This book reflects the views of an international faculty and provides an authoritative appraisal of modern radiology. It represents the sec ond volume in a planned series of competent overviews, and is mod eled on the successful first volume, Radiology Today, which was enthu siastically received by an international readership. We were encour aged by the comments we received to continue blending the latest ad vances in radiology with comprehensive teaching material concerning modern radiological practice. The Radiology Today 1982 meeting again brought together outstanding radiologists from Europe and North America for the purpose of sharing their experiences and their viewpoints of the current position and opportunities of imaging in medicine. Updating his/her knowledge of advances in medical imaging has be come an integral part of continuing medical education for every radiol ogist. Because all imaging modalities are continuously being refined, new clinical applications develop and frequently replace more com plex or more invasive procedures. Also, the relationship of imaging procedures to each other changes constantly, and with it the configura tion of critical diagnostic pathways for investigation of clinical signs and symptoms. To recognize this trend is important, because it is ex panding the role of the radiologist: our involvement in active guidance to the point of the patient's diagnostic workup has increased signifi cantly where it has become strategic.