Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: As compared to prior chest radiograph from ___ , lung volumes are increased . There is increased density of right lower lobe opacity . There is no pleural effusion or pneumothorax . Cardiomegaly is unchanged . There is calcification of the aortic arch . The mediastinal and hilar contours are unchanged .
    OUTPUT:
    
Increased density of right lower lobe opacity , which could represent either atelectasis or early pneumonia .