Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs appear slightly hyperexpanded . Patchy opacification in the left lower lobe is new since ___ . The prominent aortic knob is consistent with known aortic aneurysm seen on prior CT examination . Postoperative mediastinal contours and cardiac borders are stable . No pleural effusion . Radiopaque marker is seen to sit on the anterior chest wall on lateral view .
    OUTPUT:
    
New patchy opacification in the left lower lobe suggests pneumonia , less likely amiodarone toxicity .