Quantitative 2D Magnetorelaxometry Imaging of Magnetic Nanoparticles using Optically Pumped Magnetometers

Area of Science:

• Biophysics
• Biomagnetism
• Medical Imaging

Background:

• Accurate spatial distribution of magnetic nanoparticles (MNP) is essential for biomagnetic applications such as magnetic hyperthermia.
• Magnetorelaxometry (MRX) imaging is a key technique for extracting MNP distribution information.

Purpose of the Study:

• To present the quantification, 1D reconstruction, and 2D imaging of MNP using optically pumped magnetometers (OPM) for MRX.
• To evaluate the potential and limitations of commercially available OPMs for MRX imaging (MRXI).

Main Methods:

• Utilized optically pumped magnetometers (OPM) for magnetorelaxometry (MRX) measurements.
• Developed and implemented quantitative 1D reconstruction and 2D imaging setups for MNP phantoms.
• Assessed the precision and accuracy of MNP quantification and spatial reconstruction.

Main Results:

• Achieved precise quantification of MNP with iron amounts down to approximately 6 g using the OPM setup.
• Demonstrated high precision and accuracy in quantitatively reconstructing point-like and complex MNP phantoms in 1D.
• Successfully reconstructed point-like MNP distributions with clinically relevant iron concentrations in a 12 cm by 8 cm 2D area.

Conclusions:

• Optically pumped magnetometers show significant potential for quantitative MRX imaging of MNP.
• The developed 1D and 2D MRX imaging setups provide precise and accurate MNP distribution mapping.
• The 2D system can be readily extended for 3D, slice-selective imaging, advancing applications in biomagnetism.