Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable AP view of the chest . Relatively low lung volumes are seen compared to prior . There are bibasilar opacities with more dense consolidation identified in the retrocardiac region which silhouettes the descending thoracic aorta and medial hemidiaphragm . Superiorly the lungs are clear . Cardiomediastinal silhouette is unchanged given differences in positioning and technique . Osseous structures are unremarkable .
    OUTPUT:
    
Bibasilar opacities , more confluent at the left lung base compared to the right . Although a component of this may be due to atelectasis , underlying consolidation is also possible particularly on the left . PA and lateral views with improved inspiratory effort may help further characterize if desired .