Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The tip of the endotracheal tube is situated just at the thoracic inlet 5 .5 cm above the carina . There is atelectasis at the left lung base , although aspiration or pneumonia is another possibility . No focal consolidation is identified . The cardiomediastinal silhouette and hilar contours are normal . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Tip of the endotracheal tube at the thoracic inlet 5 .5 cm above the carina . Opacity in left lung base is most likely atelectasis , but aspiration or pneumonia are other possibilities .