Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes are present . The heart size is mildly enlarged . Aortic knob calcifications are noted . Left - sided indentation upon the trachea may be due to a left thyroid goiter or nodule . There is crowding of the bronchovascular structures with mild pulmonary vascular congestion . Patchy opacities in the lung bases may reflect atelectasis . Infection is not excluded in the correct clinical setting . Trace left pleural effusion is not excluded . There is no pneumothorax . No acute osseous abnormality seen .
    OUTPUT:
    
Mild pulmonary vascular congestion and bibasilar patchy airspace opacities , possibly atelectasis though infection is not excluded . A small left pleural effusion also may be present .