Phase II: Commercialization of a preclinical Magnetic Particle Imaging system with sub-millimeter resolution, nano-molar sensitivity, and integrated CT - Abstract
The two dominant preclinical molecular imaging techniques, optical imaging and nuclear
imaging, have technical limitations that hamper their use in applications requiring high
resolution, longitudinal tracer imaging with absolute quantitation. We are developing a new
molecular imaging modality, Magnetic Particle Imaging (MPI), which does not have these
limitations and is capable of: nanomolar sensitivity, absolute quantitation of a tracer, resolution
independent of depth, and monitoring a stable tracer for weeks to months. These capabilities
make MPI complementary to existing molecular imaging techniques and give scientists a
versatile new tool when imaging cancer, tracking therapeutic and immune cells, and imaging the
cardiovascular system.
MPI is best compared with nuclear medicine, in that both modalities “see” only the
injected tracer, “see” right through background tissue, and are translatable. The MPI technique
works by directly detecting the nonlinear magnetization of iron-oxide tracers using low-
frequency magnetic fields. MPI’s method of direct detection is exquisitely sensitive and we have
already demonstrated micro-molar sensitivities in prototype systems. Indeed, the theoretical
sensitivity limit of MPI may be as low as a single tagged cell in a voxel. MPI is unrelated to
Magnetic Resonance Imaging (MRI), and MPI scans cannot be acquired using a MRI imager.
This project aims to develop the first MPI system tailored for pre-clinical researchers
working with mouse and rat models. The proposed system will be the world’s highest sensitivity
and highest resolution tomographic MPI scanner, as well as the first MPI system with integrated
CT. First, we will build a high strength field free line magnetic field gradient mounted to a
rotating gantry to enable tomographic MPI imaging. We will then integrate CT to enable
acquisition of a tissue reference image. Last, we will test the imager in vivo with mouse and rat
models.
