Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are similar in appearance when compared to the prior study . The trachea is central . Mild splaying of the carina likely reflects left atrial enlargement . Increasing bibasilar opacities likely reflect a atelectasis however superimposed infection can not be excluded . No definite pleural effusion seen . No pneumothorax seen .
    OUTPUT:
    
Worsening bibasilar opacities may reflect atelectasis , infection can not be excluded . The appearances of the left lung base in particular are concerning .