Chest imaging findings in children with influenza A H1N1.

Objective: To assess imaging findings at presentation in children diagnosed with influenza A (H1N1) infection.

Methods: This is a retrospective observational cohort study conducted at The Children's Hospital affiliated to Soochow University, Suzhou, China between September 2009 and March 2010. Nasopharyngeal swabs and bronchial aspirate samples from 81 children with acute respiratory infections were tested positive for influenza A (H1N1) using quantitative real-time polymerase chain reaction. Chest imaging for these patients was analyzed retrospectively by 2 independent radiologists for the presence and distribution of abnormalities.

Results: Chest radiograph findings consisted of bilateral patchy areas of consolidation (n=48), diffuse areas of air-space consolidation (n=18), and lobar consolidation (n=7). Eight chest x-rays were normal. Abnormalities were observed more frequently in the lower lobes (bilateral [n=66], unilateral [n=7]). Computed tomography (CT) scans were performed in 18 cases with air-space consolidation and interstitial opacities. Cases with diffuse areas of air-space consolidation were followed-up after 3 months by high resolution CT imaging, which showed interstitial thickening.

Conclusion: The predominant imaging findings in childhood influenza A (H1N1) were bilateral patchy areas of consolidation, followed by diffuse areas of air-space consolidation, normal radiographs, and lobar consolidation.