Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable upright view of the chest . Trace pneumoperitoneum is within post surgical limits . The heart is mildly enlarged . The hilar and mediastinal contours are within normal limits . A retrocardiac left basilar opacity likely reflects atelectasis . There is no pneumothorax . Tiny bilateral pleural effusions are present .
    OUTPUT:
    
1 . Left retrocardiac opacity , likely representing atelectasis . Small consolidations in this area can not be excluded . 2 . Trace pneumoperitoneum , within post surgical limits . 3 . Trace bilateral pleural effusions .