This is a comprehensive treatise in German on the indications, techniques, and interpretation of retropneumoperitoneum and pneumomediastinum. Approximately two-thirds of the volume is devoted to retropneumoperitoneum, and the remaining one-third is devoted to pneumomediastinum. There are 142 radiographic illustrations of good quality in reverse black-and-white relationship. Many of the illustrations have accompanying explanatory line drawings. Both sections have rather complete chapters on the roentgen interpretation of the normal retropneumoperitoneum and pneumomediastinum. In addition there are chapters dealing with the anatomy pertinent to these studies. The techniques involved are fully described with excellent illustrations. There is an excellent bibliography.