Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As compared to ___ chest radiograph , cardiomediastinal contours are stable in appearance . Subtle increased opacities are present in the left perihilar region and are accompanied by mild bronchial wall thickening . Lungs are otherwise clear except for linear scar atelectasis at the right base . Upper lung predominant emphysema is again demonstrated . Healed rib fractures are incidentally noted .
    OUTPUT:
    
Subtle left perihilar opacity with associated bronchial wall thickening , concerning for an early focus of pneumonia . Acute aspiration is an additional consideration .