Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low bilateral lung volumes , with elevation the right hemidiaphragm . There is mild pulmonary vascular congestion which may be secondary to the low lung volumes . A dense retrocardiac opacity is present which may reflect atelectasis and / or consolidation . No pneumothorax identified . The cardiac silhouette is predominantly obscured by the elevated right hemidiaphragm and retrocardiac opacity however it appears enlarged .
    OUTPUT:
    
Low bilateral lung volumes and elevation of the right hemidiaphragm . A retrocardiac opacity may reflect atelectasis or consolidation .