Magnetic Particle Imaging in Vascular Imaging, Immunotherapy, Cell Tracking, and Noninvasive Diagnosis

Figure 1

MPI overview: magnetic particle imaging is a new, noninvasive, and nonradioactive tracer-based imaging technology for imaging pathologies associated with vascular defects, cell tracking, and molecular imaging. (a) Intravenously administered tracers of MPI can be engineered to either partition in the blood plasma or tag to a specific subset of immune cells using molecular targets (MNP: magnetic nanoparticles). (b) Long-circulating tracers in MPI can be used to acquire highly sensitive angiograms that could detect gastrointestinal bleeding shown here. MPI images of bleed hot spots can be observed in the abdomen overlaid over a projection X-ray for anatomical reference. (Adapted with permission from Yu et al., ACS Nano, 2017. Copyright (2017) American Chemical Society) [27] (c) Furthermore, MPI tracers with antibodies can selectively bind to molecular targets in circulating immune cells, such as neutrophils, and allow for sensitive tracking of therapeutic cells. (Reproduced under the Creative Common license) (d) MPI can image malformed angiogenic blood vessels in tumors due to enhanced permeation and retention (image overlaid over CT data for anatomical reference) (adapted with permission from Yu et al., Nano Letters, 2017. Copyright (2017) American Chemical Society [38]).

(a) MPI tracks immune cells homing to infection, inflammation, and cancer

(b) Vascular imaging

(c) Molecular imaging

(d) Cancer imaging