Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and CABG . Mild enlargement of cardiac silhouette is unchanged , and the mediastinal contours are stable . There is mild pulmonary vascular congestion . Blunting of the right costophrenic angle suggests the presence presence of a trace effusion . Retrocardiac atelectasis is noted . There is no pneumothorax . No acute osseous abnormalities are visualized .
    OUTPUT:
    
Mild pulmonary vascular congestion and probable trace right pleural effusion . Retrocardiac atelectasis .