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
Inspiration and Expiration Films