Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been interval appearance of a left lower lobe peripheral opacity concerning for developing pneumonia . Lungs are otherwise clear without effusion or pneumothorax . The cardiac silhouette and mediastinal contours remain normal . The pulmonary vasculature is normal .
    OUTPUT:
    
New peripheral left lower lobe opacity , concerning for developing pneumonia .