Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Atherosclerotic calcifications are noted within the thoracic aorta . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is normal . Patchy opacity in the left lung base is concerning for pneumonia . Minimal atelectasis is seen in the right lung base . Right lung is clear . No pleural effusion or pneumothorax is seen . Moderate to severe degenerative changes of the thoracic spine are present .
    OUTPUT:
    
Patchy left basilar opacity concerning for pneumonia .