Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left - sided dual - chamber pacemaker leads terminate in the right atrium and right ventricle in unchanged positions . There is moderate enlargement of the cardiac silhouette which is unchanged . The aorta remains unfolded . The pulmonary vascularity is not engorged . Persistent elevation of left hemidiaphragm is chronic . No definite pleural effusion or pneumothorax is noted , though there are streaky opacities at the lung bases likely reflecting atelectasis . No pneumothorax is present . There are multilevel degenerative changes in the thoracic spine . No displaced rib fractures are seen .
    OUTPUT:
    
Mild bibasilar atelectasis and chronic elevation of left hemidiaphragm . No definite displaced rib fractures seen , though if there is continued concern , then a dedicated rib series can be obtained .