Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Left lower lobe opacification is unchanged since ___ probably reflecting atelectasis , but superimposed aspiration or infection can not be excluded . There is no pleural effusion or pneumothorax . The Dobbhoff tube is in the stomach .
    OUTPUT:
    
Left basal opacities , unchanged since ___ , are probably representing atelectasis ; however , superimposed infection or aspiration can not be excluded .