Chest X-Ray Findings in Pneumonia
| Element | Comment |
|---|---|
| Focal shadowing | Required to make the diagnosis of pneumonia. Lobar pneumonia is the result of disease that starts in the periphery and spreads from one alveolus to another. As the disease reaches a fissure, this will result in a sharp delineation, since consolidation will not cross a fissure. The alveoli that surround the bronchi become denser and the bronchi become more visible, resulting in an air-bronchogram. Bronchopneumonia starts in the airways as acute bronchitis. It will lead to multifocal ill-defined densities. When it progresses it can produce diffuse consolidation. |
| Pleural effusion | If present, arrange for ultrasound-guided aspiration of effusion and send samples for Gram stain and culture, pH and biochemistry (LDH, protein, glucose). |
| Cavitation | Associated with tuberculosis and Staphylococcus aureus infection, but may also occur in Gram-negative and anaerobic infections. |
| Lung abscess | Chest X-ray typically demonstrates an air-fluid level, but chest CT is more sensitive and can confirm the diagnosis in difficult cases. Most patients with lung abscess do well with conservative management and a prolonged course of antibiotics. |
| Pneumothorax | May occur in cavitating pneumonia and is particularly associated with Pneumocystis jiroveci pneumonia (Chapter 34). |