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 . Cardiac silhouette size is mildly unchanged . The aorta remains tortuous . Mediastinal and hilar contours are similar . There is mild pulmonary vascular congestion . Patchy opacities in the lung bases may reflect areas of atelectasis with minimal blunting of the left costophrenic angle on the lateral view suggestive of a trace pleural effusion . No pneumothorax is present . Deformity of the right fourth rib posteriorly is unchanged and may reflect a remote fracture .
    OUTPUT:
    
Mild pulmonary vascular congestion and trace left pleural effusion . Bibasilar atelectasis .