Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a subtle opacity in the left lung base adjacent to the left heart border on the frontal projection . There is no other focal consolidation , pleural effusion , pulmonary edema , or pneumothorax seen . The heart and mediastinal contours are normal .
    OUTPUT:
    
Subtle opacity within the left lower lung suggestive of pneumonia .