Abstract

The thickness of the shadows that accompany ribs or border the lungs on the chest postero-anterior radiographs of 22 obese patients and 22 normal-weight subjects was measured, when present, at several rib levels. A similar measurement was made of accompanying rib shadows on chest postero-anterior radiographs of eight obese patients after weight reduction. Statistical analysis showed that there were significantly thicker soft tissue shadows adjacent to the ribs of obese subjects compared to normal-weight persons and of obese subjects before as compared to after weight reduction. Such shadows are more frequent and are seen at more rib levels of the obese.

In addition, the following pertinent features are discussed: the mechanism by which soft tissue projects a radiographic shadow, the factors affecting its appearance, and the significance of such shadows as a variant of the normal chest radiograph and not as a manifestation of pathology.