Over 10 years have passed since the first edition of The Mediastinum was published in 1977. I have been very gratified by the response to the first edition and determined to do a second edition as soon as possible. However, good intentions are sometimes difficult to achieve and a decade has passed. This period has been one of enormous growth in the discipline of diagnostic imaging. In the study of the mediastinum, computed tomog raphy, and more recently magnetic resonance, have revolutioni...