Contrast Media: History and Chemical Properties

Contrast media are essential for cardiac catheterization, and the evolution of these agents has had a significant role in cardiology. Contrast agents are classified as ionic or nonionic based on water solubility and as monomers or dimers based on their chemical structures. Furthermore, these agents are classified on osmolality as high osmolar, low osmolar, or iso-osmolar. The last century has seen a rapid evolution of these agents from their discovery during the search for syphilis treatments to advancements in their chemical properties, making them safer for patients and improving tissue visualization.