Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Right - sided pacemaker device is noted with leads terminating in the right atrium and right ventricle . Lung volumes are low . There is mild to moderate enlargement of the cardiac silhouette . Aorta appears tortuous with atherosclerotic calcifications noted at the aortic knob . Crowding of bronchovascular structures is present with possible mild pulmonary vascular congestion , but no overt pulmonary edema . Patchy opacities within the lung bases may reflect atelectasis . No definite focal consolidation , large pleural effusion or pneumothorax is present . There are no acute osseous abnormalities detected .
    OUTPUT:
    
Patchy opacities in the lung bases likely reflect atelectasis in the setting of low lung volumes . Mild pulmonary vascular congestion without overt pulmonary edema .