Design and Fabrication of High Frequency Electromagnetic Coil for Magnetic Particle Imaging

Abstract

Magnetic Particle Imaging (MPI) is a promising modality which uses Magnetic Nanoparticles (MNPs) for tracer-based imaging in biomedical applications. Aside from their use in imaging, MNPs are increasingly being utilized for therapeutics, controlled targeted drug delivery, and diagnostics. These techniques depend on the behavior of MNPs when exposed to alternating magnetic field of a certain frequency and amplitude. However, the frequency typically used for imaging is 25kHz, while the transduction behaviors desired for these biomedical applications are seen at low radio-frequencies and higher amplitude fields than ones used for imaging. This work presents a high frequency electromagnetic coil which fulfills operational, safety, and geometric parameters necessary for incorporation in a custom MPI system and will allow us to simultaneously image and stimulate at specific locations within the body of a mouse. Optimization of the instrument is done through experimentation and electromagnetic theory, with focuses on parasitic elements and metallurgical phenomena. A resonant tank and direct cooling with a water pump allows for increased field strength while maintaining thermal and radio-frequency energy absorption standards for in vivo experiments.