Functional Imaging Using Fluorine (19F) MR Methods: Basic Concepts

Abstract

Kidney-associated pathologies would greatly benefit from noninvasive and robust methods that can objectively quantify changes in renal function. In the past years there has been a growing incentive to develop new applications for fluorine (19F) MRI in biomedical research to study functional changes during disease states. 19F MRI represents an instrumental tool for the quantification of exogenous 19F substances in vivo. One of the major benefits of 19F MRI is that fluorine in its organic form is absent in eukaryotic cells. Therefore, the introduction of exogenous 19F signals in vivo will yield background-free images, thus providing highly selective detection with absolute specificity in vivo. Here we introduce the concept of 19F MRI, describe existing challenges, especially those pertaining to signal sensitivity, and give an overview of preclinical applications to illustrate the utility and applicability of this technique for measuring renal function in animal models.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.

19F MRI Nanotheranostics for Cancer Management: Progress and Prospects

“…When compared with 1 H, its NMR sensitivity (83 %), SNR (89 %), and gyromagnetic ratio (40.08 MHz/T) were only slightly inferior [35] . In the body, 19 F is mainly present in solid bones and teeth and has a very low physiological concentration (<10 −6 mol/L), resulting an extremely short T 2 and non‐detection by MRI [35,36] . Furthermore, the strong electronegativity of the fluorine atom causes the C−F bond to be highly polarized and the electron density to move specifically towards fluorine, resulting in a strong C−F bond energy (116 kcal/mol) [37] .…”

New insights into progressive ligand replacement from [Ru2Cl(O2CCH3)4]: synthetic strategies and variation in redox potentials and paramagnetic shifts

“…In addition, fluorinated compounds have received increasing interest due to their applications as responsive probes for magnetic resonance spectroscopy 51 and imaging. 52,53 Therefore, fluorinated diruthenium complexes could provide new routes into biomedical and bioinorganic applications as has recently been shown with fluorinated ligands in dirhodium complexes. 54…”

Molecular MRI-Based Monitoring of Cancer Immunotherapy Treatment Response

“…Although 1 H MRS is a powerful tool for studying the chemical composition of tissues, it lacks specificity for labeling and tracking specific cells. 19 F MRI, on the other hand, utilizes exogenously administered fluorine to provide metabolic cell information, which is considered unambiguous (given the scarcity of endogenous 19 F in the body) [121]. Recently, Croci et al successfully used perfluorocarbon-containing nanoparticles and 19 F MRI to noninvasively track tumor associated microglia and macrophages over time in response to radiotherapy [122].…”