High-sensitivity in vivo contrast for ultra-low field magnetic resonance imaging using superparamagnetic iron oxide nanoparticles

David E J Waddington; Thomas Boele; Richard Maschmeyer; Zdenka Kuncic; Matthew S Rosen

doi:10.1126/sciadv.abb0998

High-sensitivity in vivo contrast for ultra-low field magnetic resonance imaging using superparamagnetic iron oxide nanoparticles

Sci Adv. 2020 Jul 17;6(29):eabb0998. doi: 10.1126/sciadv.abb0998. eCollection 2020 Jul.

Authors

David E J Waddington^{1

2

3}, Thomas Boele^{2

4}, Richard Maschmeyer¹, Zdenka Kuncic^{1

5}, Matthew S Rosen^{2

6

7}

Affiliations

¹ Institute of Medical Physics, School of Physics A28, University of Sydney, Sydney, NSW 2006, Australia.
² A. A. Martinos Center for Biomedical Imaging, 149 Thirteenth St., Charlestown, MA 02129, USA.
³ ACRF Image X Institute, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia.
⁴ ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, University of Sydney, Sydney, NSW 2006, Australia.
⁵ The University of Sydney Nano Institute, Sydney, NSW 2006, Australia.
⁶ Department of Physics, Harvard University, 17 Oxford St., Cambridge, MA 02138, USA.
⁷ Harvard Medical School, 25 Shattuck St., Boston, MA 02115, USA.

Abstract

Magnetic resonance imaging (MRI) scanners operating at ultra-low magnetic fields (ULF; <10 mT) are uniquely positioned to reduce the cost and expand the clinical accessibility of MRI. A fundamental challenge for ULF MRI is obtaining high-contrast images without compromising acquisition sensitivity to the point that scan times become clinically unacceptable. Here, we demonstrate that the high magnetization of superparamagnetic iron oxide nanoparticles (SPIONs) at ULF makes possible relaxivity- and susceptibility-based effects unachievable with conventional contrast agents (CAs). We leverage these effects to acquire high-contrast images of SPIONs in a rat model with ULF MRI using short scan times. This work overcomes a key limitation of ULF MRI by enabling in vivo imaging of biocompatible CAs. These results open a new clinical translation pathway for ULF MRI and have broader implications for disease detection with low-field portable MRI scanners.

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY).

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.