Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Sternotomy wires are intact . Significant interval decrease in size of cardiomediastinal silhouette . Lucency at the base of the right hemidiaphragm may represent pneumoperitoneum or small basal pneumothorax . No mediastinal shift or flattening of right hemidiaphragm . No pleural effusion . New right mid lung opacity is likely atelectasis ; however , may represent evolving pneumonia . New mild left lower lobe atelectasis . Cardiac silhouette remains mildly enlarged with normal mediastinal contour and hila .
    OUTPUT:
    
1 . Significant interval decrease in size of cardiomediastinal silhouette . 2 . Possible pneumoperitoneum or small basal pneumothorax . 3 . Possible right mid lung atelectasis or in the appropriate clinical setting , pneumonia .