Correct!
5. The frontal chest radiograph shows worsening subcutaneous emphysema and pneumomediastinum
The frontal chest radiograph shows interval worsening of bilateral lung opacity. Given that the patient was found unresponsive, in cardiac arrest, surrounded by vomit, there was strong concern for aspiration pneumonia now with developing widespread lung injury. The subcutaneous emphysema and pneumomediastinum are actually improving. While lung opacity is clearly worsening, there is no evidence of cavitation with the pulmonary abnormalities. The “fallen lung” sign is not present. This chest radiographic finding may be encountered when bronchial injury is present, and the lung collapses away from the mediastinum in the presence of a pneumothorax, rather than in towards the hilum, as is the more usual case with pneumothorax. This particular radiographic findings is thought to occur as a result of loss of the normal anchoring capacity of the central bronchi. No evidence of intrathoracic herniation of the stomach is seen- this would appear as a gas lucency projected over the left lower lobe, and would raise the possibility of left diaphragmatic injury.
There was no history or evidence of thoracic trauma at physical examination. The patient’s respiratory status continued to deteriorate, however.
Repeat thoracic CT (Figure 4) was performed.
Figure 4. Left: Representative static images of repeat axial thoracic CT in lung windows performed 2 days after presentation. Right: Video of repeat thoracic CT in lung windows.
Regarding this examination, which of the following is correct? (Click on the correct answer to proceed to the seventh of eight panels)