Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size remains mildly enlarged . Mediastinal and hilar contours are within normal limits . There is a subtle patchy opacity in the medial left upper lobe which appears new in the interval . Remainder of the lungs are clear . No focal consolidation , pleural effusion or pneumothorax is detected . Pulmonary vasculature is normal . Mild degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Subtle patchy opacity in the medial left upper lobe , possibly pneumonia .