Radiological findings
Chest X-ray (CXR) was performed on admission in 105 infants for clinical indications such as when a differential diagnosis was suspected or/and if a clinical deterioration occurred. 31 out of 105 infants (29.5%) performed two CXR at least. An experienced paediatric radiologist (D.P.) evaluated each CXR and described the presence of patchy opacities, complete lobar consolidation and air trapping. Radiologist was blinded to infants’ conditions and clinical course, in order to avoid potential bias.