Tuberculosis
An abnormal chest x-ray taken from the back shows tuberculous cavities, which are indicated by irregular white areas (arrows). 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. 121-5c; right: MY Chen, Basic Radiology, 1996, McGraw-Hill, Fig. 4-1b; with permission.)