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 right ventricle , unchanged . Mild to moderate cardiomegaly is similar with tortuosity of the thoracic aorta again noted . Mediastinal and hilar contours are grossly unchanged , with a moderate size hiatal hernia again noted . There is no pulmonary vascular congestion . Low lung volumes are demonstrated with streaky atelectasis noted in the lung bases . No focal consolidation , large pleural effusion or pneumothorax is seen . Osseous structures are diffusely demineralized with mild loss of height of several upper / mid thoracic vertebral bodies , unchanged .
    OUTPUT:
    
Low lung volumes with bibasilar atelectasis . Moderate size hiatal hernia .