Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left lower lobe opacity is new from the prior study and could reflect atelectasis , though aspiration or pneumonia remain alternate considerations . There is no pleural effusion or pneumothorax . Heart is normal in size . Normal cardiomediastinal silhouette .
    OUTPUT:
    
Left lower lobe opacity could reflect atelectasis , aspiration or pneumonia .