FIGURE 1.

Radiographic and Computed Tomographic (CT) Findings in the Acute, or Exudative, Phase (Panels A,C) and the Fibrosing-Alveolitis Phase (Panels B,D) of Acute Lung Injury and the Acute Respiratory Distress Syndrome (ARDS). Panel (A) shows a chest radiograph from a patient with the ARDS associated with gram-negative sepsis who was receiving mechanical ventilation. There are diffuse bilateral alveolar opacities consistent with the presence of pulmonary edema. Panel (B) shows an anteroposterior chest radiograph from another patient with ARDS who had been receiving mechanical ventilation for seven days. Reticular opacities are present throughout both lung fields, a finding suggestive of the development of fibrosing alveolitis. Panel (C) shows a CT scan of the chest obtained during the acute phase. The bilateral alveolar opacities are denser in the dependent, posterior lung zones, with sparing of the anterior lung fields. The arrows indicate thickened interlobular septa, consistent with the presence of pulmonary edema. Panel (D) shows a CT scan of the chest obtained during the fibrosing-alveolitis phase. There are reticular opacities and diffuse ground-glass opacities throughout both lung fields, and a large bulla is present in the left anterior hemithorax. Reproduced with permission from Ware and Matthay (2000).