Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . The mediastinal and hilar contours are normal . The left pulmonary vasculature is normal . There is a large right pleural effusion with complete atelectasis of the right middle and lower lobes . No pneumothorax is seen . There are no acute osseous abnormalities .
    OUTPUT:
    
Large right pleural effusion with adjacent RML / RLL atelectasis , which appears unchanged from prior chest radiograph .