Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest provided . Cardiomegaly is unchanged . There is increased retrocardiac opacity concerning for pneumonia . There is a small left pleural effusion . Right lung is clear . Mediastinal contour is grossly unremarkable . Bony structures are intact .
    OUTPUT:
    
Retrocardiac opacity concerning for pneumonia with small left pleural effusion , new from prior . Mild cardiomegaly unchanged .