Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is borderline in size . The mediastinal and hilar contours are probably within normal limits within the limitations of technique . The left hemidiaphragm is obscured suggesting a retrocardiac opacity and there is an accompanying pleural effusion which is hard to quantify .
    OUTPUT:
    
Retrocardiac opacity , not specific ; although a pneumonia is difficult to exclude , commonly this type of appearance is associated with left basilar atelectasis . Coinciding pleural effusion on the left .