Chest X-ray (CXR) findings in viral pneumonia typically show bilateral, patchy, or diffuse interstitial infiltrates and ground-glass opacities (GGOs).
Unlike bacterial pneumonia, which often presents as a dense, localized (lobar) consolidation, viral pneumonia tends to affect both lungs and the tissue around the airways and alveoli.
Common Chest X-Ray Findings :
The specific findings can vary depending on the virus and the patient's immune status, but general patterns include:
Interstitial infiltrates:
These appear as fine or coarse linear/reticular opacities, reflecting inflammation in the supporting lung tissue.
Patchy areas of consolidation:
Ill-defined, non-homogeneous areas where the air in the alveoli has been replaced by fluid or inflammatory cells.
Ground-glass opacities (GGOs):
Hazy areas that suggest alveolar edema or hemorrhage, but through which underlying blood vessels may still be visible.
Bilateral distribution:
The opacities are frequently observed in both lungs, often with a predominance in the lower and peripheral lung zones.
Peribronchial thickening:
Thickening of the walls of the small airways is a common feature.
Ill-defined small nodules:
Small, poorly defined opacities (4-10 mm) that are typically centrilobular (around the small airways).
Atypical or Less Common Findings :
While the above are typical, imaging findings are often overlapping and not specific enough for a definitive diagnosis based on the image alone. Clinical and laboratory information is crucial for an accurate diagnosis.
Normal X-ray:
A significant percentage of patients with viral pneumonia, especially in the early stages or with milder disease (such as some SARS cases), may have a normal chest X-ray.
Pleural effusions:
Fluid surrounding the lungs is uncommon in primary viral pneumonia but its presence may suggest a bacterial superinfection.
Lobar consolidation:
A dense, single-lobe consolidation is more characteristic of bacterial pneumonia, although it can occasionally be seen in some viral types like adenovirus pneumonia.
Lymphadenopathy and Cavitation:
Enlarged lymph nodes or the formation of cavities (abscesses) are rare in uncomplicated viral pneumonia and are more suggestive of bacterial etiologies or other processes.
Ultimately, imaging findings should be integrated with clinical symptoms, patient age, immune status, and virology testing for proper diagnosis and management.
