Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size , mediastinal , and hilar contours are normal . There is a opacity / consolidation in the superior segment of the left lower lobe . The remaining lung fields are clear without pleural effusion or pneumothorax .
    OUTPUT:
    
Opacification in the superior segment of the left lower lobe , most consistent with pneumonia given the clinical history .