Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy . Coronary stenting is also noted . There is a small left pleural effusion . No right pleural effusion is seen . Subtle left base retrocardiac opacity may be due to combination of pleural effusion and atelectasis , but underlying consolidation is difficult to exclude . There is no pneumothorax . Cardiac silhouette is top - normal . Mediastinal contours are stable to slightly less prominent as compared to the prior study . No pulmonary edema is seen .
    OUTPUT:
    
Small left pleural effusion . Left base retrocardiac opacity may be due to combination of pleural effusion and atelectasis however , difficult to exclude subtle consolidation .