Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is normal in size . The mediastinal and hilar contours appear unchanged . There is a shifting pattern of opacification at the right lung base with an overall increase , while a left basilar opacity has mostly cleared . There is no definite pleural effusion or pneumothorax . A healed right posterolateral seventh rib fracture appears unchanged .
    OUTPUT:
    
Persistent right lower lobe with shifting distribution suggestive of atelectasis , but given increase in vague opacity , developing pneumonia is a consideration .