Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size , mediastinal and hilar contours are within normal limits and without change . Interval increase in small left pleural effusion as well as worsening of adjacent left basilar lung opacity . Right lung and pleural surfaces are clear .
    OUTPUT:
    
Slight increase in size of small left pleural effusion with adjacent increased left basilar lung opacity , with appearance favoring atelectasis over an infectious pneumonia .