Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes remain persistently low . Cardiac silhouette size remains within normal limits . Atherosclerotic calcifications are noted at the aortic knob . Mediastinal and hilar contours are similar . Patchy opacities are noted in the lung bases , as seen on the prior examination . No pleural effusion or pneumothorax is detected . There is no pulmonary vascular congestion .
    OUTPUT:
    
Persistent bibasilar patchy opacities , potentially atelectasis , but infection is not excluded in the correct clinical setting .