Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A portable frontal chest radiograph again demonstrates a left chest wall pacer device with the leads overlying the right atrium and ventricle . Lung volumes are low , resulting in prominence of the cardiac silhouette and bronchovascular crowding . Opacity at the left base likely represents atelectasis , but infection can not be excluded . There may be trace bilateral pleural effusions , left greater than right . No pneumothorax is seen .
    OUTPUT:
    
1 . Low lung volumes , with left base opacity likely representing atelectasis . Infection is less likely , but can not be excluded . 2 . Possible trace pleural effusions , left greater than right .