Xin Liu1, Zhong-Xing Jiang2, Bruce Y Yu3, Eun-Kee Jeong4,5. 1. Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, 84108, USA. 2. Wuhan University School of Pharmaceutical Sciences, Wuhan, 430071, People's Republic of China. 3. Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD, 21201, USA. 4. Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, 84108, USA. ek.jeong@utah.edu. 5. Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, UT, 84108, USA. ek.jeong@utah.edu.
Abstract
PURPOSE: To use 19F imaging tracer (19FIT-27) to evaluate kinetics in major organs. INTRODUCTION: Kinetics studies using proton MRI are difficult because of low concentration of 19FIT-27 protons relative to background water protons. Because there is no background source of 19F NMR in a biological body, 19F may be an ideal nucleus to directly trace 19FIT-27. However, there are several challenges for reliable 19F MR imaging and spectroscopy, particularly with clinical whole-body MRI systems, which include low concentrations and long 19F T1. METHODS AND MATERIALS: We performed a dynamic 19F 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 T1, and high hydrophilicity. Basic kinetics parameters were estimated from the 19F signal-time curve. RESULTS AND DISCUSSIONS: Resultant fluorine images show fairly high spatial (3 × 3 × 3 mm3) and temporal resolutions. Biodistribution and kinetics of 19FIT-27 are obtained via 19F images for major uptake organs. CONCLUSIONS: Whole-body dynamic 19F MRI of newly developed 19FIT-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 19F MRI using our newly developed compound to investigate major organ kinetics.
PURPOSE: To use 19F imaging tracer (19FIT-27) to evaluate kinetics in major organs. INTRODUCTION: Kinetics studies using proton MRI are difficult because of low concentration of 19FIT-27 protons relative to background water protons. Because there is no background source of 19F NMR in a biological body, 19F may be an ideal nucleus to directly trace 19FIT-27. However, there are several challenges for reliable 19F MR imaging and spectroscopy, particularly with clinical whole-body MRI systems, which include low concentrations and long 19F T1. METHODS AND MATERIALS: We performed a dynamic 19F 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 T1, and high hydrophilicity. Basic kinetics parameters were estimated from the 19F signal-time curve. RESULTS AND DISCUSSIONS: Resultant fluorine images show fairly high spatial (3 × 3 × 3 mm3) and temporal resolutions. Biodistribution and kinetics of 19FIT-27 are obtained via 19F images for major uptake organs. CONCLUSIONS: Whole-body dynamic 19F MRI of newly developed 19FIT-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 19F MRI using our newly developed compound to investigate major organ kinetics.