Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patchy opacities of the bilateral lung bases are likely due to atelectasis although infection can not be excluded . No other areas concerning for consolidation are seen . No pneumothorax or pleural effusion . The cardiomediastinal contour is unchanged compared to the prior study with mild prominence bilateral hila . No frank pulmonary edema .
    OUTPUT:
    
Bibasilar atelectasis , this has progressed slightly when compared to the prior study .