Figure 1

Flowchart illustrating group assignment. RIS/PACS, Radiology Information System and Picture Archiving and Communication Systems of the Department of Radiology. CT, computed tomography; PaO₂/FiO₂, ratio of arterial partial pressure of oxygen to fraction of inspired oxygen; reference spontaneous group, spontaneously breathing trauma patients with normal lung morphology on CT; reference ventilated group, mechanically ventilated trauma patients with normal lung morphology; ALI group, mechanically ventilated trauma patients fulfilling the criteria for acute lung injury (ALI) as defined by the American-European consensus conference (AECC) on acute respiratory distress syndrome [1]. Ø, exclusion criteria.