Chest Imaging Findings in Hospitalized Children with H1N1 Influenza

Objective: The aim was to review the radiological findings and to find new prognostic factors that determine the need for pediatric intensive care unit (PICU) in children with swine-origin influenza (H1N1) virus infection. Methods: Chest X-ray (CXR) and computed tomography (CT) findings of 18 children with laboratory-confirmed H1N1 infection (9 boys, 9 girls) with a median age of 34 (1-216) months were retrospectively evaluated. Results: CXRs were performed in 15 (83.3%) and thorax CT in 7 (38.8%) children. Abnormal findings were detected in 60% of the patients who underwent CXR and 85.7% of the patients who underwent thorax CT. Radiological findings were mostly diffuse, bilateral, and asymmetric. Ground-glass opacity (GGO) (66.6%) was the leading abnormality and was followed by reticulation (38.8%), nodules (27.7%), consolidation only (16.6%), tree-in-bud pattern (11.1%), consolidation with GGO (5.5%), and septal lines (5.5%). Lymphadenopathy (22.2%), air trapping (5.5%), and parenchymal band (5.5%) were other recorded findings. CXR was found to be insufficient to detect subpleural nodules, lymphadenopathies, and sometimes GGO. Only existence of nodules (p=0.04) affected the need for PICU admission. Conclusion: The most common radiological findings in children with H1N1 infection were bilateral, asymmetric GGO with or without associated multifocal areas of consolidation. CXR was insufficient to detect subpleural nodules, lymphadenopathies, and sometimes GGO. The existence of nodules is a bad prognostic factor in determining the need for PICU admission.