Two years only after the publication of the ? rst edition of βContrast media β Safety issues and ESUR guidelinesβ in our book series Medical Radiology in 2006, it appeared that a second edition was urgently needed. The ? rst edition was indeed an exceptional success with our readership and sold out rapidly, but moreover the safety of MR contrast media urgently required a reappraisal after the publication of a new and dramatic adverse reaction to some of the gadolini- based agents: the so called NSF syndrome. I am very much indebted to Professor Henrik S. Thomsen and his academic colleagues from the ESUR Contrast Medium Safety Committee for accepting the task to prepare a second edition of their remarkable book.Within a record short period of time they have been able to complete this fully revised new volume. It offers to the readers a comprehensive overview of all problems related to the use of contrast media in modern radiology and of our latest knowledge and insights in the mechanisms of adverse reactions related to contrast media. It answers all questions that radiologists and referring physicians are confronted with in their daily practice when they consider the administration of these agents to their patients.