Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a large right pleural effusion which is increased compared to the prior study . The left lung is clear . No left pleural effusion is seen . The right - sided cardiac and mediastinal silhouettes are difficult accurately assess due to the large pleural effusion , but the left cardiac silhouette and left - sided mediastinal contours are unremarkable .
    OUTPUT:
    
Large right pleural effusion , increased since the prior study .