ABSTRACT Magnetic resonance imaging (MRI) is a cornerstone of modern diagnostics, offering non‐invasive, high‐resolution visualization of soft tissues. The effectiveness of MRI largely depends on contrast agents (CAs) that enhance image definition by modulating local magnetic properties. This review provides a comprehensive overview of both traditional and emerging MRI CAs, categorized by their composition and mechanism of action. Traditional agents, including gadolinium‐based CAs (GBCAs), superparamagnetic iron oxide nanoparticles (SPIONs), manganese, and silica‐based systems, continue to be widely used due to their proven efficacy and well‐understood safety profiles. In contrast, novel agents, such as fluorine‐19 compounds, gold nanoparticles (AuNPs), lanthanide‐based nanoparticles, hyperpolarized, and smart agents, represent the next generation of imaging probes with enhanced specificity, sensitivity, and multifunctionality. The review discusses their mechanisms, synthesis strategies, pharmacokinetics, and toxicity, emphasizing advancements in nanochemistry and surface engineering that improve targeting efficiency and biocompatibility. By integrating insights from established and emerging agents, this work highlights ongoing innovations shaping the future of MRI contrast technologies, ultimately contributing to the development of safer, smarter, and more personalized diagnostic imaging.
Alex et al. (Wed,) studied this question.