Lobar or round consolidation favours bacterial infection; bilateral perihilar peribronchial thickening with hyperinflation favours viral; the imaging job is mostly the complications — effusion, empyema, necrosis.
Orient first
- Round pneumonia in a child under 8 is usually infection, not a mass (poorly developed collateral ventilation).
- Routine radiographs are not needed for uncomplicated community-acquired pneumonia (verify the local guideline).
- Ultrasound characterises effusions (septations, internal echoes) and guides drainage without radiation.
Acquire the study
- Frontal chest radiograph (lateral only if it changes management); chest ultrasound for effusions and consolidation.
The manoeuvre
- Frontal radiograph: lobar or round consolidation, air bronchograms, silhouette sign for the lobe.
- Viral pattern: bilateral perihilar peribronchial thickening, hyperinflation (flattened hemidiaphragms, more than 9 posterior ribs), subsegmental atelectasis.
- Pleural space: blunted costophrenic angle, meniscus; mediastinal shift.
- Compare with the prior study if the child is not improving: cavitation, pneumatocele.
What confirms it
- Consolidation in a febrile child with respiratory signs; complications confirmed on ultrasound.
What licenses you to exclude it
- A normal radiograph does not exclude early pneumonia; it excludes a large effusion or lobar consolidation.
The classic misread
- Calling a round pneumonia a tumour in a young febrile child.
- Calling the thymus consolidation on a frontal radiograph (sail sign, wavy margin).