Pneumocystis carinii pneumonia
- Most common opportunistic pulmonary infection seen in patients with AIDS.
- Usually seen in patients not receiving PCP prophylaxis and who have CD4 levels less than 200 cells per cubic millimeter.
- Complications include spontaneous pneumothorax and hypoxemia secondary to an adult respiratory distress–like syndrome.
 Imaging Findings
 Plain film
- Chest radiographs are normal in 10-39% of patients.
- Classic chest radiograph appearance is classically bilateral, often perihilar, fine reticular interstitial opacification.
- Cysts are seen in 10% of chest radiographs
Patient #1: Note the pnuemothorax