Aspiration and atelectasis on CT scan and radiography

An axial CT scan through the upper chest (A) shows atelectasis of the left lower lobe (asterisk) with aspirated contents in the left mainstem bronchus (arrowhead). The mediastinum is shifted to the left and a small pleural effusion is present (arrow). Image B is a magnified view and shows the aspirated material (arrowhead) and atelectasis (asterisk). Image C is a frontal radiograph at the time of aspiration showing the atelectasis of the left lower lobe (asterisk). The radiograph performed one week later shows clearing of the left base (D).