Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Probable background hyperinflation , which could reflect COPD . Again seen is marked , polychamber cardiomegaly , similar to ___ . The appearance raises the possibility of pericardial fluid , but no obvious interval change is identified . Sternotomy wires and prosthetic mitral valve are again noted . There is upper zone redistribution and minimal vascular plethora , without other evidence of CHF . The right hemidiaphragm is again noted to be elevated . There is patchy opacity in the right cardiophrenic region . This is similar in appearance to prior studies seen could reflect atelectasis and / or scarring . Otherwise , no focal infiltrate is identified . Minimal blunting of the posterior costophrenic angles is consistent with tiny bilateral pleural effusions versus minimal pleural thickening and is less pronounced than on ___ .
    OUTPUT:
    
1 . Marked cardiomegaly , without significant change . 2 . Upper zone redistribution , with mild vascular plethora and minimal posterior pleural fluid and / or thickening . 3 . Probable atelectasis and / or scarring in the right cardiophrenic region , similar to the prior study . 4 . Allowing for this , no new focal pneumonic infiltrate identified .