Felfoul, OuajdiBecker, Aaron T.Fagogenis, GeorgiosDupont, Pierre2016-11-182016Felfoul, Ouajdi, Aaron T. Becker, Georgios Fagogenis, and Pierre E. Dupont. 2016. “Simultaneous steering and imaging of magnetic particles using MRI toward delivery of therapeutics.” Scientific Reports 6 (1): 33567. doi:10.1038/srep33567. http://dx.doi.org/10.1038/srep33567.2045-2322http://nrs.harvard.edu/urn-3:HUL.InstRepos:29407555Magnetic 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.en-USJournal Article2016-11-1810.1038/srep33567