Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is an equivocal retrocardiac opacity which may represent atelectasis or less likely pneumonia in the proper clinical setting . Mild pulmonary vascular congestion mild pulmonary edema is new the prior study . There is no pleural effusion or pneumothorax . The cardiomediastinal silhouette is within normal limits .
    OUTPUT:
    
1 . New mild pulmonary vascular congestion and mild pulmonary edema . 2 . Equivocal retrocardiac opacity most likely atelectasis .