Figure 12a. Pyopneumothorax complicating septic emboli in a 28-year-old male IV drug user. (a) Contrast-enhanced thoracic CT image (window level = –500 HU, window width = 1500 HU) shows cavitating lesions in the left upper lobe. (b) CT image obtained inferiorly to a shows right-sided pyopneumothorax due to rupture of a peripheral pulmonary abscess into the pleural space.