Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A right - sided dual - lumen pacemaker device is noted with leads terminating in the right atrium and right ventricle . Moderate enlargement of cardiac silhouette is relatively unchanged . The aorta is tortuous and diffusely calcified . Lung volumes are decreased from the prior study , which causes crowding of the bronchovascular structures . Small right pleural effusion has developed from the prior study , and there is mild patchy opacity in the right lung base which may represent area of atelectasis . No pneumothorax is present .
    OUTPUT:
    
Small right pleural effusion and patchy opacity in the right lung base which may reflect atelectasis .