Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The ET tube is at the upper limit of acceptable position , no less than 3 cm from the carina . There are low lung volume . The left lung opacification has improved on this study . There is mild pulmonary edema . There is no mediastinal hematoma or pneumothorax .
    OUTPUT:
    
1 . Mild pulmonary edema . 2 . No mediastinal hematoma or pneumothorax .