Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Tracheostomy tube is midline . Heart size is normal . Low lung volumes are similar to prior exam , but there are new , mild bibasilar opacifications . On the right , this is most likely atelectasis . On the left , it is either atelectasis or pneumonia . No pneumothorax is seen . There may be small pleural effusions .
    OUTPUT:
    
New moderate right basal atelectasis . New left lower lobe pneumonia or atelectasis .