Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In comparison to the most recent radiograph performed on ___ , lung volumes are lower . There is at least substantial atelectasis at the bilateral lung bases . Previously noted right infrahilar opacity is difficult to assess due to elevation of the right hemidiaphragm . Upper lung zones are clear . No pleural effusion or pneumothorax . Moderate cardiomegaly is chronic . No evidence of pneumomediastinum . No acute osseous abnormalities identified .
    OUTPUT:
    
1 . No evidence of pneumomediastinum or pneumothorax . Please note that this study neither suggests nor excludes the diagnosis of pulmonary embolism . 2 . At least substantial bibasilar atelectasis in a background of low lung volumes . Consider repeating at least the lateral view , and possibly also the PA view , with deeper inspiration .