Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are unchanged , with the heart size within normal limits . The pulmonary vasculature is normal . Mild bronchiectatic changes are re - demonstrated within the lung bases . Patchy opacity in the left lung base is concerning for infection . Right lung is clear . No pleural effusion or pneumothorax is seen . No acute osseous abnormalities visualized .
    OUTPUT:
    
Patchy opacity in the left lung base is concerning for infection .