Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: 2 views were obtained of the chest . Large retrocardiac opacity is unchanged from the recent comparison from___ but progressed from ___ . On review of imaging in the ___ system , the left lower lung has not been clear since surgery . The remainder of the lung is clear . Moderate cardiomegaly and mitral valve prosthesis are unchanged . Sternal wires are intact . There is no pneumothorax or right pleural effusion .
    OUTPUT:
    
Increased retrocardiac opacity . Diagnostic considerations include pneumonia with pleural effusion , post - pericardiotomy syndrome , airway obstruction and diaphragmatic paralysis , though this is less likely given the normal position of the colonic and gastric air bubbles . Findings were discussed by phone with ___ , PA for cardiac surgery , by Dr . ___ by phone at ___ .