Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Overall , interval increase in opacity with air bronchogram in the left lower lobe is consistent with infectious etiology appropriate clinical situation . No edema , effusion , or pneumothorax . The heart size is normal . Mild aortic knob calcifications are unchanged since at least ___ . Multi - level mild to moderate degenerative changes of thoracic spine are grossly unchanged
    OUTPUT:
    
Left lower lobe pneumonia . Interval follow - up with chest radiograph after treatment to ensure resolution is recommended .