Rapid Scan EPR imaging as a Tool for Magnetic Field Mapping

Area of Science:

• Biophysics
• Medical Imaging
• Materials Science

Background:

• Electron paramagnetic resonance (EPR) imaging is a functional four-dimensional technique used in biomedical research.
• EPRI analyzes spectral and spatial data to report on tissue microenvironment parameters like oxygen partial pressure and pH.
• Current EPRI methods rely on homogeneous external magnetic fields.

Purpose of the Study:

• To propose and demonstrate a novel application of EPRI for mapping perturbed magnetic fields.
• To visualize the magnetic field generated by a magnetized object using EPRI.
• To reconstruct a three-dimensional magnetic field map with high spatial resolution.

Main Methods:

• A proof-of-concept imaging experiment was performed using EPRI.
• A single-line lithium octa-n-butoxynaphthalocyanine spin probe was employed.
• The spectral position of the EPR line was used to measure the perturbation field strength.

Main Results:

• Successful visualization of the magnetic field created by a magnetized object was achieved.
• A three-dimensional magnetic field map was reconstructed with high spatial resolution.
• The experiment confirmed EPRI's capability to measure perturbed magnetic fields.

Conclusions:

• EPRI can be adapted to visualize and map magnetic fields, extending its utility beyond traditional biomedical sensing.
• This technique offers potential for EPRI/magnetic particle imaging (MPI) co-registration and serves as an alternative to magnetic field cameras.
• Applications include internal sensing in complex assemblies, development of permanent magnets, consumer electronics, industrial sensors, and magnetic manipulation of cell cultures.