Chemical Insights into the Issues of Gd Retention in the Brain and Other Tissues Upon the Administration of Gd‐Containing MRI Contrast Agents

Gadolinium bearing contrast agents (GBCA) are commonly used in clinical settings as they add relevant physiological information to the superb anatomical resolution of the MR images. Recently it has been found that tiny amounts of gadolinium can be retained in the brain and other tissues in patients treated with GBCAs. Much work has been devoted to address the main determinants of the fate of GBCAs in vivo. Particular attention is given to the characterization of the chemical form/s (intact GBCA, soluble and insoluble Gd‐containing species) and to the relationship with the hyperintensity shown in T1w MR images. The article compares results from the authors' work with relevant achievements from other labs aimed at shedding light on the complex bio‐inorganic problems that accompany Gd‐retention in living systems. Tiny amounts of Gd have been detected in the brain and other tissues of patients treated with MRI Gd‐based Contrast Agents (GBCAs). Thermodynamic and kinetic stability, biodistribution, excretion rates, interactions with endogenous ions and biomolecules, etc. depict the complex picture associated to the metabolic fate of GBCAs in vivo.