Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are slightly low with left lower lobe atelectasis . Superimposed infection can not be excluded . Even allowing for the projection , the heart size is mildly enlarged and there is prominence of the bilateral hila consistent with mild congestive heart failure . No definite pleural effusion . No pneumothorax seen .
    OUTPUT:
    
Left lower lobe atelectasis , superimposed infection can not be excluded .