Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy . The left hemidiaphragm is elevated seen in there is overlying atelectasis . A hiatal hernia may be present . There is also likely at least a small left pleural effusion . The right lung is clear . Previously seen left pneumothorax is not appreciated on the current study . Cardiac silhouette remains mildly enlarged . Mediastinal contours are unremarkable .
    OUTPUT:
    
Volume loss at the left lung base and elevation of the left hemidiaphragm with overlying atelectasis and likely left pleural effusion . Query hiatal hernia .