Study of kinetics of F-MRI using a fluorinated imaging agent (FIT) on a 3T clinical MRI system.

PURPOSE

To use F imaging tracer (FIT-27) to evaluate kinetics in major organs.

INTRODUCTION

Kinetics studies using proton MRI are difficult because of low concentration of FIT-27 protons relative to background water protons. Because there is no background source of F NMR in a biological body, F may be an ideal nucleus to directly trace FIT-27. However, there are several challenges for reliable F MR imaging and spectroscopy, particularly with clinical whole-body MRI systems, which include low concentrations and long F T.

METHODS AND MATERIALS

We performed a dynamic F MRI study on mice at a 3T whole-body MRI system using a homemade transmit/receive (Tx/Rx) switch and a Tx/Rx volume RF coil. We used a newly developed fluorine imaging agent, which has 27 identical fluorine atoms with identical chemical shift, a relatively short T, and high hydrophilicity. Basic kinetics parameters were estimated from the F signal-time curve.

RESULTS AND DISCUSSIONS

Resultant fluorine images show fairly high spatial (3 × 3 × 3 mm) and temporal resolutions. Biodistribution and kinetics of FIT-27 are obtained via F images for major uptake organs.

CONCLUSIONS

Whole-body dynamic F MRI of newly developed FIT-27 in mice was obtained with fairly high spatial and temporal resolutions on a 3T clinical MRI system. The present study demonstrates the feasibility of F MRI using our newly developed compound to investigate major organ kinetics.