Surgical Anatomy of the Abdomen

Abstract

THE scope of this paper is concerned with certain principles which have been found helpful in the roentgenologic study of the surgical anatomy of the abdomen. These are as follows: 1. The study of the position, shape, and mobility of the diaphragm. 2. The study of the abdomen by plain views. 3. The study of the position, shape, size, and the relationship of the stomach and bowels to the neighboring viscera. 4. The study of the mobility of the gastro-intestinal tract. 5. The study of the contour of the stomach and bowels in various positions. Diaphragm.—The diaphragm, situated as it is between the thoracic and abdominal cavities, may be affected by abnormal changes of the organs therein, which may alter its position, shape, and mobility. To enable one to recognize departures from the normal, its roentgen anatomy must be understood. This having been described in a previous publication (1), attention will be called only to certain anatomical characteristics. Its shape resembles a dome, and is higher anteriorly and medially than posteriorly and laterally. By its central tendon it is attached to the pericardium, and by its lateral projection, to the thoracic cage. In the anteroposterior view of the chest (Fig. 1-A), only the crest of the diaphragm is seen, the rest of its surface being obscured; in the lateral view (Fig. 1-B), the entire extent of both leaves of the diaphragm is brought into view. There are numerous processes which may increase the intra-abdominal pressure, thus altering the shape, mobility, and position of the diaphragm. Among these may be included free fluid or gas in the peritoneal cavity, enlargement of the liver, gaseous distention of the stomach and bowels, extraneous masses, and subphrenic abscess. In all these conditions there is elevation of the diaphragm and more or less impairment of mobility. However, subphrenic abscess is differentiated from these other conditions by the elevation of the posterior boundary of the diaphragm which makes it appear flattened, resembling a “plateau.” The posterior costophrenic angle is completely obliterated. Occasionally there is noted evidence of fluid and inflammatory changes in the diaphragmatic pleura and adjacent lung, due to lymphatic permeation of the infection through the diaphragm. The following case illustrates the “plateau sign of subphrenic abscess.” Miss C. C., aged 45 years, was admitted to the Jewish Hospital with clinical and physical findings of pneumonia of the right lung. An x-ray examination of the chest in the dorsal and lateral decubitus position revealed marked elevation of the right diaphragm. The right lung, although decreased in size, appeared to be free from any involvement (Fig. 2-A). In the lateral position the right diaphragm was elevated throughout its entire extent, its surface being on the same level with the crest so that it resembled a plateau, while the posterior costophrenic space was completely obliterated (Fig. 2-B).