Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Endotracheal tube is low lying , with tip approximately 1 cm from the carina . Lung volumes are low . Heart size is normal . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is not engorged . Patchy retrocardiac opacity may reflect atelectasis though infection or aspiration can not be excluded . No large pleural effusion or pneumothorax is identified . No acute osseous abnormalities are detected .
    OUTPUT:
    
1 . Low lying endotracheal tube with tip approximately 1 cm from the carina . Recommend withdrawal by at least 2 cm . 2 . Retrocardiac opacity may reflect atelectasis though infection or aspiration can not be excluded .