Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette appears mildly enlarged . There is mild calcification of the aortic knob . There is flattening of the diaphragms and there is increased lucency of the upper lobes compatible with COPD . Note is made of calcified pleural plaques , suggestive of prior exposure to asbestos . Vague opacities in the lower lungs could represent en face calcified pleural plaque as is seen in the lateral projection however , an underlying infection can not be excluded . There is no pneumothorax .
    OUTPUT:
    
Vague opacities in the lower lungs could represent en face calcified pleural plaque as is seen in the lateral projection however , an subtle infection can not be excluded .