Coordination compounds for 19/F magnetic resonance imaging

Magnetic resonance imaging (MRI) represents a cornerstone in the field of nowa- days diagnostic imaging methods, owing to its unique combination of advan- tages such as the absence of ionizing radiation, virtually unlimited tissue pene- tration depth, high spatial resolution, and excellent signal transmission through dense tissues, including the skull. Conventional MRI can operate in the native mode, relying on the intrinsic signal of water protons (1 H MRI) in soft tissues, and occasionally on endogenous compounds such as phosphorus metabolites and other bioactive molecules (31 P MRSI - magnetic resonance spectroscopy imaging). However, contrast-enhanced imaging - especially in the context of 1 H MRI - has become widespread, with the vast majority of contrast agents based on Gd(III) complexes coordinated by polyazamacrocyclic ligands, most commonly 1,4,7,10- tetraazacyclododecane (cyclen) derivatives (Dotarem, ProHance, Gadovist etc. Fig. 1). N N N N O O- O O- O O- O O- Gd3+ N N N N O O- O O- O O- CH3 O- Gd3+ N N N N O O- O O- O O- OH Gd3+ OH OH Dotarem® ProHance® Gadovist® Figure 1: Gd(III)-based contrast agents (GBCA) in clinical use Fluorine MRI (19 F MRI) introduces distinct advantages as well as challenges. Due to the near-complete absence of endogenous fluorine in the human body, 19 F MRI...