Gadolinium Deposition in Bone Tissues After Contrast-enhanced Magnetic Resonance Imaging: A Comprehensive Review

Area of Science:

• Pharmacology and Toxicology
• Biomedical Imaging
• Materials Science

Background:

• Gadolinium-based contrast agents (GBCAs) are essential for magnetic resonance imaging (MRI).
• Recent research has focused on the long-term fate and potential toxicity of gadolinium (Gd) in human tissues.
• Bone tissue is increasingly recognized as a potential reservoir for retained gadolinium.

Purpose of the Study:

• To review the retention mechanisms and potential toxicological implications of gadolinium cation (Gd 3+ ) in bone tissues.
• To compare gadolinium retention between linear and macrocyclic GBCAs.
• To explore the interactions of Gd 3+ with bone matrix components and potential interference with bone physiology.

Main Methods:

• Literature review of studies on gadolinium pharmacokinetics and toxicology in bone.
• Analysis of factors influencing gadolinium retention in bone, including GBCA structure (linear vs. macrocyclic).
• Examination of in vitro data and comparisons with other rare earth elements (REEs) regarding bone interactions.

Main Results:

• Gadolinium (Gd 3+ ) demonstrates prolonged persistence in bone tissues.
• Linear GBCAs exhibit higher retention rates in bone compared to macrocyclic GBCAs.
• A significant fraction of retained gadolinium exists in forms other than the original intact GBCA, suggesting degradation and complex interactions with bone matrix components like hydroxyapatite and collagen.

Conclusions:

• The long-term retention of gadolinium in bone, particularly from linear GBCAs, warrants further investigation into potential toxicological effects.
• Understanding the mechanisms of Gd 3+ interaction with bone matrix is crucial for assessing long-term risks.
• While no direct clinical effects on bone physiology are currently reported, the persistence and altered forms of gadolinium in bone necessitate continued research and monitoring.