Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy and coronary bypass surgery . ICD pacing leads are unchanged in position including abandoned leads . Stable mild cardiomegaly without evidence of congestive heart failure . Lung volumes remain low . Pleural and parenchymal scarring in the left mid and lower lung are unchanged since ___ , but a new patchy left retrocardiac opacity is noted .
    OUTPUT:
    
New patchy left retrocardiac opacity which may reflect patchy atelectasis , aspiration , or a developing pneumonia . Short - term followup radiographs may be helpful in this regard .