Dear Editor:I read the recent publication on pediatric novel influenza A (H1N1) virus infection imaging with a great interest (1). Choi et al. (1) concluded that abnormal imaging was uncommon and prominent peribronchial markings and ill-defined patchy consolidation with mediastinal lymph node enlargement, pleural effusion and pneumomediastinum are the important findings. I would like to share some ideas in this report. Indeed, the low prevalence of lung abnormalities is not surprising since the nature of the novel H1N1 influenza is the upper, not lower, respiratory tract infection (2). Focusing on the described manifestations, there is no specific presentation and so these findings can help make the differential diagnosis of several other lung diseases, as Choi et al. (1) noted. A recent interesting publication noted the occurrence "bilateral extensive air-space disease in severely ill patients" and this might be used as the predictor of the disease severity (3).