Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiographs . There is an old fracture of the posterior left eighth rib . There is no pneumothorax . There is a small left pleural effusion with associated atelectasis . There is mild cardiomegaly without evidence of volume overload .
    OUTPUT:
    
1 . Mild cardiomegaly without evidence of volume overload . 2 . Left pleural effusion with associated atelectasis . Underlying pneumonia can not be excluded . 3 . Left posterior eighth rib fracture of undetermined age .