Chemistry, Physicochemical Properties and Pharmacokinetics of Gadolinium-Based Contrast Agents

Autor: Semra Yigitaslan, Kevser Erol
Rok vydání: 2021
Předmět:
Zdroj: Medical Imaging Contrast Agents: A Clinical Manual ISBN: 9783030792558
DOI: 10.1007/978-3-030-79256-5_7
Popis: Gadolinium-based contrast agents (GBCAs) are the major contrast agents used in MRI However, because free gadolinium is highly toxic, it is mandatory to attach the Gd3+ with a suitable chelating agent. The chelating agent is either linear or macrocyclic and non-ionic or ionic. The stability of the chelating agents is described by thermodynamic stability and kinetic stability. Transmetallation of Gd3+ with zinc forms a zinc chelate that will be excreted in urine. The osmolality is closely related to the ionicity of the contrast agent. The viscosity of earlier GBCAs ranges from 1.3 to 2.9 cP. However, gadobenate dimeglumine has the highest viscosity of 5.3 cP. Most GBCAs except for three (gadoxetic acid, gadofosveset and gadobenate dimeglumine) are water-soluble, low molecular weight complexes rapidly diffusing into the extravascular space after intravenous injection (distribution half-life is about 5 min), do not go biotransformation and are eliminated mainly by the kidneys. GBCAs do not generally cross the blood-brain barrier nor bind to the proteins or receptors. The recommended dose for most GBCAs is 0.1 mmol/kg with a recommended injection rate of 0.5 mmol/mL.
Databáze: OpenAIRE