Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral images of the chest demonstrate substantial worsening in pulmonary vascular congestion since previous imaging . There are small pleural effusions bilaterally and bibasilar atelectatic changes . Lateral view demonstrates a spine sign indicating a retrocardiac opacity which , in the appropriate clinical setting , could represent pneumonia . The cardiomediastinal silhouette is unremarkable . There is no pneumothorax . Visualized osseous structures are unremarkable .
    OUTPUT:
    
Interval worsening of pulmonary vascular congestion . Retrocardiac opacity suspicious for pneumonia .