In vivo quantification of SPIO nanoparticles for cell labeling based on MR phase gradient images

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Magnetic Resonance Imaging

Background:

• Super-paramagnetic iron oxide (SPIO) nanoparticles are crucial negative contrast agents in MRI for cell tracking.
• Accurate in vivo quantification of SPIO nanoparticles remains a significant challenge in current MRI applications.

Purpose of the Study:

• To develop and validate an MR phase gradient-based method for quantifying SPIO nanoparticles.
• To assess the feasibility of this method for both phantom and in vivo experiments.

Main Methods:

• A phantom experiment was conducted using known SPIO concentrations (10–250 µg/ml) for method calibration.
• An in vivo experiment involved implanting SPIO-labeled C6 glioma cells into mice for quantification.
• Magnetic resonance imaging (MRI) scans were performed to acquire phase gradient data.

Main Results:

• The proposed MR phase gradient method successfully quantified SPIO concentrations in phantom experiments.
• The method also demonstrated effectiveness for in vivo quantification of SPIO-labeled cells in mice.
• Results showed a clear correlation between SPIO concentration and MR phase gradient measurements.

Conclusions:

• The developed MR phase gradient approach provides a reliable method for SPIO nanoparticle quantification.
• This technique holds potential for enhancing the accuracy of in vivo MRI studies utilizing SPIO contrast agents.