Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and CABG . Lung volumes are reduced . The heart size remains mildly enlarged . Mediastinal contours are unchanged . Mild pulmonary edema is worse compared to the previous exam with peribronchial cuffing noted . Retrocardiac patchy opacity could reflect atelectasis . No pleural effusion or pneumothorax is identified . There are no acute osseous abnormalities . Left PICC has been removed .
    OUTPUT:
    
Mild pulmonary edema . Probable retrocardiac atelectasis .