Figure 1. Bacterial pneumonia in a 32-year-old HIV-positive man presenting with an acute onset of fever and cough. Posteroanterior (A) and lateral (B) chest radiographs demonstrate focal consolidation in the right lower lobe, which was owing to a community-acquired bacterial pneumonia. The presence of focal consolidation is highly suggestive of bacterial pneumonia. Also note a small right-sided parapneumonic pleural effusion.
Figure 2. Pneumocystis carinii pneumonia in a 33-year-old HIV-positive man presenting with an insidious onset of fever and shortness of breath. Posteroanterior chest radiograph demonstrates a bilateral, relatively symmetric distribution of hazy ground-glass opacities interspersed with areas of coalescing alveolar consolidation. A bilateral symmetric distribution of pulmonary opacities is typical of PCP. However, bacterial pneumonia can uncommonly mimic this appearance.