Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy . The heart size remains moderately enlarged . Low lung volumes contribute to bibasilar atelectasis , although there are no focal consolidations which are concerning for pneumonia . There is no pleural effusion or pneumothorax . Nodular structure projecting over the left hemidiaphgram is most compatible with a nipple shadow , given it 's not seen on the lateral radiograph .
    OUTPUT:
    
1 ) Cardiomegaly without evidence of pneumonia . 2 ) Probable nipple shadow ( left ) which can be confirmed with repeat views with nipple markers if needed .