Contrast media are drugs by default. Had there been no default, there would be no need for a related pharmacology, and thus no need for this book. Radiographic contrast media (CM) are substances whose primary purpose is to enhance diagnostic information of medical imaging systems. The position of CM in pharmacology is unique. First, there is the unusual requirement of biological inertness. An ideal CM should be completely biologically inert, i.e., stable, not pharmacologically active, and efficiently and innocuously excretable. Because they fail to meet these requirements, CM must be...