We describe a subcohort of patients who required chest X-ray for suspected pneumonia and were enrolled into a prospective study of lung ultrasound for diagnosing pneumonia that coincided with the onset and surge of the 2009 H1N1 influenza pandemic from April to June 2009 [1, 2, 13] . We also describe the application of a modified Bedside Lung Ultrasound in Emergency (BLUE) protocol [4] with posterior thorax scanning ( Figure 3 ) during the This study was approved by our institutional review board. The study population consisted of a convenience sample of patients who met predetermined inclusion criteria and in whom informed consent had been obtained and documented from the patient or guardian for enrollment into the study.