Figure 10.

Same patient as in Figure 8; the opacity is in the peripheral lung, near the injured chest wall. The lesion rapidly progresses to cavitation as seen on the axial CT scans. The appearances are those of a lung contusion. Contusion however usually occurs earlier, is usually localized to the area affected by injury (e.g., unilateral and lower or upper zones) and improves over 48-72 hours. ARDS tends to be more generalized, is later in onset and slower to resolve