AUTHOR=Rodriguez Gonzalo G. , Schürrer Clemar A. , Anoardo Esteban 

TITLE=Low-field MRI at high magnetic field instability and inhomogeneity conditions

JOURNAL=Frontiers in Physics

VOLUME=11

YEAR=2023

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2023.1249771

DOI=10.3389/fphy.2023.1249771

ISSN=2296-424X

ABSTRACT=<p>Understanding the effects of the magnetic field time instabilities in magnetic resonance imaging (MRI) is fundamental for the success of portable and low-cost MRI hardware based on electromagnets. In this work we propose a magnetic field model that considers the field instability in addition to the inhomogeneity. We have successfully validated the model on signals acquired with a commercial NMR instrument. It was used to simulate the image defects due to different types of instability for both the spin-echo and the gradient-echo sequences. We have considered both random field fluctuations, and an instability having a dominant harmonic component. Strategies are suggested to minimize the artifacts generated by these instabilities. Images were acquired using a home-made MRI relaxometer to show the consistency of the analysis.</p>