Preclinical ¹⁹F MRI cell tracking at 3 Tesla

Area of Science:

• Biomedical Imaging
• Magnetic Resonance Imaging
• Cellular Biology

Background:

• ¹⁹F MRI offers advantages for cell tracking compared to iron-based methods.
• Preclinical ¹⁹F cell tracking has been limited to high magnetic field strengths (>3 T).
• ¹⁹F MRI can serve as an imaging biomarker for tumor aggressiveness by detecting macrophages.

Purpose of the Study:

• To develop methods for ¹⁹F MRI cell tracking in mice using a 3 T clinical scanner.
• To assess the feasibility of detecting and quantifying ¹⁹F-labeled macrophages in tumors at 3 T.

Main Methods:

• Perfluorocarbon (PFC)-labeled macrophages were imaged at 3 T.
• ¹⁹F spin quantification was validated using NMR spectroscopy.
• In vivo ¹⁹F MRI was performed on tumor-bearing mice at 9.4 T and 3 T, with varying NEX at 3 T.

Main Results:

• Detection of as few as 25,000 cells in cell pellets at 3 T.
• ¹⁹F quantification in cell pellets by 3 T MRI correlated well with NMR spectroscopy.
• ¹⁹F signal was consistently observed in the liver, spleen, and tumor in all mice at both 9.4 T and 3 T, with no significant difference in spin quantification.

Conclusions:

• This study successfully demonstrates the detection and quantification of ¹⁹F signal in murine tumors using ¹⁹F MRI at 3 T.
• ¹⁹F MRI at 3 T is a viable method for preclinical cell tracking, particularly for macrophage detection in tumors.