Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A right perihilar opacity has been increasing since ___ . No pulmonary edema , large pleural effusion , or pneumothorax . Moderate cardiomegaly , low lung volumes , and bibasilar atelectasis are unchanged . Left axillary surgical clips noted .
    OUTPUT:
    
No pulmonary edema . Right perihilar opacity has been increasing since ___ which may represent asymmetric edema or atelectasis although aspiration or developing infection could have a similar appearance .