Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP upright portable view of the chest was obtained . Left - sided pacer device with leads unchanged in position . There is a large - bore right - sided catheter unchanged in position , terminating in the right atrium . The cardiac silhouette remains mildly enlarged . The mediastinal and hilar contours are stable . Subtle streaky opacity in the left retrocardiac region is again seen , although less confluent as compared to the prior study and may represent an underlying scarring . PA and lateral views may be helpful for further evaluation .
    OUTPUT:
    
Streaky left base retrocardiac opacity appears somewhat improved compared to the prior study and most likely represents atelectasis / scarring . PA and lateral views may be helpful for further evaluation . Otherwise , no significant interval change .