Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is top - normal . Small hiatal hernia is present . Mediastinal and hilar contours are otherwise unremarkable . Pulmonary vasculature is not engorged . Focal opacity within the left perihilar region / upper lung field is concerning for pneumonia . Right lung is clear . No pleural effusion or pneumothorax is present . Mild degenerative changes are noted in the thoracic spine .
    OUTPUT:
    
Focal opacity in the left perihilar region / upper lung field is concerning for pneumonia . Follow - up radiographs after treatment are recommended to ensure resolution of this finding .