Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart size is normal . The hilar and mediastinal contours are normal . Mild interstitial prominence is likely secondary to an underlying background of emphysema . There is a new focal consolidation in the left lower lobe . There is no pleural effusion or pneumothorax . Old healed rib fracture along the lateral right seventh rib are again seen . Atherosclerotic calcification of the aortic arch is noted .
    OUTPUT:
    
New focal consolidation at the left lung base concerning for pneumonia .