Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiomediastinal silhouette is normal . There is no pleural effusion or pneumothorax . There is subtle asymmetric increased opacification of the left upper lobe . There is no overt pulmonary edema .
    OUTPUT:
    
Subtle asymmetric left upper lobe opacity , could represent a developing pneumonia in the correct clinical setting .