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 . Mild cardiomegaly is noted . The mediastinal and hilar contours are unremarkable . Patchy opacities in the lung bases likely reflect areas of atelectasis . Pulmonary vasculature is not engorged . No pleural effusion , focal consolidation or pneumothorax is present . There are no acute osseous abnormalities . Spiral tacks are noted within the upper anterior abdominal wall compatible with prior hernia repair .
    OUTPUT:
    
Patchy bibasilar opacities , likely atelectasis .