Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Stable tracheostomy and post sternotomy wires in good position . The trachea is not well visualized on today 's study . No pneumothorax or significant pleural effusion . Low lung volumes with increasing subsegmental atelectasis . There is also increasing left retrocardiac opacity which is also likely atelectasis . Mild cardiomegaly .
    OUTPUT:
    
No pneumothorax . Worsening subsegmental atelectasis and low lung volumes .