Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a small pleural effusion , present on ___ , but not on ___ . There is no focal consolidation or pneumothorax . Bibasilar atelectasis is noted . The heart is normal in size . The cardiac , mediastinal , and hilar contours are within normal limits .
    OUTPUT:
    
Small left pleural effusion , unchanged from ___ . Bibasilar atelectasis , no evidence of pneumonia .