Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral images of the chest . There has been interval development of bibasilar opacities , which are concerning for a rapidly developing pneumonia versus alveolar hemorrhage . There appears to be a small left pleural effusion . There is no right pleural effusion or pneumothorax . The cardiomediastinal silhouette is unremarkable .
    OUTPUT:
    
Short interval development of bibasilar opacities , which are concerning for a rapidly developing pneumonia versus alveolar hemorrhage .