magnetic Field Lines
Magnetic field lines follow several hard-and-fast rules:
Energy In A Magnetic Field
Take an ideal inductor with zero resistance. Although it's practically impossible, assume that the coil's resistance is so small that it is practically negligible. The loss of the field's energy to dissipate thermal energy (or heat) is thus...

