Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are present , which accentuates the size of the cardiac silhouette which appears moderately enlarged , not substantially changed from the prior study . The aorta is mildly unfolded with atherosclerotic calcifications noted diffusely . Hilar contours are similar with no evidence for pulmonary vascular congestion . Patchy opacities in the lung bases may reflect atelectasis . No pleural effusion , focal consolidation or pneumothorax is detected . There are no acute osseous abnormalities .
    OUTPUT:
    
Low lung volumes with patchy bibasilar airspace opacities , likely atelectasis . Pneumonia or aspiration at the lung bases can not be completely excluded .