Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post coronary artery bypass graft surgery . The heart is mildly enlarged . There is a mild diffuse interstitial abnormality with Kerley B lines , which are noted primarily at the right lung base . This may reflect mild vascular congestion or a mild chronic interstitial abnormality could also be considered . A nodular density projecting over the right lower lung is suggestive of a nipple shadow . There is no pleural effusion or pneumothorax . The bones appear demineralized . Mild degenerative changes are noted throughout the thoracic spine .
    OUTPUT:
    
1 . Mild interstitial abnormality which could be seen with mild vascular congestion versus chronic change . These are difficult to distinguish since prior radiographs are not available . 2 . Nodular density projecting over the right lower lung suggesting a nipple shadow . When clinically appropriate , however , confirmation of a nipple shadow as opposed to a pulmonary nodule is suggested by acquiring an additional PA view with nipple markers .