Simultaneous steering and imaging of magnetic particles using MRI toward delivery of therapeutics

Abstract

Magnetic resonance navigation (MRN) offers the potential for real-time steering of drug particles and cells to targets throughout the body. In this technique, the magnetic gradients of an MRI scanner perform image-based steering of magnetically-labelled therapeutics through the vasculature and into tumours. A major challenge of current techniques for MRN is that they alternate between pulse sequences for particle imaging and propulsion. Since no propulsion occurs while imaging the particles, this results in a significant reduction in imaging frequency and propulsive force. We report a new approach in which an imaging sequence is designed to simultaneously image and propel particles. This sequence provides a tradeoff between maximum propulsive force and imaging frequency. In our reported example, the sequence can image at 27 Hz while still generating 95% of the force produced by a purely propulsive pulse sequence. We implemented our pulse sequence on a standard clinical scanner using millimetre-scale particles and demonstrated high-speed (74 mm/s) navigation of a multi-branched vascular network phantom. Our study suggests that the magnetic gradient magnitudes previously demonstrated to be sufficient for pure propulsion of micron-scale therapeutics in magnetic resonance targeting (MRT) could also be sufficient for real-time steering of these particles.

Description

Keywords

Biomedical engineering, Targeted therapies

Citation

Copyright 2016 Scientific Reports. Recommended citation: Felfoul, Ouajdi, Aaron T. Becker, Georgios Fagogenis, and Pierre E. Dupont. "Simultaneous steering and imaging of magnetic particles using MRI toward delivery of therapeutics." Scientific reports 6 (2016): 33567. DOI: 10.1038/srep33567. URL: https://www.nature.com/articles/srep33567. Reproduced in accordance with the original publisher’s licensing terms and with permission from the author(s).