Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single portable AP upright view of the chest was obtained . Port - A - Cath is unchanged in position . There is increased moderate - to - large right pleural effusion and associated atelectasis . The aerated portion of the right lung shows some vascular engorgement , but is otherwise grossly clear . The left lung is grossly clear , without CHF or focal infiltrate . There is no left effusion . No pneumothorax . There is no cardiomediastinal shift .
    OUTPUT:
    
Moderate - to - large right pleural effusion which has increased significantly compared with ___ .