Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Cardiac and mediastinal contours are unchanged with tortuosity of the thoracic aorta again noted . Pulmonary vasculature is not engorged . Patchy opacities are re - demonstrated in the lung bases , not significantly changed in the interval , most likely reflective of atelectasis . No pleural effusion or pneumothorax is demonstrated . There are no acute osseous abnormalities .
    OUTPUT:
    
Low lung volumes with patchy bibasilar opacities , likely atelectasis . Infection or aspiration is not completely excluded .