Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were performed . The lungs are hyperinflated . Linear opacification is again seen at the left lung base which likely reflects scarring as demonstrated on the prior CT . The cardiac silhouette is mildly enlarged . The mediastinum is unremarkable .
    OUTPUT:
    
Linear opacification of the retrocardiac space is likely scarring / atelectasis and is unchanged .