On a film taken in full inspiration, the right hemidiaphragm should project over the 6th anterior interspace or 10th rib posteriorly. Films taken without a full inspiration are described as having a “poor inspiratory result”. This may result from a poor inspiratory effort or any other condition that prevents full inspiration.

This patient’s chest x-ray is normal in full inspiration. In relative expiration, the cardiac silhouette appears enlarged and the pulmonary vasculature appears crowded and indistinct. This appearance is easily mistaken for pulmonary edema.