Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left - sided dual - chamber pacemaker device is noted with leads terminating in the right atrium and right ventricle . The cardiac silhouette size is unchanged , and minimally enlarged . The mediastinal and hilar contours are within normal limits . The pulmonary vascularity is not engorged . Lung volumes are low , with minimal atelectatic changes noted at the lung bases . No focal consolidation , pleural effusion or pneumothorax is present . There are no acute osseous abnormalities .
    OUTPUT:
    
Low lung volumes with mild bibasilar atelectasis . No evidence for pulmonary edema .