Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: In comparison to the chest radiograph obtained 4 hours prior , no significant changes are appreciated . Mild pulmonary edema is unchanged . Heart size top - normal . Pleural effusion small , if any . Extensive pleural calcifications somewhat limiting evaluation for pneumonia , though no focal consolidations are identified .
    OUTPUT:
    
Unchanged , mild pulmonary edema . No radiographic evidence pneumonia .