Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest demonstrate a moderate right pleural effusion and associated atelectasis . Known right lower lobe mass is unchanged . The left lung is clear . There is no pneumothorax . Heart and mediastinal contours are stable . A PleurX catheter is unchanged in position .
    OUTPUT:
    
Moderate pleural effusion , not significantly changed in size .