Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours appear very similar with cardiac enlargement as well as enlargement of central pulmonary arteries bilaterally . There is a similar mild interstitial abnormality suggesting pulmonary congestion , but the main change is a vague new retrocardiac opacity . There is a small pleural effusion on the right but probably unchanged .
    OUTPUT:
    
Vague new retrocardiac opacity , possibly atelectasis , early pneumonia possible . Mild vascular congestion .