Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable supine chest radiograph demonstrates low lung volumes . An endotracheal tube , its tip which terminates 4 mm above the level of the carina in appropriate position . There is no pneumothorax , pleural effusion , or pulmonary edema . Heart size is exaggerated secondary to the lung volumes . Blunting of the left costophrenic angle is likely sequela of atelectasis . There is mild bronchovascular crowding . No air under the right hemidiaphragm is seen .
    OUTPUT:
    
Low lung volumes . Appropriately positioned endotracheal tube .