Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Bibasilar opacities may be due to atelectasis and overlying vascular structures however , underlying aspiration or subtle infection is not excluded in the appropriate clinical setting . No large pleural effusion is seen . There is no evidence of pneumothorax . The cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
Subtle bibasilar opacities may be due to atelectasis however , infection or aspiration not excluded in the appropriate clinical setting .