Staphylococcal Pneumonia

An abnormal chest x-ray shows a large volume of pus (arrowheads) in the pleural sac surrounding a lung. In this case, this finding is related to a pneumonia caused by staphylococcus. A normal chest x-ray is shown on the right for comparison; the heart (H), lungs (L), vertebrae (v), and collarbone (C) can be seen.

(Left: AP Fishman, Fishman's Pulmonary Diseases and Disorders, 3 ed, 1998, McGraw-Hill, Fig. 89-5a; right: MY Chen, Basic Radiology, 1996, McGraw-Hill, Fig. 4-1b; with permission.)