Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal , and hilar contours are unchanged , with a heart size within normal limits . Minimal aortic knob calcifications are present . The pulmonary vascularity is normal . Patchy ill - defined opacity is noted within the lower lobe , likely on the left , concerning for infection . No pleural effusion or pneumothorax is visualized . There are no acute osseous abnormalities , with mild degenerative changes noted in the thoracic spine .
    OUTPUT:
    
Patchy opacity in the lower lobe , likely on the left , which is concerning for infection .